Park Brake Caliper With Inverted Lever Configuration

Abstract

A park brake caliper for a utility vehicle has an actuating unit, which is adapted to move a push rod, wherein the push rod is pre-tensioned by a tensioning device in one direction, but is adapted to be pressed in the opposite direction by a pneumatic, hydraulic, electromechanical or magnetic force, and an application unit which includes a brake lever, which is pivotably supported around a pivot axis and which is adapted to rest at the push rod at one side and at a bridge on the other side via an excenter. The application unit is adapted to be positioned around an axle of a utility vehicle. The bridge is adapted to press at least one brake pad against a brake disc of the utility vehicle. The lever points downwards towards the axle in all of its positions. A brake system is disclosed, where the park brake caliper and a service brake caliper are radially spaced from each other.

Claims

1.-17. (Canceled)

18. A park brake caliper for a utility vehicle, comprising: an actuating unit configured to move a push rod, wherein the push rod is adapted to be pressed in one direction, but is adapted to be pressed in an opposite direction by an energy supply; an application unit comprising a brake lever pivotably supported around a pivot axis and configured to rest at the push rod on one side and at a bridge on the other side via an excenter, wherein the application unit is configured to be positioned around an axle of a utility vehicle, the bridge is configured to press at least one brake pad against a brake disc of the utility vehicle, and the lever points towards the axle in all positions.

19. The park brake caliper according to claim 18, wherein the push rod is pre-tensioned, via a spring, in one direction in order to force the bridge to press the at least one brake pad against the brake disc of the utility vehicle, but is adapted to be pressed in the opposite direction by a pneumatic, hydraulic, electromechanical or magnetic force.

20. The park brake caliper according to claim 18, wherein an axis of motion of the push rod of the actuating unit and the axle include an angle of between 10 and 80.

21. The park brake caliper according to claim 18, wherein an axis of motion of the push rod of the actuating unit and the axle include an angle of between 45 and 75.

22. The park brake caliper according to claim 18, further comprising: a second push rod accommodated in an additional chamber, wherein the second push rod is adapted to transmit forces to the brake lever on the opposite side of the brake lever compared to the first push rod, and the additional chamber is positioned on the opposite side of the brake lever compared to the first push rod.

23. The park brake caliper according to claim 22, wherein the additional chamber is a pneumatic chamber.

24. The park brake caliper according to claim 18, wherein a middle axis of the bridge is at a smaller distance from the axle than the pivot axis of the lever.

25. The park brake caliper according to claim 16, wherein a joint between the push rod and the lever or an instantaneous center of rotation of the push rod and the lever is at a smaller distance to the axle compared to a plane of the bridge.

26. The park brake caliper according to claim 18, wherein a middle axis of the bridge has a larger distance from the axle than the pivot axis of the lever.

27. The park brake caliper according to claim 18, wherein the actuating unit has a housing and the application unit has a housing, and the actuating unit is connected to the application unit through a flange, wherein said flange lies at least partially below the bridge plane.

28. The park brake caliper according to claim 18, wherein a surface of the application unit is flat or curved, and a hump is provided in an uppermost surface of the application unit.

29. The park brake caliper according to claim 18, wherein the actuating unit and the application unit are disposed in a common housing.

30. The park brake caliper according to claim 18, wherein the push rod and the lever are integrally formed in one combined member.

31. The park brake caliper according to claim 18, wherein the caliper is of a floating type.

32. The park brake caliper according to claim 18, wherein a carrier for brake pads is provided on the caliper.

33. The park brake caliper according to claim 18, wherein brake pads are directly mounted to the caliper.

34. A brake system, comprising: a park brake caliper according to claim 18; and a service brake caliper, wherein brake pads of the park brake caliper and the service brake caliper are radially spaced from each other.

35. The brake system according to claim 34, wherein a friction pairing between park brake pads and the brake disc has a larger friction radius than a friction pairing between service brake pads and the brake disc.

