SEAT RECLINING MECHANISMS

摘要

1470370 Seat/backrest hinge mechanism I H W ENG Ltd 1 Nov 1974 [16 Nov 1973] 53357/73 Heading A4J [Also in Division E2] In a hinge, for adjustably mounting a seat backrest on a seat frame, provision is made for forward folding of the backrest without adjustment of the hinge so that the backrest can be returned to its previously adjusted position. Construction. A shaft 30 respectively interconnects a backrest plate 12, seat plate 15, thrust plate 20, interleaved friction discs 21-23 and 21A-23A, a further seat plate 24, dished plate 29, and screwed socket 32. The seat plates 15, 24 are inter-connected by pins 25 passing through holes 26, which pins also rigidly inter-connect them with a plate 16 which is secured to the seat frame. A further pin 27 holds friction discs 21-23 against rotation with respect to seat plates 15, 24. The friction discs 21A-23A are held against rotation with respect to thrust plate 20 by pin 35, the head 35A of which rides in the slot 50 of backrest plate 12. The socket 32 is secured to dished plate 29 and also engages screw threads on the shaft 30, which shaft passes right through the socket. One end 43 of spring 42 engages a slot in the end of the shaft 30, and the other end 41 is hooked round a projection 40 on the dished plate 29. A pawl 55 is pivoted to plate 12 by a pin 56. Operating lever 60 is keyed to the pawl by reason of its square crosssection engaging square hole 58. Operation. The spring 42 tends to rotate the socket and shaft in such sense as to screw them together, thereby compressing the friction discs between seat plates 15, 24. As a result the angular relationship of thrust plate 20 with respect to the seat plates 15, 24 is locked. The pawl 55 is spring- biased such that its nose 57 engages the head 35A of pin 35 to prevent it riding along slot 50 from left to right, as shown in Fig. 3, thereby effectively locking the position of backrest plate 12 with respect to seat plates 15, 24. (A) to swing backrest forward without loss of adjustment lever 60 is operated to lift the pawl 55 and allow rotation of backrest plate 12 until peg head 35A abuts the right hand end of slot 50. (B) to adjust the backrest angle shaft 30 is rotated by a knob or like (not shown) an end 31 against the action of spring 42. The compression of the friction discs is therefore relieved and the backrest plate can be freely adjusted. Release of the shaft knob allows the spring 42 to retighten the friction discs.