US 6,604,751 B2 · Inertia valve shock absorber

Abstract

A dampener including a valve movable between an open position and a closed position to selectively alter the compression damping rate of the shock absorber. The valve may include a self-centering feature which operates to keep the valve body centered about the valve shaft. The dampener may also include a timer feature, which retains the valve in an open position for a predetermined period of time after it is initially opened.

Drawings

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Drawings

Claims13

Dependent claims

An acceleration-sensitive dampener, comprising:

a cylinder at least partially defining a first chamber containing a source of fluid;
a piston movable with respect to said first chamber;
a second chamber defined by said dampener;
a first flow circuit connecting said first chamber and said second chamber;
a shaft defining a first surface;
and
an inertial mass defining a second surface facing said first surface, said first surface and said second surface cooperating to define a first annular passage and a second annular passage, said first annular passage having a first portion defining a first cross-sectional flow area and a second portion defining a second cross-sectional flow area greater than said first cross-sectional flow area, said shaft defining an opening communicating with said source of fluid, said shaft and said inertia mass having a first position wherein said fluid flows at a first rate of flow through said opening and said first annular passage and said second annular passage straddle said opening, and a second position wherein said fluid flows at a second rate of flow through said opening greater than said first rate of flow and said first annular passage and said second annular passage both extend to one side of said opening and wherein in said first position, fluid flows from said second cross-sectional area to said first cross-sectional area and, for a given fluid pressure through said opening, fluid flow through said first cross-sectional area defines a first velocity and fluid flow through said second cross-sectional area defines a second velocity, wherein said first velocity is greater than said second velocity, so that said first surface and said second surface produce, in the presence of forces tending to push said first surface off-center with respect to said second surface, forces which tend to center said first surface with respect to said second surface.

4 more elements

Dependencies are inferred from the claim text.

Description22,698 words

Summary3,793 words

#1. Field of the Invention

#The present invention relates to vehicle suspensions systems. More particularly, the present invention relates to acceleration sensitive damping arrangements suitable for use in vehicle dampeners (e.g., shock absorbers, struts, front forks).

#2. Description of the Related Art

Brief description of the drawings32 figures

#These and other features of the dampener will now be described with reference to drawings of preferred embodiments. The embodiments are illustrated in the context of use on an off-road bicycle, however, these embodiments are merely intended to illustrate, rather than limit, the present invention. The drawings contain the following figures:

#FIG. 1 is a perspective view of a bicycle including preferred front and rear shock absorbers;

#FIG. 2 is a cross-section of the rear shock absorber of FIG. 1;

Detailed description18,201 words

#FIG. 1 illustrates an off-road bicycle, or mountain bike, 20 including a frame 22 which is comprised of a main frame portion 24 and a swing arm portion 26. The swing arm portion 26 is pivotally attached to the main frame portion 24. The bicycle 20 includes front and rear wheels 28, 30 connected to the main frame 24. A seat 32 is connected to the main frame 24 and provides support for a rider of the bicycle 20.

#The front wheel 28 is supported by a preferred embodiment of a suspension fork 34 which, in turn, is secured to the main frame 24 by a handlebar assembly 36. The rear wheel 30 is connected to the swing arm portion 26 of the frame 22. A preferred embodiment of a rear shock 38 is operably positioned between the swing arm 26 and the main frame 24 to provide resistance to the pivoting motion of the swing arm 26. Thus, the illustrated bicycle 20 includes suspension members 34, 38 between the front and rear wheels 28, 30 and the frame 22, which operate to substantially reduce wheel impact forces from being transmitted to the rider of the bicycle 20. The rear shock absorber 38 desirably includes a fluid reservoir 44 hydraulically connected to the main shock body by a hydraulic hose 46. Preferably, the reservoir 44 is connected to the swingarm portion 26 of the bicycle 20 above the hub axis of the rear wheel 30.

#The suspension fork 34 and the rear shock 38 preferably include an acceleration-sensitive valve, commonly referred to as an inertia valve, which allows the damping rate to be varied depending upon the direction of an acceleration input. The inertia valve permits the suspension fork 34 and rear shock 38 to distinguish between accelerations originating at the sprung mass, or main frame 24 and rider of the bicycle 20, from accelerations originating at the unsprung mass, or front wheel 28 and rear wheel 30, and alter the damping rate accordingly. It is generally preferred to have a firm damping rate when accelerations originate at the sprung mass and a softer damping rate when the accelerations originate at the unsprung mass. On an automobile or other four-wheel vehicle, this helps to stabilize the body by reducing fore and aft pitching motions during acceleration and braking, as well as by reducing body roll during cornering.

Facts

Application

10/042,767Filed 9 Jan 2002 · us provisional application

Priority

30 Aug 2001

Published

US 2003/0042087 A16 Mar 2003

Granted

12 Aug 2003

Term ended

9 Jan 2022

Estimated · how

20 years from earliest known nonprovisional domestic filing plus recorded patent term adjustment. Maintenance-fee lapses, terminal disclaimers and statutory extensions have not been checked. The continuity chain may be incomplete; this is not an enforceability determination.

Classification8 codes

B62K 25/08
With telescopic fork, e.g. including auxiliary rocking arms: for front wheel
B62K 25/04
Axle suspensions: for mounting axles resiliently on cycle frame or fork
B62K 25/286
With pivoted chain-stay: the shock absorber being connected to the chain-stay via a linkage mechanism
F16F 9/096
Where gas is in a chamber with a flexible wall: comprising a hydropneumatic accumulator of the membrane type provided on the upper or the lower…

Timeline

30 Aug 2001Priority claimedParent application 60/316,442
9 Jan 2002Application filedUS 10/042,767
23 Apr 2002Assigned to Fox Factory, Inc.assignment of assignor's interest
6 Mar 2003PublishedUS 2003/0042087 A1
12 Aug 2003GrantedUS 6,604,751 B2
12 Feb 2008Assigned to Compass Group Diversified Holdings LLCsecurity agreement
14 Aug 2013Assigned to Fox Factory, Inc.release of security interest
15 Aug 2013Assigned to Suntrust Bank, AS Administrative Agentsecurity agreement
22 Aug 2013Assigned to Fox Factory, Inc.corrective assignment to correct the assignor's name previously recorded on reel 031007 frame 0958. assignor(s) hereby confirms the release of trademark security interest.
4 Jun 2019Assigned to Fox Factory, Inc.release of patent security interest
5 Jun 2019Assigned to Bank of America, N.A., AS Administrative Agentpatent security agreement
9 Jan 2022Term endedEstimated
5 Apr 2022Assigned to Wells Fargo Bank, National Associationsecurity interest
13 Apr 2022Assigned to Fox Factory, Inc.release of security interest
27 Oct 2025Assigned to Wells Fargo Bank, National Associationsecurity interest

Inertia valve shock absorber

Life of this patent

Inertia valve shock absorber

Life of this patent

Life of this patent

Abstract

Drawings

Drawings

Claims13

Description22,698 words

Drawings

Classification8 codes

Life of this patent

Description22,698 words