Suspension damper having inertia valve and user adjustable pressure-relief
View Patent ↗A modern suspension damper, for example, a shock absorber or a suspension fork, including an inertia valve and a pressure-relief feature is disclosed. The pressure-relief feature includes a rotatable adjustment knob that allows the pressure-relief threshold to be externally adjusted by the rider “on-the-fly” and without the use of tools.
1. A suspension damper operable between a compressed position and an extended position, comprising:
a compression chamber having a volume reducing in response to operation of the suspension damper from the extended position to the compressed position;
an inertia valve having an inertia mass slideably moveable relative to a first fluid path, the inertia mass movable to an open position, in response to acceleration of at least a portion of the suspension damper, such that fluid flow is allowed into said first fluid path;
a blowoff valve movable to an open position, in response to pressure in the compression chamber equaling or exceeding a first pressure threshold, such that fluid flow is allowed into a second fluid path; and
a pressure relief valve movable to an open position, in response to pressure in the compression chamber equaling or exceeding an adjustable second pressure threshold, such that fluid flow is allowed into a third fluid path.
2. A suspension damper operable between a compressed position and an extended position, comprising:
a compression chamber having a volume reducing in response to operation of the suspension damper from the extended position to the compressed position;
a rebound chamber having a volume reducing in response to operation of the suspension damper from the compressed position to the extended position;
a reservoir chamber for receiving fluid from the compression chamber via a first fluid path, a second fluid path, and a third fluid path;
an inertia valve having an inertia mass slideably moveable relative to the first fluid path, the inertia mass movable to an open position in response to acceleration of at least a portion of the suspension damper, such that fluid flow is allowed into said first fluid path;
a blowoff valve movable to an open position in response to pressure in the compression chamber equaling or exceeding a first pressure threshold, such that fluid flow is allowed into said second fluid path; and
a pressure relief valve movable to an open position in response to pressure in the compression chamber equaling or exceeding an adjustable second pressure threshold, such that fluid flow is allowed into said third fluid path.
3. A suspension damper operable between a compressed position and an extended position, comprising:
a damper body defining a compression chamber and a rebound chamber;
a reservoir body defining a reservoir chamber for receiving fluid from the compression chamber via a first fluid path, a second fluid path, and a third fluid path;
an inertia valve having an inertia mass slideably movable relative to the first fluid path to open and close fluid communication between the first fluid path and the reservoir chamber, wherein the inertia mass is movable in response to acceleration of at least a portion of the suspension damper;
a blowoff valve operable to open and close fluid communication between the second fluid path and the reservoir chamber, wherein the blowoff valve includes a chamber in fluid communication with the first fluid path; and
a pressure relief valve operable to open and close fluid communication between the third fluid path and the reservoir chamber, wherein the pressure relief valve is coupled to the blowoff valve such that pressure in the chamber of the blowoff valve affects the pressure relief valve.
4. A suspension damper operable between a compressed position and an extended position, comprising:
a compression chamber having a volume reducing in response to operation of the suspension damper from the extended position to the compressed position;
a rebound chamber having a volume reducing in response to operation of the suspension damper from the compressed position to the extended position;
a reservoir chamber;
damping fluid and gas disposed in the reservoir chamber;
an inertia valve, including an inertia mass slideably mounted and moveable relative to a first fluid path, said inertia mass movable to an open position in response to an acceleration of at least a portion of the suspension damper equaling or exceeding a first threshold, wherein said inertia mass moving to said open position allows fluid flow into said first fluid path between the compression and reservoir chambers;
a blowoff valve movable to an open position in response to pressure in the compression chamber equaling or exceeding a second threshold, wherein said blowoff valve moving to said open position allows fluid flow into a second fluid path between the compression and reservoir chambers; and
a pressure relief valve movable to an open position in response to pressure in the compression chamber equaling or exceeding an externally adjustable third threshold, wherein said pressure relief valve moving to said open position allows fluid flow into a third fluid path between the compression and reservoir chambers.
5. A suspension damper operable between a compressed position and an extended position, comprising:
a compression chamber having a volume reducing in response to operation of the suspension damper from the extended position to the compressed position;
a rebound chamber having a volume reducing in response to operation of the suspension damper from the compressed position to the extended position;
a reservoir chamber;
damping fluid and gas disposed in the reservoir chamber;
an inertia valve, including a valve member comprising an inertia mass slideably mounted and moveable relative to a first fluid path between the compression and reservoir chambers, said inertia mass movable to an open position in response to an acceleration of at least a portion of the suspension damper equaling or exceeding a first threshold, wherein the inertia valve comprises:
an outer flow tube having first and second flow ports formed through a wall thereof;
an inner flow tube disposed within the outer flow tube so that an annulus is formed therebetween and having a head isolating the first flow port from the annulus;
the inertia mass having a recess formed therein, and movable between the open and closed positions, wherein the recess provides fluid communication between the first and second flow ports in the open position;
a spring biasing the inertia mass toward the closed position;
a pocket receiving the inertia mass in the open position; and
a check valve allowing flow from the pocket and obstructing flow into the pocket; and
a blowoff valve movable to an open position in response to pressure in the compression chamber equaling or exceeding a second threshold, wherein said blowoff valve moving to said open position allows fluid flow into a second fluid path between the compression and reservoir chambers.