Compression isolator for a suspension damper

• US 9,038,791 B2
• Filed: 09/06/2011
• Issued: 05/26/2015
• Est. Priority Date: 01/07/2009
• Status: Active Grant

• Current Assignee: Fox Factory Incorporated
• Original Assignee: Fox Factory Incorporated
• Inventors: Marking, John
• Primary Examiner(s): SAHNI, VISHAL R
• Application Number:
  US13/226,230
• Publication Number:
  US 20120048665A1
• Time in Patent Office: 1,358 Days
• Field of Search: 188/287, 188313-318
• US Class Current: 188/314
• CPC Class Codes: B60G 13/08 hydraulic
• CPC Class Codes: B60G 2202/24 Fluid damper
• CPC Class Codes: F16F 9/065 Expansion chamber provided on the upper or lower end of a damper, separately there from or laterally on the damper
• CPC Class Codes: F16F 9/185 Bitubular units where compression of gas leads to a clear spring action F16F9/062
• CPC Class Codes: F16F 9/3235 of cylinders F16F9/483 takes precedence
• CPC Class Codes: F16F 9/3405 Throttling passages in or on piston body, e.g. slots F16F9/344, F16F9/3481 take precedence
• CPC Class Codes: F16F 9/346 Throttling passages in the form of slots arranged in cylinder walls
• CPC Class Codes: F16F 9/48 Arrangements for providing different damping effects at different parts of the stroke F16F9/346, F16F9/516 , F16F9/53 take precedence
• CPC Class Codes: 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

Abstract

A method and apparatus for a damper. The damper comprises a fluid chamber having a piston dividing the chamber into a compression and rebound sides, a reservoir in fluid communication with the compression side of the chamber, and an isolator disposed between the compression side and the reservoir, whereby the isolator obstructs fluid flow between the compression side and the reservoir. In one embodiment, a bypass provides a fluid path between the compression side and the isolator.

Claims

1. A vehicle suspension comprising:

a fluid chamber enclosed by a cylindrical wall, the fluid chamber comprising;

a compression side;

a rebound side; and

a piston dividing the fluid chamber into the compression side and the rebound side, wherein the piston comprises;

a first fluid pathway enabling fluid communication between the compression side and the rebound side;

an annular bypass chamber providing a second fluid pathway between the compression side and the rebound side, the annular bypass chamber being co-axially disposed between an outer surface of the cylindrical wall of the fluid chamber and an inner surface of a wall of an outer housing of the vehicle suspension damper and being in fluid communication with the fluid chamber via a set of ports disposed in the cylindrical wall of the fluid chamber; and

a compression isolator disposed at and sealing an end of the compression side between the compression side and a fluid reservoir, wherein the fluid reservoir comprises a floating piston that movably seals a fluid-fillable portion of the fluid reservoir from a gas pocket of the vehicle suspension damper, wherein the fluid-fillable portion of the reservoir collects fluid from the annular bypass chamber, via a third fluid pathway, as a fluid capacity of the compression side of the fluid chamber decreases due to a volume of an encroaching piston rod during a compression stroke, wherein the floating piston transfers pressure between fluid in the fluid-fillable portion of the reservoir and the gas pocket, wherein the third fluid pathway is disposed between the compression isolator and the outer housing.

2. The vehicle suspension damper of claim 1, further comprising:

at least three ports formed in the cylindrical wall of the fluid chamber and permitting fluid communication between the fluid chamber and the annular bypass chamber, the at least three ports being axially spaced along the cylindrical wall, whereby in a first position of the piston, the at least three ports are between the piston and the compression isolator and in a second position of the piston, there are at least two ports of the at least three ports between the piston and the compression isolator.

3. The vehicle suspension damper of claim 2, wherein the fluid flow through the annular bypass chamber is reduced as the piston moves in a compression stroke.

4. The vehicle suspension damper of claim 1, further comprising:

at least three sets of ports, each set including at least one port and each port formed in the cylindrical wall of the fluid chamber and permitting fluid communication between the fluid chamber and the annular bypass chamber, the at least three sets of ports being axially spaced from each other along the cylindrical wall of the fluid chamber, whereby in a first position of the piston, the at least three sets of ports are between the piston and the compression isolator and in a second position of the piston, no more than two sets of ports of the at least three sets of ports are between the piston and the compression isolator.

5. The vehicle suspension damper of claim 4, further comprising:

a third position of the piston in which no sets of the at least three sets of ports are between the piston and the isolator.

6. The vehicle suspension damper of claim 5, wherein in the first and the second position, fluid communicates between the annular bypass chamber, the fluid reservoir, the rebound side and the compression side of the vehicle suspension damper, but in the third position, fluid communicates only between the annular bypass chamber, the fluid reservoir and the rebound side.