GB339286A - Improvements in locks and keys - Google Patents

Abstract

339,286. Oldham, J. L. Sept. 3, 1929. Keyholes, obstructing; keys and key pins; lock mechanism, spring-trumbler type; locks, controlling operation of.-In a lock of the kind having a catch engaging the bolt or other movable part of the mechanism and released by an extension of the key prior to unlocking, the key extension member is slidable within the stem of the key and may be secured in its projecting and retracted positions. The catch shown comprises a pin 26 carried by a plate 27 and normally urged by a spring 28 into one or other of two apertures 25 in the bolt 1. Plate 27 overlies the keyhole and is pressed back, Fig. 4, to release the catch by a pin 32 on the key. The pin 32 is slidably mounted in the key stem 31 and movable to project from, or be housed in, the stem by a knob 33 operable in a slot 34 with lateral knob-retaining end portions 35, 36. The key is guided by the key hole 6 formed through a block 5 secured to the front of the lock and having a recessed face in which a pivoted cover-plate 14 is adapted to seat under the action of a spring 10 surrounding the pivot-pin 11 and housed in an' aperture in the block. When seated, a projection 15 engages a notch in the flange 8 round the seat. The cover is raised from its seat by using the pin 32 which may be inserted under the cover edge in an aperture 18. The lock shown has a spring tumbler 20, one limb of which is bent to provide a part engaged by the key-bit 21 and has a shoulder engaging one or other of two notches 24, 26 in the top edge of the bolt. According to the Provisional Specification the catch may be a spring-actuated hinged or sliding member engaging over the end or other part of the bolt, the lock may have a pivot pin to receive the key, and a key-hole cover may have a tumbler member at the back engaging the pivotpin with a catch engaging the pin to retain the cover in place.