JP3040310U - Fall prevention mechanism for lifting device - Google Patents

Abstract

(57) 【Abstract】 PROBLEM TO BE SOLVED: To provide a drop prevention mechanism for a lifting device, which can prevent the lifting member from falling even if the rope is cut or a problem occurs in the rope during winding / unwinding of the rope. provide. A fall prevention mechanism for a lifting device includes a base member 20, lifting members 21, 22, 23 that move up and down with respect to the base member 20, drive means 6 for moving the lifting member up and down, and In a fall prevention mechanism provided in a lifting device having a transmission means 7 for transmitting a force from a drive means to an elevating member, detection means 25, 26, 27 for detecting transmission of force by the transmission means 7 and a base member. Locking means provided on the receiving means 20c, 21c, 22c and the elevating member for locking the receiving means to prevent the elevating member from falling when the detecting means detects that no force is transmitted. 25, 26, 27 and

Description

[Detailed description of the invention]

[0001]

[Technical field to which the invention belongs]

 The present invention relates to a fall prevention mechanism suitable for a retractable elevator device used in an illumination lamp, an aerial workbench, an X-ray imaging apparatus, or the like.

[0002]

[Prior art]

 An extendable lighting device including a conventional lifting device will be described with reference to FIGS. 10 and 11. The illuminating device shown in FIG. 10 includes a base pole 1 fixed to the ground 8, a pole 2, 3, 4, which is housed in the base pole 1, and an illuminating lamp 5 attached to the tip of the pole 4, A winch 6 for raising and lowering 2 to 4 by a rope 7 is provided. FIG. 10A shows a state in which the poles 2 to 4 have retracted into the pole 1 and the illumination lamp 5 has descended, and FIG. 10B shows that the poles 2 to 4 have respectively extended and the illumination lamp 5 has risen. Indicates the status.

The lifting device will be described with reference to FIG. FIG. 11 shows a state in which the poles 2 to 4 are retracted, and is a diagram corresponding to FIG. A winch 6 is fixed to the base of the base pole 1, and a pulley 11 is fixed to the upper portion of the base pole 1. Pulleys 12 and 14 are fixed to the bottom plates of the poles 2 and 3, and pulleys 13 and 15 are fixed to the upper portions thereof. A rope 7 which can be freely wound and unwound by a winch 6 is wound around pulleys 11, 12, 13, 13, and 15 in this order, and is connected to a rope fixing portion 16 fixed to the bottom plate of the pole 4.

From the state shown in FIG. 11, when the winch 6 is driven to rotate and the rope 7 is wound up, the poles 2 to 4 are respectively lifted up, and when the illumination lamp 5 reaches a predetermined height, the winch 6 is lifted. The illumination lamp 5 is stopped and is kept at a predetermined height as shown in FIG. 10 (b). When the illumination lamp 5 is lowered, the winch 6 is driven in the reverse rotation and the rope 7 is rewound, whereby the poles 2 to 4 are lowered by their own weight, and the state shown in FIG. In this way, the lighting device shown in FIG. 10 can be raised and lowered by the lifting device.

[0005]

[Problems to be solved by the device]

 In the lifting device as described above, if the ropes 7 are damaged and the poles 2 to 4 are lifted, the poles 2 to 4 may drop due to their own weight. Checking. In addition, as a countermeasure in case the rope breaks, it is also possible to wind a wire rope, belt, etc. around the drum and install a separate retractor that detects the feeding speed of the rope and stops the rotation of the drum. It is conceivable, but the wire rope of this retractor will also need to be inspected separately. Moreover, since these ropes are built in the lifting device, it is not easy to inspect them from outside.

The present invention solves the above-mentioned problems of the prior art, such as the rope being cut or the rope falling off from the winding drum of the winch during winding and unwinding of the rope. It is an object of the present invention to provide a fall prevention device for a lifting device that can prevent a lifting member such as a pole from falling even if a problem occurs.

[0007]

[Means for Solving the Problems]

 In order to achieve the above-mentioned object, a fall prevention mechanism for a lifting device according to the present invention includes a base member, a lifting member that moves up and down with respect to the base member, a driving means for moving the lifting member up and down, and a driving device for driving the driving member. In a fall prevention mechanism provided in an elevating device having a transmission means for transmitting the force of the means to the elevating member, a detecting means for detecting the force transmission by the transmitting means and a receiving means provided in the base member. And a locking means provided on the lifting member, which locks with the receiving means to prevent the lifting member from falling when the detection means detects that no force is transmitted.

