ES3017909T3 - Method for unloading a medical transport vehicle - Google Patents

Abstract

In the method of loading and unloading an ambulance (10) with an ambulance device (14), the ambulance device (14) is locked onto the receiving trolley (30) of a receiving device (12) arranged on the ambulance (10) when it moves between a fully retracted position and a fully extended position. Only when the fully extended position is reached, the ambulance device (14) is unlocked so that it can be removed from or placed on the receiving trolley (30). When the receiving trolley (30) is fully retracted, it is locked onto the ambulance (10) and the ambulance device (14) is locked onto the receiving trolley (30). If the patient transport device (14) has a chassis (18), this chassis hangs on the bottom of a stretcher (16) of the patient transport device (14) when the patient transport device (14) is locked on the receiving trolley (30). (Automatic translation with Google Translate, no legal value)

Description

DESCRIPTION

Method of unloading a medical transport vehicle

The invention relates to a method for unloading a patient transport device from a vehicle, according to claim 1.

To improve comfort, especially for paramedics, modern patient transport devices are equipped with automatically height-adjustable chassis (see, for example, WO-A-2018/153940). These patient transport devices can be operated quite conveniently by using appropriate loading devices located on rescue vehicles when loading or unloading the patient transport vehicle. Various concepts for partially automated receiving devices are known in this regard, such as those described in EP-A-2 116216, EP-A-2 138143, or even in WO-A-2016/007290 and WO-A-2018/206834.

GB-A-2 203 999 discloses a loading and unloading table for a stretcher, in which the stretcher is already locked on an extendable table when the table is in its fully extended loading or unloading position, or is still locked when the previously retracted table is fully extended to its loading or unloading position.

Document FR-A-2 682 930 describes a table for loading and unloading stretchers, in which the stretcher is pushed sideways out of the vehicle and then rotated into the vehicle. It does not describe how the stretcher is secured to the table or when this happens when the table is loaded.

Finally, document WO-A-2004/064698 describes another table for loading and unloading stretchers.

The object of the invention is to provide improved methods for handling a patient transport device during loading and unloading of a patient transport vehicle.

Unloading the patient transport device from the vehicle

The invention proposes a method for unloading a patient transport device from a vehicle, in particular from a patient transport or rescue vehicle, in which the vehicle has a loading surface and on this a receiving device with an extendable and retractable receiving trolley for the patient transport device, on which the patient transport device is placed locked by means of a locking device located in a locked position, with the following steps:

aa) unlock the receiving carriage when it is in the fully retracted position and in this state is locked directly or indirectly to the vehicle,

bb) extend the receiving carriage to an unloading position in which the receiving carriage automatically locks and projects at least partially rearward over the loading surface of the vehicle,

cc) when the receiving trolley assumes the unloading position, the patient transport device is automatically unlocked by automatically moving the locking device from its locked position to an unlocked position and

dd) unload the patient transport device from the receiving cart to its unloading position.

According to the invention, it is advantageously provided that the locking device for locking the patient transport device to the receiving device's receiving trolley automatically moves from the locked position, in which the locking device is located during extension of the receiving trolley, to the unlocked position when the receiving trolley assumes its unloading position. In this unloading position, the receiving trolley is also automatically locked, which occurs, for example, at the latest after it has traveled 95% or 90% or 80% or 70% or 60% or 50% or 40% of the travel from the fully retracted entry position to the fully extended loading or unloading position of the receiving trolley. In the unloading position, the receiving trolley extends rearward onto the loading surface of the vehicle. The unloading position when unloading the patient transport device is identical to the loading position of the receiving trolley when it is loaded with a patient transport device, as described in detail below in connection with a loading method.

The individual embodiments of the invention described below in connection with the loading process can also be used correspondingly for the unloading process according to the invention. In this regard, it can be advantageously provided, for example, that the locking device is locked in its locked position when the receiving trolley is fully retracted and that this locking is released thereafter or when the receiving trolley leaves the fully retracted retracted position when it is extended. In the fully retracted retracted position, i.e., in the initial position of the receiving trolley for unloading the patient transport device from the vehicle, the locking device is locked in its locked position. This locking mechanism is then released when the receiving trolley is extended, for example, when the receiving trolley has left its fully retracted retracted position.

In a variant of the patient transport device, the step of unloading the patient transport device from the receiving cart comprises the step of removing the patient transport device from the receiving cart.

It may also be convenient for the patient transport device to comprise a manually operated portable stretcher having a patient transport surface without a chassis and in particular without a height-adjustable chassis, the step of unloading the patient transport device from the receiving trolley comprising the step of manually unloading the stretcher from the receiving trolley and the step of unlocking the patient transport device from the receiving trolley and the step of unlocking the stretcher from the receiving trolley.

In both of the above-described unloading processes for the patient transport device, the device remains locked directly or indirectly to the receiving trolley while it is extended until the receiving trolley has reached its unloading position. In this unloading position, the locking device opens so that the patient transport device can be removed from the receiving trolley or can be lifted above the receiving trolley and then removed. This, however, conveniently requires a height-adjustable chassis of the patient transport device.

In another convenient embodiment of the invention, it can be provided that the patient transport device has a height-adjustable and, in particular, automatically height-adjustable chassis with a patient transport surface and that the step of unloading the patient transport device from the receiving trolley has the following sub-steps:

- extend the chassis, which is in the retracted position when the receiving truck is in the unloading position, until the chassis extends to a base,

- extend the chassis further to raise the stretcher above the trolley and

- move the chassis with stretcher away from the receiving car.

In the embodiment of the aforementioned invention, it can further be provided that the step of unlocking the patient transport device from the receiving trolley comprises the step of unlocking the retracted chassis of the receiving trolley, optionally providing that the retracted chassis rests in the fully retracted retraction position of the receiving trolley in the vehicle on the loading surface of the vehicle or, if present, on a base of the receiving device fixed to the loading surface of the vehicle.

Another patient transport device that can be used according to the invention may comprise a manual portable stretcher provided with a patient transport surface, which can be placed on a height-adjustable chassis and in particular automatically height-adjustable and which can be locked on the chassis and unlocked from the chassis.

In a patient transport device of the type described above, it is desirable that

- the step of unlocking the patient transport device from the receiving trolley comprises the step of unlocking the retracted chassis of the receiving trolley, optionally providing that the retracted chassis rests on the loading surface of the vehicle or, if present, on a base of the receiving device fixed to the loading surface in the fully retracted retraction position of the receiving trolley in the vehicle,

either

- the step of unlocking the patient transport device from the receiving trolley comprises the step of unlocking the stretcher from the receiving trolley, optionally providing that the retracted chassis rests on the loading surface of the vehicle or, if provided, on a base in the fully retracted retraction position of the receiving trolley in the vehicle.

In another advantageous embodiment of the invention, the receiving device has a base mounted on the loading surface of the vehicle, on which the receiving carriage is guided so that it can be moved between its fully retracted retracted position and its loading position, the receiving carriage being locked in its fully retracted retracted position with the base and/or with the loading surface of the vehicle.

Finally, in another alternative of the invention, it may be advantageous for the receiving device to have a base that can be mounted on the loading surface of the vehicle and a central carriage that is guided to extend and retract on this base, on which the receiving carriage is guided to extend and retract, the receiving carriage being automatically locked with the central carriage in its maximum extension position with respect to the central carriage and the central carriage being automatically locked with the base and/or the loading surface of the vehicle in its maximum extension position with respect to the base.

In this variant of the invention, steps aa) to dd) comprise the following steps:

- unlock the receiving carriage in its fully retracted position and lock it in this state directly or indirectly to the vehicle,

- extend the receiving carriage together with the intermediate carriage locked to the receiving carriage to the maximum extraction position of the intermediate carriage with respect to the base,

- in the maximum extraction position of the intermediate carriage, automatically lock the intermediate carriage to the base and automatically unlock the receiving carriage with respect to the intermediate carriage,

- extend the receiving carriage on the intermediate carriage to the maximum extension position of the receiving carriage relative to the intermediate carriage to adopt the unloading position of the receiving carriage, in which the receiving carriage is automatically locked on the intermediate carriage,

- unload the patient transport device from the receiving cart.

Furthermore, in the configuration of the invention described above, the step of extending the receiving carriage together with the intermediate carriage locked to the receiving carriage to the maximum extraction position of the intermediate carriage with respect to the base or the step of extending the receiving carriage on the intermediate carriage to the maximum extraction position of the receiving carriage with respect to the intermediate carriage may include the step of releasing the locking of the locking device in its locked position after or at the start of the extension.

In the two configurations of the invention described above, the following additional steps can be conveniently provided:

- unlock the receiving trolley without a patient transport device from the intermediate trolley,

- extend the receiving carriage on the intermediate carriage to a maximum extraction position of the receiving carriage,

- before or upon reaching the maximum extraction position of the receiving carriage on the intermediate carriage, lock the intermediate carriage automatically in the base (by means of the receiving carriage),

- extend the receiving carriage and the intermediate carriage at the base to a maximum extraction position of the intermediate carriage to adopt the fully extended extraction position for (loading and) unloading of the receiving carriage and

- automatically lock the receiving carriage when it is in the fully extended extraction position for (loading and) unloading of the receiving carriage.

In this case, the step of extending the receiving carriage on the intermediate carriage to the maximum extension position of the receiving carriage with respect to the intermediate carriage may conveniently comprise the step of automatically transferring the locking device from the locking position to the unlocking position in order to unlock the patient transport device from the receiving carriage and the step of removing the locking of the locking device in its unlocking position at the latest before or upon reaching the maximum extension position of the receiving carriage with respect to the intermediate carriage, or the step of extending the receiving carriage on the intermediate carriage to the maximum extension position of the receiving carriage with respect to the intermediate carriage may comprise the step of automatically transferring the locking device from the locking position to the unlocking position in order to unlock the patient transport device on the receiving carriage and the locking of the locking device in the unlocking position is removed at the latest before or upon reaching the fully extended (loading and) unloading position of the patient transport device.

In another advantageous embodiment of the invention, it can further be provided that the receiving device has a base which can be mounted on the loading surface of the vehicle and a central carriage which can be extended and retracted thereon, on which the receiving carriage is guided so that it can be extended and retracted, the receiving carriage being automatically locked with the central carriage in its maximum extension position relative to the central carriage and the central carriage being automatically locked with the base and/or the loading surface of the vehicle in its maximum extension position relative to the base, and the steps aa) to dd) comprising the following steps:

- unlock the receiving carriage in its fully retracted position and lock it in this state directly or indirectly to the vehicle,

- extend the receiving carriage relative to the intermediate carriage locked to the base to the maximum extension position of the receiving carriage relative to the intermediate carriage and, if necessary, automatically lock the receiving carriage to the intermediate carriage,

- in the maximum extraction position of the receiving carriage, unlock the intermediate carriage automatically from the base,

- extend the intermediate carriage over the base to the maximum extension position of the intermediate carriage relative to the base to adopt the (loading and) unloading position of the receiving carriage, in which the intermediate carriage is automatically locked to the base or is already locked,

- unload the patient transport device from the receiving cart.

