JP2006264967A - Lifting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lifting device capable of stably lifting/moving a lifting base. <P>SOLUTION: A drive rotation shaft 14 rotatably driven by a drive motor and a pair of driven rotation shafts 15 for lifting operation of the lifting base are provided in such a state that driven rotation bodies provided on the pair of driven rotation shaft 15 respectively are positioned at the same position in a rotation axis direction of the drive rotation body 17 relative to the drive rotation body 17 provided on the drive rotation shaft 14. They are interlocked/connected by an endless belt type transmission mechanism 30 wrapped around with one transmission endless belt 19 over the drive rotation body 17 and the pair of driven rotation body 18. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  According to the present invention, a drive rotary shaft that is rotationally driven by a drive motor and a pair of driven rotary shafts for raising and lowering the lifting platform are arranged in a horizontal or substantially horizontal direction in a parallel or substantially parallel posture. The drive rotation shaft is provided in a state where the drive rotation shaft is positioned at an intermediate position of the driven rotation shaft, and the drive rotation shaft and the pair of driven rotation shafts are interlocked and connected by an endless belt type transmission mechanism.

  Such a lift device is used to move an elevator up and down to an elevated position and a lowered position, and to place an article placed and supported on the elevator on a high position or to move it up and down to a low position. In such a lift device, the endless belt type transmission mechanism is provided with a pair of drive rotators arranged side by side in the axial direction of the drive rotation shaft on the drive rotation shaft, and driven rotation provided on one drive rotation body and one driven rotation shaft. And the other driven rotating body and the driven rotating body provided on the other driven rotating shaft are the same in the rotating axial direction of the driving rotating body. The transmission endless belt that is provided in a position and is wound around the drive rotating body and the driven rotating body is wound between one driving rotating body and one driven rotating body and the other driving rotation. Across the body and the other driven rotor A pair of those Te wound around it was composed (for example, see Patent Document 1.).

Japanese Patent Laid-Open No. 10-182083

  However, in the above-described lift device, the transmission endless belt wound around one drive rotator and one driven rotator, and the transmission wound around the other drive rotator and the other driven rotator. Endless belt, and the pair of driven rotating shafts are individually linked to the drive rotating shaft by a pair of transmission endless belts. Due to the bending of the driven rotating shaft due to the body pulling action, the lifting amount of the lifting platform operated by the rotation of one driven rotating shaft and the lifting amount of the lifting platform operated by the rotation of the other driven rotating shaft Therefore, there is a case where the lifting platform cannot be moved up and down stably.

More specifically, if the amount of extension of the transmission endless belt due to secular change is different between one transmission endless belt and the other transmission endless belt, There is a difference between the amount of rotation of the driven rotating shaft and the amount of rotation of the other driven rotating shaft due to the difference in the extension amount of the transmission endless body, and the bearing that rotatably supports the driven rotating shaft is driven by one driven When the rotary shaft and the other driven rotary shaft are provided at the same position in the direction of the rotational axis of the driven rotary shaft, the distance between the bearing that rotatably supports the driven rotary shaft and the driven rotary body is one. Since the amount of bending of the driven rotating shaft is different between the driven rotating shaft of the other and the other driven rotating shaft, the amount of rotation of one driven rotating shaft and the other driven rotation when the driving rotating shaft is driven to rotate by the drive motor Depending on the amount of deflection of the driven rotation shaft Les is what occurs.
As described above, when a deviation occurs between the rotation amount of one driven rotation shaft and the rotation amount of the other driven rotation shaft when the drive rotation shaft is driven to rotate by the drive motor, for example, one end of the lifting platform When the other part of the lifting platform is moved up and down as the other driven rotating shaft rotates, the one end and the other end move up and down. The lifting amount of the platform is different and the lifting platform is inclined, and the lifting platform cannot be moved up and down stably.

  This invention is made in view of the said actual condition, The objective is to provide the lift apparatus which can raise / lower a raising / lowering base stably.

