EP4393863A1 - Scherenhubvorrichtung mit unterstützung - Google Patents

Scherenhubvorrichtung mit unterstützung Download PDF

Info

Publication number
EP4393863A1
EP4393863A1 EP23216832.8A EP23216832A EP4393863A1 EP 4393863 A1 EP4393863 A1 EP 4393863A1 EP 23216832 A EP23216832 A EP 23216832A EP 4393863 A1 EP4393863 A1 EP 4393863A1
Authority
EP
European Patent Office
Prior art keywords
arm
cam
scissors
wedge
scissors lift
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP23216832.8A
Other languages
English (en)
French (fr)
Inventor
Sébastien MICHOTTE
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
C P Bourg SA
Original Assignee
C P Bourg SA
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by C P Bourg SA filed Critical C P Bourg SA
Publication of EP4393863A1 publication Critical patent/EP4393863A1/de
Withdrawn legal-status Critical Current

Links

Images

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B66—HOISTING; LIFTING; HAULING
    • B66F—HOISTING, LIFTING, HAULING OR PUSHING, NOT OTHERWISE PROVIDED FOR, e.g. DEVICES WHICH APPLY A LIFTING OR PUSHING FORCE DIRECTLY TO THE SURFACE OF A LOAD
    • B66F7/00—Lifting frames, e.g. for lifting vehicles; Platform lifts
    • B66F7/06—Lifting frames, e.g. for lifting vehicles; Platform lifts with platforms supported by levers for vertical movement
    • B66F7/065—Scissor linkages, i.e. X-configuration
    • B66F7/0666—Multiple scissor linkages vertically arranged
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B66—HOISTING; LIFTING; HAULING
    • B66F—HOISTING, LIFTING, HAULING OR PUSHING, NOT OTHERWISE PROVIDED FOR, e.g. DEVICES WHICH APPLY A LIFTING OR PUSHING FORCE DIRECTLY TO THE SURFACE OF A LOAD
    • B66F7/00—Lifting frames, e.g. for lifting vehicles; Platform lifts
    • B66F7/06—Lifting frames, e.g. for lifting vehicles; Platform lifts with platforms supported by levers for vertical movement
    • B66F7/0608—Lifting frames, e.g. for lifting vehicles; Platform lifts with platforms supported by levers for vertical movement driven by screw or spindle
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B66—HOISTING; LIFTING; HAULING
    • B66F—HOISTING, LIFTING, HAULING OR PUSHING, NOT OTHERWISE PROVIDED FOR, e.g. DEVICES WHICH APPLY A LIFTING OR PUSHING FORCE DIRECTLY TO THE SURFACE OF A LOAD
    • B66F7/00—Lifting frames, e.g. for lifting vehicles; Platform lifts
    • B66F7/06—Lifting frames, e.g. for lifting vehicles; Platform lifts with platforms supported by levers for vertical movement
    • B66F7/0625—Lifting frames, e.g. for lifting vehicles; Platform lifts with platforms supported by levers for vertical movement with wheels for moving around the floor
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B66—HOISTING; LIFTING; HAULING
    • B66F—HOISTING, LIFTING, HAULING OR PUSHING, NOT OTHERWISE PROVIDED FOR, e.g. DEVICES WHICH APPLY A LIFTING OR PUSHING FORCE DIRECTLY TO THE SURFACE OF A LOAD
    • B66F7/00—Lifting frames, e.g. for lifting vehicles; Platform lifts
    • B66F7/06—Lifting frames, e.g. for lifting vehicles; Platform lifts with platforms supported by levers for vertical movement
    • B66F7/065—Scissor linkages, i.e. X-configuration

