JP2619997B2 - Electric lifting device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric hoisting apparatus for elevating and lowering electric equipment such as lighting equipment and speakers which can be raised and lowered on a high ceiling such as a ceiling of a factory or a gymnasium.

[0002]

2. Description of the Related Art FIG. 14 is a schematic view of an electric lifting device.
Reference numeral 1 denotes a lifting device main body installed on a high ceiling such as a factory or a gymnasium. The main body 1 is equipped with a motor 2 and a winding drum 4 that is rotated forward and reverse by the motor 2 to wind and rewind the wire rope 3. The wire rope 3 is routed through a plurality of wire guides 5 and also suspends a lifting / lowering body 7 that supports the lighting fixture 6. The winding and rewinding of the rope 3 onto the winding drum 4 raises and lowers the lighting fixture 6 at a gentle speed, so that maintenance and inspection of the fixture 6 and the like can be easily performed. A limit switch 8 is attached to the lifting device main body 1, and when the switch 8 is pressed by the lifting member 7, the winding operation of the winding drum 4 by the motor 2 is stopped.

[0003] A metal contact stand 1 provided on a lift apparatus main body 1
A plurality of power supply contacts 15 are attached to 6. That is, the power supply contact 15 penetrates the bush-like electric insulator 18 attached via the retaining ring 17a as shown in FIG. The screw portion 15a of the contact 15 has a crimp terminal 17
b and the spring washer 17c are fitted respectively, and the nut 19 is screwed. The crimp terminal 17b pressed against the power supply contact 15 by tightening the nut 19 is connected to a power supply side lead wire.

A plurality of power receiving contacts 9 which are urged upward and can move up and down are protruded from the elevating body 7. That is, as shown in detail in FIG. 15, the power receiving contact 9 penetrates the metal ceiling wall 7a of the elevating body 7 and vertically passes through the bush-shaped electric insulator 11 stopped by the retaining ring 10a. The contact 9 is always urged upward by a contact spring 12 and has a threaded portion 9 a formed at the lower end of the power receiving contact 9.
Flat washer 10b fitted to nut and fixed with nut 13a
Is prevented from falling upward. A crimp terminal 14a attached to the distal end of the device-side lead wire 14 of the lighting fixture 6 is fitted into the screw portion 9a, and a spring washer 1 that sandwiches the terminal 14a between the terminal portion 14a and a nut 13a.
0c is fitted. Further, a nut 13b is screwed into the screw portion 9a, and the crimping terminal 14a is pressed against the power receiving contact 9 by tightening the nut 13b, so that the contact 9 and the lighting fixture 6 are electrically connected.

[0005] The power receiving contact 9 is provided with a plurality of power supply contacts 15 provided on the main body 1 and connected to a power source when the lifting / lowering body 7 is arranged at the raised position, in other words, when supported by the lifting / lowering apparatus main body 1. Are contacted separately. At this time, the power receiving contact 9 is pressed down against the contact spring 12, so that the two contacts 9, 15 are pressed against each other. When the elevating body 7 is lowered, the power receiving contact 9 is separated from the power feeding contact 15 and simultaneously pushed up by the force of the contact spring 12.

[0006]

As described above, in the electric lifting device that raises and lowers the elevating body 7 via the wire rope 3, when the elevating body 7 is set on the elevating apparatus main body 1, the lighting fixture 6 that ascends is raised. In addition, the elevating body 7 may swing or rotate. When the elevating body 7 is set on the elevating body main body 1 due to such a movement, the position of the power receiving contact 9 with respect to the power supply contact 15 may be shifted and the contacts 9 and 15 may not be connected. Conventionally, the diameters of both contacts 9 and 15 have been increased in order to cope with this.
There was a problem that the cost was high.

Further, since the lifting of the elevating body 7 is stopped by detecting the elevating body 7 by means of the limit switch 8, the wire rope 3 may be displaced due to a variation in the mounting position of the switch 8 or a variation in the operation of the switch 8. The height position of the lifting / lowering body 7 at the time when the winding of the motor is stopped varies for each electric lifting / lowering device. As a result, the amount of deflection of the contact spring 12 cannot be made constant, so that the contact pressure of the two contacts 9 and 15 due to the amount of deflection of the contact spring 12 may be insufficient. In such a case, the contact resistance between the two contacts 9 and 15 increases, and the contacts 9 and 15 become high in temperature. Therefore, there is a problem that the electrical insulators 11 and 18 at the contact portions are likely to be burned. Was.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an electric hoisting and lowering device capable of reliably bringing a power supply contact and a power receiving contact into contact with each other and reducing the size of the contact and eliminating the risk of burning of the contact portion.