In order to achieve this object, the first characteristic configuration of the lift device according to the present invention is that a drive rotary shaft that is rotationally driven by a drive motor and a pair of driven rotary shafts for raising and lowering the lifting platform are parallel to each other. Alternatively, the drive rotary shafts are arranged in a substantially parallel posture along the horizontal or substantially horizontal direction, and the drive rotary shaft is positioned at a center or a substantially central position between the pair of driven rotary shafts. In the lift device in which the driven rotating shaft is interlocked and connected by an endless belt type transmission mechanism,
The endless belt-type transmission mechanism is the same in the direction of the rotation axis of the drive rotary body as the driven rotary body provided on each of the pair of driven rotary shafts with respect to one drive rotary body provided on the drive rotary shaft. It exists in the state located in a position, and it exists in the point comprised by winding the endless belt for transmission over the said drive rotary body and a pair of driven rotary body.

  That is, a transmission endless belt is wound around one drive rotating body and a pair of driven rotating bodies, and the pair of driven rotating shafts are integrally linked and connected by the drive rotating shaft and the transmission endless belt. Therefore, even if the endless belt for transmission changes due to secular change or the deflection of the driven rotating shaft, the lifting amount of the lifting platform operated by the rotation of one driven rotating shaft and the rotation of the other driven rotating shaft Thus, there is no difference between the lift amount of the lift table that is operated to be lifted and lowered, and the lift table can be lifted and lowered stably.

  Specifically, even if the transmission endless belt is extended due to secular change, the pair of driven rotating bodies are wound around the same transmission endless belt, so that the endless belt-shaped belt is connected to one driven rotating body. There is no difference in the amount of extension between the other endless belt for transmission, and the transmission endlessness depends on the rotation amount of one driven rotation shaft and the rotation amount of the other driven rotation shaft when the drive rotation shaft is driven to rotate by the drive motor. It is easy to configure so as not to cause a difference due to body elongation, and the bearing that rotatably supports the driven rotating shaft is the same in the rotational axis direction of the driven rotating shaft as one driven rotating shaft and the other driven rotating shaft. When provided in a position, the distance between the bearing that rotatably supports the driven rotating shaft and the driven rotating body is the same between one and the other, so that one driven rotating shaft and the other driven rotating shaft Are bent in the same way and driven by the drive motor. To the amount of rotation of one of the driven rotor at the time of rotating the drive shaft and the other rotational amount of the driven rotor, easily constructed so as not to cause misalignment due to bending of the driven rotor.

  Therefore, it can be configured so that there is no deviation between the rotation amount of one driven rotation shaft and the rotation amount of the other driven rotation shaft when the drive rotation shaft is driven to rotate by the drive motor. If one end of the lifting platform is operated to move up and down with the rotation of one driven rotating shaft and the other end is moved up and down with the rotation of the other driven rotating shaft, the one end and the other end move up and down. A lift that can be moved up and down with the amount of lift of the table being equal and maintaining the posture of the table, and can be moved up and down stably, so that the table can be moved up and down stably We have been able to provide equipment.

  A second characteristic configuration of the lift device according to the present invention is the first characteristic configuration, wherein the rotation axis of the drive rotation shaft and the rotation axis of the pair of driven rotation shafts are located in the same plane. The pair of driven rotating shafts are configured to move up and down the lifting platform by forward / reverse rotation accompanying forward / reverse rotation of the drive rotating shaft, and between the pair of driven rotating bodies in the transmission endless body Each of the pair of endless belt portions positioned is wound around the drive rotator, and the portions located on both sides of the drive rotator in each of the pair of endless belt portions are bent toward the drive rotator. The point is that an idler is provided for guiding.

