Patent ID: 7325661

Claim:
A hydraulic front fork comprising: an upper fork tube, said upper fork tube having a top end and a bottom end; a bottom fork tube axially slidably coupled to the bottom end of said upper fork tube; a hydraulic fluid movable in between said upper fork tube and said bottom fork tube; and a locking mechanism immovably mounted inside said upper fork tube below the fluid level of said hydraulic fluid and dividing said upper fork tube into a first hydraulic fluid chamber and a second hydraulic fluid chamber, said locking mechanism comprising a valve body, said valve body having an axial center through hole disposed in communication with said first hydraulic fluid chamber, at least one return-flow holes disposed in communication with said first and second hydraulic fluid chambers, at least one side hole disposed in communication with said axial center through hole and said first hydraulic fluid chamber, an inner thread formed in a top end of the axial center through hole, and a shoulder formed in said axial center through hole below said inner thread, a piston axially movably mounted in said axial center through hole of said valve body, and spring means adapted to force said piston toward said second hydraulic fluid chamber; a first adjustment mechanism coupled to the top end of said upper fork tube remote from said bottom fork tube, said first adjustment mechanism comprising a rotary knob rotatably mounted on the top end of said upper fork tube, said rotary knob having a drive unit extending to said first hydraulic fluid chamber inside said upper fork tube, a control shaft, said control shaft having an outer thread threaded into the inner thread of said valve body, a front end terminating in a cone head, a rear end terminating in a driven unit and coupled to the drive unit of said rotary knob, a through hole, and at least one radial hole disposed in communication between the axial center through hole and said first hydraulic fluid chamber, and a discharge control device set mounted in the through hole of said control shaft, said discharge control device set comprising a stopper movable in the through hole of said control shaft and a spring member, which forces said stopper to block the passage between the through hole of said control shaft and said first hydraulic fluid chamber; wherein rotating said rotary knob clockwise/counter-clockwise causes said control shaft to be moved axially forwards/backwards between a lockout position where said cone head of said control shaft is stopped at said shoulder in said axial center through hole of said valve body to block the passage through said axial center through hole of said valve body, and an open position where said cone head of said control shaft is positioned away from said shoulder for allowing said hydraulic fluid to pass through said axial center through hole of said valve body.