[0009]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention relates to a lifting / lowering apparatus main body provided with a motor for driving a winding drum arranged at a high position on a ceiling side for winding and rewinding a wire rope. A plurality of power supply contacts provided on the main body and electrically connected to a power supply; a lifting / lowering body suspended from the wire rope and connected to an electric device to lift / lower; In a motor-driven lifting device including a plurality of power receiving contacts that are respectively connected to and separated from a power supply contact and electrically connected to the electric device, a bottom wall having the power supply contact attached to the lifting device main body; A pair of side walls projecting downward from the wall and facing each other, and a pair of side walls provided with these side walls separated from each other in the longitudinal direction thereof and formed with a concave groove between which a part of the elevating body is fitted. With stopper projection With made the provision of the contact base,
This mounting base is urged downward by the contact base pressing spring,
A pair of fitting projections are provided on the outer peripheral surface of the elevating body to be fitted between the opposing surfaces of the both side walls, and a longitudinal end of the fitting projection and a lower end of the stopper projection are provided. An inclined surface is provided on at least one side, and one of the power supply contact and the power receiving contact is urged toward the other by a contact spring having a smaller elastic force than the contact base pressing spring, and the contact base is detected. And a switch for stopping the operation of the motor is attached to the lifting device main body.

[0010]

According to the above construction, when the lifting / lowering body is raised and supported by the lifting / lowering device main body, the fitting projection of the lifting / lowering body is positioned between the opposing stopper projections of the contact base just before the end of the lifting. Fit smoothly while being guided by the inclined surface. Then, both side walls of the contact base and the stopper protrusion prevent the swinging and rotating of the lifting and lowering body, and also prevent the movement of the lifting and lowering body in a direction orthogonal to the length direction of the side wall. Since the two upper end portions of the elevating body further raised under such regulation conditions are fitted into the concave grooves of the contact stand, the concave groove side portions of the stopper projections are engaged with the elevating bodies to form side walls. To prevent the elevating body from moving in the length direction. As described above, since the elevating body can be positioned on the contact base so that the power receiving contact is accurately opposed to the power feeding contact, the power receiving contact can be pressed against the power feeding contact while the contact spring is compressed by raising the elevating body. . Moreover, since the upper surface of the ascending / descending body comes into contact with the deep end face of the concave groove, the contact spring is not compressed by the ascending force of the ascending / descending body after that point, and the amount of deflection of the contact spring can be kept constant. . Then, after this, the elevating body is raised together with the contact base against the urging force of the contact base pressing spring, so that the operation of the motor is stopped by a switch that detects the elevating body, and the elevating body is supported by the elevating body. You.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. Electric lifting device 21 shown in FIGS.
Comprises a lifting device main body 22 and a lifting body 24 suspended below the main body 22 via a wire rope 23 and raised and lowered at the time of maintenance and inspection. Lifting device body 22
Is located at a high place on the ceiling side of a gymnasium or the like. As shown in FIG. 6, a lighting fixture A is connected to and supported by the elevating body 24.
The device A includes a mercury lamp (not shown) that is turned on when a lamp driving voltage is applied as a pulse.

A motor 25 and a take-up drum 26 rotated forward and reverse by the motor 25 are fixed to the lifting device main body 22. The motor 25 has a non-excited operation type electromagnetic brake and a speed reduction unit, and a winding drum 26 is connected to an output end of the speed reduction unit. As shown in FIG. 3, the drum 26 has a first winding section 26a and a second winding section 26b separated by a separator 27.

An elevating device holder 28 which mechanically supports the elevating device 24 so that the elevating device 24 is not accidentally dropped.
Has been fixed. As shown in FIGS. 1 to 3, four downward guides 71 are integrally protruded from the holder 28.
Each guide 71 has a slope 71a as shown in FIG. Each guide 71 is, as shown in FIG.
Length B reaching the lower end of the elevating body 24 supported by
have. The slope 71 a of the guide 71 is
The slope is formed so as to gradually move away from the peripheral surface of the elevating body 24 supported by the elevating body holder 28 from the root to the tip.