That is, by winding the endless belt for transmission symmetrically or substantially symmetrically about the rotation axis of the drive rotation shaft, each of the pair of driven rotation shafts can be rotated with the same torque, and the lifting platform can be stably It can be moved up and down.
Then, by providing idler wheels that guide the portions of the pair of endless belt portions located on both sides of the drive rotor to bend toward the drive rotor, each of the pair of endless belt portions can be sufficiently wound. It can be wound around the drive rotor with a corner.

  According to a third characteristic configuration of the lift device according to the present invention, in the first or second characteristic configuration, when the lifting platform is guided to be moved up and down by the guide means, and each of the pair of driven rotating shafts is in an upward posture. A swing arm connected to the lifting platform is provided to rotate integrally so that the lifting platform is in a raised state and in a downward posture when the lifting platform is in a lowered state, and the lifting platform is elastically moved upward. The elastic urging body for urging is provided in a state in which the elastic urging action is performed when at least the swing arm is located in a set angle range including the horizontal direction.

  That is, the swing arm that is operated to swing up and down by the output of the drive motor is divided into an upward posture in which the swing arm is directed upward and in a vertical posture, and a downward posture in which the swing arm is directed downward and in a vertical posture. When the swing arm is operated to swing up and down, a large output is required for the drive motor when swinging the swing arm upward with the swing arm in a horizontal posture. When the arm is positioned within a set angle range including the horizontal direction, the elastic biasing body is provided in a state of elastically biasing the lifting platform upward, thereby driving the lifting motor from the lowered state to the rising state. Therefore, a small drive motor with a small output can be used.

DESCRIPTION OF EMBODIMENTS Hereinafter, an embodiment in which a lift device according to the present invention is applied to an automatic warehouse will be described with reference to the drawings.
As shown in FIG. 1, the automatic warehouse is provided with a pair of storage shelves 1 that store articles A as opposed to each other. A stacker crane 3 that can travel along the traveling rail 2 is provided between the pair of storage shelves 1 that face each other. With the stacker crane 3, the article A is delivered from the storage shelf 1. The article A is delivered to the article loading / unloading device 4 provided on the lateral side of the storage shelf 1, and the article A received from the article loading / unloading apparatus 4 is loaded into the storage shelf 1. Note that, as shown in FIGS. 6 to 8, the article A includes a pallet and a conveyed product that is placed and supported on the pallet.

As shown in FIG. 1, the article carry-in / out device 4 includes a pair of chain conveyors 6 a and a pair of chains on one end side of the conveyor 6, which is configured to place and convey articles A. The lift device 7 is provided so as to be positioned between the conveyors 6a.
Then, the transfer conveyor 6 places and conveys the article A, which has been lowered to one end by the lift device 7, to the other end by the chain conveyor 6a, and delivers it to an external transfer device (not shown). The article A delivered to the other end side by the transfer device is placed and conveyed to one end side by the chain conveyor 6a. The article A placed and conveyed on this one end side is picked up by the lift device 7.

As shown in FIGS. 2 and 3, the lift device 7 is provided with a lifting platform 8 having a mounting portion 9 for mounting and supporting the article A. The lifting platform 8 moves up and down. The rising state (see FIG. 7) in which the placement surface of the placement unit 9 is located above the conveyance surface of the conveyance conveyor 6 and the lowered state in which the entire lifting platform 8 is located below the conveyance surface of the conveyance conveyor 6 ( (See FIG. 6).
That is, when the elevator 8 is lowered and switched from the raised state to the lowered state while the article A is placed and supported by the placing portion 9, the article A is lowered to one end of the transport conveyor 6 during the lowering. If the elevator 8 is raised and switched from the lowered state to the raised state in a state where the article A is placed and supported on one end side of the conveyor 6, the article A is placed on the placing portion 9 in the middle of the raising. It is configured to scoop up.

