Patent ID: 7172061

Claim:
A clutch linkage for a self-adjusting clutch system for automotive vehicles, wherein the clutch system includes a pedal connected by the clutch linkage to a clutch plate that is normally biased by a clutch spring to press a friction disk into engagement with a flywheel driven by an engine, the clutch linkage comprising: an actuator rod having a first end connected to the pedal and a second end having an engagement surface; a hydraulic cylinder having a first end with a stop surface therein for engagement by the engagement surface of the actuator rod that is moveably mounted in the hydraulic cylinder to pull the hydraulic cylinder when the clutch pedal is depressed to release the clutch; a piston within the hydraulic cylinder, the piston dividing the hydraulic cylinder into first and second chambers and having a piston rod connected to the clutch by a linkage portion for pulling the clutch to release the clutch when the pedal is depressed to pull the hydraulic cylinder; a normally-open valve within the first chamber of the hydraulic cylinder and disposed in tandem between the piston and the stop , the normally-open valve being closed by axial movement of the actuator rod upon depressing the clutch pedal, and a fluid passage between the first chamber of the hydraulic cylinder and the normally-open valve to allow hydraulic fluid in the first chamber to be displaced therefrom as the clutch plate wears.