A shaft 72 is provided between guides 71 facing the width direction of the elevating body holder 28, respectively. These shafts 72 have rotatable locking claws 7 which are engaged with and disengaged from a pair of fitting projections 78 integrally provided from the outer peripheral surface of the upper end of the elevating body 24.
3 and a coil spring 74 for urging the pawl 73 are attached. As shown in FIGS.
Is the overhanging hooking surface 7 on which the hooking claw 73 engages and disengages.
8a at an intermediate portion so that the shape seen from the end face is an inverted L-shape, and is fitted to a pair of side walls 62 of the contact stand 60 described later so as to be insertably and detachably between opposing surfaces. The length (length along the circumferential direction of the elevating body 24) is slightly shorter than the dimension C (see FIG. 7) between the facing surfaces. Sloped surfaces 78b are formed at both ends in the length direction of the fitting projection 78, respectively.

The locking claw 73 supports the lifting body 24 by being engaged with the locking surface 78a obliquely from below, and the coil spring 74 is bent in this state. Therefore, when the elevating body 24 is further moved upward, and the tip of the locking claw 73 is opposed to the lower peripheral surface 24b of the elevating body 24, the lower peripheral surface 24b and the locking surface 78a are at that point in time. Due to the difference in the radial position, the locking claw 73 is rotated downward by the force of the coil spring 74 so as not to obstruct the downward movement of the elevating body 24.

Reference numeral 60 in FIGS. 1 and 2 denotes an elevating body holder 28.
PBT with high heat resistance at the contact block placed inside
(Polybutylene terephthalate) or the like. As shown in detail in FIG. 7, the contact base 60 has a flat bottom wall 61 having a rectangular shape, and opposed side walls 62 integrally projecting downward from both side edges along the longitudinal direction of the wall 61. A stopper projection 63 is provided at each end of the side wall 62 so as to extend further downward. Left and right stopper projections 63 of each side wall 62
Between the gaps, there is a concave groove 64 into which a part of the elevating body 24 is fitted, and the concave groove 64 side of the stopper projection 63 is formed with an inclined surface.

As shown in FIG. 5, a plurality of power supply contacts 31 formed by providing a contact layer 66 made of cadmium silver oxide on the lower end face of the contact body 65 are attached to the bottom wall 61 as follows. I have. That is, the power supply contact 31 is fixed to the contact base 60 by passing through the mounting hole 60 a provided in the contact base 60 and screwing the nut 67 into the screw portion 65 a of the contact body 65. In FIG. 5, reference numerals 68 and 69 denote a crimp terminal and a spring washer fitted into the screw portion 65a.
The crimp terminal 68 pressed into contact with 1 is attached to the tip of a power supply side lead wire (not shown) connected to a power supply.

The contact stand 60 and the ceiling wall 2 of the lifting device main body 22
A plurality of contact point pressing springs 76 (see FIGS. 1 and 3) made of a coil spring are mounted between the contact point pressing springs 2a and 2a. The spring force of the spring 76 presses the stopper projection 63 of the contact stand 60 against the shaft 72 when the elevating body 24 is not supported, and the locking claw 7 when the elevating body 24 is not supported.
3 is pressed downward to raise and lower the lifting body 2.
4 does not move carelessly.

A limit switch 77 (see FIGS. 8 and 9) is disposed in the elevating body holder 28 on the back side (upper side) of the contact stand 60. The switch 77 is operated by being pushed by the elevating body 24 when the elevating body 24 is placed at a predetermined position, thereby stopping the winding operation of the wire rope 23 by the motor 25. It has become.

Reference numeral 32 in FIGS. 2 and 3 denotes a printed wiring board on which switches and other electric parts 33 are mounted.
34 is a circuit board on which a relay 35 is mounted, 36 is a detecting device for detecting the tension and looseness of the wire rope 23, and a spring 37
And a micro switch 40 fixed to a base 39 that pivotally supports these levers 38 and turned on and off by the seesaw lever 38.