In the embodiment of the method described above, it is further advantageous that the extension of the receiving carriage relative to the intermediate carriage locked at the base to the maximum extension position of the receiving carriage or the step of extending the intermediate carriage at the base to the maximum extension position of the intermediate carriage relative to the base to adopt the unloading position of the receiving carriage comprises the step of releasing the locking device in its locked position after or at the beginning of the extension.

In relation to the two configurations of the invention described above, the following additional steps can be conveniently provided:

- unlock the intermediate carriage from the base,

- when moving the receiving trolley without a patient transport device, extend the intermediate trolley at the base to a maximum extraction position of the intermediate trolley,

- in the maximum extraction position of the intermediate carriage, automatically lock the receiving carriage on the intermediate carriage.

- extend the receiving carriage on the intermediate carriage to a maximum extraction position of the receiving carriage to adopt the fully extended extraction position (loading and unloading) of the receiving carriage and

- automatically lock the receiving carriage when it is in the fully extended extraction position for (loading and) unloading.

In the configuration of the invention described above, additionally

- the step of extending the intermediate carriage by moving the receiving carriage to the maximum extraction position of the intermediate carriage relative to the base includes the step of automatically transferring the locking device from the locked position to the unlocked position in order to unlock the patient transport device from the receiving carriage and the step of releasing the lock of the locking device in the locked position at the latest before or upon reaching the maximum extraction position of the intermediate carriage relative to the base,

either

- the step of extending the intermediate carriage by moving the receiving carriage to the maximum extraction position of the intermediate carriage relative to the base includes the step of automatically transferring the locking device from the locked position to the unlocked position in order to unlock the patient transport device from the receiving carriage, and the locking of the locking device in its unlocked position is released at the latest before or upon reaching the fully extended extraction position of the receiving carriage.

According to another variant, the step of unlocking the patient transport device from the receiving cart comprises the step of unlocking a stretcher from the patient transport device on the receiving cart.

In a mechanically controlled locking device for locking the patient transport device to the receiving trolley, the locking device has a guided, in particular cam-guided, control lever which is kinematically coupled via a rod to at least one locking element movably arranged on the receiving trolley and preferably to two locking elements movably arranged on the receiving trolley on each longitudinal side of the patient transport device. The control lever is movable between an unlocked position in which the at least one locking element is in an unlocked position in which the at least one locking element is disengaged from a counterlocking element of the patient transport device assigned to it, and a locked position in which the at least one locking element is in locking engagement with the counterlocking element of the patient transport device assigned to it. The control lever is forced from its locked position when the receiving carriage is not in its unloading position to its unlocked position during extension of the receiving carriage, at the latest when the receiving carriage is in the loading position.

In this case, it can also be advantageously provided that the control lever is locked in the locked position at the latest when the receiving carriage is in the fully retracted retraction position.

In another convenient embodiment of the mechanically controlled locking device, the control lever and/or the rod and/or the at least one locking element and/or each locking element is spring-loaded in the direction of the respective locking position to be adopted in the locked state of the locking device, specifically so as to automatically adopt the respective locking position after removing a possible blockage when the at least one locking element interacts with the counter-locking element of the patient transport device assigned to it.

Advantageously, two control rods with locking claws can be rotated back and forth by means of the at least one control lever and the rod.

In another convenient configuration, the rod is provided with two racks, each of which meshes with a gear on another of the two control rods.

Finally, it can also be advantageously provided that two control levers are provided, each with a rod, and that each control lever with rod is operatively connected to a control rod having locking claws for rotating the respective control rod back and forth.

In another convenient embodiment of the unloading method, the receiving device has a base that is mountable on the loading surface of the vehicle and has a raised central region, on both sides of which the receiving trolley extends and above which the patient transport device is located in the fully retracted retracted position of the receiving trolley, the base having a lifting lever mechanism below its central region with two pivot arms that pivot automatically and that, when the lifting lever mechanism is in a lower position and is flat and inclined, form a first acute angle with the loading surface of the vehicle and, when the lifting lever mechanism is in a higher position and is inclined, form a second acute angle with the loading surface of the vehicle that is larger than the first acute angle, and each of the pivot arms being pivotally mounted on consoles that are mounted on the loading surface of the vehicle.

With regard to the lifting mechanism, it is advantageous to provide the consoles or the lifting mechanism itself so that they can be moved on the vehicle's loading surface in a direction orthogonal to the vehicle's longitudinal axis and secured in a movable position. This allows more space to be created in the vehicle to one side of the device if necessary (e.g., for patient care).

The actual unloading process can advantageously be followed by transferring the "empty" receiving cart to the vehicle. The following additional steps are advantageously planned:

ee) unlock the trolley without a patient transport device,

ff) leave the unloading position by retracting the receiving carriage,

gg) when the receiving carriage is retracted and thus after or upon leaving its unloading position, transfer the locking device automatically from the unlocked position to the locked position and

hh) automatically lock the carriage in its fully retracted position, directly or indirectly on the vehicle.

In this case, it can advantageously be provided that the maneuvering of the patient transport device for transferring the patient transport device to a position above the receiving trolley comprises the step of centering the patient transport device with respect to the receiving trolley by means of guide struts that can be moved along guide edges of a centering opening of the receiving trolley and that protrude from the patient transport device.

Conveniently, the guide struts and guide edges are rounded and/or curved at their respective contact sections.

In relation to the maneuverability of the patient transport device, it is convenient that the maneuvering of the patient transport device to move the patient transport device to a position above the receiving trolley, moving away from the receiving trolley, comprises the step of centering the patient transport device with respect to the receiving trolley by means of sliding or roller elements of the patient transport device that can be moved and/or shifted on tracks of the receiving trolley, each track being designed to project obliquely or is designed with an obliquely projecting section.

Each sliding or roller element is conveniently designed to narrow obliquely at its end facing the corresponding longitudinal side of the patient transport device, the inclination of the track being substantially equal to the inclination of the taper of the sliding or roller elements.

Furthermore, the tracks are advantageously arranged on both sides of the centering opening of the receiving carriage, the sections of the tracks being arranged obliquely away from the associated guide edge or the tracks extending obliquely away from the respective associated guide edge.

Preferably, the method according to the invention further comprises

- that when the receiving trolley leaves its fully retracted position by extending it, it is supported on two sliding or rolling elements arranged on both sides of its central axis on the loading surface of the vehicle or, if present, on a base of the receiving device fixed to the loading surface of the vehicle, the two sliding or rolling elements being arranged approximately at the height of half the longitudinal extension of the receiving trolley or approximately at the height of half the longitudinal extension of the patient transport device arranged on the receiving trolley,

- that the patient transport device is locked on both sides of its central axis with the receiving trolley by means of the locking device at each of two locking points, which are located in front of and behind the respective sliding or roller element seen in the longitudinal extension of the receiving trolley,

- that the receiving carriage is reinforced on both sides of its central axis by struts extending between each locking point and the respective sliding or roller element and

- that the receiving carriage is locked and/or held in its fully retracted position on the loading surface of the vehicle or, if present, on the base fixed to the loading surface of the vehicle in the fully retracted position next to the sliding or rolling elements, in particular by means of retention devices, preferably in the form of angular elements that can be locked and/or locked upwards or downwards, and the retention devices are released after or upon leaving the fully retracted position of the receiving carriage.

Furthermore, the receiving carriage can be locked and, if necessary, latched against unintentional movement in both directions along the central axis of the receiving carriage at its end furthest inside the chassis in the fully retracted retraction position and, if applicable, at the end opposite this end on the loading surface of the vehicle or, if available, on a base of the receiving device fixed to the loading surface of the vehicle and can be released when or after the receiving carriage leaves the fully retracted retraction position.

The patient transport device is conveniently locked on the receiving trolley in its fully retracted retraction position exclusively by means of the locking device (in particular against forces acting vertically upwards) and in this state is fixed in a stable position by locking the receiving trolley to the vehicle, in particular to its loading surface or, if present, to a base of the receiving device fixed to the loading surface, optionally with the interposition of an intermediate trolley between the receiving trolley and the base, whereby the intermediate trolley and the receiving trolley are locked together, this stable position fixation being released after or upon leaving the fully retracted retraction position of the receiving trolley.

Typically, the patient transport device does not have a locking mechanism that directly interacts with the vehicle's cargo surface or, if present, with a receiving device base attached to the vehicle's cargo surface when the receiving cart is in its fully retracted position.

Preferably, in a patient transport device with a stretcher and a chassis from which the stretcher can be removed, the stretcher is locked to the chassis and the stretcher is locked to the receiving trolley in the fully retracted position, the chassis being arranged below the stretcher and suspended within the receiving trolley or resting on it.

Advantageously, it is provided that there is a patient in the patient transport device when the vehicle is loaded or that there is no patient in the patient transport device when the vehicle is loaded.

Loading the vehicle with the patient transport device

According to the method according to the invention, the vehicle can also be loaded with the patient transport device. For this purpose, a method is proposed for loading a vehicle, in particular a patient transport or rescue vehicle, with a patient transport device, the vehicle having a loading surface and on it a receiving device with an extendable and retractable receiving trolley for the patient transport device, comprising the following steps:

a) unlock the trolley when it is in its fully retracted position and in this state is locked directly or indirectly to the vehicle,

b) extending the receiving trolley to a loading position in which the receiving trolley is automatically locked and protrudes at least partially rearward beyond the loading surface of the vehicle and in which a locking device for locking the patient transport device on the receiving trolley is automatically in an unlocked position for receiving the patient transport device,

c) place the patient transport device on the trolley in its loading position,

d) unlock the cart,

e) leave the loading position by retracting the receiving carriage,

f) when the receiving trolley is retracted and thus after or upon leaving its loading position, the locking device for locking the patient transport device is automatically transferred from the unlocked position to a locked position in order to lock the patient transport device to the receiving trolley and

g) automatically lock the trolley in its fully retracted position directly or indirectly to the vehicle without directly attaching the patient transport device to the vehicle.

This loading method provides that, when loading the vehicle, in particular a patient transport or rescue vehicle, with a patient transport device, a receiving device (loading and/or unloading platform) of the vehicle is first manually or automatically extended, such that a receiving trolley of the receiving device, which serves to receive the patient transport device outside the vehicle, projects rearward over the loading edge of the vehicle. According to the invention, the receiving trolley is secured in its fully retracted position in the vehicle against horizontal movements (in or against the direction of travel and transversely to it) and vertical movements. When the patient transport device is on the trolley inside the vehicle, it is locked therein, again in the horizontal (forward, backward, and sideways) and vertical directions. The patient transport device preferably does not have any locking device directly to the vehicle (e.g., to the loading surface of the vehicle).

In the loading position, the receiving trolley is located, as previously mentioned, on the outside of the vehicle. In the loading position, the patient transport device is pushed onto the receiving trolley or placed from above onto the receiving trolley. When the patient transport device is in its correct position on the receiving trolley, it is not yet locked on the receiving trolley. This locking only occurs when the receiving trolley is retracted (manually or automatically) after leaving its loading position, and conveniently takes place after the receiving trolley has traveled a maximum of half, a maximum of 2/3, a maximum of 1/4, a maximum of 1/8, or a maximum of 1/10 of its travel from its loading position to its fully retracted position. In the fully retracted position which is adopted when the receiving carriage is further retracted, the receiving carriage is then automatically locked to the vehicle, either directly to the loading surface or to other parts of the vehicle or to a base of the receiving device or to another element of the receiving device which is then in turn fixed to the loading surface or to another component of the vehicle.