According to the present invention, when a failure such as a disconnection occurs in the transmission means and the force is not transmitted between the drive means and the elevating member, the locking means provided on the elevating member acts on the base member. Since it is locked to the receiving means, the lifting member is stopped and the lifting member is prevented from falling.

Further, according to the present invention, in the above-described fall prevention mechanism, the elevating device includes a plurality of elevating members configured to be capable of expanding and contracting, and the locking means provided on each elevating member is a base of the elevating members. It is characterized in that it is engaged with a receiving means provided on an ascending / descending member on the member side.

According to the present invention, even when a plurality of lifting members are provided, the locking means of the first lifting member locks with the receiving means of the base member, and the first lifting member stops, The second lifting member locking means is locked to the first lifting member receiving means to stop the second lifting member, so that each of the plurality of lifting members is prevented from falling. You can

Further, according to the present invention, the locking means is biased by the biasing means in the direction of locking with the receiving means, and when the force of the driving means is transmitted to the elevating member, the biasing force by the biasing means. It is characterized in that it is in the non-locking position against the above and is moved to the locking position by the biasing force and locked in the receiving means when the force of the driving means is not transmitted. As the urging means, there are various springs such as a coil-shaped spring, and those which are configured so as to be dropped and urged by their own weight.

According to the present invention, the locking means can be moved between the locked position and the non-locked position depending on whether or not the biasing force by the biasing means and the force of the driving means are transmitted.

Further, when the driving means drives the lifting member via the locking means, and the driving means drives the lifting member to move the locking means to the non-locking position, the driving means is Since the force is transmitted to the lifting member via the locking means, the locking means can be moved to the unlocked position by the force of the driving means.

Further, if a plurality of receiving means are provided on the wall portion of the base member or the elevating member, the engaging means can be engaged with the nearest receiving means below regardless of the height position of the elevating member. The falling of the lifting member can be stopped immediately.

Further, the transmission means may be configured by a flexible member that transmits tension, and the drive means may be configured to raise and lower the elevating member by winding and unwinding the flexible member. Flexible members that transmit tension include ropes, wire ropes, belt-shaped members, chain-shaped members, and chain-shaped members, but any member can be used as long as it can be wound and unwound by the driving means. Good.

Further, the locking means may include a claw portion, and the receiving means may include a concave portion into which the claw portion is inserted.

Further, the locking means may be provided with a cushioning member at a tip thereof, and the receiving means may be configured such that the cushioning member abuts on the wall portion.

Further, the elevating member can be configured to extend vertically upward and retract downward. According to this configuration, the lifting device having the present fall prevention device can be applied to a retractable lighting device, a mobile work platform, or the like.

Further, the elevating member may be configured to extend vertically downward and retract upward. According to this configuration, for example, the base member is fixed to the ceiling portion, and the equipment such as an X-ray imaging device is attached to the tip of the elevating member, and the device is configured to descend when necessary. You can

[0020]

[Embodiment of the invention]

 Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows an elevating device in which the elevating member extends vertically upward and retracts downward and is provided with a fall prevention mechanism. FIG. 1 (a) is a side sectional view showing a state in which a raising / lowering member of a lifting device having a fall prevention mechanism is retracted into a base member, and FIG. 1 (b) is a lifting device of FIG. 1 (a). It is a top view at the time of cutting off and seeing a part.

The elevating device shown in FIG. 1 includes a rectangular tubular base member 20 installed on the ground or the like, a rectangular tubular first elevating member 21 arranged inside the rectangular tubular base member 20, and a rectangular tubular body arranged inside the first elevating member 21. -Shaped second elevating member 22, a rectangular cylindrical third elevating member 23 disposed inside the second elevating member 22, a rotary drive that is fixed on the bottom plate 20a of the base member 20 and is driven by a motor (not shown) or the like. The winch 6, which is wound and unwound by the winch 6, is provided with a wire rope 7 to which tension is applied to raise and lower the elevating members 21 to 24, a pulley 28 fixed above the inside of the wall portion 20b of the base member 20, and the first. A pulley 29 fixed above the inside of the wall 21b of the elevating member 21 and a pulley 30 fixed above the inside of the wall 22b of the second elevating member 22 are provided.

