Patent AU-2013204530-B1 (AU)
Title: Lock Structure
Inventor: HISCOCKS BRIAN NORMAN
IPC: E05B63/00
Filed: 2013-04-12
Abstract: Abstract A lock (10) is provided. The lock (10) includes a lock housing (16) having a cylindrical cavity (14) for receiving a rotatable and removable lock core (12). The housing (16) has upon its internal surface a concentric groove (32) and a longitudinal slot (30), which intersects the concentric groove (32). A substantially cylindrical lock core (12) is arranged to be received and rotate within the cylindrical cavity (14). The lock core (12) has a keyway (18) formed therein and extending longitudinally from an end face of the lock core (12). The lock core (12) further includes a plurality of guide bores (20) which extend outwardly from the keyway (18) and communicate therewith. Each guide bore (20) is adapted to receive a locking pin (22), wherein coding (42) on a key blade (44) inserted into the keyway (18) causes each locking pin (22) to move along the respective guide bore (20). The lock core (12) further includes a recess (24) extending outwardly from the plurality of guide bores (20) and communicating therewith. The recess (24) is adapted to receive a sidebar (26). Each locking pin (22) includes a hole (36) of a first depth, the position of the hole (36) along the pin (22) dictating a locking combination for the respective locking pin (22). At least one locking pin (22) includes a second hole (38) of a second depth, the second depth being less than the first depth. The side bar includes protrusions (28) which are directed inwardly towards the guide bores (20). The side bar (26) is biased outwardly away from the guide bores (20) and into the longitudinal slot (30). The side bar (26) further includes an outwardly directed protrusion (34) shaped and positioned to be accommodated in the concentric groove (32). Upon the insertion of an appropriately coded key blade (44) of an operation key into the keyway (18), all locking pins (22), except the at least one locking pin, is moved along the guide bores (20) until the holes (36) of the first depth are aligned with the recess (24). The at least one locking pin is instead moved until the second hole (38) of the second depth is aligned with the recess (24). Turning the operation key causes the lock core (12) to attempt to rotate causing the sidebar (26) to move inwardly against the bias and the inwardly directed protrusions (28) enter the aligned holes (36, 38). Due to the second depth of the second hole (38), the sidebar (26) is capable of moving out of the longitudinal slot (30) thereby allowing the lock core (12) to rotate; however, the extent of sidebar movement is restricted such that the outwardly directed protrusion (34) remains within the concentric groove (32) thereby preventing the lock core (12) from being removed from the lock housing (16). Upon the insertion of an appropriately coded key blade (44) of a removal key into the keyway (18), all locking pins (22) are moved along the guide bores (20) until the holes (36) of the first depth are aligned with the recess (24). Turning the removal key causes the lock core (12) to attempt to rotate causing the sidebar (26) to move inwardly against the bias and the inwardly directed protrusions (28) enter the aligned holes (36). Due to the fact that all the aligned holes (36) are of the first depth, the sidebar (26) is capable of moving out of the longitudinal slot (30), thereby allowing the lock core (12) to rotate, and the sidebar (26) is capable of moving sufficiently further to allow the outwardly directed protrusion (34) to disengage from the concentric groove (32), thereby allowing the lock core (12) to be removed from the lock housing (16).