JPH0529035A - Motor-driven lifting device - Google Patents

Abstract

PURPOSE:To reduce wear due to an arc by covering mutual contacting surfaces between a feeding contact and a receiving contact with contacting layers of a silver cadmium oxide in such a manner that the thickness of the contacting layers on the feeding contact is larger than that on the receiving contact. CONSTITUTION:Contacting layers 62 and 82 are made of silver cadmium oxide; the thickness B of the layer 62 on a feeding contact 31 is designed to be larger than that C of the layer 82 on a receiving contact 73. The contact 73 contacts with the contact 31; the contact 73 is pushed and contacted with the contact to be connected to a power supply while moving downward against a spring 74. When the lifting of the illuminating equipment is performed without turning the power supply to a motor lifting device off, an arc takes place between the contacts accompanying the contacting and leaving between the contacts 31 and 73. But, since the layers 62 and 82 made of the silver cadmium oxide are resistive against the arc, the waste of the contacts 31 and 73 due to at arc can be reduced by the protecting action of the layers 62 and 82 so that the life of these contacts 62 and 82 can be enhanced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric lifting device for moving up and down a lighting device, a speaker, and other electric devices that are installed on a high ceiling such as a ceiling of a factory or a gym.

[0002]

2. Description of the Related Art FIG. 6 is a schematic view of an electric lifting device, and reference numeral 1 is a lifting device body installed on a high ceiling of a factory or a gym. The main body 1 is equipped with a motor 2 and a winding drum 4 that winds and unwinds the wire rope 3 that is normally and reversely rotated by the motor 2. The wire rope 3 is routed through a plurality of wire guides 5 and
An elevating body 7 to which the lighting fixture 6 is connected and supported is suspended. By winding and unwinding the rope 3 around the winding drum 4, the lighting fixture 6 is moved up and down at a slow speed, so that maintenance and inspection of the fixture 6 and the like can be easily performed.

A plurality of power feed contacts 15 are attached to a metal contact attachment plate 16 provided in the lifting device body 1.
That is, as shown in FIG.
The bush-shaped electric insulator 18 attached through a is penetrated. A crimp terminal 17b and a spring washer 17c are respectively fitted to the screw portion 15a of the contact 15, and a nut 19 is screwed. Crimp terminal 17b pressed against the power supply contact 15 by tightening the nut 19
Is connected to the power supply side lead wire.

The elevator 7 is provided with a plurality of power receiving contacts 9 which are urged upward and can move up and down. That is, as shown in detail in FIG. 7, the power receiving contact 9 penetrates through the metal top wall 7a of the lifting body 7 and vertically penetrates the bush-shaped electrical insulator 11 that is stopped by the snap ring 10a. The contact 9 is constantly biased upward by a spring 12 and is pulled upward by a flat washer 10b fitted to a screw portion 9a formed at the lower end of the power receiving contact 9 and fixed by a nut 13a. It has been stopped. The screw part 9a includes
A crimp terminal 14a attached to the tip of the device-side lead wire 14 of the lighting fixture 6 is fitted, and a spring washer 10c for sandwiching the terminal 14a with the nut 13a.
Are fitted. Further, the screw portion 9a has a nut 13
b is screwed, and the crimping terminal 14a is pressed against the power receiving contact 9 by tightening, and the contact 9 and the lighting fixture 6 are electrically connected.

The power receiving contacts 9 are provided in the main body 1 when the lifting body 7 is placed in the raised position, in other words, when the lifting body 7 is supported by the lifting device main body 1, the plurality of power feeding contacts 15 connected to the power source. Are contacted separately. At that time, the power receiving contact 9 is pushed down against the spring 12, so that the contacts 9 and 15 are pressed against each other. Further, when the lifting / lowering 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 spring 12.

Each of the contacts 9 and 15 is made of a material having copper or a copper alloy as a base material, and a silver or nickel plating layer is provided on the tip surface, that is, the contact surface, The contact resistance is reduced.

[0007]

In the structure of the above-described electric lifting device, it is conceivable that the lighting fixture 6 may be raised or lowered by mistake without turning off the power supply. In such a case, an arc is generated between the power feeding contact 15 and the power receiving contact 9 that come in contact with and separate from each other due to the slow moving speed of the lighting fixture 6. By the way, in the case of the luminaire 6 including a mercury lamp of 1 KW, for example, a lamp driving voltage of 7 to 8 KV is given as a pulse, and an arc is easily generated.

Due to the arc thus generated, both contacts 9 and 15 are consumed early and their service lives are short, so that there is a problem that maintenance / inspection of the electric lifting device is frequent. In this work, in particular, since the power feeding contact 15 is provided in the lifting / lowering device main body 1 installed at a high place on the ceiling side, unlike the power receiving contact 9 mounted on the lifting / lowering body 7, the maintenance / inspection work is performed. It was extremely difficult, and the improvement was desired.