Further, in the lifting device, the first locking operation portion 25 and the second lifting member 22 fixed to the bottom plate 21 a of the first lifting member 21 are provided so that each lifting member has a locking means. Bottom plate 22a of the second locking operation portion 26, and the third lifting member 23 of the bottom plate 23a of the third locking operation portion 27 is fixed, further, the base member 20 wall portion. 20b provided inside 20b, the receiving part 21c provided inside the wall 21b of the first elevating member 21, and the wall 22b inside the second elevating member 22. The receiving portion 22c is provided.

One end of the wire rope 7 is fixed to the rotary drive winch 6 as shown by the one-dot chain line in FIG. 1 (a), and the pulley 28, the pulley 25 a of the locking operation portion 25, the pulley 29, and the lock 29 are locked. The pulley 26a and the pulley 30 of the actuating portion 26 are suspended in this order, and the other end thereof is connected and fixed to the locking actuating portion 27. When the winch 6 is rotationally driven in the p direction in the figure and the wire rope 7 is wound up, the elevating members 21 to 23 can be extended upward, and when the winch 6 is rotationally driven in the direction opposite to the p direction, the base member 20 is moved downward. Can be retracted inward.

The first locking operation portion 25 will be described with reference to FIG. 2 (a) is a front view of the locking operation part 25, FIG. 2 (b) is a side view, and FIG. 2 (c) is a front view showing only the locking operation part. As shown in FIG. 2, the locking operation portion 25 includes a fixing member 31, and the fixing member 31 includes a pair of side plates 31a and 31b (31a is not shown in FIG. 2A). And a bottom plate 31c fixed to the bottom plate 21a of the first elevating member 21.

The first locking operation part 25 has a pair of claw parts 32a that can be locked in the recesses 20d of the receiving part 20c provided inside the wall part 20b of the base member 20. The locking member 32 provided between the side plates 31a and 31b and the rotation shaft 35 provided between the locking members 32 and the side plates 31a and 31b for rotatably supporting the locking member 32 is provided on the other end side of the claw portion 32a. By urging the rotating shaft 34 of the pulley 25a to be connected and the locking member 32 between the rotating shafts 35 and 34 in the direction of arrow r in FIG. Is provided with a coil spring 33 for urging the coil spring toward the wall portion 20b.

On both side plates 31 a and 31 b of the fixing member 31 of the first locking actuating portion 25, the locking member 32 rotates about the rotation shaft 35 within a certain range indicated by an arrow r in FIG. An elongated through hole 31d is formed on the circumference around the rotary shaft 35 so that the rotary shaft 34 of the pulley 25a can be rotated accordingly when it is moved.

The second locking operation portion 26 provided on the second elevating member 22 is also configured in the same manner as the locking operation portion 25, and the claw portion of the locking member of the locking operation portion 26 is It is possible to engage with the receiving portion 21c provided on the wall portion 21b of the first elevating member 21.

FIG. 3 is a front view showing the third locking operation portion 27 in which the fixing member 41 is fixed to the bottom plate 23a of the third elevating member 23. The third locking operation portion 27 has the same structure as the first locking operation portion 25 described with reference to FIG. 2, and the locking member 42 rotates about the rotation shaft 45 within a certain range indicated by an arrow s. According to this rotation, the shaft 44 connecting the terminal end of the wire rope 7 and the end of the locking member 42 opposite to the claw 42a can also move within the range of the arrow s. Is configured to be biased by the spring member 43 toward the wall portion 22b side of the second elevating member 22.

The operation of the fall prevention mechanism of the lifting device shown in FIGS. 1 to 3 will be described. When the wire rope 7 is wound up by the winch 6 by rotating the winch 6 in the p direction from the state shown in FIG. 1 (a) by operating the elevating device, the elevating members 21-23 rise. The winch 6 stops at a predetermined height and supports the lifting members 21 to 23 in that state. Therefore, the wire rope 7 is applied with tension for supporting the elevating members 21 to 23. Therefore, in FIG. 2 (a), the wire rope 7 pulls the pulley 25a upward, that is, in the direction of arrow v in the figure. Therefore, the rotary shaft 34 is also pulled in the first locking operation portion 25, and the coil 25 2A is rotated in the through hole 31d in the direction opposite to the arrow r in FIG. 2A against the urging force of the spring 33, and the locking member 32 is also rotated about the rotation shaft 35. It rotates in a direction away from the wall portion 20 side. Then, when the shaft 34 moves to and abuts on the upper end 31e of the through hole 31d, the shaft 34 stops rotating there, and the locking member 32 is held at the position shown by the solid line in FIG. 2A. .