36. The brake system according to claim 34, wherein the brake pads of the park brake and the brake pads of the service brake are guided by a respective carrier, wherein the respective carriers are connected.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0049] FIG. 1 is a schematic view of a park brake caliper 1 according to a first embodiment of the present invention.

[0050] FIG. 2 is a schematic view of a park brake caliper 1 according to a second embodiment of the present invention.

[0051] FIG. 3 is a schematic view of a park brake caliper 1 according to a third embodiment of the present invention.

[0052] FIG. 4 is a schematic view of a park brake caliper 1 according to a fourth embodiment of the present invention.

[0053] FIG. 5 is a schematic view of a park brake caliper 1 according to a fifth embodiment of the present invention.

[0054] FIG. 6 is a schematic view of a park brake caliper 1 according to a sixth embodiment of the present invention.

[0055] FIG. 7 is a schematic view of a park brake caliper 1 according to a seventh embodiment of the present invention.

[0056] FIG. 8 shows arrangements of a park brake caliper 1 and a service brake caliper S on a brake disc D.

DETAILED DESCRIPTION OF THE DRAWINGS

[0057] It should be emphasized that FIGS. 1 to 8 are schematical drawings. Of course, housings need to provide sufficient space so that the lever can make a movement which is suitable to perform the braking/releasing action.

[0058] FIG. 1 shows a brake caliper 1 according to a first embodiment of the present invention.

[0059] An application unit 3 (with a housing 3h) engages over a brake disc D connected to an axle A. Brake pads 8 are arranged at both sides of the brake disc D. At one side, a respective brake pad 8 is connected to a bridge 7. A lever 6 on its upper side rests against the bridge 7 via an excenter 6a, and is pivotably supported around a pivot axis 6b. On the other side, the lever 6 rests against a push rod 5, which belongs to an actuation unit 2 (with a housing 2h), which is connected to the application unit 3 via a flange 10. The push rod 5 is pressed by a spring 4 in the direction of the lever 6; however, a chamber 5a, in this case pneumatic chamber, is positioned between the spring 4 and the flange 10, and if pneumatic pressure is applied to the chamber 5a, the force of the spring 4 can be overcome and the push rod 5 can be pressed against the force of the spring 4, hence releasing the lever 6, which would lead to a situation that the brake pads 8 are not forced against the brake disc D. Herein, the distance between the pivot axis 6b of the lever 6 and the axle A is larger than the distance between the middle axis of the bridge 7 and the axle A. Even smaller is the distance between the lowest part of the push rod 5 and the axle A.

[0060] In all states, the lever 6 points towards the axle, i.e. in the direction of the axle A (in the embodiment of FIG. 1 downwards, as the caliper 1 is arranged in the 12 o'clock-mounting position). That does not mean that the lever 6 strictly is aligned along the gravitational direction-but it points towards the axle A. In other words: The angle the gravitational direction and the middle axis of the lever 6 include, is less than 90.

[0061] FIG. 2 shows a second embodiment of the present invention. This embodiment is similar to the first embodiment, however, there is a second push rod 5 which can be actuated by an additional chamber 5a, in this case a pneumatic chamber. However, said additional chamber 5a is positioned on the other side of the actuation unit 3, hence, the first push rod 5 can press the lever 6 in one direction by the force of the spring 4, but if the additional chamber 5a is actuated, the second push rod 5 is adapted to push the lever 6 in the opposite direction. Again, in all states, the lever 6 points downwards, i.e. in the direction of the axle A.

