IP Library Granted Patent US 8,801,017
Granted Patent B2
US 8,801,017 · App. 13/792,154 · Granted Aug 12, 2014

Position dependent damper for a vehicle suspension system

Inventors: Erik S. Ellifson (Oshkosh, WI); Patrick S. Dillman (Lannon, WI); Jason J. Zuleger (Appleton, WI); Aaron J. Rositch (Oshkosh, WI); Robert K. Sollenskog (Oshkosh, WI)
Assignee: Oshkosh Corporation
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Quick Facts
Patent No.
US 8,801,017
App. No.
13/792,154
Granted
Aug 12, 2014
Kind
B2
Abstract

A damper assembly for a vehicle suspension system includes a primary damper and a secondary damper. The secondary damper is coupled to the primary damper and includes a housing and an annular piston. The housing includes a sidewall that partially surrounds the primary damper, and the volume between the sidewall and the primary damper defines a damping chamber. The sidewall defines a plurality of apertures. The annular piston is positioned within the damping chamber and slidably coupled to the sidewall. The primary damper provides a base damping force and the secondary damper provides a supplemental damping force that varies based on the position of the annular piston along the housing.

Claims (32)

1. A damper assembly for a vehicle suspension system, comprising:

a primary damper; and

a secondary damper coupled to the primary damper, comprising:

a housing including a sidewall that partially surrounds the primary damper, the volume between the sidewall and the primary damper defining a damping chamber, wherein the sidewall defines a plurality of apertures including a first set of apertures and a second set of apertures;

an annular piston positioned within the damping chamber and slidably coupled to the sidewall;

a first conduit forming a first flow path between the first set of apertures and a second conduit forming a second flow path between the second set of apertures, wherein movement of the annular piston along the housing activates and deactivates the first flow path and the second flow path; and

a first bidirectional flow valve positioned along the first flow path and a second bidirectional flow valve positioned along the second flow path,

wherein the primary damper provides a base damping force and the secondary damper provides a supplemental damping force that varies based on the position and the travel direction of the annular piston along the housing.

2. The damper assembly of claim 1 , wherein the first bidirectional flow valve produces recoil damping forces when the secondary damper is in a retracted position and the second bidirectional flow valve produces compression damping forces when the secondary damper is in an extended position.

3. The damper assembly of claim 2 , wherein the primary damper and the secondary damper share a common central axis thereby forming a coaxial double damper.

4. A damper assembly for a vehicle suspension system, comprising:

a primary damper, comprising:

a housing including a sidewall that defines an inner volume;

a cap coupled to an end of the housing;

an annular piston slidably coupled to the sidewall and disposed within the inner volume;

a first tubular rod extending through the cap and coupled to the annular piston; and

a tubular member partially surrounding the first tubular rod and coupled to the annular piston; and

a secondary damper coupled to the primary damper, comprising:

a housing including a sidewall that partially surrounds the primary damper, the volume between the sidewall and the primary damper defining a damping chamber, wherein the sidewall defines a plurality of apertures; and

an annular piston positioned within the damping chamber and slidably coupled to the sidewall,

wherein the primary damper provides a base damping force and the secondary damper provides a supplemental damping force that varies based on the position of the annular piston of the secondary damper along the housing.

5. The damper assembly of claim 4 , wherein the annular piston of the secondary damper is moveably coupled to the annular piston of the primary damper.

6. The damper assembly of claim 5 , wherein the annular piston of the primary damper and the annular piston of the secondary damper share a common central axis thereby forming a coaxial double damper.

7. The damper assembly of claim 5 , further comprising a conduit coupling at least two apertures, the conduit defining at least a portion of a flow path between the at least two apertures.

8. The damper assembly of claim 7 , further comprising a bidirectional flow valve disposed along the flow path, the bidirectional flow valve providing a first level of damping as the annular piston of the secondary damper extends from a first position to a second position and a second level of damping as the annular piston of the secondary damper retracts from the second position to the first position.

9. A damper assembly for a vehicle suspension system, comprising:

a housing including a sidewall that defines an inner volume, a first set of apertures including a first aperture positioned at a first end of the housing, and a second set of apertures including a second aperture positioned at a second end of the housing;

a piston disposed within the inner volume and extensible between a first position and a second position;

a first conduit extending between the first set of apertures and defining a first flow path;

a second conduit extending between the second set of apertures and defining a second flow path; and

a bidirectional flow valve positioned along the first flow path, the bidirectional flow valve providing a first level of damping as the piston extends from the first position to the second position and a second level of damping as the piston retracts from the second position to the first position.

10. The damper assembly of claim 9 , further comprising a second bidirectional flow valve positioned along the second flow path, wherein the first bidirectional flow valve and the second bidirectional flow valve have different damping characteristics.

Assignments (3)
MERGER Recorded Jan 20, 2017
From: OSHKOSH CORPORATION
To: OSHKOSH DEFENSE, LLC
Reel/Frame 041027/0796 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Apr 18, 2014
From: ELLIFSON, ERIK S.; DILLMAN, PATRICK S.; ZULEGER, JASON J.; ROSITCH, AARON J.; SOLLENSKOG, ROBERT K.
To: OSHKOSH CORPORATION
Reel/Frame 032710/0396 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Mar 4, 2014
From: ELLIFSON, ERIK S; DILLMAN, PATRICK S; ZULEGER, JASON J
To: OSHKOSH CORPORATION
Reel/Frame 032344/0901 →
Continuity (2)
Provisional Application 61615717 · Mar 26, 2012
Related Publication 20130249183A1 · Sep 26, 2013