As described above, when the lifting device is normal and tension is applied to the wire rope 7, the locking member 32 is in the non-locking position, and the claw portion 32a is the recess 20d of the receiving portion 20c. The first locking actuating portion 25 is in a non-actuated state. Further, the second and third locking actuating portions 26 and 27 are also in a non-operating state because their locking members are in the non-locking position.

In this state, consider a case where the wire rope 7 is cut and the tension is lost. When the tension of the wire rope 7 is released, the coil spring 33 in the first locking operation portion 25 causes the locking member 32 to rotate around the rotation shaft 35 in the r direction of FIG. The shaft 34 also moves downward, that is, in the direction of arrow w in FIG. The shaft 34 rotates in the through hole 31d and comes into contact with the lower end of the through hole 31d to stop, so that the locking member 32 is held at the locking position shown by the one-dot chain line in FIG. 2 (a). Then, the claw portion 32a of the locking member 32 rotates around the rotation shaft 35 toward the wall portion 20b side of the base member 20 and contacts the lower end portion 20e of the recess 20d of the receiving portion 20c. The first elevating member 21 including the locking operation portion 25 tries to drop in the w direction, but the claw portion 32a of the locking member 32 is the lower end of the recess 2d of the wall portion 20b of the fixed base member 20. Since the portion 20e is brought into contact with and locked by the portion 20e, the movement of the first elevating member 21 in the w direction including the engaging actuating portion 25 is restricted, and the first elevating member 21 is prevented from falling.

Similarly, also in the second locking operation portion 26, the claw portion of the locking member is locked to the receiving portion 21c provided on the wall portion 21b of the first elevating / lowering member 21. Further, also in the third locking operation portion 27, the locking member 42 rotates about the rotation shaft 45 in the s direction of FIG. 3 and stops and is held at the locking position shown by the one-dot chain line in FIG. . Then, the claw portion 42a also rotates to abut and lock the lower end portion 22e of the concave portion 22d of the receiving portion 22c provided on the wall portion 22b of the second elevating member 22. In this way, the second and third lifting members 22 and 23 are also prevented from falling.

When the wire rope 7 falls off from the rotary drum of the winch 6 and each locking operation portion operates, the rotary drum of the winch 6 returns to the normal state and the rope 7 is moved to the position shown in FIG. When wound in the p direction, the tension of the rope 7 causes the locking member to return to the non-locking position via the pulley of each locking operation portion, so that each elevating member can be raised as it is.

As described above, according to the fall prevention mechanism of the present embodiment, in the elevating device configured such that the elevating member extends in the vertical direction and can be retracted downward, wire cutting, etc. Even when a failure occurs and the rope no longer transmits tension, the lifting member can maintain its position, and the lifting member does not drop, which is preferable for safety management of the lifting device.

Next, a modified example of the receiving portion with which the claw portion of the locking member contacts and locks will be described with reference to FIG. In the example shown in FIG. 4A, the receiving portion 51 is integrally formed on the wall portion of the base member or the elevating member. A plurality of concave portions 51a, 51b, 51c, ... Are provided, and when the locking operation portion is activated, the claw portion can be locked in the closest concave portion below, so that the locking member stops the fall. It is possible to reduce the amount of fall.

FIG. 4B shows a receiving portion 52 that can be fixed to a wall portion such as a lifting member. A plurality of through holes 52a, 52b, 52c, 52d, ... Are formed in the receiving portion 52 to form a concave portion to which the claw portion can be locked when fixed to the wall portion.

FIG. 4C shows a receiving portion 53 which can also be fixed to a wall portion such as an elevating member. A plurality of through holes 53a, 53b, 53c, 53d, ... Are formed in the receiving portion 53, and the portion where the through holes are formed is raised in a U-shape. These through-holes form a recess in which the claw can be locked when fixed to the wall.

Next, a modified example of the locking operation portion will be described with reference to FIG. Since the locking operation portion shown in FIG. 5 has the same structure as that shown in FIG. 2, the same portions are denoted by the same reference numerals. A disk portion 32b is provided at the tip of the locking member 32, and a cushioning member 32c such as a lining is provided on the outer periphery thereof. During the operation of the locking operation portion, the buffer member 32c abuts on the wall portion 20b of the adjacent member to lock the locking member 32. The buffer member 32c can reduce the impact force when the locking member abuts against the wall and locks.

