Patent ID: 7240651

Claim:
A variable cam-timing phaser, comprising: a stator having a plurality of inwardly-extending stator lobes; a rotor having a plurality of outwardly-extending rotor lobes, the rotor being rotatably disposed within the stator so that the rotor lobes interleave with the stator lobes to form a first timing chamber and a second timing chamber between each of the stator lobes, where rotating the rotor in a first direction relative to the stator causes each of the first timing chambers to increase in volume and each of the second timing chambers to decrease in volume, and where rotating the rotor in a second opposite direction relative to the stator causes each of the second timing chambers to increase in volume and each of the first timing chambers to decrease in volume; and a plurality of hydraulic fluid orifices, one such orifice being associated with each of the first timing chambers for permitting hydraulic fluid to fill and drain from each of the first timing chambers, the orifices being positioned so that when the stator and rotor are in a first relative rotational position, each of the orifices is fluidly coupled with its associated first timing chamber, and when the stator and rotor are in a second relative rotational position, at least one of the orifices is sealed off from its associated first timing chamber and at least another of the orifices remains fluidly coupled with its associated first timing chamber.