Limiting system for a vehicle suspension component

Patent metadata

Field	Value
Publication number	US-2018335104-A1
Application number	US-201816041229-A
Country	US
Kind code	A1
Filing date	Jul 20, 2018
Priority date	Mar 10, 2013
Publication date	Nov 22, 2018
Grant date	—

Abstract

The damper assembly includes a tubular member, a rod, a primary piston, a secondary piston, and a resilient member. The tubular member includes a sidewall and a cap positioned at an end of the sidewall. The sidewall and the cap define an inner volume. The sidewall includes a shoulder separating the tubular member into a first portion and a second portion. The resilient member is disposed between the secondary piston and the cap and thereby is positioned to bias the secondary piston into engagement with the shoulder.

First claim

What is claimed is:

1 . A damper assembly, comprising:
a tubular member including a sidewall and a cap positioned at an end of the sidewall, the sidewall and the cap defining an inner volume, wherein the sidewall includes a shoulder separating the tubular member into a first portion and a second portion; a rod extending within the inner volume; a primary piston positioned within the inner volume and coupled to the rod, the primary piston defining a first contact surface; a secondary piston including a body member having a second contact surface, an opposing second surface, and an inner cylindrical face defining a central aperture that receives the rod, the secondary piston defining a channel extending from the inner cylindrical face to an outer periphery of the body member, wherein the primary piston and the secondary piston separate the inner volume into a first working chamber, a second working chamber, and a recoil chamber; and a resilient member disposed between the secondary piston and the cap and thereby positioned to bias the secondary piston into engagement with the shoulder; wherein the first contact surface and the channel are configured to cooperatively define a flow conduit upon engagement between the primary piston and the secondary piston; wherein the second contact surface is configured to engage the first contact surface such that an open flow path is formed from the recoil chamber through the central aperture and the flow conduit upon engagement between the primary piston and the secondary piston.

2 . The damper assembly of claim 1 , wherein the primary piston is moveable within the tubular member between a first location, an intermediate location, and an end of stroke, and wherein the primary piston is configured to maintain engagement with the secondary piston between the intermediate location and the end of stroke.

3 . The damper assembly of claim 1 , wherein the recoil chamber is defined between the opposing second surface of the secondary piston and the cap.

4 . The damper assembly of claim 2 , wherein the damper assembly provides a base level of damping as the primary piston moves between the first location and the intermediate location and an increased level of damping as the primary piston moves between the intermediate location and the end of stroke.

5 . The damper assembly of claim 1 , wherein the primary piston, the first portion, and the second portion have circular cross-sectional shapes.

6 . The damper assembly of claim 5 , wherein the first portion has a first diameter and the second portion has a second diameter, wherein the first diameter is greater than the second diameter, and wherein the transition between the first portion and the second portion defines the shoulder.

7 . The damper assembly of claim 6 , wherein the diameter of the primary piston is less than the second diameter such that the primary piston is extendable along the length of the tubular member.

8 . The damper assembly of claim 1 , further comprising a seal disposed between the outer periphery of the secondary piston and the sidewall of the tubular member.

9 . A damper assembly, comprising:
a housing having an end cap and defining an inner volume including a first portion and a second portion, wherein the transition between the first portion and the second portion defines a shoulder; a primary piston positioned within the housing; and a limiter positioned between the primary piston and the end cap, the limiter comprising:
a damper piston including a body member having a contact surface, an opposing second surface, and an inner cylindrical face that defines an aperture through a central portion of the body member, the primary piston and the damper piston separating the inner volume into a first working chamber, a second working chamber, and a recoil chamber; and
a resilient member disposed within the recoil chamber, between the opposing second surface of the damper piston and the end cap, the resilient member thereby positioned to bias the damper piston into engagement with the shoulder; and
a rod coupled to the primary piston and extending through the aperture defined by the damper piston; wherein the damper piston defines a channel extending laterally outward from the inner cylindrical face across the contact surface to an outer periphery of the body member, wherein the primary piston and the channel are configured to cooperatively define a first flow conduit upon engagement between the primary piston and the damper piston; and wherein an outer surface of the rod and the inner cylindrical face of the damper piston define a second flow conduit, and wherein the first flow conduit and the second flow conduit cooperate to define an open flow path from the recoil chamber.

10 . The damper assembly of claim 9 , wherein the primary piston, the first portion, and the second portion have circular cross-sectional shapes.

11 . The damper assembly of claim 10 , wherein the first portion has a first diameter and the second portion has a second diameter, wherein the first diameter is greater than the second diameter, and wherein the transition between the first portion and the second portion defines the shoulder.

12 . The damper assembly of claim 11 , wherein the diameter of the primary piston is less than the second diameter such that the primary piston is extendable along the length of the housing.

13 . The damper assembly of claim 12 , wherein the primary piston and the housing cooperatively define a space around an outer periphery of the primary piston thereby providing a flow path around the outer periphery of the primary piston.

14 . The damper assembly of claim 9 , wherein an end of the rod is coupled to the primary piston.

15 . The damper assembly of claim 9 , wherein the primary piston is moveable within the housing between a first location, an intermediate location, and an end of stroke, and wherein the primary piston is configured to maintain engagement with the limiter between the intermediate location and the end of stroke.

16 . The damper assembly of claim 15 , wherein the damper assembly provides a base level of damping as the primary piston moves between the first location and the intermediate location and an increased level of damping as the primary piston moves between the intermediate location and the end of stroke.

17 . The damper assembly of claim 9 , wherein the recoil chamber is defined between the opposing second surface of the damper piston and the end cap.

18 . The damper assembly of claim 9 , wherein the limiter further comprises a ring coupling the damper piston to the housing, wherein the ring comprises a polymeric seal.

19 . A damper assembly, comprising:
a housing having an end cap and defining an inner volume including a first portion and a second portion, wherein the transition between the first portion and the second portion defines a shoulder; a primary piston positioned within the housing; and a limiter positioned between the primary piston and the end cap, the limiter comprising:
a damper piston including a body member having a contact surface, an opposing second surface, and an inner cylindrical face that defines an aperture through a central portion of the body member, the primary piston and the damper piston separating the inner volume into a first working chamber, a second working chamber, and a recoil chamber; and
a resilient member disposed within the recoil chamber, between the opposing second surface of the damper piston and the end cap, the resilient membe

Assignees

• Oshkosh Defense Llc

Inventors

• Dillman Patrick S
• Ellifson Erik S
• Rositch Aaron J

Classifications

• F16F9/16

  involving only straight-line movement of the effective parts {(wing closers or openers with liquid piston brakes E05F3/04)} · CPC title

• F16F9/512

  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)} · CPC title

• F16F9/368

  Sealings in pistons · CPC title

• F16F2222/12

  Fluid damping · CPC title

• F16F9/49 Primary

  Stops limiting fluid passage, e.g. hydraulic stops {or elastomeric elements inside the cylinder which contribute to changes in fluid damping (fluid-actuated displacement devices with means for accelerating or decelerating the stroke F15B15/22)} · CPC title