Patent GB-782037-A (GB)
Title: Improvements in and relating to latch mechanisms
Inventor: KRAUSE HERBERT
IPC: E05B65/19
Filed: 1955-08-09
Abstract: 782,037. Latch fastenings. CHICAGO FORGING & MANUFACTURING CO. Aug 9, 1955, No. 22942/55. Class 44 In a latch mechanism for releasably securing the bonnet hood to the bonnet of a motor vehicle of the kind comprising a bolt like keeper 8 mounted on either the hood or the bonnet which is arranged to penetrate a hole in a plate 18 carried by the bonnet or hood respectively and to be held there by a pivotally mounted latch 20 which engages portion 25 of the keeper and holds it against withdrawal from the hole, a manually operable actuating member 52 being provided for disengaging the latch from the keeper, the latch is held in its keeper engaging and keeper disengaged positions by a pawl and rack mechanism 30, 46 which can be released by the manually operable actuating member the rack being arranged for limited movement and the latch being connected to the actuating member by a spring 68 which urges the latch towards its keeper disengaged position and the actuating member towards a position in which it restrains movement of the rack. As shown in Fig. 4 the latch 20 is pivotally mounted on a depending portion 19 of the plate 18 and the pawl 30 is pivotally mounted on the latch 20. Projections 34, 36 on the latch 20 limit movement of the pawl 30 and it is urged in an anti-clockwise direction to engage the projection 36 by a spring 38. The rack 46 is also pivotally mounted on the portion 19 and it has a plurality of serrations which are engaged by a detent 42 carried by the pawl. At the free end of the rack is an S-shaned slot 60 which is engaged by a projection 58 on the actuating. member 52 which is also pivotally mounted on the portion 19. The spring 68 connects the latch 20 to the actuating member 52 so that the latch is urged in a clockwise direction and the actuating member in an anti-clockwise direction. To release the keener the actuating member is rotated clockwise from the position shown in Fig. 4. Initial movement of the actuating member releases the rack and allows it to move anti-clockwise. Further movement of the actuating member causes the projection 58 to engage a camming portion 64 of the slot 60 and positively move the rack in the anti-clockwise direction. This movement of the rack releases the detent and the pressure of the spring 68 and a spring 74 which surrounds the keeper and which presses an annular member 78 against the plate 18 causes the latch 20 to be rotated clockwise to release the keeper. When the actuating member is released it is returned to its initial position by the spring 68 and also moves the rack 46 into engagement with the detent. When the keeper is moved into the hole in the plate 18 its end surface 9 engages a part 26 on the latch and rotates it anti-clockwise. This movement of the latch causes the pawl to rotate clockwise so that it is released from the rack and the latch and pawl move to the position shown in Fig. 4 in which the latch is in engagement with the surface 25 on the keeper. The pawl is then rotated by its spring 38 into engagement with the rack. In a modification, Fig. 8, a U-shaped spring 86 is provided for the keeper instead of the helical spring 74. The ends of the spring are coiled round a pivot 90 and abut an attaching portion 11a which supports the keeper 8a.