Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B66—HOISTING; LIFTING; HAULING
  • B66D—CAPSTANS; WINCHES; TACKLES, e.g. PULLEY BLOCKS; HOISTS
  • B66D1/00—Rope, cable, or chain winding mechanisms; Capstans
  • B66D1/54—Safety gear
  • B66D1/58—Safety gear responsive to excess of load
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B66—HOISTING; LIFTING; HAULING
  • B66C—CRANES; LOAD-ENGAGING ELEMENTS OR DEVICES FOR CRANES, CAPSTANS, WINCHES, OR TACKLES
  • B66C23/00—Cranes comprising essentially a beam, boom, or triangular structure acting as a cantilever and mounted for translatory of swinging movements in vertical or horizontal planes or a combination of such movements, e.g. jib-cranes, derricks, tower cranes
  • B66C23/18—Cranes comprising essentially a beam, boom, or triangular structure acting as a cantilever and mounted for translatory of swinging movements in vertical or horizontal planes or a combination of such movements, e.g. jib-cranes, derricks, tower cranes specially adapted for use in particular purposes
  • B66C23/36—Cranes comprising essentially a beam, boom, or triangular structure acting as a cantilever and mounted for translatory of swinging movements in vertical or horizontal planes or a combination of such movements, e.g. jib-cranes, derricks, tower cranes specially adapted for use in particular purposes mounted on road or rail vehicles; Manually-movable jib-cranes for use in workshops; Floating cranes
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B66—HOISTING; LIFTING; HAULING
  • B66C—CRANES; LOAD-ENGAGING ELEMENTS OR DEVICES FOR CRANES, CAPSTANS, WINCHES, OR TACKLES
  • B66C23/00—Cranes comprising essentially a beam, boom, or triangular structure acting as a cantilever and mounted for translatory of swinging movements in vertical or horizontal planes or a combination of such movements, e.g. jib-cranes, derricks, tower cranes
  • B66C23/62—Constructional features or details
  • B66C23/64—Jibs
  • B66C23/66—Outer or upper end constructions
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B66—HOISTING; LIFTING; HAULING
  • B66C—CRANES; LOAD-ENGAGING ELEMENTS OR DEVICES FOR CRANES, CAPSTANS, WINCHES, OR TACKLES
  • B66C23/00—Cranes comprising essentially a beam, boom, or triangular structure acting as a cantilever and mounted for translatory of swinging movements in vertical or horizontal planes or a combination of such movements, e.g. jib-cranes, derricks, tower cranes
  • B66C23/62—Constructional features or details
  • B66C23/64—Jibs
  • B66C23/70—Jibs constructed of sections adapted to be assembled to form jibs or various lengths
  • B66C23/701—Jibs constructed of sections adapted to be assembled to form jibs or various lengths telescopic
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B66—HOISTING; LIFTING; HAULING
  • B66C—CRANES; LOAD-ENGAGING ELEMENTS OR DEVICES FOR CRANES, CAPSTANS, WINCHES, OR TACKLES
  • B66C23/00—Cranes comprising essentially a beam, boom, or triangular structure acting as a cantilever and mounted for translatory of swinging movements in vertical or horizontal planes or a combination of such movements, e.g. jib-cranes, derricks, tower cranes
  • B66C23/62—Constructional features or details
  • B66C23/82—Luffing gear
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B66—HOISTING; LIFTING; HAULING
  • B66C—CRANES; LOAD-ENGAGING ELEMENTS OR DEVICES FOR CRANES, CAPSTANS, WINCHES, OR TACKLES
  • B66C23/00—Cranes comprising essentially a beam, boom, or triangular structure acting as a cantilever and mounted for translatory of swinging movements in vertical or horizontal planes or a combination of such movements, e.g. jib-cranes, derricks, tower cranes
  • B66C23/88—Safety gear

Definitions

• the present invention relates to a crane, in particular a mobile crane, according to the preamble of claim 1.
• Cranes have a boom and a lifting cable that runs over the boom and is mounted on a winch for winding and unwinding. Both stationary and mobile cranes can use swiveling booms that can tilt around a horizontal axis.
• a temporary attachment or fixed mounting of the hoist rope to the boom is necessary. This is the case, for example, with some smaller mobile cranes suitable for use in buildings.
• the working height of the boom which is usually a telescopic boom, is limited by the ceiling.
• a special lifting beam is used. This can directly support the load, eliminating the need for a hoist rope and load hook. In this case, the movement to lift the load is achieved, for example, by rocking the boom, thereby raising the lifting beam and the rigging or load hook.
