US Patent 7380883 Reclining apparatus

A compact and lightweight round reclining apparatus having a neutral position return function of automatically returning and securing the backrest to the preset neutral position when the backrest that has been reclined forward is raised is provided. A memory plate in approximately disc form having a center shaft at its center and a spring member for pressing the memory plate so that the memory plate always rotates in one direction intervene between a base plate and a gear plate. A guide portion, which is a long hole in approximately arc form, for restricting the movement of the lock gear outward in the direction of the radius through contact with the protrusion of the above described lock gear is provided inside the disc of the memory plate, and at least one notch is provided in the outer periphery of the memory plate so that an engaging portion provided on the above described gear plate enters into the notch and the memory plate is rotatable relative to the gear plate within the range of the notch.