DEVICE FOR RECOGNIZING WEAR OF A BRAKE PAD OF A DISC BRAKE

Abstract

A wear indication device (10) for a vehicle brake (1), preferably a disc brake of a commercial vehicle, for indicating a wear condition of a brake pad (20) comprising: a fixing section (12) for fixing the wear indication device (10) to a brake pad back plate (30), a sensor head (14) associated to the fixing section (12), and a channel (16) for receiving a signal cable (40) within the sensor head (14). According to the invention, the channel (16) is configured to receive two signal cables (40′, 40″).

Claims

1. A wear indication device (10) for a vehicle brake (1), preferably a disc brake of a commercial vehicle, for indicating a wear condition of a brake pad (20), the wear indication device comprising: a fixing section (12) for fixing the wear indication device (10) to a brake pad back plate (30), a sensor head (14) associated with the fixing section (12), and a channel (16) defined within the sensor head (14) for receiving a signal cable (40), wherein the channel (16) is sized and configured to receive two signal cables (40′, 40″).

2. The wear indication device (10) according to claim 1, wherein the channel (16) is a double channel having a first section (102) for the first cable (40′), and a second section (104) for the second cable (40″), wherein the first and second sections (102, 104) are positioned adjacent to each other radially with respect to center axes thereof.

3. The wear indication device (10) according to claim 2, wherein the center axis of first section for the first signal cable (40′) has a distance to the fixing section (12) that is greater than a distance between the center axis of the second section for the second signal cable (40″) and the fixing section (12).

4. The wear indication device (10) according to claim 2, wherein the respective cross-sections of the first and the second sections (102, 104) at least partially overlap, such that the channel (16) includes a narrow necking area (106) partly separating the first section (102) from the second section (104) by way of at least one protrusion (108) in the sensor head (14) projecting inwardly into the double channel.

5. The wear indication device (10) according to claim 2, wherein at least one of the first section (102) or the second section (104) of the double channel has at least a partly circular cross-section.

6. The wear indication device (10) according to claim 2, wherein the double channel has a geometry such that the two signal cables (40′, 40″) are arranged at least partially in parallel to each other in direct contact or at a distance from each other when arranged within the channel (16).

7. The wear indication device (10) according to claim 1, wherein the wear indication device (10) further comprises a substantially flat contact surface for contacting a brake pad back plate (30) when the wear indication device (10) is installed, said contact surface defining a zero plane (Z) having an axial axis (A) orthogonal to the plane.

8. The wear indication device (10) according to claim 7, wherein the channel (16) has a geometry such that the two signal cables (40′, 40″) are arranged perpendicular to the axial axis (A) when arranged within the channel (16).

9. The wear indication device (10) according to claim 7, wherein a center axis of the first signal cable (40′) has a distance to the zero plane (Z) that is greater than a distance between the center axis of the second signal cable (40″) and the zero plane (Z) in the direction of the axial axis (A) when arranged within the channel.

10. The wear indication device (10) according to claim 7, wherein the center axes of the first and second signal cables (40′, 40″) define a plane perpendicular to the zero plane (Z) when arranged within the channel.

11. The wear indication device (10) according to claim 7, wherein the channel (16) and the signal cables (40′, 40″), when arranged within the channel, extend at least partially parallel to the zero plane (Z).

12. The wear indication device (10) according to claim 1, wherein the channel (16) has a geometry such that the two signal cables (40′, 40″) are in contact when arranged within the channel, so that the two signal cables have the smallest possible distance from each other within the channel (16).

13. The wear indication device (10) according to claim 1, wherein the sensor head (14) is formed of a plastic material.

14. A vehicle brake (1), preferably a disc brake of a commercial vehicle, the vehicle brake (1) comprising: a brake pad back plate (30) for carrying a brake pad (20), a wear indication device (10) configured for indicating a wear condition of the brake pad (20), the wear indication device (10) including: a fixing section (12) for fixing the wear indication device (10) to the brake pad back plate (30), a sensor head (14) associated with the fixing section (12), and a channel (16) defined within the sensor head (14) for receiving a signal cable (40), wherein the channel (16) is sized and configured to receive two signal cables (40′, 40″).

15. The vehicle brake (1) according to claim 14, wherein the channel (16) is arranged outside of the brake pad back plate (30) and within the brake pad (20).