The particularity of the invention is that the patient transport device, which may be a stretcher without a frame, a stretcher with a frame from which the stretcher can be removed, or a frame with a lying and/or sitting surface permanently arranged thereon, is locked on the receiving trolley in the fully retracted position of the receiving trolley and not directly on the vehicle.

In the exemplary embodiment of the invention described above, the receiving device is designed to be easily extendable. The receiving trolley is positioned, for example, on a base of the receiving device, which is secured to the vehicle. A lifting mechanism can be located between the base and the loading surface of the vehicle, for example, to raise a patient transported in the patient transport device into the vehicle to a treatment height convenient for paramedics. However, said lifting mechanism can also be an integral part of the receiving device.

In an expedient embodiment of the invention, the aforementioned step f) additionally comprises the step of locking the locking device in its locked position at the latest before or when the receiving carriage reaches the fully retracted retraction position.

It may also be convenient for the step of moving the patient transport device onto the receiving trolley to include the step of pushing the patient transport device onto the receiving trolley. The patient transport device is pushed manually or automatically onto the trolley into its loading position. This variant is typically used when the patient transport device is designed as a stretcher or when a patient transport device has a removable chassis and stretcher combination, regardless of the reason why only the stretcher is to be used for patient transport.

In another advantageous embodiment of the invention, it can therefore be provided that the patient transport device has a manually operated portable stretcher with a patient transport surface without a chassis and in particular without a height-adjustable chassis and that the step of moving the patient transport device on the receiving trolley comprises the step of manually moving the stretcher on the receiving trolley and the step of locking the patient transport device on the receiving trolley comprises the step of locking the stretcher on the receiving trolley.

However, loading and unloading a patient transport vehicle with a patient transport device and the receiving device according to the invention is significantly more convenient if the patient transport device has a chassis that is, in particular, automatically height-adjustable and has a patient transport surface (reclining surface and/or seating surface or reclining surface that can be converted into a chair), and in principle, regardless of whether said surface is part of a separate stretcher that is designed to be removable from the chassis. In this variant, the step of moving the patient transport device onto the trolley comprises the following substeps:

- transfer the patient transport device using the chassis to the receiving cart,

- maneuver the patient transport device to transfer it to a position above the receiving cart,

- place the patient transport device on the receiving trolley by pulling the chassis inwards and

- with the patient transport device placed on the receiving trolley, retract the chassis further to its lowest position.

In this variant, too, the specially height-adjustable chassis is not yet locked in the extended carrying position of the patient transport trolley when the patient transport device is resting on the trolley in the correct position.

In another convenient embodiment of the invention, it can be provided that the aforementioned step g) of locking the patient transport device on the receiving trolley comprises the step of locking the retracted chassis on the receiving trolley, it being optionally provided that the retracted chassis rests on the loading surface of the vehicle or, if present, on a base of the receiving device fixed to the loading surface of the vehicle in the fully retracted position of the receiving trolley in the vehicle. In this variant, the chassis is locked on the receiving trolley when the receiving trolley leaves its loading position upon entering the vehicle.

In another advantageous embodiment of the invention, the patient transport device may be provided with a hand-held stretcher provided with a patient transport surface, which can be placed on a height-adjustable, and in particular automatically height-adjustable, chassis and which can be locked to and unlocked from the chassis. In this variant, the patient transport surface is part of a stretcher that can be removed from the chassis. As in the previous embodiments with a chassis of the patient transport device, the latter can also be designed in this case and in the embodiments mentioned above and below as described and shown in document WO-A-2018/153940 (see in particular Figs. 35 to 37 with the corresponding descriptive text). By reference to the aforementioned document, its content becomes the subject of the present application.

In the variant described above, it may be advantageous to provide

- that the locking step of the patient transport device to the receiving trolley comprises the locking step of the retracted chassis to the receiving trolley, optionally providing that the retracted chassis rests on the loading surface of the vehicle or, if present, on a base of the receiving device connected to the loading surface in the fully retracted retraction position of the receiving trolley in the vehicle,

either

- that the step of locking the patient transport device to the receiving trolley comprises the step of locking the stretcher to the receiving trolley, optionally providing that the retracted chassis rests on the loading surface of the vehicle or, if provided, on a base in the fully retracted position of the receiving trolley in the vehicle.

In the case of a stretcher that can be removed from the chassis, both the stretcher and the chassis can be locked to the receiving trolley. If the stretcher is locked to the receiving trolley, the chassis in its retracted position (lowest height position) "hangs" from underneath the stretcher as it rests on the receiving trolley. The stretcher is then locked to the receiving trolley (in its fully retracted position or after or upon leaving the loading position). Similarly, the stretcher can be locked to the trolley via the chassis. The stretcher is normally locked to the chassis when connected to it. The chassis is in turn locked to the receiving trolley, so that all components are secured against three-dimensional movement during transport (the receiving trolley is also locked to the vehicle).

In another advantageous embodiment of the invention, it can be provided that the receiving device has a base which can be mounted on the loading surface of the vehicle and on which the receiving carriage is guided movably between its fully retracted retracted position and its loading position, the receiving carriage being locked in its fully retracted retracted position with the base and/or with the loading surface of the vehicle.

In an expedient variant of the invention, the receiving device may have a base that can be mounted on the loading surface of the vehicle and a central carriage that can be extended and retracted on this base, on which the receiving carriage is guided so that it can be extended and retracted, the receiving carriage being automatically locked on the central carriage in its maximum extension position relative to the central carriage and the central carriage being automatically locked on the base and/or the loading surface of the vehicle in its maximum extension position relative to the base.

In such a configuration of the receiving device, steps a) to g) comprise the following steps:

- unlock the trolley in its fully retracted position, which in this state is locked to the base and/or loading surface of the vehicle,

- extend the receiving carriage together with the intermediate carriage locked on the receiving carriage to the maximum extension position of the intermediate carriage,

- in the maximum extraction position of the intermediate carriage, automatically lock the intermediate carriage to the base and automatically unlock the receiving carriage with respect to the intermediate carriage,

- extending the receiving carriage on the intermediate carriage to the maximum extension position of the receiving carriage relative to the intermediate carriage to adopt the loading position of the receiving carriage, the receiving carriage being automatically locked or already locked relative to the intermediate carriage,

- place the patient transport device on the receiving trolley,

- unlock the receiving carriage from the intermediate carriage,

- retract the receiving carriage into the intermediate carriage to a maximum retracted position of the receiving carriage,

- before or upon reaching the maximum retracted position of the receiving carriage in the intermediate carriage, automatically unlock the intermediate carriage from the base (by the receiving carriage),

- retract the receiving carriage and the intermediate carriage at the base to a maximum retracted position of the intermediate carriage to adopt the fully retracted retraction position of the receiving carriage and

- When the receiving trolley is in the fully retracted position, automatically lock the receiving trolley into the base and/or loading surface of the vehicle.

In this variant, the receiving device is designed as a double-extendable device, in which the receiving carriage is movably guided on a central carriage and the central carriage is movably guided on a base, which is in turn mounted on the vehicle (if necessary by means of a lifting device or a lifting mechanism). The receiving carriage is extended together with the intermediate carriage, to which the receiving carriage is locked when extended. When the receiving carriage and the intermediate carriage have reached the maximum extension position relative to the base, the intermediate carriage is conveniently automatically locked relative to the base, while the lock between the receiving carriage and the intermediate carriage is preferably automatically released, so that the receiving carriage then extends relative to the intermediate carriage for a further extension until the receiving carriage reaches its loading position.

As described above, the receiving trolley has a locking device for the patient transport device. This locking device is in either a locked or unlocked position. The unlocked position is assumed by the locking device when the receiving trolley is in its loading position. The locking device is preferably controlled mechanically or electronically/electrically. It is essential that the locking device is in its unlocked position when the patient transport device is placed on the receiving trolley by sliding it or lowering it from above. If the receiving trolley is then retracted (manually or automatically), the locking device automatically moves from its unlocked position to the locked position. This can occur, for example, quite soon after leaving the loading position.

It is therefore advantageous if the locking device is locked in its locked position to prevent unwanted movement into the unlocked position. This is preferably done no later than when the receiving carriage has reached its fully retracted position in the receiving device. This fully retracted position is the position of the receiving carriage or the entire receiving device in which the receiving carriage or the receiving device is located during transport on the vehicle.

Then it may be useful

- if the step of moving the receiving trolley on the intermediate trolley to the maximum retraction position of the receiving trolley relative to the intermediate trolley comprises the step of automatically transferring the locking device from the unlocked position to the locked position in order to lock the patient transport device on the receiving trolley and the step of locking the locking device in its locked position at the latest before or upon reaching the maximum retraction position of the receiving trolley relative to the intermediate trolley,

either

- if the step of retracting the receiving trolley onto the central trolley to the maximum retracted position of the receiving trolley with respect to the central trolley comprises the step of automatically transferring the locking device from the unlocked position to the locked position in order to lock the patient transport device on the receiving trolley, and the locking device is locked in the locked position at the latest before or upon reaching the fully retracted retraction position of the receiving trolley.

The locking device is therefore locked in the locked position, meaning that this locking occurs when the receiving carriage has reached its maximum retracted position relative to the intermediate carriage or when the intermediate carriage, together with the receiving carriage completely pushed onto it, has reached its maximum retracted position relative to the base.

According to a variant, the receiving device comprises a base mountable on the loading surface of the vehicle and a central carriage that is guided to extend and retract on this base, on which the receiving carriage is guided to extend and retract, the receiving carriage being automatically locked with the central carriage in its maximum extension position with respect to the central carriage and the central carriage being automatically locked with the base and/or the loading surface of the vehicle in its maximum extension position with respect to the base.

In such a configuration of the receiving device, steps a) to g) comprise the following steps:

- unlock the trolley in its fully retracted position, which in this state is locked to the base and/or loading surface of the vehicle,

- extend the receiving carriage relative to the intermediate carriage locked to the base to the maximum extension position of the receiving carriage relative to the intermediate carriage and, if necessary, automatically lock the receiving carriage to the intermediate carriage,

- in the maximum extraction position of the receiving carriage, unlock the intermediate carriage automatically from the base,

- extend the intermediate carriage on the base to the maximum extension position of the intermediate carriage relative to the base to adopt the loading position of the receiving carriage, in which the intermediate carriage is automatically locked to the base or is already locked,

- place the patient transport device on the receiving trolley,

- unlock the intermediate carriage from the base,

- when moving the receiving carriage towards the vehicle, retract the intermediate carriage at the base until the intermediate carriage reaches its maximum retracted position,

- in the maximum retracted position of the intermediate carriage, unlock the receiving carriage automatically from the intermediate carriage,

- retract the receiving carriage into the intermediate carriage to a maximum retracted position of the receiving carriage to adopt the fully retracted retraction position of the receiving carriage and

- When the receiving trolley is in the fully retracted position, automatically lock the receiving trolley into the base and/or loading surface of the vehicle.

