Abstract: A gear operated seat recliner mechanism is described which is particularly useful in connection with motor vehicle occupant seats. The recliner permits the angle between the seat back and seat bottom to be varied as desired by the seat occupant. In accordance with this invention, the upper recliner structure pivots about the lower recliner structure and a quadrant component, which pivots with the upper recliner structure, includes a curved toothed rack. The rack meshes with a gear mounted to the lower recliner structure. A pawl is adjustable between an engaged position which fixes the seat back angle to a disengaged postion permitting the seat back angle to be changed relative to the seat bottom. This design improves over prior art designs in that it employs fewer parts, is less costly to produce, and further, permits very fine adjustments in the seat back angle.

Abstract: An improved motor vehicle seat back hinge mechanism which includes an inertial sensitive latching device which prevents forward rotation of the seat back in the event of sudden vehicle deceleration. The vehicle seat hinge mechanism according to this invention improves over prior art designs by providing a quadrant component which does not present objectionable rearward protrusions which interfere with rear seat occupants while entering and egressing from the rear seat area and, further, avoids the presentation of sharp projections which could cause tearing and wearing of interior trim fabrics. Further, the pendulum type inertial sensing mechanism of the design according to this invention avoids the use of loose parts which may give rise to noise and rattle problems associated with rolling weight type inertial sensing mechanisms.