16. The vehicle brake (1) according to claim 14, wherein an end of the channel (16) closest to the brake pad back plate (30) is located at a distance from the brake pad back plate (30) that is 1 mm or less.

17. The vehicle brake (1) according to claim 14, wherein the sensor head (14) is at least partially arranged in a cut-out (110) within the brake pad (20).

18. The vehicle brake (1) according to claim 14, wherein the channel (16) is a double channel having a first section (102) for the first cable (40′), and a second section (104) for the second cable (40″), wherein the first and second sections (102, 104) are positioned adjacent to each other radially with respect to center axes thereof.

19. The vehicle brake (1) according to claim 18, wherein the respective cross-sections of the first and the second sections (102, 104) at least partially overlap, such that the channel (16) includes a narrow necking area (106) partly separating the first section (102) from the second section (104) by way of at least one protrusion (108) in the sensor head (14) projecting inwardly into the double channel.

20. The vehicle brake (1) according to claim 18, wherein the center axis of first section for the first signal cable (40′) has a distance to the fixing section (12) that is greater than a distance between the center axis of the second section for the second signal cable (40″) and the fixing section (12).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0024] These and other aspects, features and/or technical effects will be apparent from and elucidated with reference to the illustrations described hereafter, wherein:

[0025] FIG. 1 is a top view of a wear indication device according to the aspect of the disclosure;

[0026] FIG. 2 is a perspective view of a vehicle brake including the wear indication device according to as aspect of the disclosure;

[0027] FIG. 3 is a top view an alternative embodiment of a wear indication device according to the concept of the invention in;

[0028] FIG. 4 is a perspective view of the wear indication device disposed in a cut out of a brake pad;

[0029] FIG. 5 is a top view of a prior art wear indication device; and

[0030] FIG. 6 is a top view of another prior art wear indication device.

DETAILED DESCRIPTION OF THE DRAWINGS

[0031] FIG. 1 shows a wear indication device 10 in a preferred embodiment for a vehicle brake 1. The wear indication device 10 includes a fixing section 12 (not visible in FIG. 1) which is located inside the brake pad back plate 30 when wear indication device 10 is installed. For reference, FIG. 6 shows a fixing section according to the state of the art. The fixing section 12 is used to fixing the wear indication device 10 to a brake pad back plate 30. The fixing section 12 may take any appropriate shape for this purpose.

[0032] The wear indication device 10 further comprises a sensor head 14 and a channel 16 for receiving a signal cable 40 within the sensor head 14. According to the invention, the channel 16 is configured to receive two signal cables 40′, 40″ (not shown in FIG. 1). An exemplary cable routing is shown in FIG. 4.

[0033] The channel 16 of the wear indication device 10 is a double channel having a first section 102 for a first cable 40′, and a second section 104 for a second cable 40″, or respectively a first cable section 40′ and a second cable section 40″ of a signal cable, as best seen in FIG. 4.

[0034] In the top view of FIG. 1, it can be seen that the first section 102 of channel 16 has a greater distance in the direction of axis A from the fixing section 12, i.e. in the mounted state from the zero plane Z or brake pad back plate 30, than the second section 104 of channel 16. Put another way, the second section 104 is closer to the back plate 30 than the first section 102.

[0035] The double channel also has two opposing protrusions 108. These protrusions 108 are arranged to hold a respective cable section 40′, 40″ in the respective assigned section 102, 104 of the channel 16. This arrangement is particularly useful if the cable channel 16 has been ground by the brake disc and is thus partially exposed.

[0036] In addition, the cross-section of each section 102, 104 of the channel 16 is mostly circular, in order to enclose a corresponding circular cross-section of a signal cable 40. Because the signal cables 40 in the channel 16 can be in contact with each other, the respective sections 102, 104 of the channel 16 overlap at least in part. Therefore, the channel 16 has a narrow necking area 106 partly separating the first section 102 from the second section 104 by way of at least one protrusion 108. Two protrusions 108 are shown, but it will be appreciated that a single protrusion could extend from one side of the channel 16 to define the two sections 102, 104.

[0037] The wear indication device 10 further comprises a substantially flat contact surface for contacting a brake pad back plate 30 when the wear indication device 10 is installed, said contact surface defining a zero plane Z. The contact surface defining zero plane Z is located on the back side (back plate side) of the sensor head 14, so that the sensor head 14 is in contact with the zero plane Z or the brake pad back plate 30 when the wear indication device 10 is installed. The zero plane Z thus also defines the interface of the sensor head 14 and the fixing section 12 of the wear indication device 10.

