Adjusting angular position of seat backrest - involves bush with steep angle screw thread operated by vehicle driver

摘要

The seat of a motor vehicle has a backrest which can be adjusted for angular position. The base of the seat has two side plates (10) with attached bosses (15). Each boss (15) has an external screw thread with a stepp leading angle and can be a multi-start thread. Each boss (15) engages a screw thread in a bush (28) which is welded to a plate (11) fastened to one side of the back rest. A hadnwheel (20) is mounted on a shaft (16) which can rotate in the boss (15) but is prevented from axially. The shaft (16) has a self-locking screw thread (23) which engages a screw thread in a plate (26) fixed to the bush (28). As the handwheel (20) is rotated the shaft (16) is screwed further into the plate (26) driving the boss (15) into the bush (28) and so causing relative rotation between boss (15) and bush (28). At the same time the shaft (13) produces the same effect on the other side of the backrest. The backrest is thus swung through an angle relative to the seat base. USE - Motor vehicle seat with adjustment system.