Further, another modified example of the locking operation portion will be described with reference to FIG. FIG. 6A is a front view and FIG. 6B is a top view. The locking operation portion of FIG. 6 is configured such that when the tension of the wire rope 7 is released, the shaft 64 that supports the pulley 60 and is supported by the fixing member 61 falls downward in the figure by its own weight. It is a thing. A through hole 61d is formed in the fixing member 61 in the vertical direction, and a locking member 62 having a claw portion 62a is provided on the rotating shaft 65 so as to be rotatable between a locking position and a non-locking position. ing. A coil spring 63 is provided between the shaft 65 and the shaft 64 so as to bias each other.

When the tension of the wire rope 7 disappears, the shaft 64 descends in the through hole 64 downward in the figure due to its own weight together with the pulley 60, contacts the lower end of the through hole 64, and stops. Along with the movement of the shaft 64, the locking member 62 biased by the spring 63 rotates around the shaft 65 toward the wall portion 20b, and the claw portion 62a moves to the lower end portion 20e of the recess 20d of the receiving portion 20c. Abut and lock.

Next, another embodiment of the present invention will be described with reference to FIGS. 7, 8 and 9. 7 and 8 show an elevating device in which the elevating member extends downward in the vertical direction and retracts upward, and is provided with a fall prevention mechanism.

The elevating device shown in FIG. 7 includes a base member 70 fixed to the ceiling 69, an elevating member 71 extending from the base member and retracting into the base member 70, a rotary drive winch 6 fixedly installed on the ceiling 69, The winch 6 is provided with a wire rope 7 that is wound and unwound.

The wall portion 79 of the base member 70 is formed with a receiving portion for a locking member, and a plurality of concave portions 70a, 70b, 70c, 70d, 70e are formed. A locking actuating portion 68 similar to that shown in FIG. 2 is fixed on the upper plate 71a of the elevating member 71, and is suspended by the wire rope 7.

Consider a case where the wire rope 7 is cut from the state shown in FIG. 7A as shown in FIG. 7B. The urging force of the coil spring 73 causes the claw portion 72a of the locking member 73 to rotate toward the wall portion 79 side of the base member 70, and abuts and locks the lower end portion of the recess 70c as shown in FIG. 7B. This prevents the lifting member 71 from falling.

The lifting device shown in FIG. 8 includes a base member 80 fixed to a ceiling 99, first, second and third lifting members 81, 82 extending from a base member and retracting therein. 83, a rotary drive winch 6, and a wire rope 7. First to third elevating members 81-83 are provided with locking actuating portions 85, 86, 87 respectively on the lower surfaces of upper plates 81a-83a. The wire rope 7 is stretched around pulleys provided below the elevating members 81 to 83 and the respective locking operation parts. When the winch 6 is rotationally driven in the u direction in FIG. 8, the lifting members 81 to 83 respectively extend downward in the drawing, and when the winch 6 is stopped at a predetermined position, the lifting members are supported there. Will be stopped.

The locking operation portion 85 will be described with reference to FIG. The locking operation portion 85 has the same structure as that shown in FIG. 2, but the installation position is on the lower surface side of the upper plate of each elevating member. When the wire rope 7 is transmitting the tension, the shaft 94 abuts on the lower end of the through hole 91d via the pulley 98, and the locking member 92 connected to the shaft 94 is also not locked as shown in FIG. Located in the locked position. When the tension is released by cutting the wire rope 7 or the like, the biasing force of the coil spring 93 causes the locking member 92 to rotate in the direction of arrow t in FIG. The lower end 89b of the recess 89a formed in the wall 89 is brought into contact and locked. The other locking operation portions 86 and 87 also operate in the same manner and are locked in the recesses on the wall surface.

As described above, according to the fall prevention mechanism of the present embodiment, a wire rope or the like has a problem even in the lifting device configured such that the lifting member extends vertically downward and retracts upward. However, even when the rope stops transmitting tension, the lifting member can be prevented from jumping out of the base member and falling downward, which is preferable for safety management of the lifting device.

