Patent ID: 7243994

Claim:
A continuously operable seat-reclining device that can be continuously controlled in a stepless fashion, the device comprising: an upper teeth bracket and a lower teeth bracket securely fixed to a seat back frame and a cushion frame, respectively, the upper teeth bracket being provided with upper teeth, the lower teeth bracket being provided with lower teeth, the upper teeth of the upper teeth bracket being engaged with the lower teeth of the lower teeth bracket; a cam hole formed at the center of the lower teeth bracket; a cam-maintaining ring formed at the upper teeth bracket, the cam-maintaining ring being protruded toward the lower teeth bracket; and an actuator disposed between the cam hole and the cam-maintaining ring for moving the upper teeth bracket relative to the lower teeth bracket so that a reclining operation is carried out, the actuator comprising: a slide bearing disposed around the cam-maintaining ring for reducing a frictional force, and thus improving the reclining operation, the slide bearing being formed in the shape of a circle; a cam disposed inside the slide bearing, the cam being formed in the shape of a circle; a wedge groove formed inside the cam; arch-shaped wedge blocks disposed in the wedge groove for restricting the operation of the cam to control the movement of the upper teeth bracket; a release projection partially formed along the inner circumference of the wedge groove such that the release projection comes into contact with the ends of the wedge blocks to release the wedge blocks; wedge springs disposed in spring grooves formed at the opposite inner ends of the wedge blocks for increasing the distance between the wedge blocks; and a coupling attached to the outside of the cam, the coupling being fixed to a shaft disposed at the rear of the upper teeth bracket.