Brake regulating apparatus for an elevator car

• US 5,648,644 A
• Filed: 10/18/1994
• Issued: 07/15/1997
• Est. Priority Date: 10/18/1993
• Status: Expired due to Term

• Current Assignee: Inventio AG (Schindler Holding AG)
• Original Assignee: Inventio AG (Schindler Holding AG)
• Inventors: Nagel, Heinz-Dieter
• Primary Examiner(s): NAPPI, ROBERT E
• Application Number:
  US08/324,789
• Time in Patent Office: 1,001 Days
• Field of Search: 187/288, 187/359, 187/349, 187/409, 187/373, 187/374, 187/375, 187/351
• US Class Current: 187/288
• CPC Class Codes: B66B 5/18 and applying frictional retarding forces

Abstract

An elevator brake regulating apparatus includes brake actuators, a source of pressured fluid and a brake regulating control connected between the actuators and the fluid source. A fastening housing is attached to a carrier frame of a elevator car and has recesses for retaining guides of a brake shoe with elastic pads to provide vertical displacement of the guides under braking. The brake shoe has brake pads for engaging running surfaces of a guide rail. A brake sensor in each brake pad monitors the condition of the brake pad and signals the control to apply pressured fluid to actuate the corresponding brake actuator. Other sensors for speed, acceleration and retardation of the elevator car are connected to the control for selectively applied the pressured fluid to regulate the braking force on the elevator car.

Claims

1. An apparatus for applying a regulated braking force to an elevator car comprising:

a brake shoe for attachment to an elevator car;

a brake pad for engaging a running surface formed on a guide rail along which the elevator car travels, said brake pad being retained by said brake shoe for movement relative to said brake shoe toward and away from the running surface;

a fastening housing for attachment to an elevator car and having at least one recess formed therein;

a brake guide attached to said brake shoe and being retained in said recess;

at least one cushion pad formed of an elastic material and mounted in said recess in contact with said brake guide whereby said brake shoe and said retained brake pad follow deviations in a shape of the guide rail during application of the regulated braking force to prevent generation of additional forces on the guide rail; and

a brake actuator including a cylinder chamber formed in said brake shoe and a piston slidable in said cylinder chamber and being connected to said brake pad whereby selective application of pressured fluid to said cylinder chamber and removal of pressured fluid from said cylinder chamber moves said piston in said cylinder chamber and moves said brake pad into engagement with the running surface and out of engagement with the running surface to apply a regulated braking force to the elevator car.

2. The apparatus according to claim 1 including a brake regulating apparatus control having an inlet port for connection to a source of pressured fluid and an outlet port being connected to said cylinder chamber for selectively applying the pressured fluid to and removing the pressured fluid from said cylinder chamber whereby a relatively constant regulated braking force is exerted on the elevator car.

3. The apparatus according to claim 2 wherein said brake regulating apparatus control applies the pressured fluid to said cylinder chamber to move said brake pad into engagement with the running surface.

4. The apparatus according to claim 2 wherein said brake actuator includes a biasing means coupled to said piston and moving said brake pad into engagement with the running surface and said brake regulating apparatus control applies the pressured fluid to said cylinder chamber to move said brake pad out of engagement with the running surface.

5. The apparatus according to claim 4 wherein said biasing means is a compression spring.

6. The apparatus according to claim 2 wherein said brake regulating apparatus control includes a retardation sensor for sensing an actual retardation at which the elevator car is travelling during braking and said brake regulating apparatus control selectively applies the pressured fluid to said cylinder chamber to maintain the actual retardation at a predetermined value.

7. The apparatus according to claim 2 wherein said brake regulating apparatus control includes a speed sensor for sensing an actual speed at which the elevator car is travelling and said brake regulating apparatus control is responsive to the actual speed exceeding a predetermined value for selectively applying the pressured fluid to said cylinder chamber.

8. The apparatus according to claim 2 wherein said brake regulating apparatus control includes an acceleration sensor for sensing an actual acceleration at which the elevator car is travelling and said brake regulating apparatus control is responsive to the actual acceleration exceeding a predetermined value for selectively applying the pressured fluid to said cylinder chamber.

9. The apparatus according to claim 2 wherein said brake regulating apparatus control is connected to an elevator control for the elevator car and is responsive to a signal generated by the elevator control for applying a maximum braking force to maintain the elevator car in position during loading and unloading at a floor and during maintenance operations.

10. The apparatus according to claim 2 wherein said brake regulating apparatus control is connected to an elevator control for the elevator car and including a brake sensor attached to said brake pad and connected to the elevator control for sensing wear of said brake pad and generating a signal to the elevator control representing the wear of said brake pad, the elevator control and said brake regulating apparatus control being responsive to said brake sensor signal for selectively applying the pressured fluid to said cylinder chamber to stop the elevator car.

11. The apparatus according to claim 2 wherein said brake regulating apparatus control includes a control;

a control valve having said inlet port, said outlet port and an actuator connected to said control;

a pressure regulating valve having an inlet port connected to said outlet port of said control valve, an outlet port connected to one of said cylinder chamber and a fluid reservoir for the pressured fluid source and a pressure adjusting portion connected to said control;

at least one of a car speed sensor and a car acceleration sensor connected to said control; and

a car retardation sensor connected to said control, said control being responsive to a car condition sensed by said one of said car speed sensor and said car acceleration sensor for actuating said control valve and being responsive to a car condition sensed by said retardation sensor for controlling a pressure at which said pressure regulating valve regulates.