Next, the lift device 7 will be described. In addition, the conveyance direction of the conveyance conveyor 3 is called the front-back direction, and the fork withdrawal direction of the stacker crane 3 which cross | intersects this front-back direction is called a left-right direction, and is demonstrated.
As shown in FIG. 2, the lift device 7 includes a base 13 that supports a drive motor 11 that is provided with a speed reducer and a brake and is configured as a geared motor, and a lift 8 that moves up and down relative to the base 13. The elevator 8 is moved up and down by the output of the drive motor 11 and is switched between the raised state and the lowered state.

  As shown in FIG. 4, a drive rotary shaft 14 that is an output shaft of the drive motor 11 that is rotationally driven by the drive motor 11 and a pair of driven rotary shafts 15 for raising and lowering the elevator base 8 are parallel or substantially parallel to each other. The drive rotary shafts 14 are arranged in a parallel posture along the horizontal or substantially horizontal direction and located at the center or substantially the center position between the pair of driven rotary shafts 15, as shown in FIG. As described above, the rotation axis of the drive rotation shaft 14 and the rotation axis of the pair of driven rotation shafts 15 are provided in the same plane. The drive rotating shaft 14 and the driven rotating shaft 15 are provided along the front-rear direction.

The drive rotary shaft 14 and the pair of driven rotary shafts 15 are interlocked and connected by an endless belt type transmission mechanism 30.
This endless belt type transmission mechanism 30 includes a drive sprocket 17 as one drive rotator provided on the drive rotation shaft 14, a driven sprocket 18 as a driven rotator provided on each of the pair of driven rotation shafts 15, and a drive A transmission chain 19 as a transmission endless belt wound around the sprocket 17 and the driven sprocket 18 is provided.
As shown in FIG. 4, a pair of driven sprockets 18 are provided at the same position in the rotational axis direction of the drive sprocket 17 with respect to one drive sprocket 17, and the drive sprocket 17 and the One transmission chain 19 is wound around a pair of driven sprockets 18.

As shown in FIG. 5, each of the pair of chain portions 19a located between the pair of driven sprockets 18 in the transmission chain 19 is wound around the drive sprocket 17, and the pair of chain portions 19a An idle sprocket 21 is provided as an idler for guiding the portions located on both sides of the drive sprocket 17 to be bent toward the drive sprocket 17. The chain portion 19a corresponds to an endless belt portion.
That is, a pair of idle sprockets 21 are rotatably supported so as to be arranged in the vertical direction on each of the pair of support members 31 erected on the base 13 in a state of being arranged in the horizontal width direction. The rolling sprocket 21 is provided so as to contact from the outer surface side of the transmission chain 19 so as to guide the chain portion 19a to bend toward the drive sprocket 17 side.
Then, by bending the portions of the chain portions 19a located on both sides of the drive sprocket 17 toward the drive sprocket 17 with the four idle sprockets 21, each of the pair of chain portions 19a is about 120 °. It is configured to be wound around the drive sprocket 17 at a winding angle.

Then, the both ends of the pair of driven rotating shafts 15 are connected to the lift base 8 so that the lift base 8 is in an upward state when it is in an upward posture and the lift base 8 is in a downward state when it is in a downward posture. The swing arm 20 is provided so as to rotate integrally, and the pair of driven rotary shafts 15 swings up and down so as to synchronize the four swing arms 20 so that the drive rotary shaft 14 is forward / reverse. The elevator 8 is configured to be moved up and down while maintaining a horizontal posture by forward and reverse rotation accompanying rotation.
As shown in FIG. 4, the pair of driven rotary shafts 1 are rotatably supported by bearings 16 provided on a base 13 at the front and the rear. A bearing 16 that supports the front portion of one driven rotating shaft 15 and a bearing 16 that supports the front portion of the other driven rotating shaft 15 are provided so as to be aligned in the left-right direction perpendicular to the front-rear direction. The bearing 16 that supports the rear portion of the driven rotation shaft 15 and the bearing 16 that supports the rear portion of the other driven rotation shaft 15 are also arranged in the left-right direction.
Therefore, the distance from the driven sprocket 18 provided on one driven rotary shaft 15 to the bearing 16 is the same as the distance from the driven sprocket 18 provided to the other driven rotary shaft 15 to the bearing 16. It is configured.

