# US 12,000,443 B2 · Brake assembly with active piston retraction

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- Number: US 12,000,443 B2
- Document ID: US12000443B2
- Status: Granted
- Kind: B2
- Application number: 17/502,021
- Filed: 2021-10-14
- Published: 2023-04-20
- Granted: 2024-06-04
- Earliest claimed: 2021-10-14
- Assignees: Hl Mando Corporation
- Applicants: Hl Mando Corporation
- Inventors: Hyungjin Baek; Daniel Smith
- Web page: https://patentgrep.com/patent/US12000443B2

## CPC

- F16D 55/226: in which the common actuating member is moved axially {, e.g. floating caliper disc brakes}
- B60T 1/065: {employing disc (B60T1/062 takes precedence)}
- B60T 13/58: Combined or convertible systems
- B60T 13/741: {acting on an ultimate actuator}
- B60T 13/746: {and mechanical transmission of the braking action}
- F16D 65/18: adapted for drawing members together {, e.g. for disc brakes}
- F16D 65/183: {with force-transmitting members arranged side by side acting on a spot type force-applying member}
- F16D 65/42: non-automatic
- F16D 65/567: {for mounting on a disc brake}
- F16D 2065/386: {driven electrically}
- F16D 2121/24: using motors
- F16D 2125/40: Screw-and-nut
- F16D 2125/58: transmitting linear movement
- F16D 2127/02: Release mechanisms
- F16H 25/20: Screw mechanisms (with automatic reversal F16H25/12)
- F16H 2025/2075: {Coaxial drive motors}
- F16D: COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
- B60T: VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL (electrodynamic brake systems for vehicle, in general B60L; brakes per se, i.e. devices where braking effect occurs, including ultimate brake actuators, F16D); ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES
- F16H: GEARING

## Abstract

A brake assembly comprises: a brake piston configured to be movable for a brake apply or release and having an inner wall forming a piston cavity, wherein a groove is formed on the inner wall of the brake piston; a linearly movable structure positioned within the piston cavity of the brake piston and configured to be linearly movable within the piston cavity; and a resilient material, wherein a part of the resilient material is located within the groove formed on the inner wall of the brake piston and the other part of the resilient material is disposed on an outer surface of the linearly movable structure so that the resilient material is engageable with a surface of the groove formed on the inner wall of the brake piston to move the brake piston by restoring force of the resilient material in response to linear movement of the linearly movable structure.

## Claims

### Claim 1

A brake assembly comprising:
a brake piston configured to be movable for a brake apply or release, the brake piston having an inner wall forming a piston cavity, wherein a groove is formed on the inner wall of the brake piston;
a linearly movable structure positioned within the piston cavity of the brake piston, the linearly movable structure configured to be linearly movable within the piston cavity in response to rotation of a rotatable structure operably coupled to the linearly movable structure; and
a resilient material, wherein at least a part of the resilient material is located within the groove formed on the inner wall of the brake piston and an other part of the resilient material is disposed on an outer surface of the linearly movable structure positioned within the piston cavity of the brake piston so that the resilient material is engageable with side walls of the groove formed on the inner wall of the brake piston to move the brake piston by a restoring force of the resilient material in response to linear movement of the linearly movable structure,
wherein the resilient material does not contact a circumferential surface formed between the side walls of the groove of the brake piston so that the resilient material is movable between the side walls of the groove of the brake piston without contacting the side walls of the groove of the brake piston.

### Claim 2 (depends on 1)

The brake assembly of claim 1, wherein the linearly movable structure positioned within the inner wall of the brake piston is a spindle nut, and the rotatable structure operably coupled to the linearly movable structure is a spindle.

### Claim 3 (depends on 1)

The brake assembly of claim 1, wherein the resilient material fixed to the outer surface of the linearly movable structure is configured to be at least partially deformable in an area of contact with one of the side walls of the groove formed on the inner wall of the brake piston and move the brake piston by the restoring force of the resilient material against one of the side walls of the groove formed on the inner wall of the brake piston.

### Claim 4 (depends on 1)

The brake assembly of claim 1, wherein the resilient material disposed on the outer surface of the linearly movable structure is configured to retract the brake piston during the brake release.

