Cylinder type lock unit - has guide slot for flat key with side slots matching lock pins and serrated edge mating with locking peg in line with housing peg

摘要

The lock unit consists of a rotatable cylinder (1) fitting into an outer housing (2). A key channel (3) receives a flat key (4) having saw tooth and indented profiles (4) along the lower edge. Along an axis at right angles, to the key slot are two similar mushroom shaped locking pins (7,8) with tips which move into side slots in the correct key, and permit rotation of the cylinder. Along the same axis as the key slot is a cylinder core pin (10) with a trapezoidal upper tip (10a) mating with corresponding grooves in the lower edge of the key (4). The pin(10) is in line with a housing peg (15) of similar size, with a small intermediate plate (22) which assumes the correct position to permit the cylinder to rotate when the correct key is used.