• the load hook must be removed from the boom head. For this reason, the hoist rope is used for spreader operation.
• the lifting cable is temporarily stored or parked on the boom. Retracting the cable for this purpose is complex and requires at least two people. One person operates the crane and winds the cable using the winch. A second person keeps the cable taut to ensure proper winding. This is particularly important when re-stretching the cable.
• the lifting cable To minimize the distance the lifting cable needs to be pulled back, its end is attached near the free end of the telescopic boom's pivot point. This creates two clearly defined attachment points for the lifting cable. The first point is where the lifting cable connects to the boom at the free end of the pivot point. The second point is where the lifting cable runs onto the winch drum.
• the first point Since the first point is located at the pivot point, it moves around the luffing axis when the boom rocks.
• the second point is located on the superstructure and therefore does not change its position when the telescopic boom rocks. As the boom rocks, the distance, or the resulting cable length, between the two defined points changes.
• FIG. 1 and 2 The figures shown depict an example of a mobile crane in a side view.
• the mobile crane has a mobile undercarriage and a superstructure mounted on the undercarriage so as to be rotatable about a vertical axis of rotation.
• a telescopic boom 12 is attached to the superstructure so as to be rockerable about a horizontal luffing axis.
• a winch 14, not visible, is located at the rear of the superstructure in the area of a superstructure ballast and holds a hoist cable 16, which runs along the top or rear of the boom 12.
• Figure 1 Figure 1 shows the mobile crane with the boom 12 raised.
• the thick black double arrow symbolizes the distance or cable length L1 between the aforementioned defined points (attachment on the boom 12 and entry point of the winch 14) when the free end of the hoist cable 16 is attached to the free end of the linkage.
• Figure 2 Figure 12 shows the mobile crane with the boom lowered. Here is the distance or... The rope length L2 between the defined points is longer than the rope length L1 with the boom raised 12 (i.e. L2 > L1).
• the present invention is therefore based on the objective of preventing the risk of improper operation or damage to the hoisting mechanism in cases where the hoist cable is attached to the boom of such cranes. According to the invention, this objective is achieved by a crane with the features of claim 1.
• Advantageous embodiments of the invention are described in the dependent claims and the following description.
• a crane which comprises a boom that can be tilted about a horizontal pivot axis and a hoisting mechanism.
• the hoisting mechanism includes a winch and a hoisting rope that can be wound and unwound from the winch.
• a connecting element for example a rope lock, for attaching a load hook can be located at the free end of the hoisting rope.
• This connecting element is also suitable for temporarily attaching the hoisting rope to the boom (e.g., for spreader operation as explained above).
• the crane can be a stationary crane. However, it is specifically a mobile crane.
• the crane can, to solve the aforementioned problem, include a rope clamp which is arranged between the winch and the boom and is designed to limit the maximum distance of the hoist rope from the luffing axis and thus, in particular, from a pivot point of the boom.
• the term rope clamp is to be interpreted broadly and refers to any device specifically used to limit the maximum distance of the hoist rope from the luffing axis.
• the hoist cable Due to its position between the boom and the winch, i.e., in the case of a mobile crane, specifically behind the boom at the rear of the superstructure, the hoist cable is necessarily guided closer to the boom when the boom is in a steep position. This prevents a situation such as that encountered in the Figure 1 This is shown, and the difference in rope lengths L1 and L2 between the lowered and raised boom positions is reduced. This eliminates the need to retension the hoist rope when raising the boom. Furthermore, a change in the hoist rope's exit point from the winch is completely prevented.
• the crane according to the invention can, to solve the aforementioned problem, include a hoist rope holding device arranged on the boom, by means of which the hoist rope can be temporarily attached to the boom in a parked position.
• the hoist rope holding device is designed to release the connection between the hoist rope and the boom when a defined hoist rope force is exceeded. This measure prevents damage to the hoisting mechanism or the boom in cases where the crane operator mistakenly tensions the rope while the boom is in a steep position. If the force in the hoist rope becomes too high, a connection between the hoist rope and the boom is deliberately released in time to prevent damage from occurring, so that the hoist rope detaches from its attachment. This makes more length available again, and the boom can preferably be safely lowered.
• the hoist rope should not fall off the boom when the connection is released (which could lead to further damage or risks to human personnel). (would lead to), but is still held on the boom via the hoist rope holding device and/or another holding device, but with more freedom for boom movement.
• both measures are used together on the crane according to the invention.
• the rope clamp comprises a bracket and a guide rod detachably mounted in the bracket.
