Patent ID: 7568458

Claim:
A variable cam timing phaser for an internal combustion engine having at least one camshaft with an intake or exhaust valve comprising: a housing having an outer circumference for accepting drive force and chambers; a rotor for connection to a camshaft coaxially located within the housing, the housing and the rotor defining at least one vane separating a chamber in the housing into an advance chamber and a retard chamber; the vane being capable of rotation to shift the relative angular position of the housing and the rotor; a controlled bypass valve providing fluid communication between the advance and retard chambers, wherein when the controlled bypass valve is closed, the control bypass valve blocks the passage between the advance chamber and the retard chamber and wherein when the controlled bypass valve is open, fluid flows through the passage extending from the advance chamber to the retard chamber, such that the phaser and the camshaft are moved to a first position during the intake or exhaust valve opening, prior to the intake or exhaust valve reaching peak lift and such that camshaft torque, oil pressure or a combination of camshaft torque and oil pressure rapidly moves the phaser and the camshaft to a second position prior to the intake or exhaust valve reaching zero lift.