In this variant of the receiving device, the extension movement of the receiving carriage in the case of a doubly extendable receiving device is carried out in that the receiving carriage is first extended relative to the intermediate carriage locked at the base, up to the maximum extension position, in which the receiving carriage is preferably automatically locked with the intermediate carriage and the locking between the intermediate carriage and the base is released, so that when the receiving carriage is further extended, the intermediate carriage moves relative to the base until the intermediate carriage assumes its maximum extension position relative to the base.

In a suitable configuration of the variant described above, it can also be foreseen

- that the step of moving the central carriage to the maximum retracted position of the central carriage with respect to the base by moving the receiving carriage in the direction of the vehicle comprises the step of automatically moving the locking device from the unlocked position to the locked position in order to lock the patient transport device to the receiving carriage and the step of locking the locking device in the locked position at the latest before or upon reaching the maximum retracted position of the central carriage with respect to the base, which means that the receiving carriage reaches its fully retracted retraction position, or

- that the step of retracting the intermediate carriage by moving the receiving carriage in the direction of the vehicle to the maximum retraction position of the intermediate carriage relative to the base comprises the step of automatically transferring the locking device from the unlocked position to the locked position in order to lock the patient transport device to the receiving carriage, and the locking of the locking device in its locked position takes place at the latest before or upon reaching the fully retracted retraction position of the receiving carriage.

In this variant, the locking device is automatically locked when the receiving carriage is in its maximum retracted position relative to the intermediate carriage or when the intermediate carriage is in its maximum retracted position (with the receiving carriage fully open) relative to the base.

It may also be convenient for the step of locking the patient transport device to the receiving cart to include the step of locking a stretcher from the patient transport device to the receiving cart.

As described above, the locking device is mechanically or electrically controlled to be able to move from its locked position to the unlocked position and vice versa. The mechanical control is conveniently carried out via a control lever, for example guided by a cam, which is preferably arranged on the receiving trolley and which is kinematically coupled via a rod to at least one locking element movably arranged on the receiving trolley and preferably to two locking elements movably arranged on the receiving trolley on each longitudinal side of the patient transport device, the control lever being movable between an unlocked position in which the at least one locking element is in an unlocked position in which the at least one locking element is out of engagement with a counterlocking element of the patient transport device assigned to it, and a locked position in which the at least one locking element is in locking engagement with the counterlocking element of the patient transport device assigned to it, the aforementioned step f) comprising the step of transferring the control lever from its unlocked position, which is forcibly assumed in the loading position of the receiving trolley, to its locked position during retraction of the receiving carriage, and only after the carriage has left its loading position.

It may also be expedient for the aforementioned step g) to comprise the step of locking the control lever in its locked position at the latest when the receiving carriage is in its fully retracted position. In this variant, rotational mobility or the like is therefore reduced. The mobility of the control lever is locked in the fully retracted position of the receiving carriage, so that the control lever can no longer move due to vibrations or the like. In this situation, the control lever is in its locked position and, therefore, the locking device is also in its locked position.

In another advantageous embodiment of the invention, it is provided that the control lever and/or the rod and/or the at least one locking element and/or each locking element is elastically prestressed in the direction of the respective locking position to be adopted in the locked state of the locking device, specifically so that the respective locking position is automatically assumed after a possible blockage has been eliminated when the at least one locking element interacts with the counterlocking element of the patient transport device assigned to it. In this variant, the locking device is spring-loaded in its locked position. As mentioned above, the control lever is biased from the unlocked position into the locked position when the receiving trolley leaves the loading position or shortly after leaving it. In the locked position, the locking elements or at least one locking element are in operative connection with counterlocking elements or at least one counterlocking element on the patient transport device. For example, the locking elements are designed as clamping claws or clamping rings, which are moved by hooks on the stretcher to the locked position of the locking device. The locking elements of the locking device can conveniently rotate around an axis parallel to the extraction and retraction direction of the receiving device. However, the rotation could also take place around a rotation axis perpendicular to the aforementioned axis. However, this variant has the advantage that the locking elements, in their unlocked position, free up the necessary path to slide the stretcher onto the receiving trolley.

The spring pretensioning of the locking device for the automatic subsequent assumption of the locked position of the locking device has the advantage that if, for any reason, the locking elements of the locking device do not engage with the counter-locking elements of the patient transport device (do not interact with them), the subsequent engagement occurs automatically when the blockage between the locking element and the counter-locking element is released. For example, a belt of the patient restraint system, typically found in patient transport devices, may be positioned between the locking element of the locking device and the counter-locking element of the patient transport device. If the belt is subsequently moved between the two elements, the locking device automatically snaps into place and moves to its locked position. An example of such a patient restraint system is described in document DE-A-102018 111 654, the content of which is hereby incorporated by reference into the subject matter of the present application.

In another advantageous embodiment, the centering of the patient transport device can be ensured by positioning it on top of the receiving trolley. This is conveniently achieved because the maneuvering of the patient transport device to transfer the patient transport device to a position above the receiving trolley comprises the step of centering the patient transport device relative to the receiving trolley by means of guide struts that can be moved along the guide edges of a centering opening of the receiving trolley and that protrude from the patient transport device. The guide struts protrude from the stretcher or, if available, from its chassis. In the latter case, the guide struts must be substantially aligned with the front wheels or rollers of the chassis when loading the trolley with the patient transport device, i.e., they must be located substantially vertically above these wheels or rollers. Experience has shown that it is advisable to center the patient transport device with the chassis substantially at the height of the front wheels. This makes it much easier to maneuver the mobile patient transport device when placed on the receiving trolley.

The guide struts and the guide edges are suitably rounded and/or curved at their respective contact sections. For example, the guide struts can be designed as vertically aligned rollers and the guide edges as horizontally aligned rounded strips. The advantage of rounding the guide edges on the receiving trolley is, in particular, that the patient transport device can be pushed onto the receiving trolley by means of the centering guide struts even if, for whatever reason, the patient transport device and the vehicle are slightly skewed relative to each other when viewed in the direction of travel (e.g., due to a laterally inclined surface behind the vehicle, which in turn lies on a surface oriented in the opposite direction).

In the embodiments described above, with the possibility of centering the patient transport device on the receiving trolley, the latter has, when viewed from above, a substantially U-shaped shape, i.e., it is provided with a recess open at the rear. The longitudinal edges of the recess are then designed as guide edges, preferably rounded. Next to the guide edges, there are tracks on the receiving trolley, on which sliding or rolling elements of the patient transport device can be moved or shifted. To improve the maneuverability of the patient transport device, it is advantageous if the transfer of the patient transport device to a position above the receiving trolley comprises the step of centering the patient transport device relative to the receiving trolley by means of sliding or rolling elements of the patient transport device, which can be moved and/or shifted on tracks of the receiving trolley, each track being designed to project at an angle or having an inclined protruding section. Inclined tracks or at least with inclined sections, together with correspondingly inclined sliding or roller elements of the patient transport device, provide additional centering when the patient transport device is pushed onto the receiving trolley or when the patient transport device is lowered onto the receiving trolley from above.

In this respect, it is also advantageous if each sliding or roller element is designed to narrow obliquely at its end facing the corresponding longitudinal side of the patient transport device, the inclination of the slope of the track being substantially equal to the inclination of the taper of the sliding or roller elements.

As already mentioned above, it is advantageous if the tracks are arranged on both sides of the centering opening of the receiving carriage and if the obliquely projecting sections of the tracks are arranged facing away from the associated guide edge or if the tracks run obliquely and protrude away from the respective associated guide edge.

As already described above, the receiving device may be provided with a lifting mechanism to be able to raise the receiving trolley within the vehicle, which is particularly advantageous if the patient is to be treated during transport in the patient transport vehicle. For this purpose, it is advantageous if the receiving device has a base that can be mounted on the loading surface of the vehicle and has a raised central area, on both sides of which the receiving trolley extends and above which the patient transport device is located in the fully retracted retracted position of the receiving trolley, the base having below its central area a lifting lever mechanism with two automatically pivoting pivot arms that, when flat and inclined in a lower position of the lifting lever mechanism, form a first acute angle with the loading surface of the vehicle and, when inclined in a higher position of the lifting lever mechanism, form a second acute angle with the loading surface of the vehicle that is larger than the first acute angle, and each of the pivot arms being pivotably mounted on consoles that are mounted on the loading surface of the vehicle. Since, according to the invention, it is not necessary to secure the patient transport device to the loading surface of the vehicle or to a base secured thereto, the central area beneath the patient transport device is free when the patient transport device is on the receiving device. This free space can then preferably be used for the arrangement of a lifting mechanism (using levers, hydraulic cylinders, spindle drives, or the like). The lifting lever mechanism described here has the advantage of being flat in its lowest position.

The lifting lever mechanism or other lifting mechanism for the receiving device is conveniently covered on all sides by a panel that can be independently adjusted in height. These could be, for example, panel frames that can be moved relative to one another, one of which is arranged and protrudes permanently over the vehicle's loading surface or the base of the receiving device, while the other is arranged over the height-adjustable element of the receiving device. In the lowest position of the lifting mechanism, these two panels overlap the maximum, while the degree of overlap is lowest when the lifting mechanism is raised. A triple-frame cladding or a multi-frame overall cladding is also conceivable. However, it is advantageous if the cladding is realized by means of a wraparound bellows.

For the alignment of the receiving device with lifting mechanism within the vehicle during mounting of the receiving device on the vehicle, it may be advantageous if the brackets or the lifting mechanism are arranged on the loading surface of the vehicle such that they can be moved in a direction orthogonal to the longitudinal axis of the vehicle and are fixed in a movable position.

For safety reasons, when transporting a patient in a patient transport vehicle on a patient transport device, it is essential that the patient transport device be protected from acceleration forces that occur in the event of an accident, for example, in the event of a rear-end collision or similar. According to the invention, the patient transport device is locked to the receiving device, while the receiving device itself is locked to the vehicle. The patient transport device is conveniently locked to the receiving device's receiving carriage on both sides of the patient transport device's center of gravity when a patient is on it. This is typically the case in the patient's pelvic area.

In this respect, it is therefore advantageous that:

- the receiving trolley is supported during movement into its fully retracted retraction position by means of two sliding or rolling elements arranged on both sides of its central axis on the loading surface of the vehicle or, if present, on a base of the receiving device fixed to the loading surface of the vehicle, the two sliding or rolling elements being arranged approximately at the height of half the longitudinal extension of the receiving trolley or approximately at the height of half the longitudinal extension of the patient transport device arranged on the receiving trolley,

- the patient transport device is locked to the receiving trolley on both sides of its central axis by means of the locking device at two locking points each, which are located in front of and behind the respective sliding or roller element when viewed in the longitudinal extension of the receiving trolley, so that the receiving trolley is reinforced on both sides of its central axis by struts extending between each locking point and the respective sliding or roller element and

- the receiving carriage is locked and/or retained on the loading surface of the vehicle or, if present, on the base fixed to the loading surface of the vehicle in the fully retracted retracted position adjacent to the sliding or rolling elements, in particular by means of retaining devices and preferably by means of retaining devices in the form of angular elements that can be moved upwards or downwards, under which the receiving device moves or over which the receiving device moves enclosing the retaining devices.

