Tooth driven over-torque protection mechanism for a slack adjuster or an air disc brake clutch

Patent metadata

Field	Value
Publication number	US-11828343-B2
Application number	US-202117350575-A
Country	US
Kind code	B2
Filing date	Jun 17, 2021
Priority date	Jun 17, 2021
Publication date	Nov 28, 2023
Grant date	Nov 28, 2023

Abstract

A tooth driven over-torque protection mechanism for use in a slack adjuster or as an air disc brake clutch, includes a shaft, toothed gear, a clutch device, a first spring, and a second spring. The toothed gear is disposed on the shaft. The toothed gear has a first pinion teeth set that extends along a first direction and a second teeth set that extends along a second direction. The clutch device that is also disposed on the shaft and includes an upper cam and a lower cam. The first spring biases the toothed gear against the clutch device. The second spring biases the clutch device against the toothed gear. The upper cam has cam teeth that cooperate with the second teeth set of the toothed gear in a torque transmitting manner, such that a torque applied in a clockwise direction to the first pinion teeth is transmitted to the upper cam through the second teeth set, but torque applied in a counterclockwise direction is opposed by the first spring.

First claim

What is claimed is:

1. A tooth driven over-torque protection mechanism for use in a slack adjuster or as an air disc brake clutch, comprising:
a shaft;
a toothed gear that is disposed on the shaft, the toothed gear having a first pinion teeth set that extends along a first direction and a second teeth set that extends along a second direction;
a clutch device that is also disposed on the shaft, the clutch device having an upper cam and a lower cam;
a first spring that biases the toothed gear against the clutch device;
a second spring that biases the clutch device against the toothed gear, wherein
the upper cam has cam teeth that cooperate with the second teeth set of the toothed gear in a torque transmitting manner, such that a torque applied in clockwise direction to the first pinion teeth is transmitted to the upper cam through the second teeth set, but torque applied in a counterclockwise direction is opposed by the first spring,
at a region of the shaft where the clutch device is disposed the shaft has a given cross-sectional shape which differs from a cross-sectional shape at other regions of the shaft, and
the lower cam defines an axial opening having a same shape as the given cross-sectional shape of the shaft, so that the lower cam form fits the shaft and is slidable thereupon.

2. The tooth driven over-torque protection mechanism according to claim 1 , wherein the first direction is radially outward from the toothed gear and the second direction is axially away from the toothed gear.

3. The tooth driven over-torque protection mechanism according to claim 1 , wherein the first direction is orthogonal to the second direction.

4. The tooth driven over-torque protection mechanism according to claim 1 , wherein the first teeth set is configured to rotate in a first direction and a second direction that is opposite of the first direction, and the second teeth set is configured to rotate in a single direction.

5. The tooth driven over-torque protection mechanism according to claim 1 , wherein the given cross-sectional shape is one of hexagonal, pentagonal, quadrangular, or triangular.

6. The tooth driven over-torque protection mechanism according to claim 1 , wherein at least one of the upper cam and the toothed gear define an axial opening having a different shape as the shape of the axial opening of the lower cam.

7. The tooth driven over-torque protection mechanism according to claim 1 , wherein at least one of the upper cam and the toothed gear define an axial opening having a same shape as a shape of the axial opening of the lower cam.

8. The tooth driven over-torque protection mechanism according to claim 1 , wherein the second spring has a higher spring constant than the first spring.

9. The tooth driven over-torque protection mechanism according to claim 1 , wherein the first pinion teeth are a two-way teeth set that extends radially outward from the shaft and the second teeth set are a one way teeth set that extends orthogonal to the first pinion teeth set.

10. A tooth driven over-torque protection mechanism for use in a slack adjuster or as an air disc brake clutch, comprising:
a shaft;
a toothed gear that is disposed on the shaft, the toothed gear having a first pinion teeth set that extends along a first direction and a second teeth set that extends along a second direction;
a clutch device that is also disposed on the shaft, the clutch device having an upper cam and a lower cam;
a first spring that biases the toothed gear against the clutch device;
a second spring that biases the clutch device against the toothed gear, wherein the upper cam has cam teeth that cooperate with the second teeth set of the toothed gear in a torque transmitting manner, such that a torque applied in clockwise direction to the first pinion teeth is transmitted to the upper cam through the second teeth set, but torque applied in a counterclockwise direction is opposed by the first spring; and
a locking mechanism interposed between the toothed gear and the upper cam, the locking mechanism being configured to load the second spring, which load corresponds to maximum allowable torque before the clutch device rotates.

11. The tooth driven over-torque protection mechanism according to claim 10 , wherein the locking mechanism comprises at least one of a pair of half-moon shaped locks.

12. The tooth driven over-torque protection mechanism according to claim 11 , wherein the shaft defines a trench that runs around an outer diameter thereof, the trench being configured to receive the pair of half-moon locks or a snap ring.

13. The tooth driven over-torque protection mechanism according to claim 12 , further comprising: a cover that is disposed on the shaft so as to contact the first spring.

14. The tooth driven over-torque protection mechanism according to claim 13 , wherein the cover is removable from the shaft.

15. A slack adjuster for a vehicle brake, comprising:
a housing being configured to be operatively coupled to a brake actuator;
a link disposed in the housing;
a shaft operatively coupled to the link;
a clutch device disposed on the shaft, the clutch device having an upper cam and a lower cam;
at least one spring disposed on the shaft;
tooth driven means for preventing over torque of the slack adjuster, the tooth driven means being disposed on the shaft, wherein
the tooth driven means includes first pinion teeth and a second teeth set, and torque applied in clockwise direction to the first pinion teeth is transmitted to clutch device via the second teeth set, but torque applied in a counterclockwise direction is opposed by the at least one spring; and

a locking mechanism interposed between the toothed driven means and the upper cam, the locking mechanism being configured to load a second spring, which load corresponds to maximum allowable torque before the clutch device rotates.

16. A tooth driven over-torque protected air disc brake clutch, comprising:
a shaft;
a toothed gear that is disposed on the shaft, the toothed gear having a first teeth set that extends along a first direction and a second teeth set that extends along a second direction;
a clutch device that is also disposed on the shaft, the clutch device having an upper cam and a lower cam;
a threaded tube adapter that is disposed on a distal end of the shaft;
a first spring that biases the toothed gear against the clutch device;
a second spring that biases the clutch device against the toothed gear, wherein
the upper cam has cam teeth that cooperate with the second teeth set of the toothed gear, such that a torque applied to the toothed gear is transmitted to the clutch device, and
the cam teeth and the second teeth set of the toothed gear are one-way teeth; and

a locking mechanism interposed between the toothed gear and the upper cam, the locking mechanism being configured to load the second spring, which load corresponds to maximum allowable torque before the clutch device rotates.

Assignees

• Bendix Commercial Vehicle Systems Llc

Inventors

• Oberdorfer Erik W

Classifications

• F16D7/024 Primary

  with axially applied torque limiting friction surfaces · CPC title

• F16D65/52 Primary

  self-acting in one direction for adjusting excessive play · CPC title

• F16D7/044

  the axially moving part being coaxial with the rotation, e.g. a gear with face teeth · CPC title