Methods and apparatus for combined variable damping and variable spring rate suspension
View Patent ↗Pressure-sensitive vales are incorporated within a dampening system to permit user-adjustable tuning of a shock absorber. In one embodiment, a pressure-sensitive valve includes an isolated gas chamber having a pressure therein that is settable by a user.
1. A vehicle suspension damper comprising:
a cylinder;
a piston assembly comprising a piston and piston rod within said cylinder;
a first chamber within said cylinder, said first chamber having a first pressure and a working fluid therein;
a second chamber within said cylinder, said second chamber having a second pressure, the second chamber fluidly isolated from said first chamber and having pressurized gas therein, said second chamber having a portion thereof disposed in said piston;
a pressure-sensitive valve disposed in said piston, said pressure-sensitive valve further disposed between the first chamber and the second chamber such that said first chamber is adjacent a first side of said pressure sensitive valve, and such that said second chamber is adjacent a second side of said pressure sensitive valve, the valve including:
a first valve surface in communication with the pressurized gas; and
an opposing valve surface in communication with the working fluid; and
a suspension gas spring coupled with said cylinder, said suspension gas spring comprising:
an enclosure, said enclosure movable with respect to said cylinder; and
a third chamber at least partially enclosed by said enclosure, said third chamber having a third pressure, said third chamber fluidly coupled with said second chamber, wherein a pressure change of said third pressure within said suspension gas spring will cause a pressure change to said second pressure within said cylinder.
2. The vehicle suspension damper of claim 1 further comprising:
a fourth chamber disposed within said cylinder, said fourth chamber having a pressurized gas therein at a fourth pressure.
3. The vehicle suspension damper of claim 2 further comprising:
a floating piston movably disposed within said cylinder between said fourth chamber and said first chamber.
4. The vehicle suspension damper of claim 3 wherein said floating piston is configured to move axially within said cylinder upon a pressure change within said first chamber.
5. The vehicle suspension damper of claim 1 wherein a movement of said piston and said piston rod will cause a pressure change to said first pressure.