In this way, the patient transport device is secured to the receiving trolley. The receiving trolley conveniently has sliding or roller elements by means of which it can rest and move on the loading surface of a possibly existing base of the receiving device when it is moved within the vehicle. These additional "support points" of the receiving trolley, which are equipped with rollers or similar. The movable guide devices provided with rolling elements are guided and retained in the receiving device and are located essentially at the height of the center of gravity of the patient transport device when a patient is on it. The patient transport device is then locked to the trolley on both sides of the patient, in front of and behind the aforementioned support points of the receiving trolley, as seen in the direction of travel of the vehicle. Each side of the receiving trolley is reinforced in the area of its support point by reinforcing struts that extend essentially from the support point to each of the two locking points for the patient transport device provided on each side of the receiving trolley. This means that the force is then transmitted from the possibly loaded patient transport device from its locking points with the receiving trolley via the reinforcing struts to the receiving trolley's support points on the loading surface or base. At these points, the receiving trolley is locked in the loading area or base when the receiving trolley is in its fully retracted position in the vehicle. If vertical acceleration forces act on the receiving trolley during travel, these are absorbed at the center of gravity of the patient transport device on which the patient is located, so that the effect of torques on the support device resulting from the vertical acceleration forces is minimized. Furthermore, the receiving trolley can be locked at both ends or at least at one of its two ends, and in particular at the end furthest from the interior of the vehicle in the fully retracted position, toward the loading surface of the vehicle or toward the base (if present) of the receiving device.

In this regard, it is therefore advantageous if the receiving carriage is additionally blocked against unintended movements in the direction of retraction and extension of the receiving carriage and, if necessary, is additionally held downwards at its far end on the chassis in the fully retracted retraction position and, if applicable, at the end opposite this on the loading surface of the vehicle or, if available, on a base of the receiving device fixed to the loading surface of the vehicle.

Furthermore, with regard to the stability of the fixing of the receiving device to the patient transport device (if necessary with a patient lying thereon), it is advantageous if the patient transport device is locked on the receiving trolley in its fully retracted position exclusively by means of the locking device and is secured in a stable position in this state by locking the receiving trolley to the vehicle, in particular to its loading surface or, if present, to a base of the receiving device fixed to the loading surface and, if necessary, by interposing an intermediate trolley between the receiving trolley and the base, the intermediate trolley and the receiving trolley being locked together.

When the receiving device is viewed in the direction of travel of the vehicle or in the opposite direction, i.e. when the receiving device is viewed in the respective direction of travel of the receiving carriage on the receiving device or in the opposite direction, the receiving device or its receiving carriage essentially has a U-shape, this U-shape more or less enclosing the base of the receiving device on the sides and at the top. If the receiving device also has an intermediate carriage on the base, this is located between the receiving carriage and the base in the viewing direction described above, i.e. it also has a U-shape. The central area freed by the receiving carriage and, if present, the central carriage due to its respective U-shape, can be used for a lifting device (see above).

It is therefore advantageous in the invention that the patient transport device does not have a locking mechanism that interacts directly with the loading surface of the vehicle or directly with a base of the receiving device that is fixed to the loading surface of the vehicle, if present, when the receiving cart is in its fully retracted position.

If the patient transport device is provided with a stretcher and a chassis from which the stretcher can be removed, the stretcher is locked to the chassis during transport of a patient and is locked to the receiving trolley in the fully retracted position, the chassis being arranged below the stretcher and suspended within the receiving trolley or resting on it.

At this point it is worth noting that steps a) and b) mentioned initially are not necessary if the patient transport device has already been unloaded from the vehicle before loading it and, therefore, the receiving cart is already in its loading position.

Typically, there is one patient in the patient transport device when the vehicle is loaded or there is no patient in the patient transport device when the vehicle is loaded.

As already highlighted above, various movement sequences of the receiving device and individual locking mechanisms, including locking the patient transport device on the receiving trolley, can be carried out purely mechanically or electromechanically. So-called snap-bolt locks are preferably suitable for purely mechanical locking, in which one or more latches are pre-tensioned in an open position and then automatically transferred to the locked position when a locking pin is inserted into the opening and the locking pin comes into contact with an actuating element or one of the snap-bolts. For this purpose, the latches are pre-tensioned in the open position. The snap-bolt is opened from its closed position by moving a release lever, which returns the snap-bolt(s) to the open position, where they are again automatically held. The American company Southco offers this type of snap-bolt in various versions.

With an electromechanical solution for the automatic locking and unlocking of the individual components of the receiving trolley and the patient transport device with a receiving trolley, which are arranged movably relative to one another, a control signal can be applied to a lock that is opened and closed electromechanically, for example, via limit switches. The extension and retraction movements of the individual components of the holding device can also be provided with additional drives.

The extension and retraction movements of the holding device can be performed essentially manually, with automatic assistance, or fully automatically. For any necessary supply of electrical power to the individual components of the patient transport device, i.e., the stretcher and/or chassis, and the support device, from the on-board power supply of the patient transport vehicle, plug, slide, or electrical contact arrangements can be provided. An example of an electrical contact created when pushing and placing the stretcher onto the chassis or the stretcher or chassis onto the support device is described in German utility model application 20 2020 102 715.8, filed on May 14, 2020, the content of which is hereby incorporated by reference into the subject matter of this application.

The invention is explained in more detail below by means of an exemplary embodiment and with reference to the drawing. Specifically, it is shown in:

Fig. 1 a rear view of an open patient transport vehicle with a receiving device arranged inside and a patient transport vehicle above it,

Fig. 2 a side view of the receiving device (without the patient transport device on it),

Fig. 3 a perspective side view of the support device in the simply extended state (again without patient transport device),

Fig. 4 a perspective view of the receiving device with double extension and also without patient transport device,

Fig. 5 a view of the receiving device from inside the patient transport vehicle in the state in which the receiving device is located shortly before assuming its position during the double extraction,

Fig. 6 a view to illustrate the locking device with which the patient transport device (not shown) is locked to the receiving device,

Fig. 7 an enlarged view of area VII of Fig. 5 to illustrate the locking elements (hooks) of the locking device,

Fig. 8 a perspective view of the receiving device from the inside of the patient transport vehicle in the situation where the receiving device is in its doubly extended state and the locking device is open,

Fig. 9 similar to Fig. 6, but with the locking device in the unlocked position (indicated by arrows),

Fig. 10 an enlarged view of area X of Fig. 8 to illustrate the open locking hooks for the patient transport device,

Fig. 11 a perspective view of the extended receiving device in its fully extended state (loading and unloading state),

Fig. 12 shows how, in the loading or unloading state of the receiving device according to Fig. 11, a stretcher or a stretcher with chassis (chassis extended or not) is taken out of the receiving device or pushed into the receiving device,

Fig. 13 the situation in the loading or unloading position of the receiving device with the patient transport device on it (in this case a stretcher with chassis),

Fig. 14 in side view the situation where the stretcher is still resting on the support device during unloading or loading without the chassis being fully extended,

Fig. 15 the situation where the chassis is extended so far that the stretcher is positioned above the support device in its loading or unloading position,

Fig. 16 a perspective view of the receiving device in the loading or unloading state with the patient transport device being maneuvered into position on or above the receiving device,

Fig. 17 an enlarged view of area XVII of Fig. 16,

Fig. 18 shows how the patient transport device can still be pushed or placed centrally on the receiving device even if it is tilted laterally with respect to the receiving device,

Fig. 19 centering of the patient transport device on the receiving device,

Fig. 20 a representation of the situation in which the receiving device is pushed back into the patient transport vehicle from its fully extended loading or unloading position,

Fig. 21 a perspective view of the receiving device from inside the vehicle shortly after leaving the loading or unloading position (see also Fig. 5),

Fig. 22 the situation in which the support device is pushed back to its first extraction position and the locking of the individual extractable elements is released,

Fig. 23 a side view of the receiving device in the fully retracted retraction position (partially cut away) to illustrate the attachment points of the receiving device to the vehicle and the patient transport device to the receiving device,

Fig. 24 a representation of the lifting mechanism for lifting the receiving device into its fully retracted retraction position and

Fig. 25 a representation of the lifting mechanism with the receiving device raised.

Fig. 1 shows the rear view of a patient transport vehicle 10 on which an extendable receiving device 12 for a patient transport device 14 is located. In this embodiment, the patient transport device 14 comprises a stretcher 16 and a chassis 18, which in particular is automatically height-adjustable and with which the stretcher 16 can be easily moved and raised and lowered outside the patient transport vehicle 10. The stretcher 16 is locked to the chassis 18 and can be removed from the chassis 18 to be used as a manually operated portable stretcher 16. The stretcher 16 has a patient transport surface 20 having adjustable back, thigh and lower leg portions and a fixed seat portion, which can be adjusted as a reclining surface or, if necessary, as a chair surface. In this context, reference may be made to WO-A-2018/153940, which shows and describes a patient transport device 14 that can be used within the scope of the invention. Further design configurations of the patient transport device 14 with convertible patient transport surface 20 are presented in EP-A-3 613 396, the content of which is hereby incorporated by reference into the subject matter of the present application.

Figs. 2 to 5 show various perspective views of the receiving device 12. The receiving device 12 can be removed in two steps and has a base 26 which is mounted on the vehicle floor 22 or on the loading surface 24 of the patient transport vehicle 10 in a height-adjustable manner and has an elongated, raised guide housing 27 over which an intermediate carriage 28 is guided, which surrounds the guide housing 27 on three sides in a longitudinally displaceable manner, and a receiving carriage 30 is guided, which also surrounds the intermediate carriage 28 on three sides in a longitudinally displaceable manner. In this way, a receiving device 12 is created which can be extended twice. The locking of the receiving device 12 in the patient transport vehicle 10 is carried out by two clamping devices 32 and also two locking locks 34 in this embodiment, as shown in Figures 2 and 3. The clamping devices 32 and the locking locks 34 are arranged on the base 26 and hold the receiving trolley 30 horizontally, laterally and vertically in its fully retracted retracted position in the patient transport vehicle 10 (see Fig. 2). The patient transport device 14 is in turn locked to the receiving trolley 30, as can be seen, for example, in Figs. 2 to 5, by locking claws 36 (see also Fig. 17), which cooperate with the locking hooks 38 of the patient transport device 14 (indicated, for example, in Figs. 7 and 9).

Starting from the situation according to Fig. 2 (fully retracted retraction position of the receiving device 12), a release lever 40 shown in Fig. 2 is actuated at the end of the base 26 facing the loading edge, which is connected via a Bowden cable or the like. The release mechanism unlocks the locking locks 34. In this way, the locking pins 42 that were previously locked by the locking locks 34 and protrude from the receiving carriage 30 are released, so that the receiving carriage 30 can be pulled out in the direction of the arrow in the pull-out direction 44. This pull-out movement is performed by pulling out the receiving carriage together with the intermediate carriage 28. In this case, each of the two support structures 46 with support roller 48 arranged in the central region of the receiving carriage 30 moves away from a clamping pin 50 which is previously housed in a receiving opening 51 in the support structure 46 (see also Fig. 5).

