REMOTELY OPERATED BYPASS FOR A SUSPENSION DAMPER
A damper assembly with a bypass for a vehicle comprises a pressure cylinder with a piston and piston rod for limiting the flow rate of damping fluid as passes from a first to a second side of said piston. A bypass provides fluid pathway between the first and second sides of the piston separately from the flow rare limitation. In one aspect, the bypass is remotely controllable from a passenger compartment of the vehicle. In another aspect, the bypass is remotely controllable based upon one or more variable parameters associated with the vehicle.
1 . A vehicle suspension damper comprising:
a damper cylinder;
damping fluid disposed within said damper cylinder;
a piston assembly disposed within said damper cylinder, said piston assembly comprising:
a piston having a flow path formed through said piston;
a shim disposed to meter flow of said damping fluid through said flow path; and
a piston rod coupled to said piston;
a bypass assembly providing a fluid pathway between a first side of said piston and a second side of said piston, said bypass assembly comprising:
a remotely controllable needle valve for controlling the flow of said damping fluid through said bypass assembly, said remotely controllable needle valve controlled by an operator-actuated switch located in a passenger compartment of a vehicle to which said vehicle suspension damper is coupled, said remotely controllable needle valve comprising:
a valve body;
a movable piston housed within said valve body, an axial position of said movable piston controllable with respect to said valve body, said axial position of said movable piston controlling fluid flow through said remotely controllable needle valve, said movable piston having a shaft extending from a first end of said movable piston;
a spring mounted coaxially on said shaft;
a movable member telescopically mounted to said shaft, said spring biasing said movable member in an extended position with respect to said first end of said movable piston;
an inlet formed in said valve body;
an outlet formed in said valve body, said inlet and said outlet for enabling said fluid flow through said valve body; and
a control fluid inlet formed in said valve body, a pressure of control fluid at said control fluid inlet configured to adjust said axial position of said movable piston and determine a bypass pressure required to open said remotely controllable needle valve, wherein said axial position of said movable piston is changed when said movable member is in a locked out position with respect to said inlet and a pressure acting over a surface area of said movable member exceeds a pressure of said control fluid acting over a surface area of said movable piston.