Pick proof lock

Abstract

A directional control and time delay interlock for making a key operable rotatable tumbler lock substantially pick-proof. When the proper key is inserted the core of the lock is rotatable in a first direction for elevating a biased pawl from locking engagement with a cam surface carried by the rotatable portion of the lock. The distal end of a pawl engaging an indentation in the rotatable portion of the lock prevents initial rotation of the rotatable portion of the lock in a second direction opposite to the first direction of rotation. After rotation in the first direction of rotation, the distal end of the pawl is elevated away from the rotational portion of the lock freeing its engagement with the rotatable portion of the lock. With the pawl elevated, the rotational portion of the lock can be quickly rotated in the second direction past the pawl before the distal end of the pawl returns under a slight bias to the surface of the rotatable portion of the lock. The quick rotation of the rotatable portion of the lock rotates the indentation away from the distal end of the pawl preventing engagement therewith allowing the lock core to rotate to the lock open position. Anyone attempting to pick the lock in a conventional manner will be prevented from rotating the core of the lock past the key insertion position due to the tumblers and the pawl engagement interrupting the rotation.

Dependencies are inferred from the claim text.