Fig. 3 shows the situation in which the intermediate carriage 28, which is slidably guided on the guide housing 27 of the base 26, has moved to its maximum extension position. In this position, the intermediate carriage 28 is then locked with the base 26 or its guide housing 27 by means of an automatic locking lock 52 (see Fig. 5), which can be automatically opened (later) by actuating/acting on a release lever. At the same time, the receiving carriage 30 is unlocked from the state in which it was previously fixed to the intermediate carriage 28, so that the receiving carriage 30 can subsequently be extended in the extension direction 44.

During this further extraction movement of the receiving trolley 30, its locking device 54 is in its locked state for locking the patient transport device 14 located on the receiving trolley 30. The operation of this locking device 54 and its automatic transfer from the locked state to the unlocked state is explained below with reference to Figs. 5 to 10.

Fig. 5 shows the situation in which the receiving carriage 30 is located shortly before its maximum extension position (loading or unloading position). As can be best seen in Fig. 6, the locking device has a locking element that can be actuated, for example, by a cam-like or similarly guided pivotable control lever 56, which is provided with a roller 58 that rolls on the intermediate carriage 28 when the receiving carriage 30 moves relative to the intermediate carriage 28 (see also Fig. 5). The control lever 56 is mounted so that it can rotate on a pivot bearing 60 of the receiving carriage 30, and can therefore pivot to the left in the direction of arrow 62 in Fig. 6 from the position shown there. The pivot bearing end of the control lever 56 has two projecting connecting levers 64, 66, to each of which a control lever 68, 70 is hingedly coupled, which lead from the respective levers 64, 66 to both longitudinal sides 72 of the receiving carriage 30. On these two longitudinal sides 72 are control rods 74, from each of which two locking claws 36 of the locking device project.

In the maximum extraction position of the receiving carriage 30 with respect to the intermediate carriage 28, the roller 58 of the control lever 56 rests on a cam block 76, which ensures that the control lever 56 automatically pivots in the direction of the arrow 62 in Fig. 6. While previously the locking claws 36 were positioned in their locked position, they are then pivoted into the open position by this movement of the control lever and the link formed by the levers 64, 66, 68, 70 and the control rods 74 (see Fig. 10). In this situation, the locking claws 36 release the locking hooks 38 of the patient transport device 14, which occurs at the latest after 95% or 90% or 80% or 70% or 60% or 50% or 40% of the travel from the fully retracted retraction position to the fully extended loading and unloading position of the receiving trolley 30. This means that the patient transport device can be removed from the receiving trolley 30 in the loading or unloading position (maximum extraction position) or, if the chassis 18 is present on the stretcher 16 of the patient transport device 14, the stretcher 16 can be lifted above the receiving trolley 30 by extending the chassis 18 so that the patient transport device 14 can then be moved away from the receiving trolley 30.

As an alternative to actuating the two control rods 74 by means of the single control lever 56, it is also possible to provide a separate control lever for each control rod 74, which is provided with or coupled to an axially displaceable rack, for example, and which moves this rack, for example, in a cam-guided manner. The rack meshes with a pinion or gear that is fixedly connected to the control rod and rotates the control rod when the rack is moved clockwise or counterclockwise in order to bring the locking claws 36 into locking engagement with the locking hooks 38 or release them from locking engagement with them.

During the movement of the locking device 54 from the locked position to the unlocked position, the preloading springs 78 are tensioned (see Figs. 7 and 9). In this configuration, the preloading springs 78 are designed as four-legged springs, the helical section of which extends around the control rods 74 in the region of the locking claws 36 and whose projecting legs bear on the one hand on the receiving carriage 30 and on the other hand on the locking claws 36. Of course, other designs of the pretensioning device for pretensioning the locking claws 36 and thus the locking device 54 in the locked position are also possible.

The special feature of the locking device 54 is that the patient transport device 14 is not locked to the receiving trolley 30 when the receiving trolley 30 is in its loading or unloading position (maximally extended). In contrast, the patient transport device 14 is only locked to the receiving trolley 30 and thus to the receiving device 12 after the receiving trolley 30 has left its fully extended extraction position, i.e. its loading or unloading position, for example after covering a maximum of 5% or a maximum of 10% or a maximum of 20% or a maximum of 30% or a maximum of 40% or a maximum of 60% of the retraction travel starting from the fully extended extraction position to the fully retracted retraction position of the receiving trolley 30.

In other words, when the receiving trolley 30 is extended, the patient transport device 14 is unlocked at the latest after 95% or 90% or 80% or 70% or 60% or 50% or 40% of the travel from the fully retracted retraction position to the fully extended loading or unloading position of the receiving trolley 30.

Figs. 11 to 19 show different views of the receiving device with and without a patient transport device to illustrate the loading and unloading process. In Fig. 11 it can be seen that the intermediate carriage 28 is locked to the base 26 or to the guide housing 27 of the base 26 by means of the locking lock 52. Also shown is a locking lock 80 on the receiving carriage 30, which can be automatically opened by actuating/acting on a release lever (which will be discussed again later) and by means of which the receiving carriage 30 is locked in the maximum extraction position on the intermediate carriage 28. The roller 58 has moved over the cam block 76 so that the locking claws 36 are in their open position. The receiving carriage 30 has two arms 82 that form the longitudinal sides 72 of the receiving carriage 30. Each arm 82 is supported by a support structure 46 with a support roller 48 at the base 26 when the receiving cart 30 is fully retracted. At the ends of the two side arms 82, the receiving cart 30 has handles 84 by which the receiving cart 30 is manually grasped to extend or retract the receiving cart 30. On the upper side of each arm 82 is a sliding or roller receiving track 86 on which the sliding or roller bodies 88 of the patient transport device 14 slide or roll when the patient transport device 14 is pushed onto the receiving cart 30 or its arm 82 (see Fig. 12).

Fig. 13 shows the situation in which the patient transport device 14 rests on the fully extended receiving trolley 30 with the chassis 18 retracted. The running or steering rollers 90 of the chassis 18 are located directly below the receiving trolley 30, i.e., they are positioned above the base 26 so that the receiving trolley 30 can be pushed into the patient transport vehicle 10 or pulled out of the patient transport vehicle 10.

Fig. 13 shows the situation in which the patient transport device 14, i.e. the stretcher 16 and the chassis 18, are positioned on the receiving trolley 30. However, the receiving trolley 30 can also be loaded with only the stretcher 16. The stretcher 16 has the aforementioned locking hooks 38, which interact with the locking claws 36 of the locking device 54. The chassis 18, in turn, is locked to the stretcher 16, for example, by an upper frame (not shown) of the chassis 18 which supports the stretcher 16 and is locked to it. The chassis 18 has, as shown for example in Figs. 14 and 15, a height adjustment mechanism 92 in the form of a scissor lift with drive 94, which rests on a lower frame 96, which in turn is provided with running/steering rollers 90. Of course, other height adjustment mechanisms can also be used for the chassis 18 of the patient transport device 14.

Fig. 14 shows the situation in which the receiving device 12 or its receiving trolley 30 is in the loading or unloading position and the patient transport device 14 is located on the receiving trolley 30, where the chassis 18 is partially extended or retracted. The chassis 18 thus hangs, so to speak, from below over the stretcher 16. The stretcher 16 is not locked on the receiving trolley 30 (see above the description of the locking device 54, which is in its unlocked position when the receiving trolley 30 is fully extended).

If the chassis 18 is then extended further (starting from the situation according to Fig. 14), the running/steering rollers 90 of the chassis 18 finally rest on the base 98 (e.g., the roadway). If the chassis 18 is extended further from this situation, its upper frame with the stretcher 16 supported on it is lifted upwards from the receiving trolley 30 (see Fig. 15). The patient transport device 14 can then be moved away from the receiving trolley 30.

The situation is then correspondingly reversed when the receiving device 12 is loaded with the patient transport device 14, which then moves on the receiving trolley 30 when it is in the loading position, and then is automatically deposited on the receiving trolley 30 or its arm 82 when the chassis 18 is retracted.

Fig. 16 illustrates this process again, with Fig. 16 showing the situation in which the patient transport device 14 is maneuvered to drive towards or onto the receiving trolley 30. Fig. 17 shows area XVII of Fig. 16 on an enlarged scale. The upper frame 100 of the chassis 18 is provided with locking locks (not shown) which can be unlocked by two release levers 102. Each longitudinal beam of the upper frame 100 is provided with a release lever 102. For example, two locks arranged on each longitudinal beam of the upper frame 100 can be opened by a rod which is moved by the release lever 102. The stretcher has locking pins or the like (also not shown) which interact with the locking locks. The stretcher is further provided with roller elements 104 which taper conically outwards and which, as described below, serve for centering when the stretcher (particularly without frame 18) pushes on the receiving tracks 86 of the arms 82. Since, as shown, for example, in Fig. 11, the receiving tracks 86 are aligned so that they run upwards at an angle to the outside, centering is achieved with the roller elements 104 tapering conically outwards on the stretcher (see Figs. 18 and 19).

The above-described centering of the stretcher 16 on the arms 82 of the receiving carriage 30 is particularly necessary if the stretcher 16 is to be positioned on the receiving carriage 30 without the chassis 18. If, on the other hand, the stretcher 16 is located on the chassis 18 or if the chassis 18 is to be positioned on the receiving carriage 30 without the stretcher 16, two guide struts 106 projecting downwards from the upper frame 100 of the chassis 18 and designed as pivot sleeves serve to improve the maneuverability of the chassis 18. The guide struts 106 interact with the inner leading edges on the receiving tracks 86, which form inner guide edges 108 on the two arms 82. The guide edges 108 are further separated from each other at the ends of the two arms 82 in the area of the respective handles 84 than in the adjacent section of the arms 82. The guide struts 106 are positioned on the upper frame 100 of the chassis 18 above the front running/steering rollers 90 of the chassis 18 during loading, which makes the maneuverability of the chassis 18 and of the patient transport device 14 as a whole much easier, since the contact of the guide struts 106 at the level of the front running/steering rollers 90 makes it easier to thread the chassis 18 when it is not pushed onto the receiving trolley 30 in exact alignment with the clearance between the two arms 82.

The centering of the chassis 18 by means of the guide struts 106 is shown in Figs. 18 and 19. Fig. 18 shows another special feature. As can be seen, the guide edges 108 are convexly curved. This means that even if the chassis 18 rotates with respect to the horizontal alignment of the receiving device or the receiving trolley 30, the guide struts 106 can still be retracted within the space defined by the guide edges 108. If, for example, the chassis 18 is retracted in the situation according to Fig. 18, the chassis 18 is automatically positioned with respect to its upper frame 100 and the stretcher 16 is centered on the receiving trolley 30 or on its arm 82 (see Fig. 19).

With regard to Figs. 20 to 23, the process of retraction of the possibly loaded receiving carriage 30 will be briefly discussed below.

