IP Library Granted Patent US 12,409,697
Granted Patent B2
US 12,409,697 · App. 18/144,792 · Granted Sep 9, 2025

Self-pumping spring preload system

Inventor: Connor Randall (Salida, CO)
Assignee: Fox Factory, Inc.
B60G17/0272B60G15/066B60G17/021B60G2202/24B60G2202/312B60G2500/114B60G2500/20
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Quick Facts
Patent No.
US 12,409,697
App. No.
18/144,792
Granted
Sep 9, 2025
Kind
B2
Abstract

A spring preload system comprising a cylinder with an outer diameter, a body to house at least the cylinder, a piston shaft, and a main damping piston. The main damping piston is coupled to the piston shaft and configured for operation within the cylinder. The main damping piston is further configured to divide the cylinder into a compression side and a rebound side. The spring preload system further comprises a preload cylinder and a valve that is fluidly disposed between the compression side and the preload cylinder.

Claims (63)

1. A spring preload system comprising:

a cylinder, said cylinder comprising an outer diameter;

a body to house at least said cylinder;

a piston shaft;

a main damping piston, said main damping piston coupled to said piston shaft and configured for operation within said cylinder, said main damping piston configured to divide said cylinder into a compression side and a rebound side;

a reservoir fluidly coupled with said cylinder via a pair of parallel fluid flow pathways, said parallel fluid flow pathways comprising:

a first fluid flow pathway comprising a base valve fluidly disposed between said cylinder and said reservoir; and

a second fluid flow pathway comprising:

a preload cylinder to provide for a change in a suspension preload, wherein said suspension preload is changed by a pressure change of a fluid in said preload cylinder;

an orifice fluidly disposed between said compression side and said preload cylinder; and

a valve fluidly disposed between said preload cylinder and said reservoir, wherein a flow passage of said valve is larger than a flow passage of said orifice, and wherein said valve is configured to control a pressure of said fluid in said preload cylinder.

2. The spring preload system of claim 1 wherein said reservoir is a remote reservoir; and

said base valve meters fluid flow between said compression side and said remote reservoir.

3. The preload cylinder of claim 1 further comprising:

a preload flange, wherein said preload flange is disposed around said outer diameter, wherein said preload flange moves along said cylinder;

a cavity, said cavity formed by said cylinder, said preload flange, and said body; and

a spring, wherein said spring is braced against said preload flange.

4. The spring preload system of claim 1 wherein, a compression stroke is used to pump fluid into said preload cylinder in order to increase the preload.

5. The spring preload system of claim 1 wherein, when said valve is in an open position there is a decrease in the preload and the compression damping.

6. The spring preload system of claim 1 wherein, when said valve is in a closed position there is an increase in the preload and the compression damping.

7. The spring preload system of claim 1 wherein, changes in the preload will also change the damping.

8. A spring preload system comprising:

a cylinder, said cylinder comprising an outer diameter;

a body to house at least said cylinder;

a piston shaft;

a main damping piston, said main damping piston coupled to said piston shaft and configured for operation within said cylinder, said main damping piston configured to divide said cylinder into a compression side and a rebound side;

a reservoir fluidly coupled with said cylinder via a pair of parallel fluid flow pathways, said parallel fluid flow pathways comprising:

a first fluid flow pathway comprising a base valve fluidly disposed between said cylinder and said reservoir; and

a second fluid flow pathway comprising:

a preload cylinder to provide for a change in a suspension preload, wherein said suspension preload is changed by a pressure change of a fluid in said preload cylinder;

an orifice fluidly disposed between said compression side and said preload cylinder; and

a valve fluidly disposed between said preload cylinder and said reservoir, wherein a flow passage of said valve is larger than a flow passage of said orifice, and wherein said valve is configured to control a pressure of said fluid in said preload cylinder; and

wherein said preload cylinder comprises;

a preload flange, wherein said preload flange is disposed around said outer diameter, wherein said preload flange moves along said cylinder;

a cavity, said cavity formed by said cylinder, said preload flange, and said body; and

a spring, wherein said spring is braced against said preload flange.

9. The spring preload system of claim 8 wherein said reservoir is a remote reservoir; and

said base valve meters fluid flow between said compression side and said remote reservoir.

10. The spring preload system of claim 8 wherein, a compression stroke is used to pump fluid into said preload cylinder in order to increase the preload.

11. The spring preload system of claim 8 wherein, when said valve is in an open position there is a decrease in the preload and the compression damping.

12. The spring preload system of claim 8 wherein, when said valve is in a closed position there is an increase in the preload and the compression damping.

13. The spring preload system of claim 8 wherein, changes in the preload will also change the damping.

14. A suspension system comprising:

a cylinder, said cylinder comprising an outer diameter;

a body to house at least said cylinder;

a piston shaft;

a main damping piston, said main damping piston coupled to said piston shaft and configured for operation within said cylinder, said main damping piston configured to divide said cylinder into a compression side and a rebound side;

a reservoir fluidly coupled with said cylinder via a pair of parallel fluid flow pathways, said parallel fluid flow pathways comprising:

a first fluid flow pathway comprising a base valve fluidly disposed between said cylinder and said reservoir; and

a second fluid flow pathway comprising a spring preload system, said spring preload system comprising:

a preload cylinder to provide for a change in a suspension preload, wherein said suspension preload is changed by a pressure change of a fluid in said preload cylinder;

an orifice fluidly disposed between said compression side and said preload cylinder; and

a valve fluidly disposed between said preload cylinder and said reservoir, wherein a flow passage of said valve is larger than a flow passage of said orifice, and wherein said valve is configured to control a pressure of said fluid in said preload cylinder.

15. The suspension system of claim 14 wherein said reservoir is a remote reservoir; and

said base valve meters fluid flow between said compression side and said remote reservoir.

16. The preload cylinder of claim 14 further comprising:

a preload flange, wherein said preload flange is disposed around said outer diameter, wherein said preload flange moves along said cylinder;

a cavity, said cavity formed by said cylinder, said preload flange, and said body; and

a spring, wherein said spring is braced against said preload flange.

17. The suspension system of claim 14 wherein, a compression stroke is used to pump fluid into said preload cylinder in order to increase the preload.

18. The suspension system of claim 14 wherein, when said valve is in an open position there is a decrease in the preload and the compression damping.

19. The suspension system of claim 14 wherein, when said valve is in a closed position there is an increase in the preload and the compression damping.

20. The suspension system of claim 14 wherein, changes in the preload will also change the damping.

Assignments (1)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Jul 7, 2025
From: RANDALL, CONNOR
To: FOX FACTORY, INC.
Reel/Frame 071622/0176 →
Continuity (2)
Provisional Application 63339342 · May 6, 2022
Related Publication 20240116324A1 · Apr 11, 2024
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