Axial tumbler lock

Claim 1

An axial tumbler lock comprising a body portion including a casing member having a plurality of axial bores extending therethrough and exposed at the forward surface thereof, a cylinder member mounted within the rear portion of said casing member with one of said members being fixed to a stationary support and the other member being rotatable relative thereto, said cylinder member having a forward surface forming a shear plane with a confronting rear surface of said casing member and having a plurality of axial bores each aligned with a corresponding bore of said casing member, latch means operatively connected to said rotatable member for movement to a lock-open position when said rotatable member is rotated relative to said fixed member, a plurality of axial tumbler means movably mounted, one each, in selected bores of said plurality of bores, each of said tumbler means comprising a lock pin slidably mounted in a respective bore of said cylinder member, a tumbler pin slidably mounted in a respective bore of said casing member and a compression spring within said cylinder member bore normally urging said lock pin to a locked position in which it extends across said shear plane between said members, thus preventing rotation of said rotatable member relative to said fixed member, said tumbler pins having varying lengths, and key means for rotating said rotatable member to move said latch means to its lock-open position, said key means comprising a body having a plurality of posts projecting from an end surface thereof and positioned for insertion into the exposed ends of the bores at the forward surface of the casing member, said pins being sized to engage said tumbler means to slide said lock pins and tumbler pins to a position in which their confronting ends are located on said shear plane thereby permitting rotation of said movable member relative to said fixed member, and a plurality of dummy pins mounted in at least some of the axial bores of said casing member.