• the guide rod limits the distance of the lifting rope to the luffing axis or the boom by making contact with it. Because the guide rod is detachably attached and can therefore be removed, the rope clamp can be used only in specific situations, particularly during parking operations where the lifting rope is temporarily attached to the boom.
• the rope clamp is preferably not in use, so it does not need to be designed for the high forces generated during normal operation when lifting loads.
• the guide rod can be removed and, for example, secured in a parking position in a parking bracket (second bracket).
• the latter can be located axially next to the bracket, so that the guide rod only needs to be offset axially.
• the guide rod could also be mounted in the bracket during normal operation, with the lifting cable running above it rather than underneath it.
• the guide rod preferably runs parallel to the rocker axis.
• the guide rod can be detachably mounted in the bracket via a locking mechanism, the locking mechanism comprising a locking bolt and/or at least one locking pin to enable quick and easy installation and removal.
• the rope clamp includes a guide element designed to prevent the hoist rope from contacting the boom when the boom is in a flat position.
• This guide element can be a known guide roller (also called a deflector roller). It can be mounted either in the clamp or in a separate clamp.
• the guide element's function is to keep the hoist rope away from the boom (especially the pivot point of a telescopic boom) when the boom is in a flat position, thus preventing contact and potential damage from friction.
• the rope clamp is not connected to the boom.
• the rope clamp is rigidly connected to the crane structure (especially the steel structure of a superstructure), so that the boom moves relative to the rope clamp when it rocks.
• the rope clamp can be positioned in the area of the boom's luffing axis. If the rope clamp is located near the luffing axis, the difference in rope length (L1 vs. L2) is minimized.
• the lifting rope has a connecting element, in particular a rope lock, at its free end, through which the lifting rope can be detachably connected to the lifting rope holding device.
• the connecting element can simultaneously serve to attach a load-bearing device (e.g., a hook block) to the lifting rope.
• the lifting rope holding device has a predetermined breaking point which is designed to break when a defined lifting rope force is exceeded, thereby releasing a connection between the boom and the lifting rope.
• the hoist rope holding device can include a release mechanism designed to reversibly disconnect the hoist rope, directly or indirectly, from the boom when a defined hoist rope force is exceeded. Unlike an irreversible disconnection at a predetermined breaking point, this release mechanism allows the connection to be reversed or "repaired.” This can be achieved by any mechanical mechanism, such as releasing the hoist rope or a guide connected to it from a spring-loaded holder attached to the boom.
• the lifting rope holding device comprises at least one holding element via which the lifting rope can be connected to the boom.
• the holding element is preferably a rope (holding rope), a chain, or a combination of rope and chain.
• the holding element is connected to the boom via a first connecting element and can be connected (directly or indirectly) to the lifting rope via a second connecting element.
• the first and/or the second connecting element can be, for example, a carabiner, a shackle, a plate, a bolt, a screw, or a combination thereof.
• the predetermined breaking point is formed on the holding element (e.g., on a holding cable or a chain link in the case of a chain), or the alternative release mechanism is arranged on the holding element.
• the predetermined breaking point or the release mechanism can also be located on the first or second connecting element.
• the lifting cable holding device comprises a crossbeam and two holding elements connected to the crossbeam.
• the holding elements are connected to the crossbeam, in particular via the aforementioned second connecting elements, preferably movably connected.
• the crossbeam has a connecting element to which the lifting cable can be detachably connected.
• this connecting element can be a bolt receptacle. This is for attaching a carabiner, rope lock, bolt, or similar device.
• the lifting cable is attached to the boom via a connection to the crossbeam, which in turn is attached to the boom by means of the securing devices. These securing devices are typically designed as ropes or chains, allowing the crossbeam to be movably mounted on the boom.
• the connecting element is positioned closer to one end of the crossbeam than to the other.
• This asymmetrical or off-center arrangement of the connecting element results in one of the holding elements, namely the one attached closer to the connecting element, being subjected to a greater load than the other holding element when a force is exerted via the hoist cable.
• the holding elements and/or its connection points with the boom or crossbeam (in particular the aforementioned first or second connecting element) has the predetermined breaking point or the release mechanism. If, in the event of an overload of the hoist rope, the connection of the hoist rope to the boom is broken or released by means of the release mechanism, the hoist rope continues to be held on the boom via the crossbeam and the other holding element and thus cannot fall from the boom and cause damage or injury.
• the combined lengths of the intact holding element and the crossbeam, both of which are preferably pivotally mounted advantageously provide sufficient clearance for the hoist rope so that the boom can be rocked without the hoist rope becoming taut.