As shown in FIG. 4, guide rails as guide means for guiding the lifting / lowering base 8 so as to be movable up and down in a state in which movement in the horizontal direction is restricted are respectively provided in the left and right central portions of the front and rear portions of the base 13. The guide rail 22 is formed in a U-shape that is provided in the front portion of the base 13 and opens forward in plan view, and is provided in the rear portion of the base 13. It is formed in a U shape that opens rearward in a plan view.
Each of the guide rails 22 is engaged with guided means 23 provided in a fixed position on the lifting platform 8, and by this engagement, the lifting platform 8 is moved horizontally by the guide rail 22. It is configured to be guided so as to be movable up and down in the vertical direction in a state in which the movement is restricted. The guided means 23 includes three rollers that are in contact with the inner surfaces of the guide rails 22.

A pair of elevating frames 24 are provided on the elevating table 8 with a gap in the width direction so as to be along the front-rear direction, and a pair of mounting frames 25 are provided with a gap in the front-rear direction so as to be along the left-right direction. Each mounting frame 25 is connected to the upper part of each lifting frame 24 and spans the pair of lifting frames 24. And the mounting part 9 is comprised by a pair of mounting frame 25, and it is comprised so that the article A may be mounted over a pair of mounting frame 25, and also mounted in the mounting frame 25. A space for inserting and removing forks is formed between the lifting frame 24 and the article A placed and supported on the placing frame 25 so that the article A can be loaded and unloaded by the stacker crane 3.
In addition, a pair of operated frames 26 that are moved up and down by swinging up and down the swing arm 20 are provided on the lifting platform 8 at intervals in the front-rear direction so as to follow the left-right direction. Each of 26 is connected with the lower part of each raising / lowering frame 24, and is spanned over a pair of raising / lowering frame 24. As shown in FIG. An L-shaped plate 27 having a lower end portion bent inwardly on the outer surface side of each of the operated frames 26 and having a guided means 23 in a fixed position is connected to the left and right central portions.

That is, the operation roller 20a provided at the tip of the swing arm 20 is engaged with the lower end of the operated frame 26 and the L-shaped plate 27 so as to be movable in the left-right direction. When the moving arm 20 swings upward, the operation roller 20a moves upward so as to draw an arc, and the lower end portion of the operated frame 26 is pushed up by the operation roller 20a due to the movement of the operation roller 20a, so that the elevator 8 When the swinging arm 20 is moved upward and the swinging arm 20 is in an upward posture in a vertical posture, the lifting platform 8 is configured to be in the highest lifted state (see FIG. 7). When the swing arm 20 swings downward, the operation roller 20a moves downward so as to draw an arc, and the elevator 8 is moved downward by its own weight so as to follow the movement of the operation roller 20a. When the moving arm 20 is in a downward posture in which the moving arm 20 is in a vertical posture downward, the lifting platform 8 is configured to be in a lowered state (see FIG. 6) that is lowered most.
Since the operation roller 20a is engaged with the elevator 8 so as to be relatively movable in the left-right direction, even if the operation roller 20a moves in the left-right direction so as to draw an arc, the elevator 8 is guided by the guide rail 22. Thus, the movement in the horizontal direction is restricted so that the operation roller 20a does not follow the movement in the left-right direction and does not move in the left-right direction.

  Further, four swing arms 20 are provided corresponding to the four corners of the lifting platform 8 by being connected to both ends of the output shaft 14 and the driven shaft 15, respectively. The both ends of the pair of operated frames 26 are moved up and down, and the four corners of the lift base 8 are moved up and down, and the lift base 8 is moved up and down while maintaining a horizontal state.

