Variable valve timing mechanism

Claim 1

VALVE OPERATING MECHANISM FOR AN INTERNAL COMBUSTION ENGINE INVOLVING, A CYLINDER, A COOPERATING PISTON, AND A VALVE FOR SAID CYLINDER, SAID VALVE OPERATING MECHANISM COMPRISING: (A) A ROTARY CAM SHAFT AND CONNECTIONS INCLUDING A CAM FOLLOWER BETWEEN SAID CAM SHAFT AND VALVE, (B) A PRIMARY CAM ELEMENT ON SAID CAM SHAFT AND HAVING DIAMETRICALLY OPPOSED ARCUATE PERIPHERAL HEEL AND TOE SURFACES, A LIFTING SURFACE TANGENTIALLY CONNECTING ONE END OF SAID TOE SURFACE TO THE ADJACENT END PORTION OF SAID HEEL SURFACE, AND A LOWERING SURFACE TANGENTIALLY CONNECTING THE OTHER END PORTION OF SAID TOE SURFACE TO THE ADJACENT END OF SAID HEEL SURFACE, SAID SURFACES ENGAGING SAID FOLLOWER IN SUCCESSION RESPONSIVE TO ROTATION OF SAID CAM SHAFT, ENGAGEMENT OF SAID LIFTING SURFACE WITH SAID FOLLOWER IMPARTING OPENING MOVEMENTS TO SAID VALVE, ENGAGEMENT OF SAID LOWERING SURFACE WITH SAID FOLLOWER PERMITTING THE VALVE TO CLOSE, SAID VALVE REMAINING CLOSED DURING ENGAGEMENT OF SAID FOLLOWER BY SAID HEEL SURFACE;