JPH0845332A - Lifting device for lighting equipment - Google Patents

Abstract

(57) [Summary] (Correction) [Purpose] To provide a lifting device for lighting fixtures without the risk of incorrect wiring. [Structure] Synchronous motor 5 that drives a drum that winds a wire that is connected to an AC power supply 1 and that suspends a lighting fixture.
And an elevating switch 2 arranged between the AC power supply and the synchronous motor to turn ON / OFF the supply of electric power to the synchronous motor.
A timer 6 that is powered by an AC power supply and that operates when the lift switch is turned on; a relay contact that is operated by this timer; and a slack detection limit switch 8
And a top dead center detection limit switch 9, and the slack detection limit switch 8 and the top dead center detection limit switch 9 are connected in series to the synchronous motor 5, and the relay contact of the timer 6 is connected in parallel to this series circuit. Lift switch 2
When is turned on, the timer 6 operates and its relay contact closes to form a bypass circuit, which temporarily invalidates the operation of the slack detection limit switch 8 and the top dead center detection limit switch 9.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lifting device for lighting equipment.

[0002]

2. Description of the Prior Art Lighting equipment used in facilities with high ceilings such as gymnasiums, warehouses, and event halls is provided with a lifting device so that the lighting equipment can be lowered to the floor when changing lamps. There is. As shown in FIG. 2, for example, the lifting device includes a fixing portion 14 mounted on the ceiling and a lighting device 15, and the fixing portion 14 suspends the lighting device 15 from the wire 1.
6, a drum 17 for winding the wire, and a motor 18 for driving the drum.

As the motor 18, conventionally, an induction motor capable of forward and reverse rotation is used. As shown in FIG. 5, this lifting device has a circuit configuration using three operation lines.
That is, 20 is an AC power source, 21 is a select switch, 22 is a terminal block, 23 is a slack detection limit switch, and 24 is a top dead center detection limit switch. The slack detection limit switch 23 and the top dead center detection limit switch 24 are normally closed.

When the select switch 21 is put in the descending side a, the motor 18 rotates in the normal direction, the wire 16 is paid out from the drum 17, and the luminaire 15 starts descending as shown in FIG. As shown in FIG. 4, when the lighting fixture 15 is attached to the floor 19, the wire 16 sags, the slack detection limit switch 23 opens, and the motor 18 stops.

After the lamp replacement, select switch 2
When 1 is put in the ascending side b, the motor 18 reversely rotates, the drum 17 winds up the wire 16, and the lighting fixture 15 ascends.
When the luminaire reaches the top dead center as shown in FIG. 2, the contact point 15a of the luminaire 15 and the contact point 14a of the lifting device 14 come into contact with each other, the top dead center detection limit switch 24 is opened, and the motor 18 is stopped.

[0006]

However, since the circuit of such a conventional lifting device is of the three-wire type, there is a drawback that incorrect wiring may occur during installation work.

It is an object of the present invention to provide a lifting device for lighting equipment which is free from the risk of incorrect wiring.

[0008]

SUMMARY OF THE INVENTION In a lifting device for lighting equipment according to the present invention, a synchronous motor for driving a drum that winds a wire that is connected to an AC power supply and suspends the lighting equipment, and an AC power supply and a synchronous motor are provided. An elevating switch that is arranged between the ON / OFF switches to turn ON / OFF the power supply to the synchronous motor,
A timer that is powered by an AC power supply and that operates when the up / down switch is turned on, a relay contact that operates by this timer, and a slack in the wire that occurs when the lighting fixture touches the floor when the lighting fixture descends Equipped with a slack detection limit switch that stops the supply of power to the above, and a top dead center detection limit switch that operates when the luminaire rises and reaches top dead center when the luminaire rises, and that stops the supply of power to the synchronous motor. However, the slack detection limit switch and the top dead center detection limit switch are connected in series to the synchronous motor, and the relay contact of the timer is connected in parallel to this series circuit. The contact is closed to form a bypass circuit, and the slack detection limit switch and top dead center detection limit switch are temporarily It is configured to disable operation.

[0009]

When the luminaire is lowered, the luminaire is at the top dead center and the top dead center detection limit switch is activated so that power is not normally supplied to the synchronous motor, but the lift switch is turned off.
When it is N, the timer operates to close the relay contact and form a bypass circuit in parallel with the top dead center detection limit switch, so that power is supplied to the synchronous motor regardless of the operation of the top dead center detection limit switch. . Therefore, the synchronous motor tries to rotate in the forward direction, but the lighting fixture is at the top dead center and cannot rotate in the forward rotation direction. The synchronous motor starts rotating in the opposite direction, the luminaire begins to descend, and the descent of the luminaire closes the top dead center detection limit switch. After that, the relay contact opens, but the top dead center detection limit switch is already closed, so that power to the synchronous motor is continuously supplied through the circuit of the top dead center detection limit switch.

When the lighting fixture descends and reaches the floor, the wire is slackened, and the slack detection limit switch is activated by opening the slack and the power is stopped from being supplied to the synchronous motor. Then turn off the lift switch. The timer is reset when the lift switch is turned off.

