Parking brake system

• US 6,279,692 B1
• Filed: 06/29/1999
• Issued: 08/28/2001
• Est. Priority Date: 05/21/1996
• Status: Expired due to Term

• Current Assignee: Bayerische Motoren Werke AG
• Original Assignee: Bayerische Motoren Werke AG
• Inventors: Siepker, Achim, Ziebarth, Thomas, Niklas, Johann, Gutt, Axel, Reis, Wolfgang, Boedrich, Harald
• Primary Examiner(s): Oberleitner, Robert J.
• Assistant Examiner(s): RODRIGUEZ, PAMELA
• Application Number:
  US09/194,156
• Time in Patent Office: 791 Days
• Field of Search: 188/105, 188/106.P, 188/106.F, 188/162, 188/157, 188/156, 188/2.D, 743/88.R, 745/30, 745/29, 745/23, 745/016
• US Class Current: 188/105
• CPC Class Codes: B60T 11/103 in combination with other control devices conjoint control of brake system and at least another sub-unit B60W10/188
• CPC Class Codes: B60T 13/746 and mechanical transmission of the braking action
• CPC Class Codes: B60T 7/107 with electrical power assistance
• CPC Class Codes: Y10T 74/19535 Follow-up mechanism

Abstract

The parking brake of a vehicle is operated by a power-generating generating actuating unit 4. For maintaining the function of the parking brake in the event of a failure of the power operating device 1, an emergency operating device 2 is provided which can be operated by muscle force. Both operating devices 1, 2 have mechanical transmissions 5, 12 which act upon a common threaded spindle 3 for tensioning and releasing the parking brake. By way of the mutual self-locking design of the mechanical transmission 5, 12 which depends on the type of operation, it is achieved that both operating modes (power or muscle force) can be carried out in any sequence and without any limitation of the adjusting path(s).

Claims

1. Parking brake system for a vehicle, having a power operating device, which, by way of an actuating unit, drives a threaded spindle which acts upon the parking brake, and having an emergency operating device for operating the parking brake by muscle force in the event of a failure of the power operating device, wherein the power operating device as well as the emergency operating device each have a direct mechanical transmission for adjusting the threaded spindle.

2. Parking brake system according to claim 1, wherein the mechanical transmission of the emergency operating device is formed by a worm, which can be driven by way of muscle force as well as by a worm gear which interacts with the worm and which drives the threaded spindle.

3. Parking brake system according to claim 1, wherein the mechanical transmission of the power operating device is formed by a worm which can be driven by the actuating unit as well as by a worm gear which interacts with the worm and which drives the threaded spindle by way of an internal thread.

4. Parking brake system according to claim 1, wherein the mechanical transmission of the emergency operating device is formed by a skew gear which can be driven by way of muscle force as well as by a straight-toothed gear wheel which interacts with the skew gear and which drives the threaded spindle.

5. Parking brake system according to one of the preceding claims, wherein, in the power operation, the threaded spindle is fixed with respect to a rotation.

6. Parking brake system according to claim 5, wherein the non-rotatable support of the threaded spindle takes place by the self-lockingly designed mechanical transmission of the emergency operating device.

7. Parking brake system according to claim 1, wherein the threaded spindle has a longitudinal groove or a flattening in which a gear wheel of the emergency operating device engages in a non-rotatable and axially displaceable manner.

8. Parking brake system according to claim 1, wherein a gear wheel of the power operating device, during the drive of the threaded spindle by way of the emergency operating device, is fixed with respect to a rotation.

9. Parking brake system according to claim 8, wherein the rotation of the gear wheel is prevented by the self-lockingly designed mechanical transmission of the power operating device.

10. Parking brake system according to claim 1, having a force transmitting device between the threaded spindle and the parking brake which transmits the adjusting movement of the threaded spindle to the parking brake, wherein a bearing device which is arranged between the threaded spindle and the force transmitting device and which causes an uncoupling of the rotating movement of the threaded spindle from the axial movement.

11. Parking brake system according to claim 1, wherein the spindle is constructed as a hollow shaft through an interior of said spindle at least one element of the force transmitting device is guided.

12. Parking brake system according to claim 1, wherein an operating element by which a vehicle user can apply a rotating movement to a shaft is arranged between the operating element and the mechanical transmission of the emergency operating device.

13. Parking brake system according to claim 12, wherein the shaft can be telescoped.

14. Parking brake system according to claim 12, wherein on an end section facing the operating element, the shaft is bent for forming a lever arm, and the operating element is formed by an oblong grip end which on an end area is hinged to the bent end section of the shaft so that the operating element can take up

a first position transversely to the longitudinal axis of the shaft, with a form closure to the bent end section, and

a second, freely rotating position in parallel to the longitudinal axis of the shaft.

15. Parking brake system according to claim 12, wherein the operating element is constructed as an approximately T-shaped grip which has a rotatably disposed button extending at a distance and in parallel to the longitudinal axis of the shaft, which button can be pulled out for forming a crank.

16. Parking brake system according to claim 12, wherein the shaft has two joints in the area of an end section facing an operator of the vehicle, which said joints permit an approximately Z-shaped bending of two sections formed by the joints so that the shaft forms a crank section with a lever arm.

17. Parking brake system according to claim 12, wherein during the power operation, the rotating movement of the threaded spindle is prevented by a form-locking fixing of the operating element of the emergency operating device.

18. Parking brake system according to claim 1, wherein the emergency operating device has an operating element which, in an inoperative position, can be displaced into a recess of an element of interior fittings of the vehicle.

19. Parking brake system according to claim 1, wherein a wind-around spring is provided on the emergency operating device for protection against rotation.

20. Parking brake system according to claim 19, having a shaft by way of which a user of the vehicle can apply a rotating movement to the mechanical transmission of the emergency operating device, wherein the shaft is divided into two sections which engage in one another in a form-locking manner and thereby can be rotated with respect to one another to a limited extent, the wind-around spring being triggered by way of the limited rotation of the sections.

21. Parking brake system according to claim 19, wherein the wind-around spring is arranged close to the mechanical transmission of the emergency operating device.

22. Parking brake system according to claim 1, having a force transmitting device between the threaded spindle and the parking brake which transmits the adjusting movement of the threaded spindle to the parking brake, wherein the force transmitting device comprises a rocker which is tiltably arranged on the threaded spindle and accommodates two Bowden cables leading to the parking brakes.

23. Parking brake according to claim 22, wherein the rocker is linked by way of a bolt with a spherical head to the threaded spindle.

24. Parking brake according to claim 22, wherein a device for the automatic threading of the Bowden cables into the rocker is provided.

25. Parking brake according to claim 1, wherein in the area of a triggering device, in which the power operating device and the emergency operating device are combined, an adjusting device is provided for compensating wear and settling phenomena in the parking brake system.

26. Parking brake according to claim 25, the spindle being constructed as a hollow shaft through an interior a rod is guided for transmitting the brake locking force, wherein

the adjusting device comprises a carriage which can be displaced together with the spindle along a longitudinal axis,

the carriage has a tooth element which interacts with the rod by way of a releasable locking, when the parking brake is released, the tooth element being disengaged from the rod, and

a spring element supported with respect to the body of the vehicle exercises a pretressing onto the rod which acts against a restoring force of the parking brake.

27. Parking brake according to claim 26, wherein stop slopes are provided which permit a self-threading inserting of the rod into the triggering device.