[0062] FIG. 3 shows a third embodiment of the present application. Herein, the difference is that the distance between the middle axis of the bridge 7 and the axle A is larger than the distance between the pivoting axis 6b of the lever 6 and the axle A. Also, the arrangement of the spring 4 and the chamber 5a with regard to the push rod 5 has been changed compared to the first embodiment (FIG. 1). Herein, the spring 4 pushes the push rod 5 in the direction away from the lever 6, leading to a state that the lever 6 is pulled, but pushes the bridge 7 against one of the brake pads 8, hence actuating the park brake. Upon pressurization of the chamber 5a (in this case: pneumatic chamber), the force of the spring 4 can be overcome, hence pushing the push rod 5 in the direction of the lever 6, leading to the state that the bridge 7 can move in the direction away from the one brake pad 8, hence leading to a released state of the brake. Herein, the flange 10 being adapted to connect the actuating unit 2 and the application unit 3 is at least partly below the bridge plane, being a plane parallel to the axle A and including the middle axis of the bridge 7.

[0063] However, if the force of the spring 4 is dominant over the force of the chamber 5a (in this case: pneumatic chamber), the push rod is forced in a direction so that it pulls the lever 6, hence pushing the bridge 7 against the brake pad 8, which again is pushed against the brake disc D.

[0064] FIG. 4 shows a fourth embodiment of the present invention. Herein, the flange 10 being adapted to connect the actuating unit 2 and the application unit 3 is realized differently, and the flange is provided on the side part of the actuation unit 2. Herein, the flange 10 is positioned above the bridge plane, being a plane parallel to the axle A and including the middle axis of the bridge 7.

[0065] Herein, packaging or accessibility of the flange connection can be improved, and still, a compact design can be achieved.

[0066] FIG. 5 shows an embodiment where the actuation unit 2 and the application unit 3 are disposed in a common housing 11. Hence, no flange is necessary any more.

[0067] FIG. 6 shows a sixth embodiment of the present invention. The main difference compared to the fifth embodiment is that there is a combined lever 6, which fulfills the function of a push rod of the previous embodiments and the lever of the previous embodiments together.

[0068] FIG. 7 shows a seventh embodiment of the present invention. Herein, the surface of the application unit 3 is very flat, and the arrangement of the whole park brake caliper 1 compared to a rim R of a wheel is shown. On the upper surface of the application unit 3, a hump 9 is provided. Such hump 9 can add additional stiffness to the caliper 1.

[0069] A high stiffness is always preferential, because it reduces the necessary clamping stroke in a caliper.

[0070] FIG. 8 shows two arrangements of a park brake carrier 12 with a respective brake pad 8 and a service brake carrier 112 with a respective brake pad 108 on a brake disc D.

[0071] In FIG. 8a), the park brake carrier 12 with respective brake pad 8 and the service brake carrier 112 with a respective brake pad 108 are radially separated around the brake disc D, the park brake carrier 12 being on the 3 o'clock-position and the service brake carrier 112 being at the 12 o'-clock position in this example. The park brake caliper 1 and the service brake caliper S are also separated.

[0072] In FIG. 8b), the park brake carrier 12 and the service brake carrier 112 are connected.

[0073] However, the brake pad 8 of the park brake and the brake pad 108 of the service brake are still radially separated. Calipers are not shown in this figure.

[0074] The present invention is not limited to the embodiments as described above.

[0075] It would also be possible that the lever 6 can have different shapes.

[0076] Furthermore, different springs 4 can be used, for example flat springs or coil springs.

[0077] Not only pneumatic actuation, but also hydraulic, magnetic or electromechanical actuation is possible.

REFERENCE SIGN LIST

[0078] 1 Park brake caliper [0079] 2 Actuation unit [0080] 2h Actuation unit housing [0081] 3 Application unit [0082] 3h Application unit housing [0083] 4 Spring [0084] 5, 5 First push rod, second push rod [0085] 5a Chamber, additional chamber [0086] 6, 6 Lever [0087] 6a Excenter [0088] 6b Pivot axis [0089] 7 Bridge [0090] 8 Brake pad (park brake) [0091] 9 Hump [0092] 10 Flange [0093] 11 Housing [0094] 12 Carrier (park brake) [0095] 108 Brake pad (Service brake) [0096] 112 Carrier (Service brake) [0097] D Brake disc [0098] A Axle [0099] R Rim [0100] S Service brake caliper