Reduced profile piston adjuster

Patent metadata

Field	Value
Publication number	US-12577993-B2
Application number	US-202318193166-A
Country	US
Kind code	B2
Filing date	Mar 30, 2023
Priority date	Mar 30, 2023
Publication date	Mar 17, 2026
Grant date	Mar 17, 2026

Abstract

In some examples a piston-bushing assembly includes a bushing with an opening and a piston slidably disposed within the bushing. The piston includes a bottom end disposed within the bushing and an exterior end extending a distance outward from the opening of the bushing. The exterior end of the piston is configured to engage with a disc stack of a brake assembly. The piston-bushing assembly also includes an adjuster tube including a first end of the adjuster tube, wherein, when the piston-bushing assembly is in an unactuated state, a length between the first end of the adjuster tube and the bottom end of the piston defines a step-back gap.

First claim

What is claimed is:

1 . A piston-bushing assembly comprising:
a bushing comprising an opening; a piston slidably disposed within the bushing, the piston comprising:
a bottom end disposed within the bushing; and
an exterior end extending a distance outward from the opening of the bushing and
configured to engage with a disc stack of a brake assembly; an adjuster tube comprising a first end of the adjuster tube; and an expander disposed within the adjuster tube, wherein when the piston-bushing assembly is in an unactuated state, a length between the first end of the adjuster tube and the bottom end of the piston defines a step-back gap, and wherein when the piston-bushing assembly is in an actuated state, an actuation force causes the bottom end of the piston to directly contact the first end of the adjuster tube and apply a compressive force between the bottom end of the piston and the expander to cause the adjuster tube to slip over the expander in response to the compressive force exceeding a threshold.

2 . The piston-bushing assembly of claim 1 ,
wherein the distance comprises a first distance, and wherein the adjuster tube is configured to slip over the expander in response to the compressive force exceeding threshold to allow the exterior end of the piston to extend a second distance outward from the opening of the bushing wherein the second distance is larger than the first distance.

3 . The piston-bushing assembly of claim 2 , wherein the adjuster tube is configured not to buckle in response to the compressive force.

4 . The piston-bushing assembly of claim 1 , further comprising:
a spring retainer disposed within the piston; and a spring disposed within the piston, wherein the spring sits against the bottom end of the piston and biases the spring retainer against the adjuster tube.

5 . The piston-bushing assembly of claim 4 ,
wherein the piston comprises a generally cylindrical body defining an interior wall, wherein the spring comprises a helix defining an outer diameter and an inner diameter, wherein the outer diameter of the spring is adjacent the interior wall, and wherein the inner diameter of the spring is adjacent the adjuster tube.

6 . The piston-bushing assembly of claim 4 ,
wherein the distance comprises a first distance; wherein the spring retainer is configured to apply a tensile force to the adjuster tube, and wherein the adjuster tube is configured to slip over the expander at least partially in response to the tensile force to allow the exterior end of the piston to extend a second distance outward from the opening of the bushing wherein the second distance is larger than the first distance.

7 . The piston-bushing assembly of claim 6 ,
wherein the adjuster tube is configured to slip over the expander in response to a combination of both the compressive force and the tensile force exceeding the threshold, allowing the exterior end of the piston to extend the second distance outward from the opening of the bushing.

8 . The piston-bushing assembly of claim 1 , wherein the adjuster tube comprises a metal alloy material.

9 . The piston-bushing assembly of claim 1 , further comprising an actuator configured to cause the exterior end of the piston to translate outward from the bushing in response to one or more of a pressurized hydraulic fluid and/or an electric motor.

10 . An assembly comprising:
a wheel configured to rotate around a wheel axis; a brake assembly comprising:
a disc stack comprising a rotor disc and a stator disc, wherein the rotor disc is rotationally coupled to the wheel, and wherein the wheel is configured to rotate relative to the stator disc; and
an actuator configured to compress the disc stack via a piston-bushing assembly comprising:
a bushing comprising an opening;
a piston slidably disposed within the bushing, comprising:
a bottom end disposed within the bushing; and
an exterior end extending a distance outward from the opening of the bushing and configured to engage with the disc stack of the brake assembly;

an adjuster tube comprising a first end of the adjuster tube; and
an expander disposed within the adjuster tube,
wherein when the piston-bushing assembly is in an unactuated state, a length between the first end of the adjuster tube and the bottom end of the piston defines a step-back gap, and
wherein the actuator is configured to actuate the piston-bushing assembly and cause an actuation force to push on and cause the bottom end of the piston to directly contact the first end of the adjuster tube and apply a compressive force between the bottom end of the piston and the expander to cause the adjuster tube to slip over the expander in response to the compressive force exceeding a threshold.

11 . The assembly of claim 10 ,
wherein the distance comprises a first distance, and wherein the adjuster tube is configured to slip over the expander in response to the compressive force exceeding a threshold to allow the exterior end of the piston to extend a second distance outward from the opening of the bushing wherein the second distance is larger than the first distance.

12 . The assembly of claim 11 , wherein the adjuster tube is configured not to buckle in response to the compressive force.

13 . The assembly of claim 10 , further comprising:
a spring retainer disposed within the piston; and a spring disposed within the piston, wherein the spring sits against the bottom end of the piston and biases the spring retainer against the adjuster tube.

14 . The assembly of claim 13 ,
wherein the piston comprises a generally cylindrical body defining an interior wall, wherein the spring comprises a helix defining an outer diameter and an inner diameter, wherein the outer diameter of the spring is adjacent the interior wall, and wherein the inner diameter of the spring is adjacent the adjuster tube.

15 . The assembly of claim 13 ,
wherein the distance comprises a first distance; wherein the spring retainer is configured to apply a tensile force to the adjuster tube, and wherein the adjuster tube is configured to slip over the expander at least partially in response to the tensile force to allow the exterior end of the piston to extend a second distance outward from the opening of the bushing wherein the second distance is larger than the first distance.

16 . The assembly of claim 15 ,
wherein the adjuster tube is configured to slip over the expander in response to a combination of both the compressive force and the tensile force exceeding the threshold, allowing the exterior end of the piston to extend the second distance outward from the opening of the bushing.

17 . The assembly of claim 11 , wherein the expander is configured to remain stationary with respect to the bushing during actuation of the piston-bushing assembly.

18 . The assembly of claim 10 , wherein the adjuster tube comprises a metal alloy material.

19 . The assembly of claim 10 , wherein compression of the disc stack results in a braking force applied to the wheel.

20 . The assembly of claim 10 , wherein the actuator is configured to cause the exterior end of the piston to translate outward from the bushing in response to one or more of a pressurized hydraulic fluid and/or an electric motor.

Assignees

• Honeywell Int Inc

Inventors

• Pajak William E
• Beehler Jonathan T
• Shula Brian

Classifications

• F16D2125/06

  Pistons · CPC title

• F16D2121/04

  acting on a piston-type actuator, e.g. for liquid pressure · CPC title

• F16D2055/0075

  Constructional features of axially engaged brakes · CPC title

• F16D2055/0008

  Brake supports · CPC title

• F16D65/18

  adapted for drawing members together {, e.g. for disc brakes} · CPC title