Patent ID: 8840514

Claim:
A bi-directional overrunning clutch assembly for engaging secondary driven shafts in a four wheel drive vehicle, the assembly comprising: a differential housing including a differential case and a cover removably mounted to the case; a pinion input gear rotatably disposed within case and including a shaft extending out from the case and adapted to engage a drive shaft, the pinion input gear rotatable within the case; a ring gear located within the differential case and engaged with the pinion input gear such that rotation of the pinion input gear produces rotation of the ring gear; a bi-directional overrunning clutch housing formed on or attached to the ring gear such that rotation of the ring gear produces corresponding rotation of the clutch housing, the clutch housing having an internal diameter with a contoured surface a pair of hubs substantially coaxially aligned with each other and located within the clutch housing, each hub adapted to engage an end of a secondary driven shaft; a roll cage assembly located within the clutch housing and including a roll cage with two sets of rolls, each roll disposed within a slot formed in the roll cage, the rolls spaced around the circumference of the cage, and a plurality of springs for positioning the rolls in the slots, wherein one set of rolls is located between a portion of the contoured surface of the clutch housing and an outer surface of one hub, and the other set of rolls is located between a portion of the contoured surface of the clutch housing and an outer surface of the other hub; an electromagnetic system for indexing the roll cage relative to the clutch housing, the electromagnetic system including first and second indexing devices for indexing the roll cage, and an electronic control system connected to each indexing device for activating the indexing devices; the first indexing device configured when activated to cause the roll cage to index in a first direction relative to the clutch housing so as to index the roll cage into an active drive state where the rolls are positioned to cause the drive shaft to be coupled to the secondary driven shafts when four wheel drive is needed; and the second indexing device configured when activated to cause the roll cage to rotate in a second direction relative to the clutch housing that is opposite from the first direction so as to cause the roll cage to index into an active backdrive state where the rolls are positioned to cause the secondary driven shafts to be coupled to the drive shaft for providing torque transfer from the secondary driven shafts to the drive shaft during an engine braking condition, the second indexing device including an electronically controlled assembly, and a hub plate engaged with one of the hubs so as to rotate in combination with that hub, wherein the electrically controlled assembly is configured, when activated, to cause the hub plate to engage with the roll cage so as to index the roll cage in the second direction.