### Claim 5 (depends on 1)

The brake assembly of claim 1, wherein the other part of the resilient material is disposed in another groove formed on the outer surface of the linearly movable structure, and the at least part of the resilient material is positioned within the groove formed on the inner wall of the brake piston.

### Claim 6 (depends on 1)

The brake assembly of claim 1, wherein the linearly movable structure comprises a head portion configured to contact the brake piston during the brake apply, and a body portion extended from the head portion of the linearly movable structure, wherein an outer diameter of the head portion of the linearly movable structure is larger than an outer diameter of the body portion of the linearly movable structure, and the resilient material is mounted to the head portion of the linearly movable structure.

### Claim 7 (depends on 6)

The brake assembly of claim 6, wherein one or more holes are formed at the head portion of the linearly movable structure.

### Claim 8 (depends on 1)

The brake assembly of claim 1, wherein the resilient material is mounted to a portion of the linearly movable structure where an outer diameter of the linearly movable structure is largest.

### Claim 9 (depends on 1)

The brake assembly of claim 1, wherein the resilient material has a shape of an O-ring.

### Claim 10 (depends on 1)

The brake assembly of claim 1, wherein the resilient material has a shape of a polygonal ring.

### Claim 11 (depends on 1)

The brake assembly of claim 1, wherein the groove formed on the inner wall of the brake piston has a space that the resilient material is movable therein.

### Claim 12

A brake assembly comprising:
a caliper having a caliper cavity;
a brake pad coupled to the caliper;
a brake piston mounted in the caliper cavity and configured to be movable to displace the brake pad for a brake apply or release, the brake piston having an inner wall forming a piston cavity, wherein a groove is formed on the inner wall of the brake piston;
a spindle nut positioned within the piston cavity of the brake piston, the spindle nut configured to be linearly movable within the piston cavity in response to rotation of a spindle;
the spindle operably coupled to the spindle nut; and
a resilient material, wherein at least a part of the resilient material is located within the groove formed on the inner wall of the brake piston and an other part of the resilient material is disposed on an outer surface of the spindle nut positioned within the piston cavity of the brake piston so that the resilient material is engageable with side walls of the groove formed on the inner wall of the brake piston to move the brake piston by a restoring force of the resilient material in response to linear movement of the spindle nut,
wherein the resilient material does not contact a circumferential surface formed between the side walls of the groove of the brake piston so that the resilient material is movable between the side walls of the groove of the brake piston without contacting the side walls of the groove of the brake piston.

### Claim 13 (depends on 12)

The brake assembly of claim 12, wherein the resilient material fixed to the outer surface of the spindle nut is configured to be at least partially deformable in an area of contact with one of the side walls of the groove formed on the inner wall of the brake piston so that the resilient material exerts the restoring force against one of the side walls of the groove formed on the inner wall of the brake piston to move the brake piston.

### Claim 14 (depends on 12)

The brake assembly of claim 12, wherein the resilient material disposed on the outer surface of the spindle nut is configured to retract the brake piston during the brake release so that the brake pad is retracted in a direction away from a brake rotor.

### Claim 15 (depends on 12)

The brake assembly of claim 12, wherein the other part of the resilient material is disposed in another groove formed on the outer surface of the spindle nut, and the at least a part of the resilient material is located within the groove formed on the inner wall of the brake piston.

### Claim 16 (depends on 12)

The brake assembly of claim 12, wherein the spindle nut comprises a head portion configured to contact the brake piston during the brake apply, and a body portion extended from the head portion of the spindle nut, wherein an outer diameter of the head portion of the spindle nut is larger than an outer diameter of the body portion of the spindle nut, and the resilient material is mounted to the head portion of the spindle nut.

### Claim 17 (depends on 16)

The brake assembly of claim 16, wherein one or more holes are formed at the head portion of the spindle nut.

### Claim 18 (depends on 12)

The brake assembly of claim 12, wherein the resilient material is mounted to a portion of the spindle nut where an outer diameter of the spindle nut is largest.

### Claim 19 (depends on 12)

The brake assembly of claim 12, wherein the resilient material has a shape of an O-ring or a polygonal ring.

### Claim 20 (depends on 12)

The brake assembly of claim 12, wherein the groove formed on the inner wall of the brake piston has a space that the resilient material is movable therein.