Patent ID: 7878593

Claim:
An anti back drive device for releasably securing a seat back with respect to a seat cushion, comprising: an upper gear plate adapted to be affixed to the seat back, the upper gear plate defining gear teeth; a lower gear plate secured to a seat bottom, the lower gear plate defining gear teeth that cooperate with the gear teeth of the upper plate, the upper gear plate being able to rotate about an axis of rotation that is displaced from an axis associated with the lower gear plate; at least one wedge that is mounted in relation to the upper gear plate; a clutch spring that is located within the lower gear plate so that an outside surface of the clutch spring may frictionally engage a central bore of the lower gear plate; the clutch spring having two driving legs projecting radially inwardly and axially, by which the wedges are engaged; a wedge spring having one turn and support splines projecting almost perpendicularly therefrom, the support splines engaging the at least one wedge and bias the at least one wedge so that the at least one wedge may engage an inner surface of the clutch spring; and a driver extending between the lower gear, the clutch spring, the wedge spring, and the upper gear, the driver engaging a leg of the clutch spring that is mounted inside the lower gear plate so that, depending on the direction of driver rotation, the at least one wedge exerts gripping forces between a ring and the inside of the clutch spring.