• the predetermined breaking point or the release mechanism can preferably be located on the holding element or its connection points that is closer to the connecting element of the crossbeam and is therefore subject to greater stress.
• the crossbeam and the holding devices are designed such that, in a released or broken state, the boom can be fully rocked without operating the winch and without tensioning the hoist rope. After the hoist rope fastening fails due to overload, the crane operator can thus fully rock the boom and move the crane into a safe position without further safety measures.
• one of the holding elements includes a predetermined breaking point on a first connecting element between the holding element and the boom.
• the first connecting element can be attached to the steel structure of the boom via a bolted connection, with the predetermined breaking point preferably located on a bolt. If the load on the hoist cable, and thus on the bolt, exceeds a defined value, the bolt breaks and the connection between the holding element and the boom is released.
• the first connecting element can be designed as a sheet metal plate or connecting plate and/or include other components such as a carabiner or shackle.
• the first connecting element comprises a connecting plate bent or angled at a specific angle. This allows the length of the crossbeam to be shorter than the distance between the first connecting elements of the holding devices, enabling the crossbeam to be positioned, for example, between or within a second rope clamp mounted on the boom.
• the connecting plates can be angled slightly inwards so that the holding devices converge towards each other in the direction of the crossbeam.
• the bending angle of the connecting plate can preferably be between 135° and 179°, and in particular between 150° and 175°. This refers to the angle between the angled plate sections (a flat plate would correspond to a "bending angle" of 180° according to this definition).
• the hoist rope holding device is arranged on and/or between a second rope clamp, which is pivotably mounted on the boom.
• the latter can be used in a known manner to prevent the hoist rope from contacting the boom during normal operation (in which the hoist rope runs, in particular, to a sheave head at the end of the boom).
• the at least one holding element can be mounted on a connecting section between the second rope clamp and the boom.
• the crane is designed as a mobile crane with a rotating superstructure.
• the boom is designed as a telescopic boom with a pivoting section and one or more telescopic sections slidably mounted within it, and is arranged on the superstructure.
• the hoist rope holding device is located on the pivoting section of the telescopic boom.
• the rope hold-down device can be arranged on the superstructure between the boom and a superstructure ballast.
• the winch can be arranged on the superstructure ballast or on a steel structure of the superstructure.
• FIGS. 1 and 2 They show an example of a mobile crane known from the state of the art and have already been discussed in the introduction.
• Figure 1 shows an embodiment of the rope clamp 20 arranged according to the invention between the boom 12 and the winch 14 in a perspective view.
• the crane 10 according to the invention can be constructed according to the example shown in Figure 1.
• Figure 1-2 However, its use is not limited to such a mobile crane. Rather, the rope hold-down device 20 can be used with any crane with a luffing jib 12.
• the rope hold-down device 20 is arranged near the pivot axis of the boom 12 and comprises a bracket 22 rigidly connected to the superstructure 11 or the superstructure steel structure and a guide rod 24 detachably mounted in the bracket 22.
• the latter is mounted in two lateral receptacles of the bracket 22 and can be locked and secured by means of one or more locking bolts 26 and, if necessary, one or more cotter pins.
• the lifting rope 16 can be guided outside the rope retainer 20 in normal operation (in which the lifting rope 16 is guided in particular over a roller head arranged at the end of the boom).
• the guide rod 24 can be held in a parked position in which no contact with the lifting cable 16 can occur.
• a second bracket 23 is arranged axially offset from the bracket 22 along the guide rod 24, so that the guide rod 24 only needs to be axially offset.
• a second bracket for the guide rod 24 could be arranged at any point on the crane 10.
• the hoist rope 16 runs directly from the winch 14 and over the boom's pivot point 12 to the sheave head during normal operation.
• the guide rod 24 of the rope clamp 20 can be in a parked position in a second bracket 23. If the crane operator wants to use the mobile crane 10, for example, with a crossbeam, he lowers the boom 12. The hoist rope 16 then runs from the winch 14 parallel to and close to the pivot point towards the sheave head. The crane operator then releases the guide rod 24 from the second bracket 23, slides or positions it over the hoist rope 16, and secures or locks the guide rod 24 in the bracket 22.
• Figure 1 shows an embodiment of the lifting rope holding device 30 according to the invention on a boom 12 of a crane 10.
• the crane can again be the one described in Figure 1.
• Fig. 1-2 The mobile crane shown, or any other crane, can be used.
• the hoist rope holding device 30 can be used on a lattice boom or any other boom 30.
• the hoist rope holding device 30 comprises an elongated crossbeam 34, which is attached to the steel structure of the boom 12 or the pivot section via two holding elements 32.