Definitions

  • Scissor lift platforms are well known for selectively raising or lowering objects to facilitate their loading/unloading.
  • scissor lifts are used inside "stacker units" to facilitate stacking of sheets of paper or booklets.
  • the scissor lift platform is initially inserted in the stacker and receives sheets that have been processed in neighboring connected units (printed, folded, cut,).
  • the platform of the scissor lift starts in a high position (to be close to the paper output) and slowly lowers down upon accumulation of paper on the pile.
  • the scissor lift is extracted from the stacker, and an operator needs to take the pile. For ergonomic reasons, the platform is raised to facilitate this operation.
  • the scissor lift is reinserted in the stacker and a new cycle is started. The vertical movement of the platform is accomplished using a scissor arm mechanism.
  • the motor usually drives a horizontal lead screw imparting an horizontal movement to a crossbar (or transversal beam) connected to the lower ends of one of the elongated element, the end of the elongated elements can thereby be drawn closer to each other, which result in the platform lifting, or apart from each other, which results in the platform moving down.
  • a spring assist assembly is arranged to, when the platform is in its lower position, exert a pulling tension which transmits to an arm equipped with a roller which pushes up the platform.
  • the assisting arm can be driven (pushed instead of pulled with the spring) by the front of a sliding carriage which imparts force on the assisting arm, up to a point where the rear of the sliding carriage comes into contact with the end of the elongated element and pulls it forward for driving the remaining upward movement of the lift.
  • This assistance mechanism is typically effective for angles between 8° and 21°.
  • US2003/0075657A1 discloses a scissors lift with a lead screw (and actuator) connected to a carriage with rollers that are arranged to roll on a ramp while contacting a cam surface mounted on a first arm of the scissors upon the initial phase of the uplifting movement thereby imparting un upward movement to said arm.
  • the carriage also supports a rod for imparting a horizontal movement to the second arm of the scissors.
  • An offset mechanism (sliding link) on the carriage allows the rollers to move first, until reaching an abutment which allows the carriage to then action the rod or crossbar.
  • the carriage is rather bulky and takes significant space at the basis of the system.
  • the position of the cams, close to the pivot points of the arms result in inefficient "lever-effect".
  • the forces exerted on such mechanisms are very high and the multiplicity of pieces result in a multiplication of weakness points of potential failure.
  • the applicant has therefore judged necessary to manufacture more robust mechanisms that can be very compact while allowing lifting of heavy charges.
  • the invention relates to a lifting device including a base and platform placed over a scissors mechanism comprising a first arm with a traveling lower end and a second arm pivotably mounted on the base, both arms being joined together around their middle point by a pivot and describing an angle ⁇ with the base, and wherein the platform is movable from a down-position to an up-position upon action of an actuator arranged to action means traversing the lower end of the first arm through a groove having a larger section than said means thereby allowing said means to slide within said groove, said means being pivotably connected to one end of a wedge mechanism having:
  • the means traversing the lower end of the first arm can for example be a transversal beam arranged perpendicular to the plane of the scissors arms, said beam being movable horizontally perpendicularly to its axis.
  • the actuator is driving the movement of the traversing means.
  • the actuator is driving a horizontal movement of the transversal beam.
  • the beam is not necessarily long. It could be part of another element, like a protrusion from a leadscrew.
  • the length of the wedge arm is at least 50% lower than the length of the scissors arms.
  • the length of the wedge arm represents less than 35% of the length of the scissors are, preferably less than 30%. This allows an optimized lever effect.
  • the groove in the mobile scissors arm has a section that is larger than the section of the transversal beams allows the creation of an offset between the actioning of the wedge arm and the actioning of the scissors arm at the beginning of the upward movement, thereby creating an assistance mechanism to the lifting.
  • the groove can advantageously have a circular shape or an elongated shape, but any shape, like for example a polygon, can be used, to the discretion of the person skilled in the art.
  • the edges of the groove can be machined to minimize the friction of the transversal beam therein or can be covered with another material.
  • the groove is further designated as "bushing" in the description, whatever its shape and whether it comprises or not an insert or an element of another material.
  • the means to prevent friction can alternatively or additionally be installed on the transversal beam.
  • the bushing can have any suitable shape, and can for example be circular, or a groove into which the transversal beam can slide.
  • a groove can for example be a few millimeters for a few centimeters longer than the section of the bar, and is typically calculated to obtain the desired offset.
  • the transversal bar moves horizontally so as to impart a movement to the wedge mechanism: one wheel of the roller rolls up the bottom cam thereby pushing onto the upper cam to impart a vertical upward movement to the second arm. Meanwhile, the transversal bar moves within the bushing without inducing a translation effect to the scissors arm.
  • the cams are positioned close to the extremity of the scissors arms, which allows a powerful lever-effect for lifting up the scissors and the platform.
  • the transversal bar has reached the opposite end of the bushing and starts imparting a translational movement to the extremity of the scissors arm, ensuring a smooth continuation of upward movement of the platform.
  • roller wheels are each free to rotate in both directions, depending on the upward or downward movement of the lift. They can run in opposite directions.
  • the lower cam has a substantially triangular profile with a cam base lying onto the base of the lifting device, a rising side arranged for supporting the rise of the rollers during the action of the wedge mechanism upon the lifting phase and a downwards side.
