# US 11,898,620 B2 · Hydraulic damper with piston assembly having blow-off valves

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 11,898,620 B2
- Document ID: US11898620B2
- Status: Granted
- Kind: B2
- Application number: 17/670,456
- Filed: 2022-02-12
- Published: 2022-10-13
- Granted: 2024-02-13
- Earliest claimed: 2021-04-12
- Assignees: Beijingwest Industries Co., Ltd.
- Applicants: BeijingWest Industries Co., Ltd.
- Inventors: Jakub Wrzesinski; Pawel Slusarczyk; Bartlomiej Franczyk
- Web page: https://patentgrep.com/patent/US11898620B2

## CPC

- F16F 9/348: Throttling passages in the form of annular discs {or other plate-like elements which may or may not have a spring action}, operating in opposite directions {or singly, e.g. annular discs positioned on top of the valve or piston body (F16F9/341, F16F9/3415 take precedence)}
- F16F 9/10: using liquid only; using a fluid of which the nature is immaterial
- F16F 9/3214: {of pistons (F16F9/0227 and F16F9/36 take precedence; throttling passages in or on piston body F16F9/3405)}
- F16F 9/3482: {the annular discs being incorporated within the valve or piston body (F16F9/3484, F16F9/3485 take precedence)}
- F16F 9/512: Means responsive to load action, {i.e. static load} on the damper or {dynamic} fluid pressure {changes} in the damper, {e.g. due to changes in velocity (F16F9/504, F16F9/516 take precedence; non-automatic damper adjustment from a distance using servo control, the servo pressure being created by the flow of damping fluid F16F9/465; self-pumping fluid springs in vehicle suspensions B60G17/044)}
- F16F: SPRINGS; SHOCK-ABSORBERS; MEANS FOR DAMPING VIBRATION

## Abstract

The present invention relates to a hydraulic damper comprising a tube and a piston assembly provided with rebound valve assemblies and compression valve assemblies, wherein each valve assembly comprises a deflectable-disc valve and a blow-off valve. The piston assembly comprises two sleeve-shaped members each provided with a plurality of blow-off valve flow passages, a plurality of deflectable-disc valve flow passages, and a central opening, wherein the piston rod passes through said central openings to secure the piston assembly, a plurality of deflectable disc(s) of the deflectable-disc valve cover(s) said deflectable-disc valve flow passages , wherein a plurality of disc(s) of the blow-off valve adjoin(s) said blow-off valve flow passages, wherein the piston assembly further comprises two spring seats abutting said disc(s) of the blow-off valve, and at least one spring disposed within said internal chamber that biases said spring seats towards said number of discBP-S20010US(s).

## Claims

### Claim 1

A hydraulic damper (1), comprising:
a tube (3) filled with working liquid;
a piston assembly (4) disposed slidably inside the tube (3), dividing the tube (3) into a rebound chamber (11) and a compression chamber (12), the piston assembly including two sleeve-shaped members (44), a rebound valve assembly (41r, 42r), and a compression valve assembly (41c, 42c), wherein each of the rebound valve assembly (41r, 42r) and the compression valve assembly (41c, 42c) includes a deflectable-disc valve (41) and a blow-off valve (42);
an internal chamber (43) extending between the two sleeve-shaped members (44);
a piston rod (5) attached to the piston assembly (4) and extending outside the tube (3) through a sealed piston rod guide (6);
wherein each of the sleeve-shaped members (44) defines a plurality of blow-off valve flow passages (442), which are radially proximal, a plurality of deflectable-disc valve flow passages (441), which are radially distal, and a central opening (443),
wherein the piston rod (5) passes through said central openings (443) in each of said sleeve-shaped members (44);
each of the deflectable-disc valves (41) including at least one deflectable disc (411) covering an external end of said deflectable-disc valve flow passages (441) of a corresponding one of said sleeve-shaped members (44);
wherein each of said at least one deflectable disc (411) is axially fixed at said piston rod and defines a plurality of radially proximal flow passages (4111) corresponding to said blow-off valve flow passages (442) of a corresponding one of said sleeve-shaped members (44);
each of the blow-off valves (42) including at least one disc (422, 423) adjoining an internal end of said blow-off valve flow passages (442) of a corresponding one of said sleeve-shaped members (44);
wherein a flow channel (4221, 426) fluidly connects said internal chamber (43) with said blow-off valve flow passages (442) of each sleeve-shaped members (44); and
wherein the piston assembly (4) further comprises a spring seat (425) abutting said at least one disc (422, 423) of each of the blow-off valves (42), and at least one spring (47) disposed within said internal chamber (43) and configured to bias said spring seats (425) towards said at least one disc (422, 423).