The lifting device main body 22 has first to first rotatable guide pulleys located around a lifting body holder 28.
Fifth wire guides 41 to 45 are attached. The first and second wire guides 41 and 42 are connected to the elevating body holder 28.
Is arranged on the opposite side of the motor 25 with
The third wire guide 43 is disposed close to the side surface of the lifting body holder 28 on the printed wiring board 32 side. The fourth wire guide 44 is disposed close to the side surface of the elevating body holder 28 on the detection device 36 side, and the fifth wire guide 45 is disposed between the detection device 36 and the first wire guide 41. ing.

First, second, and fifth wire guides 4
1, 42, 45 are horizontal ceiling walls 22 of the lifting device main body 22.
a, and the third and fourth wire guides 43 and 44 are mounted vertically along the outer surface of the vertical side wall of the elevating body holder 28.

The wire rope 23 is wound with one end thereof fixed to the first winding portion 26a of the winding drum 26, and the other end is wound on the second winding portion 2 of the winding drum 26.
6b, and is wound around, and the intermediate portion is wound around the first to fifth wire guides 41 to 45.

That is, as shown in FIG. 3, one end of the wire rope 23 is connected to the detecting device 3 by the first winding portion 26a.
6 is sequentially passed over the first to third wire guides 41 to 43 through one seesaw lever 38, and the other end of the wire rope 23 is connected to the other end of the detection device 36 from the second winding portion 26b. Through the seesaw lever 38 of the fifth and fourth
It is laid over the wire guides 45 and 44 sequentially. Further, an intermediate portion of the wire rope 23 located between the third and fourth wire guides 43 and 44 is wound around a pair of rotatable guide pulleys 46 (see FIG. 1) built in the elevating body 24.

Therefore, both winding portions 2 of the winding drum 26
When the wire rope 23 is simultaneously wound on the wire ropes 6a and 26b, the elevating body 24 is lifted.
The elevating body 24 is lowered by rewinding the wire ropes 23 simultaneously to 6a and 26b. The lifting body 2
In the final stage of ascending, the engaging surface 7 of the fitting projection 78 is
The engaging claw 29 is automatically engaged with the lifting member 8a, and the lifting body 24 is mechanically supported by the lifting device main body 22. When the descent is started, the descent operation is performed after the elevating body 24 is first slightly raised until the locking claws 29 face the lower peripheral surface 24b of the elevating body 24.

As shown in FIGS. 1 and 3, the elevating body 24 has a short and cylindrical metal elevating body main body 51 with open upper and lower ends, and has a high heat resistance attached by closing the upper end opening. The contact mounting base 52 is made of a synthetic resin such as PBT, and a bottom lid 53 made of a synthetic resin and attached by closing the lower end opening of the elevating body 51. The fitting protrusion 78 is integrally provided on the upper part of the outer peripheral surface of the lifting / lowering body 51. A pair of notch grooves (not shown) are provided in the periphery of the contact mount 52, and the wire rope 23 hung on the pulley 46 is passed through these grooves.

The contact mount 52 has a plurality of thick portions 52a.
(See FIG. 5), and guide holes 81 are vertically penetrated in these portions 52a, respectively. A power receiving contact 82 that comes into contact with and separates from the power supply contact 31 is supported through the hole 81 so as to be slidable in the vertical direction. The contact 82 is always urged upward by a coil-shaped contact spring 83 and, as shown in FIG. 2, is fitted to a screw portion 82a formed at the lower end of the power receiving contact 82 with a smaller diameter than the upper portion thereof. Together, the flat washer 85 fixed with the nut 84 prevents the upper part from falling off. A crimp terminal 86 fixed to a device-side lead wire (not shown) is fitted into the screw portion 82a. The crimp terminal 86 is composed of a flat washer 85 and a nut 8
4 between.

As shown in FIG. 5, each power receiving contact 82 has a stepped rod-shaped contact body having a nut 87 serving as a spring receiver fixed to the outer periphery of the upper end and having the screw portion 82a at the lower portion. A contact layer 89 made of cadmium silver oxide is provided on the upper end surface of the substrate 88. As the contact spring 83 for urging the power receiving contacts 82, a spring whose elastic force is weaker than the elastic force of the contact base pressing spring 76 is used.

The elevating body 24 of the electric elevating device having the above-described structure
In maintenance and inspection of the lighting fixture A connected to it,
As described above, both winding portions 26a, 26b of the winding drum 26
The wire rope 23 is lifted by winding the wire rope 23 at the same time.
At the same time.

