Electromagnetic brake configured to slow deceleration rate of passenger conveyer during braking

Patent metadata

Field	Value
Publication number	US-12110207-B2
Application number	US-201916683328-A
Country	US
Kind code	B2
Filing date	Nov 14, 2019
Priority date	Nov 14, 2019
Publication date	Oct 8, 2024
Grant date	Oct 8, 2024

Abstract

This disclosure relates to an electromagnetic brake configured to slow a deceleration rate of a passenger conveyer, such as an elevator car, during braking. In particular, this disclosure relates to a passenger conveyer system including the electromagnetic brake and a corresponding method. An example system includes a controller and an electromagnetic brake. The electromagnetic brake includes a disc configured to interface with a drive shaft, a spring, and a plate biased in a first direction into engagement with the disc by a bias force of the spring. The electromagnetic brake further includes an electromagnet selectively activated in response to a command from the controller to produce a magnetic field attracting the plate in a second direction opposite the first direction to partially offset the bias force of the spring. Further, when the electromagnet is activated, the plate engages the disc.

First claim

The invention claimed is:

1. A passenger conveyer system, comprising:
a controller;
an electromagnetic brake, the electromagnetic brake comprising:
a disc configured to interface with a drive shaft;
a spring;
a plate biased in a first direction into engagement with the disc by a bias force of the spring;
an electromagnet selectively activated in response to a command from the controller to produce a magnetic field attracting the plate in a second direction opposite the first direction to partially offset the bias force of the spring, such that when the electromagnet is activated the plate engages the disc.

2. The passenger conveyer system as recited in claim 1 , wherein the electromagnet is a secondary electromagnet, and wherein the electromagnetic brake further comprises:
a primary electromagnet selectively activated in response to a command from the controller to produce a magnetic field attracting the plate in the second direction and sufficient to overcome the bias force of the spring, such that when the primary electromagnet is activated the plate moves in the second direction and out of engagement with the disc.

3. The passenger conveyer system as recited in claim 2 , wherein the primary and secondary electromagnets include a respective primary coil and a secondary coil.

4. The passenger conveyer system as recited in claim 3 , wherein the primary and secondary coils are arranged circumferentially about a central axis of the electromagnetic brake, and the primary coil radially surrounds the secondary coil.

5. The passenger conveyer system as recited in claim 3 , wherein:
the primary electromagnet includes a primary power supply electronically connected to the primary coil, and
the secondary electromagnet includes a secondary power supply electronically connected to the secondary coil.

6. The passenger conveyer system as recited in claim 5 , wherein a level of current flowing through the secondary coil is adjustable.

7. The passenger conveyer system as recited in claim 6 , wherein the controller issues a command to the secondary power supply to adjust the level of current flowing through the secondary coil based on a weight within an elevator car.

8. The passenger conveyer system as recited in claim 6 , wherein the controller issues a command to the secondary power supply to adjust the level of current flowing through the secondary coil based on a deceleration rate of an elevator car.

9. The passenger conveyer system as recited in claim 5 , wherein the level of current flowing through the secondary coil produces a magnetic field that offsets between 20-30% of the bias force of the spring on the plate.

10. The passenger conveyer system as recited in claim 1 , wherein activation of the electromagnet alone does not result in movement of the plate in the second direction.

11. The passenger conveyer system as recited in claim 1 , further comprising:
an electric motor;
a drive shaft mechanically connected to the electric motor; and
an elevator car suspended from at least one suspension member wrapped around the drive shaft.

12. The passenger conveyer system as recited in claim 11 , wherein the electromagnet is activated when slippage of the at least one suspension member is detected.

13. The passenger conveyer system as recited in claim 1 , wherein the plate includes a brake pad configured to directly contact the disc.

14. The passenger conveyer system as recited in claim 1 , wherein the passenger conveyer system is an elevator system.

15. A method, comprising:
slowing a deceleration rate of an elevator car when an electromagnetic brake is engaged by activating an electromagnet to partially offset a bias force of a spring, wherein the slowing step includes adjusting a level of current flowing through a coil of the electromagnet based on either (i) the deceleration rate of the elevator car or (ii) a weight of a load within the elevator car.

16. The method as recited in claim 15 , wherein:
the spring is configured to urge a plate into engagement with a disc, and
the disc is interfaced with a drive shaft,
the elevator car is suspended from at least one suspension member wrapped around the drive shaft.

17. A method, comprising:
slowing a deceleration rate of an elevator car when an electromagnetic brake is engaged by activating an electromagnet to partially offset a bias force of a spring, wherein the spring is configured to urge a plate into engagement with a disc, wherein the disc is interfaced with a drive shaft, wherein the elevator car is suspended from at least one suspension member wrapped around the drive shaft, and wherein the slowing step occurs in response to slippage of the at least one suspension member.

18. The method as recited in claim 15 , wherein the slowing step includes adjusting the level of current flowing through the coil based on the deceleration rate of the elevator car.

19. The method as recited in claim 15 , wherein the slowing step includes adjusting the level of current flowing through the coil based on a weight of a load within the elevator car.

20. The passenger conveyer system as recited in claim 1 , wherein, when the electromagnet is activated, the magnetic field attracts the plate in the second direction to at most partially offset the bias force of the spring.

Assignees

• Otis Elevator Co

Inventors

• Wei Wei

Classifications

• B61H7/08

  electromagnetically operated · CPC title

• B66B1/44

  and for taking account of disturbance factors, e.g. variation of load weight · CPC title

• B66D5/14 Primary

  embodying discs · CPC title

• B66B11/043

  actuated by rotating motor; Details, e.g. ventilation (roping on drum, sheave, winch or pulley B66B11/0065; power supply or control B66B1/28, H02P; motor construction H02K) · CPC title

• B66B9/00

  Kinds or types of lifts in, or associated with, buildings or other structures (characterised by control systems B66B1/00; apparatus for raising or lowering persons on stages of theatres A63J5/12) · CPC title