As shown in FIGS. 2 to 4, the coil spring 28 as an elastic biasing body that elastically biases the lifting platform 8 upward is positioned at least within the set angle range in which the swing arm 20 includes the horizontal direction. Sometimes it is provided in a state in which it is elastically biased.
In other words, the base 13 is provided with a protrusion 29 so as to protrude upward, and the elevator 8 is provided with a protrusion 29 so as to protrude downward. The spring 28 is provided in a compressed state between the lifting platform 8 and the base 13 so that the lower portion is fitted to the projection 29 of the base 13 and the upper portion is fitted to the projection 29 of the lifting platform 8. It is configured to always urge upward with respect to the lifting platform 8.
A pair of front and rear projections 29 are provided on both the front and rear sides of the base 13 so that four projections 29 are provided on each of the base 13 and the lift 8. A pair of front and rear projections 29 are provided for each, and four coil springs 28 are detachably provided on the lift device 7.
The change of the urging force that urges the lifting platform 8 upward is changed by one or more elastic biasing bodies 28 provided in the lift device 7 so that the swing arm 20 is in a horizontal posture. In the intermediate state between the raised state and the lowered state, the lifting platform 8 is configured to be elastically biased to the upward side with an urging force that is about half of the rated load.
Therefore, for example, in the state where the swing arm 20 is in a horizontal posture as shown in FIG. 8, when the rated load is 1000 kg, the coil spring 28 elastically biases the lifting platform 8 to the ascending side by 400 kg. When the rated load is 1350 kg, it is possible to cope with a change in the rated load by attaching and detaching the coil spring 28 so that the coil spring 28 elastically biases the lifting platform 8 upward by 700 kg. It is comprised so that it is not necessary to prepare the several drive motor 11 according to the rated load to be performed.

[Another embodiment]
(1) In the above embodiment, the drive rotator is the drive sprocket 17, the driven rotator is the driven sprocket 18, the transmission endless belt is the transmission chain 19, and the endless belt transmission mechanism 30 is a chain transmission mechanism. However, the drive rotating body may be a driving pulley, the driven rotating body may be a driven pulley, the transmission endless belt may be a transmission belt, and the endless belt transmission mechanism 30 may be a belt transmission mechanism.

(2) In the above embodiment, the swing arm 20 connected to the lift base 8 is provided to rotate integrally with each of the pair of driven rotary shafts 15, and the swing arm 20 is swung to thereby lift the lift base. 8 is configured to move up and down. A pinion gear meshing with a rack gear provided on the lifting platform 8 is provided to rotate integrally with each of the pair of driven rotating bodies 15, and the rack gear is moved up and down by rotating the pinion gear. Then, the lifting platform 8 may be configured to move up and down.

(3) In the above embodiment, the swing arm 20 is provided so as to rotate integrally with both ends of the driven rotary shaft 14, and the lift device 7 is provided with a total of four swing arms 20. The oscillating arm 20 may be provided only at one end of the driven rotary shaft 14 so that the link device 7 is provided with a total of two oscillating arms 20.

(4) In the above embodiment, the four idlers 21 are guided so as to guide the portions located on both sides of the drive rotator 17 in each of the pair of endless belt portions 19a to bend toward the drive rotator 17 side. Although provided, the two endless belt portions 19a may be provided with only two idlers 21 that guide the portions located on both sides of the drive rotator 17 to bend toward the drive rotator 17 side.

(5) In the above-described embodiment, when the swing arm 20 is in the upward position in which the swing arm 20 is directed upward and is in the vertical position, the lift 8 is in the raised state, and the swing arm 20 is in the downward position in which the swing position is directed downward. Then, the elevator 8 is configured to be in the lowered state. However, the elevator 8 may be configured to be in the upward state when the swing arm 20 is in the upward posture that is inclined upward. You may comprise so that the raising / lowering stand 8 may be in a descent | fall state when the arm 20 becomes the downward attitude | position which becomes an inclination attitude | position toward the downward direction. Further, when the swing arm 20 is in a horizontal posture, the elevator base 8 may be configured to be in an up state or a down state.

