Seatback reclining device of vehicle, uses large and small diameter winding portions formed in reclining shaft coupled to main and subsidiary seatbacks to hold spiral springs of smaller and larger number of windings

摘要

The divided main and subsidiary seatbacks (14,12) of seat (10), are coupled to a reclining shaft (18) formed with spaced apart winding portions (22,20) of larger and smaller diameters. Spiral springs (26,24) with larger and smaller number of windings, are wound around the winding portions having respective larger and smaller diameters.