GB737547A - Cylinder lock - Google Patents

Abstract

737,547. Barrel locks. SAARENTO, A. A. Dec. 21, 1953, No. 35504/53. Class 44. A cylinder lock comprises a casing 1 having two diametrically opposite internal grooves 7 formed therein, a cylinder 2 rotatably mounted within the casing, and a plurality of tumblers 3 disposed within the cylinder, certain of which tumblers normally engage one of the grooves 7 while other tumblers engage the other groove, the tumblers having central key openings uniform in size and shape and defined by pairs of parallel lines for engagement with a key 4 having notches on both edges thereof, the total height of each pair of diametrically opposite notches being equal to the height of the key openings whereby rotation of the key in one direction disengages the tumblers from the grooves and rotation in the other direction engages the tumblers with the grooves. As shown, plate tumblers 3 are arranged in sliding contact with one another in the cylinder 2 and are loaded by a spring 6 against a front cover disc 5 provided with a stop 8 arranged to move in a groove 9 on the casing walls. In the locked position, projecting lugs on the tumblers 3 engage respective grooves 7 on the casing and in the unlocked position all tumblers are rotatable with the cylinder to release a lock bolt operatively connected with the lock. During this rotational movement, the stop 8 moves towards one end of the groove 9. During a locking movement the cylinder is rotated in the reverse direction until the tumbler lugs are again aligned with the grooves 7 whereupon further rotation of the cylinder projects the tumblers into their respective grooves and frees the key.