(6) In the above embodiment, the elastic biasing body 28 is provided between the base 13 and the lifting platform 8, but may be provided between the floor surface and the lifting platform 8. The elastic biasing body 28 only needs to be elastically biased when at least the swing arm is positioned within a set angle range including the horizontal direction. The elastic biasing body 28 is elastic in a state where the lifting platform 8 is switched to the raised state. The upper end of the urging body 28 is provided on the base 13 or the floor so that it does not contact the lifting platform 8, or the lower end of the elastic biasing body 28 is the base when the lifting platform 8 is switched to the raised state. 13 is provided on the lifting platform 8 so as not to contact the floor surface, and is configured so that the lifting platform 8 is elastically biased upward by the elastic biasing body 28 when the lifting platform 8 is lowered by a predetermined amount from the raised state. Also good.

(7) In the above embodiment, the urging force for urging the lifting platform 8 to the upward side is configured to be changeable. However, the elastic urging body 28 may be made detachable so that the urging force cannot be changed. Good. In the above-described embodiment, the plurality of elastic urging bodies 28 are provided. However, only one elastic urging body 28 may be provided, or the elastic urging body 28 may not be provided. .

(8) In the above embodiment, the elastic biasing body 28 is a coil spring, but it may be a leaf spring or may be made of a resin material such as rubber.

Floor plan of automated warehouse Top view of lift device Side view of lift device Front view of lift device Front view of endless belt type transmission mechanism Action diagram of lift device Action diagram of lift device Action diagram of lift device

Explanation of symbols

DESCRIPTION OF SYMBOLS 8 Elevator 11 Drive motor 14 Drive rotary shaft 15 Drive rotary shaft 17 Drive rotary body 18 Drive rotary body 19 Endless belt for transmission 20 Swing arm 21 Free rotating body 22 Guide means 28 Elastic biasing body 30 Endless belt type transmission mechanism

Claims (3)

A pair of driven rotary shafts are arranged in a horizontal or substantially horizontal direction in a parallel or substantially parallel posture with a drive rotary shaft that is rotationally driven by a drive motor and a pair of driven rotary shafts for raising and lowering the lifting platform. Is provided in a state where the drive rotation shaft is located at the center or substantially the center position between
A lift device in which the drive rotary shaft and the pair of driven rotary shafts are interlocked and connected by an endless belt type transmission mechanism;
The endless belt-type transmission mechanism is the same in the direction of the rotation axis of the drive rotary body as the driven rotary body provided on each of the pair of driven rotary shafts with respect to one drive rotary body provided on the drive rotary shaft. A lift device that is provided in a position and is configured by winding one endless belt for transmission over the drive rotator and the pair of driven rotators. The rotation axis of the drive rotation shaft and the rotation axis of the pair of driven rotation shafts are provided so as to be located in the same plane, and the pair of driven rotation shafts accompanies forward and reverse rotation of the drive rotation shaft. It is configured to raise and lower the elevator by forward and reverse rotation,
Each of the pair of endless belt portions positioned between the pair of driven rotating bodies in the transmission endless body is wound around the drive rotating body, and the drive rotating body in each of the pair of endless belt portions. The lift device according to claim 1, further comprising an idler that guides portions located on both sides of the motor to bend toward the drive rotor. The lifting platform is guided by a guide means so as to be raised and lowered,
Each of the pair of driven rotating shafts is integrally rotated with a swinging arm connected to the lifting platform so that the lifting platform is raised when it is in an upward position and is lowered when it is in a downward posture. Provided to
The elastic urging body that elastically urges the lifting platform to the ascending side is provided in a state in which it elastically urges at least when the swing arm is positioned within a set angle range including a horizontal direction. Lifting device according to.

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