• the crossbeam 34 can have receptacles 37 at each of its ends (see figure). Fig. 5 Instead of carabiners 42, any other connecting elements (e.g., shackles) can be used.
• the crossbeam 34 receives the holding elements 34, in particular symmetrically, at the lateral receptacles 37.
• the holding elements 32 are movably connected to the boom 12 via first connecting elements 41.
• Figure 7 Figure 1 shows an enlarged view of one of the first connecting elements 41. This can include a connecting plate 44 connected to the steel structure of the boom 12 via a screw 48 and a carabiner 49.
• the connecting plate 44 is shown separately in the Figure 6
• the connecting plate 44 comprises a first end with a first receptacle 45 for the carabiner 49, which movably connects the connecting plate 44 to the retaining element 32.
• Any other connecting elements e.g., shackles
• the connecting plate 44 comprises a second end with a second receptacle 46 for receiving the screw 48. This screw can be secured by a nut.
• the boom 12 can have a second rope clamp 18, which is preferably pivotably mounted on the steel structure of the boom 12 or the pivot section.
• the first connecting elements 41 of the hoist rope holding device 30 can be connected to the boom 12 at the connection point of the second rope clamp 30.
• the crossbeam 34 can be shorter than the distance between the first connecting elements 41, so that the crossbeam 34 can be arranged between the lateral legs of the second rope clamp 18.
• the connecting plates 44 can be angled between their first and second ends (see figure). Fig. 6 ), so that the holding means 32 do not run parallel to each other, but converge towards each other.
• the crossbeam 34 has a connecting element 36, which in the exemplary embodiment of the Fig. 5
• the lifting cable can be designed as a receptacle or bolt eye.
• a cable lock 17, attached to the end of the lifting cable 16, can be fastened in this eye.
• the lifting cable 16 can be connected to the crossbeam 34 and thus to the boom 12 via the cable lock 17. This connection can be made using a bolt.
• the lifting cable 16 can preferably be connected to either a load-handling device (e.g., a hook block) or a sheave head via the cable lock 17, depending on the reeving configuration.
• the lifting cable holding device 30 is designed according to the invention such that it releases the connection between the lifting cable 16 and the boom 12 when a defined lifting cable force is exceeded.
• a predetermined breaking point can be provided in the lifting rope holding device 30 at a suitable location, which breaks under excessive load.
• the predetermined breaking point is implemented in one of the screws 48 of the first connecting elements 41.
• the screw 48 is dimensioned sufficiently small for this purpose.
• a small screw connection consisting of screw 48, nut, and washer can be used here.
• Screw 48 is subjected to shear stress, which it can withstand during normal operation. However, if a fault occurs (retensioning of the lifting cable 16 followed by rocking of the boom 12 without slackening of the lifting cable 16), the tension in the lifting cable 16 and in the lifting cable retaining device 30 increases. The weakest link in this force transmission chain is the screw 48, which is subjected to shear stress. At a predefined force, screw 48 shears off. All other connections are protected, and no damage occurs there.
• the predetermined breaking point is preferably provided on only one of the retaining elements 32. If the corresponding screw 48 breaks, the lifting cable 16 does not fall, but continues to be held on the boom 12 via the crossbeam 34 and the other retaining element 32, which remains intact and connected to the boom 12. The only part that falls is the small broken screw 48, which poses no risk of damage or injury.
• the connecting element 36 of the crossbeam 34 is arranged off-center, i.e., closer to one of the receptacles 37 than to the opposite receptacle 37, as shown in the Fig. 5 This is illustrated.
• the force flow is also asymmetrical, and the predetermined breaking point (screw 48) of the retaining element 32, which is located closer to the connecting element 36, is subjected to a significantly higher load than the opposite screw 48.
• the predetermined breaking point breaks, the tension is released, and the crossbeam 34 can pivot about its other mounting point 37 or about the associated second connecting element 42. This pivoting range provides sufficient freedom of movement. This allows the boom 12 to be fully lowered again. Additionally, the crane operator receives safe feedback from the use of the predetermined breaking point and can, if necessary, also release the hoist rope 16.

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• Mechanical Engineering (AREA)
• Jib Cranes (AREA)

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• 2024
  • 2024-05-21 DE DE102024114126.3A patent/DE102024114126B4/de active Active
• 2025
  • 2025-05-15 EP EP25176567.3A patent/EP4663594A3/fr active Pending
  • 2025-05-15 JP JP2025082120A patent/JP2025176693A/ja active Pending

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