An object of the present invention is to elevate the elevator body so that the service life of the power supply contact and the power receiving contact, which come into contact with and separate from each other, can be improved, and the frequency of troublesome maintenance / inspection at a ceiling-side high place can be reduced. To get the equipment.

[0010]

In order to achieve the above object, the electric lifting device of the present invention is wound and unwound on a winding drum provided in a lifting device body arranged at a high place on the ceiling side. The mutual contact surfaces of the power receiving contact provided on the lifting body suspended via the wire rope and the power feeding contact provided on the main body and coming into contact with and separated from the power receiving contact are each covered with a contact layer of cadmium silver oxide. The thickness of the contact layer of the power feeding contact is made larger than the thickness of the contact layer of the power receiving contact.

[0011]

According to the above construction, since the contact layer of silver cadmium oxide has a strong property against arcs, this contact layer can reduce the abrasion of the power supply contact and the power reception contact due to the arc generation. Since the thickness of the contact layer of the power feeding contact is made larger than the thickness of the contact layer of the power receiving contact, the contact life of the arc can be made longer than that of the power receiving contact.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described below with reference to FIGS. The electric lifting device 21 shown in FIGS.
The lifting / lowering device main body 22 and a lifting / lowering body 24 which is suspended below the main body 22 via a wire rope 23 and which is lifted / lowered at the time of maintenance / inspection are provided. The lifting / lowering device main body 22 is arranged at a high place on the ceiling side such as a gym. As shown in FIG. 5, a lighting fixture A is connected to and supported by the lift 24. This fixture A is equipped with a mercury lamp (not shown) which is turned on when a lamp driving voltage is applied as a pulse.

A motor 25 and a winding drum 26, which is rotated forward and backward by the motor 25, are fixed to the lifting / lowering device body 22. The motor 25 has a non-excitation actuated electromagnetic brake and a deceleration portion. A winding drum 26 is connected to the output end of the deceleration portion. As shown in FIG. 4, the drum 26 has a first winding portion 26a and a second winding portion 26b partitioned by a separator 27.

An elevating body holder 28 for supporting the elevating body 24 from being accidentally dropped is fixed to the elevating device body 22. The holder 28 has a rotatable locking claw 29 that engages with and disengages from a pair of locking step portions 24 a formed on the outer periphery of the elevating body 24, and a coil spring 30 that urges the claw 29.

The locking claw 29 is, as shown in FIG.
4a is engaged diagonally from the lower side to raise and lower the body 24.
The coil spring 30 is bent in this state. Therefore, when the elevating body 24 is moved further upward so that the tip of the locking claw 29 comes to face the lower peripheral surface 24b of the elevating body 24, at that time, the lower peripheral surface 24b.
The locking claw 29 is pivoted downward by the force of the coil spring 30 due to the difference in the radial position between the locking step portion 24a and the locking step portion 24a, which obstructs the downward movement of the elevating body 24. It will not happen.

1 to 4, reference numeral 60 designates a lifting body holder 28.
A contact mounting plate made of a synthetic resin such as PBT (polybutylene terephthalate) having a high heat resistance, which is disposed on the inner side of the contact mounting plate, in which a contact layer 62 is provided on a contact body 61. The power feeding contact 31 is attached as described below. As shown in detail in FIG. 1, the contact body 61 is
A head portion 61b having a larger diameter and a circular shape than the body portion 61a is provided at one end of the body portion 61a, and a screw portion 61c having a diameter smaller than that of the body portion 61a is provided at the other end. .. The contact body 61 is made of copper or copper alloy.

The contact layer 62 contains 10% cadmium with respect to silver.
It is formed of silver cadmium oxide added before and after, which is attached by brazing or spot welding so as to cover the tip surface of the head portion 61b. This contact layer 62
Has a thickness B (see FIG. 1) larger than a thickness C (see FIG. 1) of the contact layer 82 of the power receiving contact 73 described later. The thickness B is preferably 1.5 times or more the thickness C, and is about twice the thickness in this embodiment.

The body portion 61a of each of the power feeding contacts 31 penetrates a mounting hole 60a formed in the contact mounting plate 60. A crimp terminal 63 and a spring washer 64 are fitted to the screw portion 61c, respectively, and a nut 65 is screwed. By tightening the nut 65, the power supply contact 31
Are fixed to the contact mounting plate 60. The crimp terminal 63 pressed against the power supply contact 31 is connected to the tip of a power supply side lead wire (not shown) connected to the power supply.

The contact mounting plate 60 and the lifting device body 2
A plurality of coil springs 66 are provided between the second ceiling wall 22a and the second ceiling wall 22a.
(See FIG. 4) is attached, and the elevating body 24 supported by the locking claw 29 is pressed downward by its spring force so that the elevating body 24 does not move accidentally.