[0038] The cables 40, 40′ run essentially parallel to each other within the channel 16, or the cable sections 40, 40′ of the U-shaped contact loop run parallel to each other, so that they also run parallel to the zero plane Z.

[0039] In the embodiment shown in FIG. 1, the sections 102, 104 of the channel 16 are arranged one above the other in the axial direction A, such that the center axes of the first and second signal cables 40′, 40″, when arranged inside of the double channel of channel 16, define a plane perpendicular to the zero plane (Z). In an alternative embodiment, see FIGS. 3 and 4 for an example, the sections 102, 104 of channel 16 are offset in relation to the axial axis A. In this case, the center axes of the first and second signal cables 40′, 40″, when arranged inside of the double channel of channel 16, define a plane with an angle smaller than 90° to the zero plane (Z). As can be seen in FIGS. 1, 3 and 4, the cables (or sections) 40, 40′ inside the sensor head 14 run parallel to the zero plane Z and perpendicular to the axial axis A.

[0040] The cables (or sections) 40, 40′ are adjacent to each other within the channel 16, so that the size of channel 16 can therefore correspondingly be small.

[0041] FIG. 2 shows a disc brake 1 including a brake carrier 70, which is mountable to a corresponding receiving section of a vehicle. The disc brake 1 further includes a brake caliper 60, which forms an accommodation space for, among others, brake pad back plate 30, configured to carry a brake pad 20 having a friction lining that comes into contact with the disc of the brake (not shown) during braking in order to apply a braking force.

[0042] Further, the brake pad back plate 30 has a wear indication device 10, which is configured to assess the degree of wear of the brake pads 20. The wear indication device 10 is coupled to the brake pad back plate 30 and is at least partly received in a recess (not shown) of the brake pad back plate 30.

[0043] The wear indication device 10 is coupled to a signal cable 40 having a connector on its distal end. When the wear indication device 10 is installed, a cable section 40′, 40″ of the signal cable 40 runs in a U-shaped contact loop through the channel 16 inside the sensor head 14 of the wear indication device 10. Accordingly, the entire cable channel 16 is located at the level of the brake pad 20, as best seen in FIG. 4.

[0044] The distance of the lower end of the channel 16, i.e. in particular the distance of the lower end of the second section 104 to the zero plane Z is preferably 1 mm or less.

[0045] The brake pad 20 has a cut-out 110 surrounding the recess in which the fixing section 12 is received (see FIG. 4) such that the recess is arranged within the region of the cut-out 110. Thus, the wear indication device 10 is surrounded by the brake pad 20, wherein the cut-out 110 allows an easy access to the wear indication device 10.

[0046] The brake pad back plate 30 carrying the brake pad 20 is held in position by a spring hanger 50. The spring hanger 50 is preferably connected to the brake caliper 60 by a spring hanger seat 54 on one side and by a spring hanger fixation means 52 on the other side. After releasing the spring hanger fixation means 52 and guiding the spring hanger 50 out of its seat 54, the spring hanger 50 may be removed. When the spring hanger 50 is removed, the brake pads 20, together with brake pad back plates 30, may be removed likewise and may be exchanged.

[0047] FIGS. 5 and 6 show prior art wear indication devices. Here, the signal cable (or sections) 40 are routed along two separate channels 16′,16″ within the sensor head 14, as seen in FIG. 5 or with the first channel 16′ arranged within the sensor head 14 and the second channel 16″ arranged within the fixing section 12, as seen in FIG. 6. The fixing section 12 of the present disclosure may be similar to the fixing sections shown in FIGS. 5 and 6.

[0048] It should of course be understood that various modifications and changes in form or detail could readily be made without departing from the scope of the invention. It is therefore intended that the invention may not be limited to the exact form and detail shown and described herein, nor to anything less than the whole of the invention disclosed herein and disclaimed hereinafter. Further, the features described in the description, the drawings and the claims disclosing the invention may be essential for the invention considered alone or in combination. In particular, any reference signs in the claims shall not be construed as limiting the scope of the invention. The word “comprising” does not exclude other elements or steps. The wording “a” or “an” does not exclude a plurality.