IP Library › Granted Patent US 12,578,003
Granted Patent B2
US 12,578,003 · App. 18/099,970 · Granted Mar 17, 2026

Hydraulic compression stop with closable windows

Inventors: Mateusz Szymon Sarapata (Wysoka, PL); Dominik Kasprzyk (Debica, PL)
Assignee: BeijingWest Industries Co., Ltd.
F16F9/49F16F9/34
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Quick Facts
Patent No.
US 12,578,003
App. No.
18/099,970
Granted
Mar 17, 2026
Kind
B2
Abstract

A hydraulic compression stop (HCS) assembly includes an HCS base defining an HCS window providing fluid communication between a compression chamber of a damper and an exterior space; a spring guide movable relative to the HCS base by action of a piston; and a closure member attached to the spring guide and configured to selectively and progressively cover a portion of the HCS window to restrict fluid flow therethrough, with the portion of the HCS window covered varying with a position of the spring guide relative to the HCS base. A damper assembly includes a tube defining an interior chamber; a piston slidably disposed in the tube and dividing the interior chamber into a rebound chamber and a compression chamber; and the HCS assembly disposed at least partially within the compression chamber to restrict fluid flow therethrough, the restriction varying in response to the piston moving toward the HCS base.

Claims (48)

1 . A damper assembly comprising:

a tube defining an interior chamber;

a piston slidably disposed in the tube and dividing the interior chamber into a rebound chamber and a compression chamber; and

a hydraulic compression stop (HCS) assembly disposed at least partially within the compression chamber and including an HCS base defining an HCS window providing fluid communication between the compression chamber and an exterior space, the HCS assembly further including a closure member configured to selectively and progressively cover a portion of the HCS window to restrict fluid flow therethrough, the portion of the HCS window covered varying in response to the piston moving toward the HCS base, wherein the HCS base includes an adapter configured to attach to the tube and a replaceable disc defining the HCS window, the replaceable disc including one of a plurality of different discs, each of the different discs having a different configuration of the HCS window.

2 . The damper of claim 1 , further comprising:

a conical belt spring disposed in the compression chamber and including a band of material formed as spiral-shaped coil with a base adjacent to the HCS base; and

wherein the closure member includes the conical belt spring progressively covering the portion of each of the HCS windows in response to the piston compressing the conical belt spring as the piston moves toward the HCS base.

3 . The damper of claim 2 , further comprising:

the conical belt spring including a proximal end adjacent to the HCS base and a distal end opposite the proximal end; and

a spring guide disposed in the compression chamber and attached to the distal end of the conical belt spring, the spring guide configured to engage the piston and to maintain the distal end of the conical belt spring aligned with a center axis of the damper.

4 . The damper of claim 1 , further comprising:

a spring guide disposed in the compression chamber;

a first spring attached to the spring guide and extending from the spring guide toward the HCS base; and

a second spring attached to the spring guide and extending from the spring guide toward the HCS base,

wherein during a compression stroke, during the spring guide being moved toward the HCS base, the first spring firstly starts to cover a first region of the HCS window, and as the spring guide continues to be moved toward the HCS base, the second spring then starts to cover a second region of the HCS window.

5 . The damper of claim 4 , further comprising a third spring extending between the HCS base and the spring guide and configured to bias each of the first spring and the second spring away from the HCS base.

6 . The damper of claim 4 , further comprising:

a first spring cap attached to the first spring opposite the spring guide, the first spring cap configured to selectively cover the first region of the HCS window;

a second spring cap attached to the second spring opposite the spring guide, the second spring cap configured to selectively cover the second region of the HCS window; and

wherein the closure member includes the first spring cap and the second spring cap.

7 . The damper of claim 1 , further comprising: the HCS base defining a return fluid passage configured to transmit fluid from the exterior space and to the compression chamber in response to the piston moving away from the HCS assembly.

8 . The damper of claim 7 , further comprising a check valve configured to allow fluid flow through the return fluid passage from the exterior space and to the compression chamber while blocking fluid flow in an opposite direction.

9 . The damper of claim 8 , wherein the return fluid passage is disposed adjacent to the tube; and wherein the check valve includes a sealing ring extending annularly and adjacent to an interior wall of the tube and configured to selectively cover the return fluid passage to block fluid flow therethrough and in response to a pressure differential between the compression chamber and the exterior space.

