Cylinder lock using key with blade of undulating section - has successive keyhole peaks projecting beyond central key plane to inhibit picking

摘要

The cylinder lock is designed to inhibit lock-picking. It utilises a blade key and keyhole of an undulating cross-sectional profile, the arrangement preventing the sliding insertion of a card. The undulations may be of uniform amplitude and relatively uniform pitch, successive peaks (41) projecting (9, 10, 11) in opposite directions beyond the centroidal key plane to form relatively large overlaps. Holes in the base of the keyhole locate sliding recoil sprung locking pins (32) engaged by triangular indentations (31) in the bottom edge (16) of the key. The holes may extend somewhat towards the back (15) of the key, thus, avoiding fouling of the pins when key details are modified.