Patent GB-904387-A (GB)
Title: Automobile door latches and the mounting thereof
Inventor: COVERLEY HAROLD ERNEST
IPC: C08G59/32
Filed: 1960-01-29
Abstract: 904,387. Latch fastenings. GENERAL MOTORS Ltd. Jan. 25, 1961 [Jan. 29, 1960], No. 3352/60. Class 44. An automobile door latch comprises a frame having two plates 1, 2, one of such plates 1 (the jamb plate) mounting a latch bolt (not shown), while the other 2 (the inside plate) mounts a locking trip lever 18 and a spindle 38 journalled on the jamb plate and carrying two arms 43, 44 lying on opposite sides of the inside plate 2, one arm 43 being connected to the trip lever and the other being for connection to a sill button rod, the space between the second arm and the latch frame being sufficient to accommodate the window glass of the door. The latch bolt is of the gear type and it is connected by a spindle 3 to a toothed ratchetwheel 4, free rotation of the ratch wheel in one direction being prevented by a detent lever 5 which engages the ratchet wheel by means of a tooth 6. Both the detent lever and the bolt are mounted on the jamb plate 1 and this plate also mounts a push-button lever 7; when the lever 7 is moved by an outside push-button which is connected to the lever by a rod attached at 8, an intermittent link 9 is moved to release the detent lever from the ratchet wheel. The intermittent link 9 is connected to one end 10 of the push-button lever 7 by means of a dumbbell-shaped hole 11; the intermittent link 9 is cut-out in the middle to form a surface 12 which thrusts against one end 13 of the detent lever 5 to lift the tooth 6 from engagement with the ratchet teeth 4 thus allowing the bolt spindle 3 to revolve to permit the door to be opened. To unlatch the ratchet wheel from inside the door a bell-crank lever 14 is pivoted to the inside plate 2 and one arm 15 of this is connected by linkage to the inside handle while the other arm 17 bears on the end 10 of the push-button lever 7 adjacent the intermittent link 9 when the inside door handle is turned. The locking trip lever 18 has an inturned flange 20 with a slot 21 in it through which loosely passes the end 22 of the intermittent link 9. By pivoting the lever 18 clockwise, as shown in Fig. 2, from its normal unlocked position to its locked position the intermittent link is rocked anti-clockwise about its point of connection with the push-button lever by an angle sufficient to remove the surface 12 from opposite the detent lever end 13. Thus when the pushbutton lever 7 is rocked to move the intermittent link the surface 12 does not make contact with the detent lever end 13 but moves idly passed it. The lever 18 is connected to the arms 43 of the spindle 38 by a rod 45 and through this rod the spindle 38 and arms 43, 44; it is operated by the sill button from inside the vehicle. It is also connected to a key-operable lock on the outside of the vehicle door. The lever 18 is biased to either of its two positions by a spring 31. On the plate 2 is pivoted a lever 28, one end of which is forked, the end 13 of the detent lever 5 being positioned between the prongs of the fork end so that when the door is slammed shut the rotation of the bolt spindle by the toothed bolt wheel as it meshes with the striker causes rocking of the detent lever 5 and hence rocking of the lever 28. A tab 29a on the lever 28 contacts the intermittent link 9 and pivots it and the trip lever 18 to unlocked position; this provision prevents the door automatically locking when it is slammed shut. By depressing the outside pushbutton however the intermittent link 9 is thrust downwards so that the tab 29a on the lever 28 is above a recessed part 30 of the link 9; then if the latch is set to locked position when the door is opened by means of the door sill button and the door is then slammed with the outside push-button held depressed, the lever 18 remains in locked position because the tab 29a moves idly above the part 30. A helical compression spring 32 is positioned between tabs on the lever 5 and lever 7.