As shown in Fig. 20, the locking lock 80, which locks the receiving carriage 30 relative to the intermediate carriage 28, is released by means of a release lever or a release button 110 on one of the two handles 84 of the receiving carriage 30 via a Bowden cable. In this state, the intermediate carriage 28 is still locked relative to the guide housing 27 of the base 26. When the receiving carriage 30 is then inserted, it moves in the opposite direction to the intermediate carriage 28 and along it. In this case, the locking device 54 is locked shortly after the receiving carriage 30 has left the loading position, i.e., it moves from its unlocked position to the locked position, which conveniently has already taken place after covering a maximum of half, 2/3, 1/4, 1/8 or 1/10 of the travel of the receiving carriage from its loading position to its fully retracted position. The control lever 56 rolls on its roller 58 from the cam block 76. Because the locking claws 36 are pretensioned in the locked position, the entire locking device 54 moves into the locked position. The control lever 56 rotates correspondingly to the position shown in Fig. 6 (see also Fig. 21).

Finally, the situation according to Fig. 22 is reached, in which the receiving carriage 30 is pushed completely onto the intermediate carriage 28. In this situation, the receiving carriage 30 releases the locking lock 52 between the intermediate carriage 28 and the guide housing 27 of the base 26. Immediately beforehand, the control lever 56 is retracted by means of a pin 112 projecting therefrom towards a retaining hook 114 arranged on the intermediate carriage 28. This ensures that the control lever 56 is locked from its locked position (see Fig. 6), in which the locking device 54 is locked. When the receiving carriage 30 is completely pushed onto the intermediate carriage 28, the vibrations acting on the receiving device 12 cannot accidentally open the locking device 54. The locking device 54 is thus locked and latched in its locked position. This is to ensure safety during transportation of the patient transport device and a patient in the patient transport vehicle 10.

In the situation according to Fig. 22, the locking device 54 is locked and the intermediate carriage 28 is unlocked with respect to the base 26 or the guide housing 27. However, the receiving carriage 30 is in turn locked on the intermediate carriage 28. Both will then move further in the direction of the patient transport vehicle 10 until they finally reach the situation shown in Fig. 23. Here, the locking locks 34 and the clamping devices 32 then act to secure the patient transport device 14 three-dimensionally to the receiving device 12, as already described above.

With reference to Fig. 23, a further special feature of the invention will now be discussed. As can be seen, the support structure 46 is located approximately in the center of the patient transport device or the stretcher 16. In this exemplary embodiment, the support structure 46 is located essentially below the seat part of the stretcher 16. In this exemplary embodiment, there are foldable side parts 115 on both sides of the seat part of the stretcher 16. Starting from the support structure 46, two struts 116 extend to the front and rear ends of the patient transport device 14. These struts 116, like the support structure 46, form part of each arm 82 of the receiving trolley 30. The struts 116 terminate in the area of the locking claws 36, in which the patient transport device is in locking engagement with the locking device 54 with its locking hooks 38. These locking catches are then also located via the arm 82 of the receiving carriage 30 in the area of the seat part of the stretcher 16. When a patient is transported, the center of gravity of the patient transport device 14 and the patient is located in the area of the seat part of the stretcher 16. It is therefore advantageous if the stretcher 16 is locked on the receiving carriage 30 of the receiving device 12 on each side of the patient transport device 14 in front of and behind the center of gravity and that the force flow to the support structure 46 continues from these locking points via the struts 116, it then also being provided that the support structure 46 is locked against vertical acceleration forces by means of the clamping device 32. In this way, short "force flow paths" are created, which start from the center of gravity of the patient transported in the patient transport device 14 to the base 26 and from there to the loading surface 24 of the patient transport vehicle 10.

The receiving trolley 30 would experience a torque around its rear end located furthest from the vehicle in the event of accelerations acting vertically upwards on the patient transport device 14. However, since the patient transport device 14 is held downwards at its center of gravity (when loaded with a patient) by the securing devices 32, the torques can be absorbed. Movements of the receiving trolley 30 in the longitudinal direction are prevented by the locking locks 34. In turn, the securing devices 32 prevent movements of the receiving trolley 30 transversely thereto.

With reference to Figs. 24 and 25, another special feature of the invention is now discussed. The receiving device 12 can be lifted by means of a lifting mechanism 118 when the receiving trolley 30 is fully retracted into the vehicle. If a patient transport device 14 with a patient is placed on the receiving trolley 30, it is possible to lift this patient to a height at which the paramedic or emergency physician can comfortably care for him or her during transport.

In the receiving device 12, the lifting mechanism 118 is housed in the guide housing 27 to save space. As can be seen from the drawings described so far, the guide housing 27 protrudes centrally from the base 26. The central U-shaped construction of the intermediate carriage 28 and the receiving carriage 30, in combination with the guide housing 27, ensures a compact and space-saving design of the receiving device 12. The space gained in the middle below the patient transport device 14 to be transported can then be advantageously used to accommodate the lifting mechanism 118. A key reason for there being space in this area of the receiving device 12 is that, according to the invention, it is not the patient transport device 14 itself that is locked directly, for example, to the loading surface 24 of the patient transport vehicle 10, but rather it is the receiving trolley 30 that is locked to the base 26 or, if applicable, also to the loading surface 24, and the patient transport device 14 is in turn locked to the receiving trolley 30. Therefore, no locking element protrudes downwards from the patient transport device 14 to lock directly to the base 26 or to the loading surface 24 of the patient transport vehicle 10.

The lifting mechanism 118 in this embodiment of the invention is characterized by a low overall height. It consists of two pivot arms 120, which are pivotally mounted in pivot bearings 124, which in turn are arranged below the base 26. The two pivot arms 120 are designed as angled arms which, viewed from the pivot bearing 124, extend essentially at right angles to one another. The first arm part 126, aligned essentially horizontally, rests on a console 128 on the floor 22 of the patient transport vehicle 10, while the second arm part 130 in this exemplary embodiment cooperates, for example, with a spindle drive 132. The spindle drive 132 has a spindle 134 which cooperates with the spindle sleeves 136 on the second arm parts 130. If the spindle drive 132 rotates the spindle 134, the spindle sleeve 136 moves axially on the spindle 134 and moves the arms 130 of the two pivot arms 120 towards or away from each other, so that the pivot arms 120 rotate about their pivot bearings 124. In this way, when the pivot arms 120 rotate about the pivot bearings 124, their essentially horizontal arms 126 press against the consoles 128, which causes the lifting mechanism 118 to be raised or lowered.

The arms 126 of the two pivot arms 120 are rotatably mounted on brackets 128. The consoles 128 may be mounted on a rail system or the like transversely to the longitudinal extent of the patient transport vehicle 10. This allows the receiving device 12 to be shifted laterally in the patient transport vehicle 10 to provide more space to one side of the receiving device 12 for a paramedic or emergency physician attending to a patient in the vehicle.

In this embodiment, a wrap-around bellows 138 is used to cover the area below the base 26 and thus the lifting mechanism 118, which extends like a cover with two longitudinal sides and two transverse sides along the edge of the base 26, is fixed there, and is mounted at its other end on the floor 22 of the vehicle.

List of reference signs

10 patient transport vehicles

12 receiving device

14 patient transport device

16 stretcher

18 chassis

20 patient transport surface

22nd floor of the vehicle

24 loading surface

26 base

27 guide housing

28 intermediate car

30 receiving car

32 clamping device

34 locking locks

36 locking claws

38 locking hook

40 release lever

42 locking pin

44 extraction direction

46 support structure

48 support roller

50 retaining pin

51 Receiving opening for the retaining pin

52 lock lock

54 locking device

56 pivoting control lever

58 roller

60 slewing bearing

62 arrow

64 connecting lever

66 connecting lever

68 control lever

70 control lever

72 longitudinal sides

74 control bars

76 cam block

78 preload springs

80 lock lock

82 arm

84 handles

86 roller receiving track

88 roller body

90 running/steering rollers

92 height adjustment mechanism

94 drive

96 frame

98 base

100 upper frame

102 release lever

104 roller elements

106 guide struts

108 guide edges

110 release button

112 pin

114 retaining hook

115 side parts

116 struts

118 lifting mechanism

120 swing arms

124 slewing bearing

126 first part of the arm of the swing arm

128 console

130 second part of the swing arm arm

132 spindle drive

134 spindle

136 spindle sleeve

138 bellows surround

Literature

German Utility Model Application 202020 102715.8 DE-A-102018 111 654

EP-A-2 116216

EP-A-2 138143

EP-A-3613396

WO-A-2004/064698

WO-A-2016/007290

WO-A-2018/153940

WO-A-2018/206834

GB-A-2203999

FR-A-2682930

Claims (22)

