Patent GB-733309-A (GB)
Title: Improvements in automobile door locks
IPC: E05B65/34
Filed: 1953-12-17
Abstract: 733,309. Door locks. GENERAL MOTORS CORPORATION. Dec. 17, 1953 [Dec. 30, 1952]. No. 35119/53. Class 44. An automobile door lock comprises an angle plate frame, one plate 21 of which carries a pivoted bolt 25 and a pivoted detent 51 engageable with ratchet teeth to retain the bolt in latching position, while the other plate 20 of the frame carries an angularly adjustable detent member 68 in one angular position of which longitudinal sliding movement of the member by a push button withdraws the detent 51 while in another angular position the sliding movement is idle, the detent withdrawing member 68 being arranged substantially parallel and adjacent to the vertex of the angle plate so that the lower end of the member is engageable with one end of the detent 51. As shown the bolt 25 is partially enclosed by a housing 30 and is formed with teeth 26 on one part of its periphery which can engage a toothed striker (not shown) on the door frame and on another part, the bolt is provided with two ratchet teeth 28 to engage the detent 51. The movement of the bolt is limited by stops 36 and 37 on the plate 21 and the bolt is urged to unlatching position by a spring 34. This form of bolt gives the advantage that all the moving parts are mounted on the outside of the frame, the inside being left clear, thus providing space for a sliding window. In a modification however the bolt has a rotor with a plurality of evenly spaced teeth on the outside of the plate 21 and a corresponding ratchet wheel on the inside of the plate. In this modification the detent 51 is also mounted on the inside of the plate with its free end protruding through an aperture in plate 20 and it is urged into contact with the ratchet wheel by a spring since in this construction the bolt has no biassing spring and is free to rotate. In a further modification the bolt consists of a lever pivotally mounted at one end on the inside of the plate 21 and which at the other end is provided with a shank which protrudes through an elongated aperture in the plate 21 ; a roller is mounted on the shank on the outside of the plate 21 which engages a cam slot in a striker plate on the door frame and the bolt has ratchet teeth on one edge which are engaged by the detent 51 which in this construction is also mounted on the inside of the plate 21 with its free end protruding through an aperture in plate 20 ; the bolt is biassed by a hair-pin spring. In all three constructions the remainder of the mechanism is identical. The detent 51 is moved from its latch locking to its unlocking position by the detent member 68 and by a pivotal member 85. The detent member 68 is pivotally mounted between ears 64, 65 of a yoke 60, and is biassed by a spring 70. The yoke in turn is pivotally mounted between tabs 61, 62 of a member 56 which is pivotally mounted on the plate 20. The detent member 68 may thus be moved vertically as shown in Fig. 2 between a position on which its end depresses the end of the detent 51 to cause it to release the latch bolt and a retracted position in which it is out of engagement with the detent 51. It may also be swung from the vertical position shown to an inclined position in which it cannot engage the detent 51. Thus the swinging movement ensures that the detent 51 locks the bolt. The sliding movement is caused by the push button on the outside of the door through an actuating rod 72 which extends slidably but non-rotatably through the pivot of the member 56 in the plate 20 to engage an end of the yoke 60. Depression of the push button thus rotates the yoke 60 which in turn moves the detent member. The swinging movement of the detent member is caused by a push button on the inside of the door which is connected to the member 56 through a rod 76 and a link 77, to rotate it so as to move the detent member to its locking position. The member 56 is biassed to either of its positions by an overcentre spring 81. The member 56 may also be rotated from the outside of the door by turning the actuating rod through a conventional key operated lock device and when the actuating rod is thus turned depression of the outside push button is ineffective. The bolt can be released from inside the door by a handle which is connected through linkage to the pivotal member 85 so as to rotate it. Member 85 has jaw portions 91 which embrace the free end of the detent 51 so that movement of the member 85 frees the bolt. The member 85 is biassed to bolt latching position by a spring 88 and if when it is moved to unlatch the bolt, the detent 51 is in its locking position the previously mentioned arm 94 moves it back to its unlocking position. Thus the opening of the door automatically unlocks the bolt so that it cannot be accidentally locked from the outside by slamming the door but must be deliberately locked by the key.