### Claim 2 (depends on 1)

The hydraulic damper according to claim 1, wherein said sleeve-shaped members (44) each include a cylindrical section (444) that extends annularly around said internal chamber (43) of the piston assembly (4a), and wherein said piston assembly (4) further includes an annular seal (45) configured to seal between the cylindrical sections (444) and the tube.

### Claim 3 (depends on 1)

The hydraulic damper according to claim 1, wherein the piston assembly (4b, 4d, 4e) further comprises a body (48) defining said internal chamber (43) of the piston assembly (4b, 4d, 4e) and is provided with an annular seal (45) configured to seal against the tube.

### Claim 4 (depends on 1)

The hydraulic damper according to claim 1, wherein said at least one disc (422, 423) of the blow-off valve (42) is deflectable or displaceable.

### Claim 5 (depends on 1)

The hydraulic damper according to claim 1, wherein said piston assembly (4d, 4e) further comprises at least one internal flange (483, 491) and said at least one spring (47e, 47f) disposed within said internal chamber (23) is compressed between said internal flange (483, 491) and one of said spring seats (425) and biases said one of said spring seats (425) towards said at least one disc (422, 423).

### Claim 6 (depends on 5)

The hydraulic damper according to claim 5, wherein the piston assembly (4d) further comprises at least one insert (49) disposed within said internal chamber (43) and including said at least one internal flange (491).

### Claim 7 (depends on 5)

The hydraulic damper according to claim 5, wherein the piston assembly (4d) further comprises at least one second spring (47d) disposed within said internal chamber (43) and compressed between said internal flange (483, 491) and one of said spring seats (425), and biases said one of said spring seats (425) towards said at least one disc (422, 423).

### Claim 8 (depends on 1)

The hydraulic damper according to claim 1, wherein said internal chamber (43) is cylindrical.

### Claim 9 (depends on 1)

The hydraulic damper according to claim 1, wherein said rebound valve assemblies (41r, 42r) and said compression valve assemblies (41c, 42c) are made of identical parts.

### Claim 10 (depends on 1)

The hydraulic damper according to claim 1, wherein said flow channel is defined by a plurality of radially external notches (4221) of the at least one disc (422, 423) of the blow-off valve (42).

### Claim 11 (depends on 1)

The hydraulic damper according to claim 1, wherein said flow channel is defined by a space separating the at least one disc (422, 423) and said blow-off valve flow passages (442) of the blow-off valve (42).

### Claim 12 (depends on 2)

The hydraulic damper according to claim 2, wherein said cylindrical sections (444) of said sleeve-shaped members (44a) define an annular gap (447) therebetween, and the piston assembly (4a) further comprises an internal sleeve (448) disposed within said internal chamber (43) abutting an internal wall of each of said cylindrical sections (444) and covering said annular gap (447).

### Claim 13 (depends on 2)

The hydraulic damper according to claim 2, wherein said cylindrical sections (444) of said sleeve-shaped members (44a) define an annular gap (447) therebetween, and said annular seal (45) includes a narrowed section (451) defining an annular chamber (453) between said annular seal (45) and the tube (3), said annular seal (45) defining a plurality of radial openings (452) that fluidly join said internal chamber (43) of the piston assembly (4a) with said annular chamber (453) to balance hydraulic pressure therebetween.

### Claim 14 (depends on 1)

The hydraulic damper according to claim 1, wherein the hydraulic damper is a motor vehicle hydraulic suspension damper.