  • One of the roller wheel rolls on the rising side of the cam during the initial phase of lifting.
  • the rising side of the lower cam can be linear.
  • a linear rising side makes an angle ⁇ 1 with the base (horizontal or resting side) comprised between 10 and 65°.
  • the upper cam also has a substantially triangular profile pointing downwards with a cam base lying on and along the second arm (fixedly attached to this arm and parallel to it) of the lifting device, a downwards side arranged for contacting the rollers during the action of the wedge mechanism upon the lifting phase and a third side.
  • the downwards side of the upper cam can be linear.
  • a linear downwards side makes an angle ⁇ 2 with the second arm (its resting side) comprised between 10 and 65°.
  • the downwards side of the upper cam has a concave curved profile or slope, i.e. a non-linear profile following a function of a least 1 st order.
  • This angle preferably starts between 1° and 20°, preferably between 5° and 15°. This allows a low rising angle at the beginning of the assistance, to increase efficiency and a higher angle later in the assistance to keep the cam short enough.
  • the rising side of the lower cam has a hybrid profile comprising a concave curved section prolonged with a linear section. This allows a smoother backward movement of the roller when the lift goes down, and allows a slightly longer assistance than with a curved only profile.
  • the upper cam and the lower cams are arranged such that one of the roller wheel rolls on the downwards side of the upper cam, while the other of the roller wheel rolls on the rising side of the lower cam.
  • a forward force is applied by the wedge arm onto the roller, which is converted into an upward force when the roller rolls on the rising side of the lower cam and the upward force is transferred to the downwards side of the upper cam and consequently to the second arm of the lift.
  • the scissors lift of the invention can be a single or multiple stage lift.
  • a scissors arm can comprise one or more segment, typically arranged in accordion.
  • the lift is a double stage lift, where each arm has two segments pivotally connected at one extremity.
  • the platform can be any suitable surface for supporting weights. Depending on the type of weights, it can be a plate, a plate comprising openings, a grid or have any other shape.
  • end A and B of the arms of both sets form a rectangle on the base 11 of the lifting device. This also means that the upper end of the arms define a rectangle for supporting the platform 12.
  • the transversal beam is arranged to, upon actuation, displace the traveling lower end A if the first arm towards or away from the end B of the second arm.
  • the transversal beam is coupled to a lead screw, horizontally arranged on the base of the lifting device, the screw being actioned by a motor.
  • the static condition is obtained if an external force F is applied essentially horizontally on the scissor arm pivot at point A.
  • the lifting mechanism 20 further comprises a wedge arm (or wedge pivot linkage)21 arranged in a parallel plane to the arms 13 and 14 of the scissors arms and having a length of less than half of the length of the scissors arms, i.e. less than L.
  • a wedge arm or wedge pivot linkage
  • On end A' of the wedge arm 21 is located close to the lower end A of the first arm 13.
  • a double-wheel roller 22 is mounted on the other end O of the wedge arm 21.
  • the double wheel roller 22 here has a smaller wheel 221 and a larger wheel 222 mounted parallel to each other on the same axis.
  • r1 14mm
  • r2 12mm
  • h W 24mm
  • L W 52mm
  • the transversal beam 116 is arranged to, upon actuation, displace the traveling lower end 123 of the first arm towards or away from the end 124 of the second arm.
  • the transversal beam is coupled to a lead screw, horizontally arranged on the base of the lifting device, the screw being actioned by a motor.
  • the external wheel 154 of the roller starts to roll onto the lower cam 155 rising profile.
  • the associated internal wheel 153 of the roller rolls along the upper cam 156, imparting to said upper cam an upward reaction force which leads to the second arm 114 (to which the upper cam is fixed) being lifted up.
  • FQx F screw tan ⁇ 2 + ⁇ tan ⁇ 1 + tan ⁇ 2 + ⁇
  • an upper cam 180 has a downward slope which is a second order curve as illustrated on figure 8 along a portion of its length (left of the vertical pointed line). The end of the slope (right of the vertical pointed line) is however further machined to a straight line.
  • a first beneficial effect observed is a smoother backward movement of the roller wheels when the lift is moving down, especially when the contact between the cams and the wheels is reestablished.
  • the slight machining of the upper cam has allowed the system to lift total weights up to 50 kg.
  • a linear lower cam 155 was used for the active part during the assistance as shown in Fig. 20 .
  • an upper cam 156 has a downward slope which is a second order curve (parabola) as illustrated along a portion of its length (left of the vertical line).
  • the end of the slope (right of the vertical line) is however further machined to a straight line (for a smoother backward movement of the roller wheels when the lift is moving down, especially when the contact between the cams and the wheels is reestablished).
  • a larger offset and a linear lower cam facing a parabolic upper cam permits for instance to reach a similar level of good assistance this time over the whole assisted region.
  • the guiding groove is always larger than the diameter of the wheel 154, such that this guide does not take up any force, but can help to correctly pre-position this wheel 154 outside the phases when the assistance mechanism is actually in action.
  • This guide can further comprise a lateral wall 157, illustrated on figure 23 as a vertical pane bridging the guide and lower cam, at the exterior side of the lift.
  • This lateral wall preferably extends externally to the lift mechanism, in a parallel plane to the cams, over at least a surface covering the path of the roller wheel.
  • This lateral wall 157 protects the roller wheel from dust and further acts as a safety shield to prevent any exterior element from penetrating the lift in this sensitive area, including fingers or hair or any other element. This lateral protection could also be implemented without the guide. These two elements are not necessarily combined.

