Patent ID: 8529387

Claim:
A pulley assembly for use in an automobile accessory drive system, the pulley assembly comprising: a shaft engaging hub including an axis of rotation, an outer threaded surface, and a bore for receiving an accessory input shaft for engagement therewith; a pulley member including a bore that receives the shaft engaging hub, the pulley member including an inner coupling surface and an outer peripheral belt-engaging surface; a nut including an inner threaded surface that is engaged with the outer threaded surface of the shaft engaging hub, the nut also including an outer coupling surface that is angled relative to the axis of rotation of the shaft engaging hub; and a brake member interposed between the pulley member and the nut, the brake member being radially expandable outward toward the pulley member and including a first coupling surface in frictional contact with the outer coupling surface of the nut and a second coupling surface in frictional contact with the inner coupling surface of the pulley member; wherein, when the torque applied member is in a first direction, the brake member rotates with the pulley member, and, as a result of the frictional engagement of the first coupling surface of the brake member with the outer coupling surface of the nut, the brake member urges the nut to rotate and thereby travel the outer threaded surface of the shaft engaging member for axial translation of the nut into the brake member to radially expand the brake member outward toward the pulley member to frictionally couple the nut and brake member to the pulley member for rotation therewith.