Foot brake module with a guiding feature on a relay piston

Patent metadata

Field	Value
Publication number	US-12540682-B2
Application number	US-202318134924-A
Country	US
Kind code	B2
Filing date	Apr 14, 2023
Priority date	Apr 14, 2023
Publication date	Feb 3, 2026
Grant date	Feb 3, 2026

Abstract

A valve assembly is provided comprising: an air supply port; an air delivery port; a guide sleeve; and a piston positioned in the guide sleeve and movable between first and second positions to allow air to flow from the air supply port to the air delivery port, wherein a gap is defined between a minor outer diameter of a shaft of the piston and the guide sleeve; wherein the shaft defines an inner bore for passage of air and comprises a plurality of raised surfaces around a circumference of the shaft that narrows the gap and thereby reduces tilting of the piston as it moves in the guide sleeve between the first and second positions. Other embodiments are provided.

First claim

What is claimed is:

1 . A valve assembly comprising:
an air supply port; an air delivery port; a guide sleeve; and a piston positioned in the guide sleeve and movable between first and second positions to allow air to flow from the air supply port to the air delivery port, wherein a gap is defined between a minor outer diameter of a shaft of the piston and the guide sleeve; wherein the shaft defines an inner bore for passage of air and a plurality of raised surfaces around a circumference of the shaft that narrows the gap and thereby reduces tilting of the piston as it moves in the guide sleeve between the first and second positions.

2 . The valve assembly of claim 1 , wherein the plurality of raised portions comprises three raised portions.

3 . The valve assembly of claim 2 , wherein the three raised portions are arranged in a tri-lobular manner around the circumference of the shaft.

4 . The valve assembly of claim 1 , wherein the plurality of raised portions comprises fewer than eight raised portions.

5 . The valve assembly of claim 1 , further comprising a spring positioned around the piston and configured to induce a moment to cause the piston to tilt as it moves in the guide sleeve.

6 . The valve assembly of claim 1 , further comprising a single O-ring around the piston, wherein the single O-ring is insufficient to prevent the piston from tilting as it moves in the guide sleeve.

7 . The valve assembly of claim 1 , wherein the air supply and delivery ports and the piston are part of a secondary braking circuit of the foot brake assembly.

8 . A valve assembly comprising:
primary and secondary supply ports; primary and secondary delivery ports; a guide sleeve; a first piston configured to move in response to actuation of a brake pedal, wherein movement of the first piston causes air to flow from the primary supply port to the primary delivery port and to cause air to accumulate in a chamber of the foot brake assembly; a second piston configured to move within the guide sleeve in response to an accumulation of air in the chamber, wherein movement of the second piston causes air to flow from the secondary supply port to the secondary delivery port; and a set of guiding features positioned on the second piston to reduce tilting of the second piston in the guide sleeve.

9 . The valve assembly of claim 8 , wherein the set of guiding features comprise a plurality of raised portions.

10 . The valve assembly of claim 8 , wherein the set of guiding features are arranged in a tri-lobular manner around a circumference of a shaft of the piston.

11 . The valve assembly of claim 9 , wherein the set of guiding features comprise fewer than eight guiding features.

12 . The valve assembly of claim 8 , further comprising a spring around the second piston that is capable of inducing a moment to cause the second piston to tilt in the guide sleeve.

13 . The valve assembly of claim 8 , further comprising a single O-ring around the second piston, wherein the O-ring is insufficient to prevent the second piston from tilting in the guide sleeve.

14 . The valve assembly of claim 8 , wherein the set of guiding features are manufactured with the second piston.

15 . The valve assembly of claim 8 , wherein the set of guiding features are added onto the second piston after manufacturing of the second piston.

16 . A valve assembly comprising:
a guide sleeve; a relay piston positioned in the guide sleeve; and means for reducing tilting of the relay piston as it moves in the guide sleeve, wherein the means for reducing tilting comprises a plurality of raised surfaces along a circumference of a shaft of the relay piston.

17 . The valve assembly of claim 16 , wherein the plurality of raised surfaces are arranged in a tri-lobular pattern.

18 . The valve assembly of claim 16 , further comprising a spring positioned around the relay piston so as to induce a moment to cause the relay piston to tilt as it moves in the guide sleeve.

19 . The valve assembly of claim 16 , further comprising only a single O-ring around the relay piston, which is insufficient to prevent the relay piston from tilting as it moves in the guide sleeve.

Assignees

• Bendix Commercial Vehicle Systems Llc

Inventors

• Carbaugh Kristina
• Brubaker Christopher L
• Alvarado Joel
• Rottinger Mark B
• Riley Brian J

Classifications

• B60T15/04

  Driver's valves · CPC title

• F16K17/10

  with auxiliary valve for fluid operation of the main valve · CPC title

• F16K21/04 Primary

  Self-closing valves, i.e. closing automatically after operation {(pneumatic tools B25B9/00)} · CPC title

• B60T13/26 Primary

  Compressed-air systems · CPC title