12. The apparatus according to claim 11 including a pair of pressure switches each having an input connected to said control valve outlet port and an output connected to said brake regulating apparatus control for sensing and generating signals representing a maximum fluid pressure and a minimum fluid pressure and wherein said outlet port of said pressure regulating valve is connected to the fluid reservoir for the pressured fluid source and said control is responsive to said signals generated by said switches for turning said control valve on and off.

13. The apparatus according to claim 2 wherein the pressured fluid source includes an electric motor connected to said brake regulating apparatus control, an hydraulic pump coupled to be driven by said motor and having an inlet connected to said brake regulating apparatus control and an outlet, a reservoir for fluid connected to said pump inlet, a pressured fluid accumulator connected to said pump outlet, first and second pressure switches each having an input connected to said fluid accumulator and an output connected to said brake regulating apparatus control and a pressure limiting valve connected between said pump outlet and said reservoir, said switches sensing and generating signals representing a minimum fluid pressure and a maximum fluid pressure, said brake regulating apparatus control being responsive to said switch signals for turning on and off said motor.

14. An apparatus for applying a regulated braking force to an elevator car comprising:

a fastening housing for attachment to an elevator car and having at least one recess formed therein;

a brake shoe having at least one brake guide attached thereto and being retained in said recess;

at least one brake pad for engaging a running surface formed on a guide rail along which the elevator car travels, said brake pad being retained by said brake shoe;

at least one brake actuator mounted in said brake shoe and being coupled to said brake pad for moving said brake pad into engagement with the running surface;

a brake regulating apparatus control for selectively applying pressured fluid to said brake actuator whereby a relatively constant regulated braking force is exerted on the elevator car;

a control valve having an inlet port for connection to a source of pressured fluid, an outlet port being connected to said brake actuator and an actuator connected to said brake regulating apparatus control;

a pressure regulating valve having an inlet port connected to said outlet port of said control valve, an outlet port connected to one of said brake actuator and a fluid reservoir for the pressured fluid source and a pressure adjusting portion connected to said brake regulating apparatus control;

at least one of a car speed sensor and a car acceleration sensor connected to said brake regulating apparatus control;

a car retardation sensor connected to said brake regulating apparatus control, said brake regulating apparatus control being responsive to a car condition sensed by said one of said car speed sensor and said car acceleration sensor for actuating said control valve and being responsive to a car condition sensed by said retardation sensor for controlling a pressure at which said pressure regulating valve regulates; and

a pair of pressure switches each having an input connected to said control valve outlet port and an output connected to said brake regulating apparatus control for sensing and generating signals representing a maximum fluid pressure and a minimum fluid pressure and wherein said outlet port of said pressure regulating valve is connected to the fluid reservoir for the pressured fluid source and said brake regulating apparatus control is responsive to said signals generated by said switches for turning said control valve on and off.

15. An apparatus for applying a regulated braking force to an elevator car comprising:

a brake shoe for attachment to an elevator car;

a brake pad for engaging a running surface formed on a guide rail along which the elevator car travels, said brake pad being retained by said brake shoe for movement relative to said brake shoe toward and away from the running surface;

a brake actuator including a cylinder chamber formed in said brake shoe and a piston slidable in said cylinder chamber and being connected to said brake pad;

a brake regulating apparatus control connected to said brake actuator for selectively applying pressured fluid to said cylinder chamber and removing pressured fluid from said cylinder chamber to move said piston in said cylinder chamber and to move said brake pad into engagement with the running surface and out of engagement with the running surface to apply a regulated braking force to the elevator car; and

a retardation sensor connected to said brake regulating apparatus control for sensing an actual retardation at which the elevator car is travelling during braking whereby said brake regulating apparatus control is responsive to said actual retardation for selectively applying the pressured fluid to said cylinder chamber to maintain the actual retardation at a predetermined value to exert a relatively constant regulated braking force on the elevator car, said predetermined value being at least one of approximately equal to gravitational acceleration during downward travel of the elevator car and less than gravitational acceleration during upward travel of the elevator car.

16. An apparatus for applying a regulated braking force to an elevator car comprising:

a fastening housing for attachment to an elevator car;

a brake shoe being retained in said fastening housing;

at least one brake pad for engaging a running surface formed on a guide rail along which the elevator car travels, said brake pad being retained by said brake shoe;

at least one pressure fluid actuated brake actuator mounted in said brake shoe and being coupled to said brake pad for moving said brake pad into engagement with the running surface;

a brake regulating means connected to said brake actuator for selectively applying pressured fluid from a source to said brake actuator whereby a relatively constant regulated braking force is exerted on the elevator car;

a speed sensor connected to said brake regulating means for sensing an actual speed at which the elevator car is travelling;

an acceleration sensor connected to said brake regulating means for sensing an actual acceleration at which the elevator car is travelling; and

a retardation sensor connected to said brake regulating means for sensing an actual retardation at which the elevator car is travelling during braking whereby said brake regulating means selectively applies the pressured fluid to said brake actuator when the actual speed exceeds a first predetermined value, when the actual acceleration exceeds a second predetermined value, and to maintain the actual retardation at a third predetermined value.

17. The apparatus according to claim 16 wherein said fastening housing is adapted to be attached to an upper yoke of a carrier frame for the elevator car.

18. The apparatus according to claim 16 wherein said fastening housing is adapted to be attached to a lower yoke of a carrier frame for the elevator car.

19. The apparatus according to claim 16 wherein during downward travel of the elevator car said brake regulating apparatus control maintains the actual retardation predetermined value approximately equal to gravitational acceleration.

20. The apparatus according to claim 16 wherein during upward travel of the elevator car said brake regulating apparatus control maintains the actual retardation predetermined value ess than gravitational acceleration.