[0048]

[Effect of the invention]

 According to the present invention, in an elevating device for extending and retracting an elevating member, even if a failure occurs in driving means for driving the elevating member or transmission means for transmitting force from the driving means and the force is not transmitted, the elevating member This is preferable for safety management of the lifting device because it can be prevented from falling.

[Brief description of the drawings]

FIG. 1 is a side sectional view (a) and a top view (b) of a lifting device equipped with a fall prevention device according to an embodiment of the present invention.

FIG. 2 is a front view (a) mainly showing the locking operation part shown in FIG. 1, a side view (b), and a front view (c) showing only the locking operation part.

3 is a front view similar to FIG. 2 (a) showing a locking operation portion on the terminal end side of the wire rope shown in FIG. 1.

FIG. 4 is a cross-sectional view (a), a front view / top view (b), and a front view / top view (c) showing three modified examples of a receiving portion provided on a wall portion of a base member or an elevating member. .

5 is a view showing a modified example of the locking operation portion shown in FIG.
It is a front view similar to (a).

FIG. 6 is a view showing another modification of the locking operation part shown in FIG.
It is the same front view (a) and top view (b) as (a).

FIG. 7 is a front view (a) of a lifting device in a normal state showing another embodiment according to the present invention and a front view (b) of the lifting device showing a state when a wire rope is cut.

8 is a front view showing a modified example of the lifting device of FIG.

9 is a front view similar to FIG. 1 (a) showing the locking operation portion of FIG.

FIG. 10 is a diagram showing an illumination lamp device including a conventional lifting device, and is a diagram showing a state in which each pole is retracted (a) and a diagram showing a state in which each pole is extended (b).

FIG. 11 is a side sectional view showing a conventional lifting device.

[Explanation of symbols]

 6 Winch 7 Wire rope 20, 70, 80 Base member 21, 22, 23 Lifting member 71, 81, 82, 83 Lifting member 25, 26, 27 Locking operation part 68, 85, 86, 87 Locking operation part 32, 42, 62, 72, 92 Locking member 20c, 21c, 22c Retaining part 51, 52, 53 Retaining part 33, 43, 63, 73, 93 Spring member

Claims (10)

[Utility model registration claims] 1. A base member, an elevating member for elevating and lowering with respect to the base member, a drive means for elevating and lowering the elevating member, and a transmitting means for transmitting a force by the driving means to the elevating member. In a fall prevention mechanism included in an elevating device having: a detecting means for detecting the transmission of force by the transmitting means; a receiving means provided on the base member; and a detecting means provided on the elevating member. A fall prevention mechanism for a lifting device, comprising: locking means that locks the receiving means to prevent the lifting member from falling when it detects that the force is not transmitted. 2. The elevating device comprises a plurality of elevating members configured to extend and contract, and the locking means provided on each elevating member is provided on an elevating member adjacent to the base member side of the elevating members. The fall prevention mechanism for an elevating device according to claim 1, wherein the fall prevention mechanism is engaged with a receiving means provided. 3. The locking means is biased by a biasing means in a direction to lock with the receiving means, and is biased by the biasing means when the force of the driving means is transmitted to the elevating member. 3. The device is in a non-locking position against a force, and when the driving force is not transmitted, the urging force moves to a locking position to lock the receiving device.
Fall prevention mechanism for the lifting device described. 4. The driving means drives the lifting member via the locking means, and the driving means drives the lifting member to move the locking means to a non-locking position. The fall prevention mechanism for a lifting device according to claim 1, 2, or 3. 5. The fall prevention mechanism for a lifting device according to claim 1, wherein a plurality of the receiving means are provided on a wall portion of the base member or the lifting member. 6. The transmission means is composed of a flexible member that transmits tension, and the drive means moves up and down the elevating member by winding and unwinding the flexible member. The fall prevention mechanism for a lifting device according to claim 1. 7. The fall prevention mechanism for a lifting device according to claim 1, wherein the locking means includes a claw portion, and the receiving means includes a recess into which the claw portion is inserted. 8. The locking means includes a cushioning member at the tip,
7. The fall prevention mechanism for an elevating device according to claim 1, wherein the receiving means is composed of a wall portion with which the cushioning member abuts. 9. The elevating member extends vertically upward,
9. The fall prevention mechanism for a lifting device according to claim 1, wherein the fall prevention mechanism is retracted downward. 10. The fall prevention mechanism for an elevating device according to claim 1, wherein the elevating member extends vertically downward and retracts upward.