Next, the operation when the elevating body 24 is raised and supported by the elevating apparatus main body 21 will be described in detail. As shown in FIG. 8, by lifting the suspended lifting body 24, the lifting body 24 first enters the inside of the holder 28 while being guided by the guide 71 of the lifting body holder 28. At this time, the lifting and lowering body 2, which is hung freely by the influence of the wind and the like because it is hung by the wire rope 23, is easily moved.
4 is displaced with respect to the contact stand 60 as shown in FIG.
As shown in (1), the lifting body 24 can be roughly positioned with respect to the lifting body holder 28.

As the lifting body 24 continues to rise, the lifting body 24
Are fitted between the stopper protrusions 63 facing each other in the width direction of the contact stand 60. In this fitting, even if the elevating body 24 is slightly displaced from the contact stand 60 as shown in FIG. Since the elevating body 24 is slightly rotated while sliding on the lower end of the portion 63, the elevating body 24 can be accurately positioned with respect to the contact stand 60 as shown in FIG.

As described above, the pair of fitting projections 78 of the elevating body 24 are smoothly fitted between the stopper projections 63 facing in the width direction of the contact base 60, so that the both side walls 6 of the contact base 60 are formed.
2 and the stopper protrusion 63 prevent the swinging and rotating of the elevating body 24 and prevent the elevating body 24 from moving in a direction orthogonal to the length direction of the side wall 62.
In the state of FIG. 12, the power receiving contact 82 contacts the power feeding contact 31.

Then, the lifting body 24 is further raised under the regulation conditions shown in FIG. 12, and the upper surface of the lifting body 24 is provided at two places of the contact stand 60 as shown in FIG.
At the same time, the outer peripheral surface of the elevating body 24 is engaged with the concave groove 64 side portion of the stopper projection 63. Therefore, movement of the elevating body 24 in the length direction of the side wall 62 is prevented. At the same time, the power receiving contact 82 moves downward against the contact spring 83 as the elevating body 24 rises, and
Is pressed against. Thereby, the lighting fixture A and the power supply are electrically connected. This state is shown in FIG.

While maintaining this electrical connection state, the elevating body 24 is raised while deflecting the contact base pressing spring 76 and pushing up the contact base 60. Then, when it is raised to a predetermined position, the locking surface 78 of the fitting projection 78 is
The engagement of the locking claw 73 with the a is performed, and the lifting body 24 is attached to and supported by the lifting device main body 21. At the same time, the elevating body 24 pushes the limit switch 77 by the above ascent,
The winding operation of the wire rope 23 by the motor 25, that is, the raising operation of the elevating body 24 is immediately stopped. This state is shown in FIGS.

As described above, the power receiving contact 82 can be pressed against the power supply contact 31 by accurately positioning the elevating body 24 with respect to the contact base 60 irrespective of the swing or the like at the time of ascent. Therefore, the mutual contact portion between the two contacts 31 and 82 can be reduced, and the cost of the contacts 31 and 82 can be reduced accordingly.

In addition, the upper surface of the elevating member 24 is brought into contact with the inner end surface 64a of the groove 64 by the side wall 62 serving as a stopper. Is not compressed, and this spring 83
Can be made constant. Then, after obtaining this constant amount of deflection, in other words, the limit switch 77 is pressed and the operation of the motor 25 is stopped with the contact pressures of the two contacts 31, 82 kept constant. Therefore, both contact points 31,
Since the contact pressure of the switch 82 is not affected by the variation of the mounting position of the limit switch 77 or the variation of the operation of the switch 77, the contact resistance between the two contacts 31 and 82 becomes large, and these contact portions become high temperature. There is no risk of burning.

The present invention is not limited to the above embodiment. For example, the lifting body holder 28 may be omitted. In this case, the upper end of the contact point pressing spring 83 may be fixed to the ceiling wall 22a and the lower end of the contact point pressing spring 83 may be fixed. Wire rope 2 braked at 25
3 is done. Also, contrary to the above-described embodiment, the power receiving contact 82 is attached to the elevating body 24 so as not to be able to move up and down.
The power supply contact 31 may be urged downward by a contact spring 83 while being attached to the contact base 60 so as to be movable up and down.