When the luminaire is raised, the slack detection limit switch of the luminaire operates and power is not normally supplied to the synchronous motor, but when the up / down switch is turned on, the timer operates to close the relay contact. By forming a bypass circuit in parallel with the slack detection limit switch,
Power is supplied to the synchronous motor regardless of the operation of the slack detection limit switch. Therefore, the synchronous motor rotates forward and the luminaire moves up. When the luminaire rises and the top dead center detection limit switch is activated, the power supply to the synchronous motor is stopped. After that, when the lift switch is turned off, the timer is reset.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In FIG. 1, 1 is an AC power source, 2 is a lifting switch, and 3 is a fixed part of a lifting device. Inside the fixed portion 3, the terminal block 4, the motor 5, the timer 6, the relay contact 7 of the timer,
A slack detection limit switch 8 and a top dead center detection limit switch 9 are arranged. The motor 5 is a synchronous motor, and is connected to the AC power source 1 in parallel with the timer 6. The sagging detection limit switch 8 and the top dead center detection limit switch 9 are connected in series, and the series circuit is connected to the motor 5 in series. In addition, the timer relay contact 7
The sagging detection limit switch 8 and the top dead center detection limit switch 9 are connected in parallel with a series circuit. It should be noted that the timer 6 may be arranged at any location as long as the power is supplied from the AC power supply 1 without being affected by the slack detection limit switch 8 and the top dead center detection limit switch 9.

The motor 5 is wired so that the normal rotation direction thereof is the upward direction of the lighting fixture. The slack detection limit switch 8 is normally closed, and when the luminaire is lowered, the slack detection limit switch 8 opens when the wire hanging around the floor slackens to stop the motor 5. The top dead center detection limit switch 9 is normally closed, and the wire that suspends the luminaire when the luminaire is raised is wound around the drum, and when the luminaire reaches the top dead center, it is opened and the motor 5 is stopped.

When lowering the lighting fixture for lamp replacement, as shown in FIG. 2, the lighting fixture is at the top dead center and the top dead center detection limit switch 9 is open, but the lifting switch 2 is turned on (closed). ), The timer 6 is turned on, the relay contact 7 is closed, a bypass circuit is formed, and the motor 5 starts forward rotation. The motor 5, which is a synchronous motor, originally can only perform normal rotation, but the synchronous motor has a phenomenon in which the rotation is reversed at the time when a force greater than the maximum torque of the motor itself is applied in the reverse direction. The descent starts, and the top dead center detection limit switch 9 is closed.

The timer 6 opens its relay contact 7 after a set time (for example, 1 to 3 seconds). Since the top dead center detection limit switch 9 is already closed at that time, the current switches to the flow through the series circuit of the slack detection limit switch 8 and the top dead center detection limit switch 9, and the lighting fixture continues to descend.

As shown in FIG. 4, when the luminaire continues to descend and reaches the floor, the wire that suspends the luminaire sags, and the slack detection limit switch 8 opens to stop the motor 5. When the lift switch 2 is turned off (open), the timer 6 is reset.

Next, when the lamp replacement is completed and the elevating switch 2 is turned on (closed), the timer 6 is turned on to start the operation,
The relay contact 7 closes. At that time, the slack detection limit switch 8 is open, but the relay contact 7 is closed, so that a bypass circuit is formed and a current flows through the bypass circuit, the motor 5 starts forward rotation, and the lighting fixture starts rising. .
When the luminaire starts to rise and the slack of the wire is removed, the slack detection limit switch 8 is closed.

The timer 6 opens its relay contact 7 after a set time (for example, 1 to 3 seconds). Since the slack detection limit switch 8 is already closed at that time, the current switches to the flow through the series circuit of the slack detection limit switch 8 and the top dead center detection limit switch 9, and the lighting fixture continues to rise.

When the luminaire continues to rise and reaches the top dead center as shown in FIG. 2, the top dead center detection limit switch 8 is opened and the motor 5 is stopped. When the lift switch 2 is turned off (open), the timer 6 is reset.

[0020]

INDUSTRIAL APPLICABILITY The present invention utilizes the reverse rotation phenomenon of a synchronous motor in which it reversely rotates when a force exceeding the maximum torque is applied, and the detection limit switch and the top dead center detection limit switch are temporarily operated by a timer and its relay contact. By forming the bypass circuit of and supplying electric power to the synchronous motor regardless of the operation of the detection limit switch and the top dead center detection limit switch, it is possible to do with 2-wire wiring There is also no merit that there is no possibility of incorrect wiring because there is no lowering, and there is an advantage that the construction is easy and the construction time can be shortened.

[Brief description of drawings]

FIG. 1 is a circuit diagram of an embodiment of a lifting device for lighting equipment according to the present invention.

FIG. 2 is a diagram showing a state in which the lighting equipment is at top dead center.

FIG. 3 is a diagram showing a state in which the lighting fixture is being lowered.

FIG. 4 is a diagram showing a state in which a lighting fixture is on the floor.

FIG. 5 is a circuit diagram of a conventional lifting device for lighting equipment.

[Explanation of symbols]

 1 AC power supply 2 Lift switch 3 Fixed part of lifting device 4 Terminal block 5 Synchronous motor 6 Timer 7 Timer relay contact 8 Slack detection limit switch 9 Top dead center detection limit switch

Claims (1)

[Claims] 1. A synchronous motor that drives a drum that winds a wire that is connected to an AC power supply and that suspends a lighting fixture; and a synchronous motor that is arranged between the AC power supply and the synchronous motor to turn on power to the synchronous motor. A lift switch that turns off,
A timer that is powered by an AC power supply and that operates when the up / down switch is turned on, a relay contact that operates by this timer, and a slack in the wire that occurs when the lighting fixture touches the floor when the lighting fixture descends Equipped with a slack detection limit switch that stops the supply of power to the above, and a top dead center detection limit switch that operates when the luminaire rises and reaches top dead center when the luminaire rises, and that stops the supply of power to the synchronous motor. However, the slack detection limit switch and the top dead center detection limit switch are connected in series to the synchronous motor, and the relay contact of the timer is connected in parallel to this series circuit. The contact is closed to form a bypass circuit, and the slack detection limit switch and top dead center detection limit switch are temporarily Lifting device for lighting equipment, characterized in that disabling the operation.