1. Method for unloading a patient transport device from a vehicle, in particular from a patient transport or a rescue vehicle, the vehicle comprising a loading surface (24) and a receiving device thereon having an extendable and retractable receiving carriage (30) for the patient transport device on which the patient transport device is positioned to be locked by means of a locking device (54) in a locked position, comprising the following steps: aa) unlock the receiving carriage (30), which is in its fully retracted position and locked directly or indirectly to the vehicle (10) in this state, bb) extending the receiving carriage (30) to an unloading position in which the receiving carriage (30) is automatically locked and protrudes at least partially rearward beyond the loading surface (24) of the vehicle (10), cc) automatically unlock the patient transport device (14) when the receiving trolley (30) adopts the unloading position by automatically transferring the locking device (54) from its locked position to an unlocked position, and dd) unload the patient transport device (14) from the receiving cart (30) in its unloading position. 2. Method according to claim 1, characterized in that the locking device (54) is locked in its adopted locked position when the receiving carriage (30) is in a fully retracted retraction position, and this locking is released after or when the receiving carriage (30) leaves the fully retracted retraction position by extending the receiving carriage (30). 3. Method according to claim 1 or 2, characterized in that the step of unloading the patient transport device (14) from the receiving trolley (30) comprises the step of removing the patient transport device (14) from the receiving trolley (30). 4. Method according to any one of claims 1 to 3, characterized in that the patient transport device (14) comprises a manually operated portable stretcher (16) having a patient transport surface without a chassis (18) and in particular without a height-adjustable chassis (18), and in that the step of unloading the patient transport device (14) from the receiving trolley (30) comprises the step of manually unloading the stretcher (16) from the receiving trolley (30) and the step of unlocking the patient transport device (14) from the receiving trolley (30) comprises the step of unlocking the stretcher (16) from the receiving trolley (30). 5. Method according to any one of claims 1 to 3, characterized in that the patient transport device (14) comprises a height-adjustable and in particular automatically height-adjustable chassis (18) having a patient transport surface, and in that the step of unloading the patient transport device (14) from the receiving trolley (30) comprises the following partial steps: - extending the chassis (18), which is in a retracted state when adopting the unloading position of the receiving carriage (30), the chassis (18) extending until it reaches a base, - further extend the chassis (18) to raise the stretcher (16) above the receiving trolley (30), and - move the chassis (18) with the stretcher (16) away from the receiving cart. 6. Method according to claim 5, characterized in that the step of unlocking the patient transport device (14) from the receiving trolley (30) comprises the step of unlocking the retracted chassis (18) of the receiving trolley (30), it being possible for the retracted chassis (18) to rest in the fully retracted retraction position of the receiving trolley (30) in the vehicle (10) on the loading surface (24) of the vehicle (10) or, if present, on a base (26) of the receiving device (12) mounted on the loading surface (24) of the vehicle (10). 7. Method according to any one of claims 1 to 3, characterized in that the patient transport device (14) comprises a manual portable stretcher (16) having a patient transport surface, which is adapted to be placed on a height-adjustable chassis (18) and in particular automatically height-adjustable and locked with the chassis (18) as well as unlocked with respect to the chassis (18). 8. Method according to claim 7, characterized in that - the step of unlocking the patient transport device (14) on the receiving trolley (30) comprises the step of unlocking the retracted chassis (18) on the receiving trolley (30), it being possible for the retracted chassis (18) to rest in the fully retracted retraction position of the receiving trolley (30) in the vehicle (10) on the loading surface (24) of the vehicle (10) or, if present, on a base (26) of the receiving device (12) mounted on the loading surface (24), or - the step of unlocking the patient transport device (14) from the receiving trolley (30) comprises the step of unlocking the stretcher (16) from the receiving trolley (30), it being possible to provide that the retracted chassis rests in the fully retracted retraction position of the receiving trolley (30) in the vehicle (10) on the loading surface (24) of the vehicle (10) or, if present, on a base (26). 9. Method according to any one of claims 1 to 8, characterized in that the receiving device (12) comprises a base (26) mounted on the loading surface (24) of the vehicle (10), on which base the receiving carriage (30) is guided to be able to move between its fully retracted retraction position and its unloading position, the receiving carriage (30) being locked in its fully retracted retraction position on the base (26) and/or on the loading surface (24) of the vehicle (10). 10. A method according to any one of claims 1 to 5 and 7, characterized in that the receiving device (12) comprises a base (26) adapted to be mounted on the loading surface (24) of the vehicle and an intermediate carriage (28) guided in an extensible and retractable manner thereon, on which the receiving carriage (30) is guided in an extensible and retractable manner, the receiving carriage (30) being automatically locked on the intermediate carriage (28) in its maximum extension position seen with respect to the central carriage (28) and the central carriage (28) is automatically locked on the base (26) and/or the loading surface (24) of the vehicle in its maximum extension position seen with respect to the base (26), and steps aa) to dd) comprising the following steps: - unlocking the receiving carriage (30) when it is in its fully retracted position and, in this state, locked directly or indirectly to the vehicle (10), - extend the receiving carriage (30) together with the intermediate carriage (28) locked on the receiving carriage (30) to the maximum extraction position of the intermediate carriage (28) with respect to the base (26), - in the maximum extraction position of the intermediate carriage (28), automatically lock the intermediate carriage (28) to the base (26) and automatically unlock the receiving carriage (30) of the intermediate carriage (28), - extend the receiving carriage (30) onto the intermediate carriage (28) to the maximum extraction position of the receiving carriage (30) relative to the intermediate carriage (28) to adopt the unloading position of the receiving carriage (30), in which the receiving carriage (30) is automatically locked on the intermediate carriage (28), - unload the patient transport device (14) from the receiving cart. 11. Method according to claim 10, characterized in that the step of extending the receiving carriage (30) together with the intermediate carriage (28) locked on the receiving carriage (30) to the maximum extraction position of the intermediate carriage (28) with respect to the base (26) or the step of extending the receiving carriage (30) on the intermediate carriage (28) to the maximum extraction position of the receiving carriage (30) with respect to the intermediate carriage (28) comprises the step of releasing the locking of the locking device (54) in its locked position after or at the beginning of the extension. 12. A method according to any one of claims 1 to 5 and 7, characterized in that the receiving device comprises a base (26) adapted to be mounted on the loading surface (24) of the vehicle and an intermediate carriage (28) guided in an extensible and retractable manner thereon, on which the receiving carriage (30) is guided in an extensible and retractable manner, the receiving carriage (30) being automatically locked on the intermediate carriage (28) in its maximum extraction position seen with respect to the intermediate carriage (28) and the intermediate carriage (28) being automatically locked on the base (26) and/or on the loading surface (24) of the vehicle in its maximum extraction position seen with respect to the base (26), and steps aa) to dd) comprising the following steps: - unlocking the receiving carriage (30) when it is in its fully retracted retraction position and, in this state, locked directly or indirectly to the vehicle (10), - extend the receiving carriage (30) relative to the intermediate carriage (28) locked on the base (26) to the maximum extraction position of the receiving carriage (30) relative to the intermediate carriage (28) and, if applicable, automatically lock the receiving carriage (30) relative to the intermediate carriage (28), - in the maximum extraction position of the receiving carriage (30), automatically unlock the intermediate carriage (28) from the base (26), - extending the intermediate carriage (28) on the base (26) to the maximum extraction position of the intermediate carriage (28) with respect to the base (26) to adopt the unloading position of the receiving carriage (30), in which the intermediate carriage (28) is automatically locked on the base (26) or is already locked, - unload the patient transport device (14) from the receiving cart. 13. Method according to claim 12, characterized in that the step of extending the receiving carriage (30) with respect to the intermediate carriage (28) locked on the base (26) to the maximum extraction position of the receiving carriage (30) or the step of extending the intermediate carriage (28) on the base (26) to the maximum extraction position of the intermediate carriage (28) with respect to the base (26) to adopt the unloading position of the receiving carriage (30) comprises the step of releasing the locking of the locking device (54) in its locked position after or at the beginning of the extension. 14. Method according to any one of claims 1 to 13, characterized in that the step of unlocking the patient transport device (14) from the receiving trolley (30) comprises the step of unlocking a stretcher (16) from the patient transport device (14) from the receiving trolley (30). 15. Method according to any one of claims 1 to 14, characterized in that the locking device (54) comprises at least one guided, in particular cam-guided, control lever (56) for locking the patient transport device (14) with the receiving trolley (30), which is kinematically coupled by means of a rod to at least one locking element movably arranged on the receiving trolley (30) and preferably to two locking elements movably arranged on the receiving trolley (30) on each longitudinal side of the patient transport device (14), the at least one control lever (56) being movable between an unlocking position, in which the at least one locking element (36) is disengaged from a counterlocking element (38) of the patient transport device (14) assigned thereto, and a locking position, in which the at least one locking element (36) is in locking engagement with the counterlocking element (38) of the device. (14) of patient transport assigned to it, forcing the transfer of the at least one control lever (56) from its locked position taken outside the unloading position of the receiving trolley (30) to its unlocked position during the extension of the receiving trolley (30), at the latest in the loading position of the receiving trolley (30). 16. Method according to claim 15, characterized in that - the at least one control lever (56) is locked in the locked position at the latest in the fully retracted retraction position of the receiving carriage (30), - the at least one control lever (56) and/or the rod and/or the at least one locking element and/or each locking element is elastically biased toward the respective locking position to be adopted in the locked state of the locking device (54), i.e. to automatically adopt the respective locking position after releasing a potential lock when the at least one locking element (36) interacts with the counterlocking element (38) of the patient transport device (14) assigned thereto, and/or - two control bars (74) having locking claws (36) are adapted to rotate back and forth by means of the at least one control lever (56) and the rod, - the rod comprises two racks, each of which is engaged with a gear on another of the two control bars (74), and/or - two control levers (56) with a rod each are provided, and each control lever (56) with rod is in operative connection with a control rod (74) having locking claws (36) for rotating the respective control rod (74) back and forth. 17. Method according to any one of claims 1 to 16, characterized in that the maneuvering of the patient transport device (14) for transferring the patient transport device (14) to a position above the receiving trolley (30) comprises the step of centering the patient transport device (14) with respect to the receiving trolley (30) by means of guide struts (106) movable along guide edges (108) of a centering opening of the receiving trolley (30) and protruding from the patient transport device (14) and/or in that the guide struts (106) and the guide edges (108) are rounded and/or bulged in those areas that come into contact with each other. 18. A method according to claim 17, characterized in that the maneuvering of the patient transport device (14) to transfer the patient transport device (14) to a position above the receiving trolley (30) away from the receiving trolley (30) comprises the step of centering the patient transport device (14) relative to the receiving trolley (30) by means of sliding elements or rollers of the patient transport device (14) movable and/or slideable on tracks of the receiving trolley (30), each track being shaped to project obliquely or shaped with an obliquely projecting area. 19. Method according to any of claims 1 to 18, characterized in that - the receiving trolley (30), when leaving its fully retracted retraction position by extension, is supported by two sliding or roller elements arranged on both sides of its central axis on the loading surface (24) of the vehicle (10) or, if present, on a base (26) of the receiving device (12) mounted on the loading surface (24) of the vehicle (10), the two sliding or roller elements being arranged approximately at the height of the center of the longitudinal extension of the receiving trolley (30) or approximately at the height of the center of the longitudinal extension of the patient transport device (14) arranged on the receiving trolley (30), - the patient transport device (14) is locked to the receiving trolley (30) on both sides of its central axis by means of the locking device (54) at respectively two locking points, each located in front of or behind the corresponding sliding and roller element when viewed in the longitudinal extension of the receiving trolley (30), - the receiving carriage (30) is reinforced on both sides of its central axis by struts extending between each locking point and the corresponding sliding or roller element, and - the receiving carriage (30) is locked and/or held in its fully retracted retraction position towards the loading surface (24) of the vehicle (10) or, if present, towards the base (26) mounted on the loading surface (24) of the vehicle (10) in the fully retracted retraction position, respectively adjacent to the sliding or roller elements, in particular by clamping devices (32), preferably in the form of angled elements adapted to be accessible from below or from above, the clamping devices being exposed after or upon leaving the fully retracted retraction position of the receiving carriage (30). 20. Method according to claim 19, characterized in that the receiving carriage (30) is additionally blocked and, if necessary, locked against unwanted movements in both directions along the central axis of the receiving carriage (30) up to its end located furthest inside the chassis (18) in the fully retracted retraction position and, if necessary, up to the end opposite this end on the loading surface (24) of the vehicle (10) or, if necessary, up to a base (26) of the receiving device (12) mounted on the loading surface (24) of the vehicle (10), and is released after or upon leaving the fully retracted retraction position of the receiving carriage (30). 21. Method according to any one of claims 1 to 20, characterized in that the patient transport device (14) is locked in the fully retracted retraction position of the receiving trolley (30) relative to the latter exclusively by means of the locking device (54), in particular against forces acting vertically upwards, and is fixed in a stable position in this state by locking the receiving trolley (30) to the vehicle (10), in particular to its loading surface (24), or, if present, to a base (26) of the receiving device (12) mounted on the loading surface (24), if necessary by interposing an intermediate trolley (28) between the receiving trolley (30) and the base (26), the intermediate trolley (28) and the receiving trolley (30) being locked together, and this locking being released in a stable position after or upon leaving the fully retracted retraction position of the receiving trolley (30). 22. Method according to claim 21, characterized in that the patient transport device (14) does not comprise a lock that directly interacts with the loading surface (24) of the vehicle (10) or, if present, with a base (26) of the receiving device (12) mounted on the loading surface (24) of the vehicle (10), when the receiving cart (30) is in its fully retracted retraction position.