Brake control apparatus with auxiliary power source means

• US 6,311,801 B1
• Filed: 05/03/2000
• Issued: 11/06/2001
• Est. Priority Date: 01/25/1999
• Status: Expired due to Fees

• Current Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation), Mitsubishi Kenki Kabushiki Kaisha
• Original Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Inventors: Takagi, Hiroyuki, Yamakawa, Shigeki
• Primary Examiner(s): Salata, Jonathan
• Application Number:
  US09/564,478
• Time in Patent Office: 552 Days
• Field of Search: 187/290, 187/291, 187/288, 187/207, 187/296, 307/64, 307/66
• US Class Current: 187/290
• CPC Class Codes: B66B 1/32 effective on braking devices , e.g. acting on electrically controlled brakes brake control H02P, lift brakes per se B66B5/02

Abstract

A brake control apparatus for an elevator includes an auxiliary power source for storing energy for driving a brake coil of an electromagnetic brake upon release of a brake wheel. A DC voltage is boosted only when the brake is released, and the voltage-boosting function ceases when the brake is held in a released condition. This brake control apparatus for an elevator uses a lower voltage and only one DC power source and immediately supplies the necessary energy to the brake coil to release the brake independently of the power source voltage at the time.

Claims

1. A brake control apparatus for an elevator, comprising:

control means for controlling raising and lowering of an elevator cage;

brake means, having a brake wheel on a rotary shaft of a drive motor of a hoisting machine for raising and lowering the elevator cage, for braking rotation of the drive motor by clamping the brake wheel with a lining attached to a plunger biased by a spring, and releasing the brake wheel by retracting the plunger against force of the spring by supplying energy to a brake coil wound around the plunger;

brake releasing means for exciting the brake coil by supplying energy to the brake coil based on an instruction from the control means to release the brake wheel; and

auxilary power source means for storing energy for driving the brake coil, and exciting the brake coil by supplying stored energy to said brake releasing means upon release of the brake wheel.

2. The brake control apparatus for an elevator according to claim 1, wherein the auxiliary power source means supplies the energy, which is stored prior to the release of the brake wheel, to the brake means upon the release of the brake wheel by exciting the brake coil, thereby retracting the plunger and releasing the brake wheel.

3. The brake control apparatus for an elevator according to claim 1, wherein the auxiliary power source means supplies energy to the brake coil in response to a brake release instruction upon the release of the brake wheel, and the brake releasing means supplies energy to the brake coil after the brake wheel is released, subsequent to the brake release instruction, to maintain the release of the brake wheel.

4. The brake control apparatus for an elevator according to claim 3, further comprising a release detector for detecting the release of the brake wheel, wherein energy is supplied to the brake coil from the auxiliary power source means from a time point at which the brake release instruction is outputted to excite the brake coil until a time point when the release detector detects the release of the brake wheel.

5. The brake control apparatus for an elevator according to claim 1, wherein the auxiliary power source means includes voltage boosting means for boosting a power source voltage, and a condenser charged by the voltage boosted by the voltage boosting means, and wherein a current based on the boosted voltage of the condenser and a current provided by the voltage boosting means are supplied to the brake coil.

6. The brake control apparatus for an elevator according to claim 1, wherein the auxiliary power source means applies a first boosted voltage to the brake coil upon the release of the brake wheel, and applies a second voltage, lower than the first voltage, to the brake coil in sustaining the brake release.

7. A brake control apparatus for an elevator, comprising:

control means for controlling raising and lowering of an elevator cage;

brake means, having a brake wheel on a rotary shaft of a drive motor of a hoisting machine for raising and lowering the elevator cage, for braking rotation of the drive motor by clamping the brake wheel with a lining attached to a plunger biased by a spring, and releasing the brake wheel by retracting the plunger against force of the spring by supplying energy to a brake coil wound around the plunger;

brake releasing means for releasing the brake wheel by exciting the brake coil;

a brake power source connected to the brake releasing means through a contact that is closed based on a brake release instruction, the brake power source including auxiliary power source means for boosting a power source voltage to be supplied; and

voltage boosting instruction means for instructing the brake power source to supply the voltage-boosted power source voltage to the brake releasing means from a time point when the brake release instruction is outputted so that the brake is activated until the brake is released.

8. The brake control apparatus for an elevator according to claim 7, wherein the auxiliary power source means applies a first boosted voltage to the brake coil upon the release of the brake wheel, and applies a second voltage, lower than the first boosted voltage, to the brake coil when the brake release is sustained.