Landscapes

  • Life Sciences & Earth Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Geology (AREA)
  • Mechanical Engineering (AREA)
  • Structural Engineering (AREA)
  • Transmission Devices (AREA)
  • Handcart (AREA)
  • Forklifts And Lifting Vehicles (AREA)
EP23216832.8A 2022-12-26 2023-12-14 Scherenhubvorrichtung mit unterstützung Withdrawn EP4393863A1 (de)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
BE20226091A BE1031201B1 (fr) 2022-12-26 2022-12-26 Appareil de levage à ciseaux avec assistance

Publications (1)

Publication Number Publication Date
EP4393863A1 true EP4393863A1 (de) 2024-07-03

Family

ID=85382688

Family Applications (1)

Application Number Title Priority Date Filing Date
EP23216832.8A Withdrawn EP4393863A1 (de) 2022-12-26 2023-12-14 Scherenhubvorrichtung mit unterstützung

Country Status (2)

Country Link
EP (1) EP4393863A1 (de)
BE (1) BE1031201B1 (de)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN119548333A (zh) * 2025-01-24 2025-03-04 浙江迈德斯特医疗器械科技有限公司 起身辅助装置

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2862689A (en) * 1955-11-03 1958-12-02 Southworth Machine Co Paper lift
WO1986006054A1 (en) * 1985-04-16 1986-10-23 Hymo Ab Device at a hydraulic lifting table
US20030075657A1 (en) 2001-10-18 2003-04-24 Pierre Joubert Scissors lift with combination wedge and lever mechanism
US9310753B2 (en) 2013-04-22 2016-04-12 Xerox Corporation Spring assist scissor lift

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2862689A (en) * 1955-11-03 1958-12-02 Southworth Machine Co Paper lift
WO1986006054A1 (en) * 1985-04-16 1986-10-23 Hymo Ab Device at a hydraulic lifting table
US20030075657A1 (en) 2001-10-18 2003-04-24 Pierre Joubert Scissors lift with combination wedge and lever mechanism
US9310753B2 (en) 2013-04-22 2016-04-12 Xerox Corporation Spring assist scissor lift

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN119548333A (zh) * 2025-01-24 2025-03-04 浙江迈德斯特医疗器械科技有限公司 起身辅助装置

Also Published As

Publication number Publication date
BE1031201B1 (fr) 2024-07-23
BE1031201A1 (fr) 2024-07-18

Similar Documents

Publication Publication Date Title
EP4393863A1 (de) Scherenhubvorrichtung mit unterstützung
US4114854A (en) Scissors lift work platform
EP0329697B1 (de) Anordnung einer an ein kraftfahrzeug angepassten hebevorrichtung
US20030047388A1 (en) Scissors lifter drive apparatus
US9004471B2 (en) Workpiece elevating support device
JP2022526150A (ja) 積荷取り扱い装置
US20090129906A1 (en) Method of Stowing Wheelchair Lift
JPH0696439B2 (ja) 車両の連続組立の際車体部分を人間工学的に好適に準備するための車体用傾倒兼昇降装置
DE2801735C2 (de) Wagenheber
RU2765183C1 (ru) Гидравлическое подъемное устройство с вертикальным подъемным перемещением для автомобилей и подобных транспортных средств
JP2717083B2 (ja) 車体修理装置
JP6687606B2 (ja) 階段昇降機
EP0266381B1 (de) Fahrzeughebebühne
US5236065A (en) Lift used for maintenance of vehicles
CN1127540A (zh) 折叠式椅子
JPH084838B2 (ja) 折曲げプレス機
KR101967220B1 (ko) 승강작업대
EP1432634B1 (de) Bogenfaltvorrichtung
JP3932220B2 (ja) ジャッキ装置
JP2021129659A (ja) 乗降補助装置
JPS6058334B2 (ja) 海上構造物のプラツトフオ−ム錠止装置
GB2050887A (en) Folding machine
US4331018A (en) Folding machine
JP2000351589A (ja) 昇降装置
CN220719784U (zh) 一种应用于预制梁顶板钢筋绑扎的自动行走小车

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION HAS BEEN PUBLISHED

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC ME MK MT NL NO PL PT RO RS SE SI SK SM TR

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION IS DEEMED TO BE WITHDRAWN

18D Application deemed to be withdrawn

Effective date: 20250104