10 . The damper of claim 1 , wherein the HCS window is one of a plurality of HCS windows in the HCS base; and

wherein the closure member is configured to selectively and progressively cover a portion of each HCS window of the plurality of HCS windows.

11 . The damper of claim 1 , wherein the closure member includes a rotary disc defining a hole and configured to rotate relative to the HCS base, the rotary disc being rotatable between a first position with the hole overlying the HCS window and a second position with the hole rotationally spaced away from the HCS window and with the rotary disc blocking the HCS window.

12 . The damper of claim 11 , wherein the HCS assembly further comprises a translating member configured to rotate the rotary disc between the first position and the second position in response to a compression force applied thereto.

13 . The damper of claim 12 , wherein the translating member further comprises a pin extending radially outwardly; and

wherein the HCS base defines an inclined grove configured to receive the pin of the translating member to rotate the translating member and the rotary disc in response to the translating member moving axially within the HCS base.

14 . The damper of claim 12 , wherein the HCS assembly further comprises a spring guide located within the compression chamber and a spring compression spring disposed between the spring guide and the translating member, the compression spring imparting the compression force to the translating member in response to the piston biasing the spring guide toward the HCS base.

15 . The damper of claim 12 , wherein the HCS assembly further comprises a return spring disposed between the rotary disc and the translating member, the return spring configured to bias the translating member toward the piston.

16 . The damper of claim 1 , further comprising a safety valve disposed within the HCS base and configured to provide fluid communication between the compression chamber and the exterior space, independent of the HCS window, in response to a pressure differential therebetween exceeding a predetermined safety value, thereby bypassing fluid restriction through the HCS window.

17 . The damper of claim 1 , further comprising:

a housing having a tubular shape disposed around the tube and coaxially therewith to define an exterior chamber extending annularly between the tube and the housing;

an end cap enclosing an end of the housing; and

a base valve disposed in the main chamber of the housing adjacent to the end cap and configured to restrict fluid flow between the exterior space and the exterior chamber.

18 . A hydraulic compression stop (HCS) assembly comprising:

an HCS base defining an HCS window providing fluid communication between a compression chamber of a damper and an exterior space;

a spring guide movable relative to the HCS base by action of a piston; and

a closure member attached to the spring guide and configured to selectively and progressively cover a portion of the HCS window to restrict fluid flow therethrough, with the portion of the HCS window covered varying with a position of the spring guide relative to the HCS base, wherein the HCS base includes an adapter and a replaceable disc defining the HCS window, the replaceable disc including one of a plurality of different discs, each of the different discs having a different configuration of the HCS window.

19 . The damper of claim 18 , further comprising: a spring attached to the spring guide and configured to bias the spring guide away from the HCS base, wherein the closure member comprises the spring.

20 . A damper assembly comprising:

a tube defining an interior chamber;

a piston slidably disposed in the tube and dividing the interior chamber into a rebound chamber and a compression chamber; and

a hydraulic compression stop (HCS) assembly disposed at least partially within the compression chamber and including an HCS base defining an HCS window providing fluid communication between the compression chamber and an exterior space, the HCS assembly further including a closure member configured to selectively and progressively cover a portion of the HCS window to restrict fluid flow therethrough, the portion of the HCS window covered varying in response to the piston moving toward the HCS base,

wherein the damper further comprises:

a conical belt spring disposed in the compression chamber and including a band of material formed as spiral-shaped coil with a base adjacent to the HCS base; and

wherein the closure member includes the conical belt spring progressively covering the portion of each of the HCS windows in response to the piston compressing the conical belt spring as the piston moves toward the HCS base.

Assignments (2)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Jan 23, 2023
From: SARAPATA, MATEUSZ SZYMON; KASPRZYK, DOMINIK
To: BWI POLAND TECHNOLOGIES SP. Z O.O
Reel/Frame 062446/0877 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Jan 23, 2023
From: BWI POLAND TECHNOLOGIES SP. Z O.O
To: BEIJINGWEST INDUSTRIES CO., LTD.
Reel/Frame 062446/0891 →
Priority Claims (1)
CN 202210207655.0 · Mar 3, 2022 · national
Continuity (1)
Related Publication 20230279921A1 · Sep 7, 2023
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