Braking device

• US 9,120,644 B2
• Filed: 05/21/2010
• Issued: 09/01/2015
• Est. Priority Date: 05/21/2010
• Status: Active Grant

• Current Assignee: Otis Elevator Company (Otis Worldwide Corp.)
• Original Assignee: Otis Elevator Company (Otis Worldwide Corp.)
• Inventors: Piech, Zbigniew, Watson, Benjamin J.
• Primary Examiner(s): SALATA, ANTHONY J
• Application Number:
  US13/640,081
• Publication Number:
  US 20130025974A1
• Time in Patent Office: 1,929 Days
• Field of Search: 187/247, 187/288, 187/289, 187/290, 187/391, 187/393, 318362-372, 318/375, 318/376
• US Class Current: 1/1
• 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
• CPC Class Codes: B66B 5/02 responsive to abnormal operating conditions

Abstract

A braking device for an elevator is disclosed. The device may include a motor, a braking system, a first switch, and a second switch. The motor may be capable of generating a counter-electromotive force. The braking system may move to a disengaged position upon being energized and may move to an engaged position upon being de-energized. The first and second switches may have an open state. In the open state, the switches electrically couple the motor to the braking system so that the counter-electromotive force of the motor may energize the braking system.

Claims

1. A braking device for an elevator, comprising:

a motor capable of generating a counter-electromotive force;

a braking system having a disengaged and an engaged position, wherein the braking system moves to the disengaged position upon being energized and moves to the engaged position upon being de-energized; and

first and second switches having an open state, wherein in the open state, the first and second switches electrically couple the motor to the braking system, enabling the counter-electromotive force of the motor to energize the braking system.

2. The device of claim 1, further includes a motor driver capable of energizing the motor, and a brake driver capable of energizing the braking system.

3. The device of claim 2, wherein the first and second switches further include a closed state, wherein in the closed state, the first switch enables the motor driver to energize the motor and the second switch enables the brake driver to energize the braking system.

4. The device of claim 2, wherein the motor driver, the brake driver, the first switch, and the second switch are energized by a power supply.

5. The device of claim 1, wherein the motor is a permanent magnet motor.

6. The device of claim 1, wherein the braking system is an electromechanical braking system.

7. The device of claim 6, wherein the electromechanical braking system includes a brake coil, the brake coil disengages the braking system upon being energized and engages the braking system upon being deenergized.

8. The device of claim 1, wherein the first and second switches are electrically coupled to a power supply, whereupon the power supply deenergizes the first and second switches causes the first and second switches to transition into the open state.

9. The device of claim 1, wherein the first and second switches are electrically coupled to a safety chain, whereupon the safety chain signaling a malfunction mode to the first and second switches causes the first and second switches to transition into the open state.

10. The device of claim 1, wherein in the open state, the motor is electrically coupled to the braking system with a signal converter in between, the signal converter is capable of converting the counter-electromotive force of the motor to be in an acceptable format to be received by the braking system.

11. The device of claim 10, wherein the signal converter includes a transformer and a rectifier.

12. An elevator with a braking device, comprising:

an elevator car;

a motor associated with the elevator and capable of generating a counter-electromotive force;

a braking system operatively coupled to the motor and having a disengaged and an engaged position, wherein the disengaged position the motor is free to rotate and in the engaged position the motor is prohibited from rotating, the braking system moves to the disengaged position upon being energized and moves to the engaged position upon being de-energized;

a tension member operatively coupled to the motor and the elevator car, whereupon rotating the motor moves the elevator car; and

an electronic controller, including first and second switches having an open state, wherein in the open state, the first and second switches electrically couple the motor to the braking system, enabling the counter-electromotive force of the motor to energize the braking system.

13. The elevator of claim 12, wherein the electronic controller further includes a motor driver capable of energizing the motor, and a brake driver capable of energizing the braking system.

14. The elevator of claim 13, further includes a power supply electrically coupled to the electronic controller and capable of energizing the motor driver, the brake driver, first switch, and second switch.

15. The elevator of claim 13, wherein the first and second switches further include a closed state, wherein in the closed state, the first switch enables the motor driver to energize the motor and the second switch enables the brake driver to energize the braking system.

16. The elevator of claim 12, further includes a safety chain electrically coupled to the electronic controller and capable of providing a signal indicating a malfunction mode to the electronic controller, causing the first and second switches to transition into the open state.

17. The elevator of claim 12, wherein the motor is a permanent magnet motor.

18. A method for controlled stopping an elevator, comprising:

providing a motor capable of generating a counter-electromotive force;

providing a braking system having a disengaged and an engaged position, wherein the braking system moves to the disengaged position upon being energized and moves to the engaged position upon being de-energized;

electrically coupling the motor to the braking system;

creating a braking torque for the elevator from the counterelectromotive force of the motor;

energizing the braking system with the counter-electromotive force of the motor; and

releasing the braking system to the engaged position as the counterelectromotive force dissipates into the braking torque for the elevator.

19. The method of claim 18, wherein electrically coupling the motor to the braking system is performed by first and second switches transitioning into an open state, wherein in the open state, the first and second switches have a signal converter in between, the signal converter capable of converting the counter-electromotive force into an acceptable format to be received by the braking system.

20. The method of claim 18, wherein releasing the braking system to the engaged position is performed when the counter-electromotive force is insufficient to energize a brake coil in the braking system.