Removable core lock with latch alignment and limited latch rotation

A lock mechanism comprising:

• a generally cylindrical housing having a bore extending axially therethrough, a key-controlled core rotatable within said bore between locked and unlocked conditions and removable from said bore, a latch shifter adapted to be coupled to said core for rotation therewith within said bore and adapted to be coupled to an associated latch member, first and second coupling structures respectively on said core and said shifter and shaped and dimensioned for mating engagement with each other in only a single rotational orientation thereof relative to each other for rotating said shifter in response to rotation of said core in said bore, and stop structures respectively formed on said housing and said shifter, one of said stop structures including a cylindrical surface and an arcuate groove formed in said cylindrical surface coaxially therewith and defining first and second stop surfaces, the other of said stop structures including a radially extending tab receivable in said arcuate groove and engageable with said first and second stop surfaces respectively in the locked and unlocked conditions of said core for limiting rotation of said shifter, and further including a notch in said one stop structure communicating with said arcuate groove to accommodate passage of said tab therethrough in only a predetermined rotational position of said shifter thereby to permit axial movement of said shifter relative to said housing.