US Patent 7578558 Seat lock device

A seat lock device for fixing a rotatable seat back of a rear seat to a vehicle body includes: a striker which is disposed in the vehicle body; a lock mechanism which includes a base plate which is mounted to a seat back frame inside the seat back and has an engagement groove engaging with the striker, a latch which holds the striker in the engagement groove, a ratchet which maintains the latch in a lock direction and a release lever which moves the ratchet in a lock release direction; and a rod spring of which one end is attached to the seat back frame and of which the other end is bowed while coming into contact with the striker during a locking operation.