[0038]

As described above in detail, in the electric lifting device according to the present invention, the swing and rotation of the lifting member just before the end of the lifting, the movement of the lifting member in the length direction of the side wall of the contact stand, The lifting body can be positioned on the contact base by preventing movement of the lifting body in the direction perpendicular to the length direction of the side wall, so that the power supply contact and the power receiving contact can be securely contacted, and these can be reduced in size and The motor can be stopped by a switch that detects the lifting of the lifting body, while keeping the amount of bending of the contact spring constant by bringing the lifting body into contact with the deep end face of the concave groove. The contact pressure between the power supply contact and the power receiving contact by the contact spring can be kept constant without being affected by the variation in the mounting position, and the contact spring can be prevented from burning due to poor contact.

[Brief description of the drawings]

FIG. 1 is a perspective view of an electric lifting device according to an embodiment of the present invention in a state where a lifting body is separated from the lifting device main body;
Sectional drawing shown along a Z line.

FIG. 2 is a side view showing the electric lifting / lowering apparatus according to the same embodiment with its covers removed.

FIG. 3 is a diagram showing the electric lifting device according to the same embodiment, with its covers removed, looking up from the direction of arrow Y in FIG. 2;

FIG. 4 is a perspective view showing a lifting body main body and a contact mounting stand of the lifting body in the same embodiment separated from each other.

FIG. 5 is a sectional view showing a power supply contact and a power reception contact according to the same embodiment.

FIG. 6 is a perspective view showing a state in which the electric lifting device according to the same embodiment supports a lighting fixture.

FIG. 7 is a perspective view showing a contact stand according to the same embodiment.

FIG. 8 is a diagram schematically showing a state in which the lifting body is separated from the lifting device main body of the electric lifting device according to the same embodiment.

FIG. 9 is a diagram schematically showing a state in which a lifting body is supported by a lifting device main body of the electric lifting device according to the same embodiment.

FIG. 10 is a view schematically showing the electric lifting / lowering device according to the same embodiment as viewed from an arrow X direction in FIG. 9;

FIG. 11 is a view for explaining a contact positioning operation of the electric lifting device according to the same embodiment.

FIG. 12 is a view for explaining a contact positioning operation of the electric lifting device according to the same embodiment.

FIG. 13 is a view for explaining a contact positioning operation of the electric lifting device according to the same embodiment.

FIG. 14 is a diagram schematically showing a configuration of an electric lifting device.

FIG. 15 is a cross-sectional view showing a power supply contact and a power receiving contact of a conventional electric lifting device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 21 ... Electric lifting device, 22 ... Lifting device main body, 23 ... Wire rope, 24 ... Lifting body, 25 ... Motor, 26 ... Winding drum, 31 ... Feeding contact, 60 ... Contact stand, 61 ... Bottom wall, 6
2 ... side wall, 63 ... stopper protrusion, 64 ... concave groove, 76 ... contact base pressing spring, 77 ... limit switch, 82 ... power receiving contact, 83 ... contact spring, A ... lighting equipment (electric equipment).

Claims (1)

(57) [Claims] 1. A lifting / lowering apparatus main body provided with a motor for driving a winding drum which is disposed at a high position on the ceiling side and winds and rewinds a wire rope, and a plurality of main units provided on the main body and electrically connected to a power supply. A power contact, and a lifting / lowering body suspended from the wire rope and connected to and connected to an electric device,
An electric lifting / lowering device provided on the lifting / lowering body and having a plurality of power receiving contacts which are respectively connected to and separated from the respective power supply contacts and are electrically connected to the electric device, wherein the power supply contact is attached to the lifting / lowering device main body. A bottom wall, a pair of side walls projecting downward from the bottom wall and facing each other, and provided on the side walls so as to be separated from each other in the length direction thereof, and a part of the elevating body is fitted therebetween. A contact base formed with a pair of stopper protrusions having concave grooves formed therein, and urges the contact base downward by a contact base pressing spring; Providing a pair of fitting projections fitted between the opposed surfaces of the fitting projections, and providing an inclined surface on at least one of both ends in the longitudinal direction of the fitting projections and the lower end of the stopper projection. Contact point with less elastic force than the contact block pressing spring A spring for urging one of the power supply contact and the power receiving contact toward the other, and a switch for detecting the contact block and stopping the operation of the motor is attached to the lifting device main body. Electric lifting device.