In FIGS. 3 and 4, reference numeral 32 is 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, and 36 is a wire rope 2.
3 is a detection device for detecting tension and looseness, and is fixed to a pair of seesaw levers 38 urged by a spring 37 and a base 39 pivotally supporting the levers 38, and is turned on / off by the seesaw lever 38. And a switch 40.

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

First, second and fifth wire guides 4
1, 42 and 45 are horizontal ceiling walls 22 of the lifting device body 22.
The third and fourth wire guides 43 and 44 are mounted vertically along the outer surface of the vertical side wall of the lifting body holder 28 while being mounted in such a posture as to follow a.

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

That is, as shown in FIG. 4, the end portion of the wire rope 23 extends from the first winding portion 26a to the detecting device 3a.
The first to third wire guides 41 to 43 are sequentially passed through one of the seesaw levers 38 of 6, and the other end side portion of the wire rope 23 extends from the second winding section 26b to the other side of the detection device 36. 5th and 4th through the seesaw lever 38 of
The wire guides 45 and 44 are successively wound around. Further, an intermediate portion of the wire rope 23 located between the third and fourth wire guides 43, 44 is stretched over a pair of rotatable guide pulleys 46 (see FIG. 3) built in the lifting body 24.

Therefore, both winding parts 2 of the winding drum 26 are
The wire rope 23 is simultaneously wound around 6a and 26b, so that the elevating body 24 is raised, and conversely, both winding portions 2
When the wire rope 23 is simultaneously unwound on the 6a and 26b, the elevating body 24 is lowered. In addition, the lifting body 2
In the final stage of the ascending of 4, the locking claw 29 is automatically engaged with the locking step portion 24a, and the lifting body 24 is lifted by the lifting device body 22.
Mechanically supported by. When the descent is started, the descent operation is first performed after the elevating body 24 is slightly raised until the locking claw 29 faces the lower peripheral surface 24b of the elevating body 24.

As shown in FIG. 2, the lifting / lowering body 24 is made of a metal having a short cylindrical shape with both upper and lower ends opened.
1, a contact mounting base 52 made of synthetic resin such as PBT having a high heat resistance with the upper end opening closed, and a synthetic resin bottom cover 5 attached with the lower end opening of the elevator body 51 closed.
3 and 3. A pair of notch grooves (not shown) are provided in the peripheral portion of the contact mount 52, and the wire rope 23 hung on the pulley 46 is passed through these notch grooves.

The contact mount 52 has a plurality of thick portions 52a.
Each of these portions 52a has a guide hole 72 (see FIG. 1) penetrating in the vertical direction. A power receiving contact 73 that comes in contact with and separates from the power feeding contact 31 is penetratingly supported in the hole 72 so as to be vertically slidable. The contact 73 is constantly urged upward by a coiled spring 74, and is fitted to a screw portion 81a formed in the lower end portion of the power receiving contact 73 with a diameter smaller than that of the upper portion thereof as shown in FIG. A flat washer 76 fixed with a nut 75 prevents the upper washer from coming off. A crimp terminal 77 fixed to a device-side lead wire (not shown) is fitted to the screw portion 81a. This crimp terminal 77 is a flat washer 76 and a nut 75.
It is sandwiched between and.

As shown in FIG. 1, each power receiving contact 73 has a stepped rod-shaped contact body in which a nut 78 serving as a spring receiver is fixed to the outer periphery of the upper end portion and the screw portion 81a is provided on the lower portion. 81 and a contact layer 82 covering the upper end surface of the main body 81. The contact body 81 is made of copper or a copper alloy. The contact layer 82 is made of cadmium silver oxide, which is similar to that of the feeding contact 31, and is attached by brazing or spot welding.

The lifting body 24 of the electric lifting device having the above-mentioned structure is
For maintenance and inspection of the lighting equipment A connected to it,
As described above, both winding portions 26a and 26b of the winding drum 26 are provided.
The wire rope 23 is lifted up by simultaneously winding the wire rope 23 around it, and conversely, the wire rope 23 is wound around the winding portions 26a and 26b.
It is lowered by rewinding at the same time.

When the elevating body 24 is raised and held in engagement with the elevating device body 21, the power receiving contact 73 contacts the power feeding contact 31, and the power receiving contact 73 moves downward against the spring 74. While being pressed against the power supply contact 31. Thereby, the lighting fixture A and the power supply are electrically connected. In addition,
The pressure contact is strengthened by not only the biasing force of the spring 74 but also the biasing force of the coil spring 66 that biases the contact attachment plate 50 downward. Also, when the lifting body 24 descends,
The power receiving contact 73 is separated from the power supplying contact 31, the lighting fixture A is disconnected from the power source, and the power receiving contact 73 is separated from the spring 74.
Pushed up by.

