Front bicycle suspension assembly with inertia valve
A front bicycle suspension assembly having an inertia valve is described. The front bicycle suspension assembly may include at least upper and lower telescoping tubes and include a damping tube containing an inertia valve. The inertia valve may include an inertia mass movable along the outer surface of a valve shaft as the inertia valve moves between first and second positions.
1. A shock absorber, comprising:
a first fluid chamber;
a second fluid chamber, said second chamber comprising a reservoir chamber having a floating piston movably separating a gas chamber from a fluid receiving portion;
a fluid circuit connecting said first fluid chamber and said second fluid chamber;
an inertia valve comprising an inertia mass having an annular shape, said inertia mass surrounding a flow tube having an aperture there through wherein the inertia mass is moveable between a first position and a second position such that the inertia mass covers the aperture in the first position and uncovers the aperture in the second position, said inertia valve permitting a first rate of fluid flow through said fluid circuit in said first position of said inertia mass and said inertia valve permitting a second rate of fluid flow through said fluid circuit in said second position of said inertia mass, said second rate of fluid flow being non-equal to said first rate, said inertia mass comprising a collapsible section defining at least a portion of an external surface of said inertia mass, said collapsible section having a first orientation when said inertia mass is moving in a first direction from said first position to said second position and said collapsible section having a second orientation when said inertia mass is moving in a second direction from said second position to said first position, said inertia mass having a first flow resistance when said collapsible section is in said first orientation and a second flow resistance when said collapsible section is in said second orientation, said second flow resistance being greater than said first flow resistance, and
an end cap, said end cap closing an end of a tube which defines said second fluid chamber, said end cap having a cavity formed therein, said cavity having a bottom surface, and said cavity defining a pocket which is shaped to receive at least a lower portion of said inertia mass.
2. The shock absorber of claim 1 wherein said inertia mass defines a first area normal to said first direction and defines a second area normal to said second direction, said second area being greater than said first area.
3. The shock absorber of claim 1 , wherein said collapsible section comprises an annular skirt extending from a sidewall of said inertia mass.
4. The shock absorber of claim 1 , wherein said second flow resistance is at least approximately two times greater than said first flow resistance.
5. The shock absorber of claim 1 , wherein said inertia mass moves in said first direction in response to an acceleration force over a predetermined threshold.
6. A shock absorber, comprising:
a first fluid chamber;
a second fluid chamber, said second chamber comprising a reservoir chamber having a floating piston movably separating a gas chamber from a fluid receiving portion;
a fluid circuit connecting said first fluid chamber and said second fluid chamber;
an inertia valve comprising an inertia mass having an annular shape, said inertia mass surrounding a flow tube having an aperture there through wherein the inertia mass is moveable between a first position and a second position such that the inertia mass covers the aperture in the first position and uncovers the aperture in the second position, said inertia valve permitting a first rate of fluid flow through said fluid circuit in said first position of said inertia mass and said inertia valve permitting a second rate of fluid flow through said fluid circuit in said second position of said inertia mass, said second rate of fluid flow being non-equal to said first rate, said inertia mass comprising first and second opposing end surfaces oriented generally normal to a direction of motion of said inertia mass and a side wall extending between said first and second opposing end surfaces, said inertia mass additionally comprising at least one movable, annular skirt extending from said side wall, wherein at least an outer portion of said at least one skirt moves toward said side wall when said inertia mass moves in a first direction and moves away from said side wall when said inertia mass moves in a second direction opposite said first direction, said at least one skirt increasing a fluid flow drag coefficient of said inertia mass when moving in said second direction compared to movement of said inertia mass in said first direction, and
an end cap, said end cap closing an end of a tube which defines said second fluid chamber, said end cap having a cavity formed therein, said cavity having a bottom surface, and said cavity defining a pocket which is shaped to receive at least a lower portion of said inertia mass.
7. The shock absorber of claim 6 , wherein said inertia mass moves in said first direction in response to an acceleration force over a predetermined threshold.
8. The shock absorber of claim 6 , wherein said inertia mass moves in a linear path between said first position and said second position.
9. The shock absorber of claim 6 , wherein said at least one skirt comprises a rubber material.
10. The shock absorber of claim 6 , wherein said at least one skirt comprises a plastic material.