Patent ID: 7188905

Claim:
A reclining device for vehicle seats, comprising: a base plate adapted to be mounted to a seat cushion frame of a vehicle seat, with a shaft hole formed through a central portion of the base plate; an arm plate adapted to be mounted to a seat back frame of the vehicle seat, with a shaft hole formed through a central portion of the arm plate, and internal gear teeth provided along an inner circumferential surface of the arm plate; a central shaft inserted into the shaft holes of both the base plate and the arm plate and coupled at a first end thereof to an interlocking shaft adapted to be provided in the vehicle seat; a cam having a pair of locks positioned thereabout; a guide plate placed adjacent the cam about the central shaft between the base plate and the arm plate; an action spring to rotate the central shaft in a predetermined direction; a return spring coupled to a second end of the central shaft outside the base plate; and an actuating lever coupled to the second end of the central shaft, wherein: the base plate comprises: a fastening hole formed around the shaft hole in the base plate so that an outer end of the action spring is held in the fastening hole, the central shaft comprises: a first angled part provided on an intermediate portion of the central shaft so that an inner end of the action spring is fitted over and fastened to the first angled part of the central shaft; and a second angled part provided on the second end of the central shaft, the cam comprises: a through hole formed at a predetermined position in the cam in a shape corresponding to an outline of the first angled part of the central shaft; a main cam heel provided on each of diametrically opposite sides of the cam; and a pair of subsidiary cam heels provided on opposite sides of the main cam heel, with a cam recess formed between the main cam heel and each of the subsidiary cam heels, each of the locks comprises: a main lock heel and a pair of subsidiary lock heels provided on the lock to correspond to both the main cam heel and the subsidiary cam heels of the cam, with a lock recess formed between the main lock heel and each of the subsidiary lock heels; and a guide protrusion provided on a surface of the lock in a direction parallel to an axis of the central shaft, the guide plate comprises: a coupling hole formed in a central portion of the guide plate and having a shape corresponding to an outline of the cam, and the actuating lever comprises: an angled hole formed at a predetermined position in the actuating lever so that the second angled part of the central shaft is inserted into the angled hole of the actuating lever.