Patent ID: 7562935

Claim:
A seat reclining apparatus comprising: a first member attached to one of a seatback frame and a seat cushion frame and including engaged portions; a second member attached to an other one of the seatback frame and the seat cushion frame and rotatably engageable with the first member; engaging members interposed between the first member and the second member; a cam member rotatably guided by the second member and bringing the engaging members engageable with the engaged portions to move in a radial direction so as to engage or disengage between the engaged portions and the engaging members; the cam member including a pivot axis arranged in such a manner that a simultaneous engagement or disengagement is achieved among each engaging member and the corresponding engaged portion when a center axis of the first member and a center axis of the second member are offset to each other by an amount corresponding to a clearance formed at a rotatably connecting portion between the first member and the second member because of a load applied to the seatback frame in a case where a seatback is tilted; the first member including a first sliding face having a circumferential shape in cross-section and the engaged portions arranged along a periphery coaxial with the first sliding face; the second member including a second sliding face having a circumferential shape in cross-section and facing the first sliding face so as to be slidable thereon; and the pivot axis of the cam member arranged in an offset manner relative to a center axis of the second sliding face so that a center axis of the periphery where the engaged portions are formed and the pivot axis of the cam member overlap each other when a center axis of the first sliding face and the center axis of the second sliding face are made offset to each other by the amount corresponding to the clearance formed between the first sliding face and the second sliding face because of the load applied to the seatback frame in a case where the seatback is tilted.