GB1114111A - Improvements in or relating to plug and cylinder lock mechanisms - Google Patents

Abstract

1,114,111. Cylinder lock mechanisms. 777 LOCK & ENGINEERING CORPORATION. 24 May, 1965 [29 May, 1964], No. 21889/65. Heading E2A. A plug 28 for use in a plug and cylinder lock mechanism has two sets of engaging pins 31, 32 in a side wall of a key slot 29 therein, the pins being adapted to engage in complementary depressions 35, 34 in a key 33 for use with the plug. In one embodiment, as shown, the pins 31, 32 are carried in slots 30 in one side wall of the key slot and two further sets of pins staggered with respect to the first sets are present in the other side wall of the slot 29. In use the plug is inserted in the bore 22 of a cylinder 21 in the side walls of which are slots 23. Drivers 24, 25 in the slots 23 engage the rear faces of the pins 31 32 and the drivers and pins are biassed inwardly by springs 26, 27. Insertion of the key causes outward movement of the pins and drivers so that the surfaces of contact therebetween which are part cylindrical come to lie in the surface of contact of the plug and cylinder, thus permitting rotation of the plug in the cylinder. The pins 31, 32 have interengaging shoulder and recess means to prevent relative rotation. In a second embodiment the pins and drivers are of rectangular crcss-section. In a further embodiment the pins are so arranged that the key frees the plug for rotation irrespective of which way up it is inserted into the key slot. In another embodiment the pins all run in separate bores or bores which are linked in pairs or groups lengthwise of the key. In the latter case relative rotation of the pins is prevented by providing an arcuate section groove lengthwise of each pin which either receives part of an adjacent pin or a rib forming part of the plug.