US Patent 10058178 Reclining device

A reclining device includes: a reclining mechanism, which is capable of tilting of a seat back relative to a seat cushion to be locked or unlocked; a hinge pin, which is engaged with the reclining mechanism and configured to cause the reclining mechanism to be in an unlocked state; a first biasing member, one end of which is hooked to a hooking part provided at a seat-cushion-side member; and a second biasing member, one end of which is engaged to a periphery of an engagement part formed at the hinge pin and the other end of which is hooked to the seat-cushion-side member, wherein a vertical cross-section of the engagement part of the hinge pin has a non-circular shape.