Seat reclining device with planetary gears

摘要

A seat reclining device comprises a base plate secured to a seat base of a seat, an arm plate secured to a seatback of the seat, and a planetary gear mechanism interposed between the base and arm plates in such a manner that operation of the mechanism induces a stepless pivoting movement of the arm plate relative to the base plate. The mechanism uses respective given portions of the base and arm plates as essential parts thereof, so that separation of the given portions from each other tends to cause malfunction of the mechanism. A retainer is employed which holds the base plate and the arm plate in such a manner as to suppress the separation of the base and arm plates.