By the way, when the lighting fixture A is raised and lowered as described above without supplying power to the electric lifting device, the power receiving contact 73 is separated from the power feeding contact 31 and both of them are connected. An arc is generated between the contacts 31 and 73.

However, since the contact layers 62 and 82 made of silver cadmium oxide covering the mutual contact surfaces of the contacts 31 and 73 have a strong arc resistance property, the contact layers 62 and 8 are formed.
By the protection effect of 2, the wear of the power feeding contact 31 and the power receiving contact 73 due to the arc is reduced, and these contacts 62, 8
The life of 2 can be improved. Therefore, the interval between the periodic inspections of the electric lifting device, which is determined based on the consumption of both contacts 31, 73, can be lengthened, and the number of maintenances can be reduced.

Further, the thickness B of the contact layer 62 of the power supply contact 31 provided on the lifting / lowering device main body 21 installed at a high place on the ceiling side.
By about twice the thickness C of the contact layer 82 of the power receiving contact 73, the life of both contacts 31, 73 due to the arc is
The feeding contact 31 can be made longer than the receiving contact 73. Therefore, it is possible to reduce the frequency of troublesome maintenance and inspection work at a high place on the ceiling side.

Moreover, in this embodiment, both contacts 31, 73 are
Since the mounting parts are formed by the contact mounting plate 60 or the contact mounting base 52 each made of a heat-resistant synthetic resin, the parts for insulation and the mounting thereof are different from the conventional ones in which these mounting parts are made of metal. The parts can be omitted, and the structure and assembly of the contact portion can be simplified. In addition, as described above, since the contact points 31 and 73 are less likely to be worn by the arc, the contact points 3 of carbon and oxide are accordingly reduced.
Adhesion to 1, 73 is small, and an increase in contact resistance during conduction can be prevented. Therefore, it is possible to prevent both the contacts 31, 73 from becoming hot. In the conventional configuration shown in FIG. 7, when the electric insulators 11 and 18 are synthetic resin,
By heating from the contacts 31 and 73 which become high temperature due to the increase in contact resistance, the insulators 11 and 18 around them are melted,
Although there is a risk of insulation failure, such a risk of burning does not occur in this embodiment.

The present invention is not limited to the above-described embodiment. The power receiving contact 73 is fixed so as not to move up and down, the power feeding contact 31 is attached so as to move up and down, and the spring is urged downward by a spring. You may attach it. The present invention can also be applied to an electric lifting device in which both contacts are attached to a metal component via an electrical insulator (including an insulator) as in the conventional example shown in FIG.

[0036]

As described above in detail, in the electric lifting apparatus of the present invention, the contact surfaces of the power feeding contact and the power receiving contact which are contacted and separated from each other are covered by the contact layer of silver cadmium oxide having a strong arc resistance. As a result, the wear of the power supply contact and the power reception contact due to the arc can be reduced, the life of these contacts can be improved, and the thickness of the contact contact layer of the power supply contact can be made larger than the contact contact The life of the power supply contact can be made longer than that of the power receiving contact, and the frequency of troublesome maintenance and inspection work at high places on the ceiling can be reduced.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a power feeding contact and a power receiving contact of an electric lifting device according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing the electric lifting device according to the same embodiment taken along the line ZZ in FIG. 4 in a state where the lifting body is separated from the lifting device body.

FIG. 3 is a side view showing an electric lifting device according to the same embodiment with its covers removed.

FIG. 4 is a diagram showing an electric lifting device according to the same embodiment, with its covers removed, looking up from the direction of arrow Y in FIG.

FIG. 5 is a perspective view showing a state in which the electric lifting device according to the same embodiment supports a lighting fixture.

FIG. 6 is a diagram schematically showing a configuration of an electric lifting device.

FIG. 7 is a cross-sectional view showing a power feeding contact and a power receiving contact of a conventional electric lifting device.

[Explanation 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, 62, 82 ... Contact layer, 73 ... Power receiving contact, A … Lighting equipment (electrical equipment).

Claims (1)

Claim: What is claimed is: 1. A lifting device main body provided with a motor for driving a winding drum for winding and rewinding a wire rope, which is arranged at a high place on the ceiling side, and a power supply provided in the main body. A plurality of power supply contacts electrically connected, and an elevating body that is suspended by the wire rope and that is elevated by connecting an electric device,
In an electric lifting device having a plurality of power receiving contacts which are provided on the lifting body and are respectively brought into contact with and separated from each of the power feeding contacts and electrically connected to the electric device, the mutual contact surfaces of the both contacts are made of silver cadmium oxide. The electric lifting device is characterized in that the thickness of the contact layer of the power feeding contact is larger than the thickness of the contact layer of the power receiving contact.