Lock apparatus

A lock apparatus comprising:

• a lock shell having front and rear end portions and a cylindrical lock core receiving space extending through said front and rear end portions;
• and
• a cylindrical lock core unit including
• a cylindrical inner shell received rotatably in said receiving space of said lock shell, said inner shell having a front chamber and a rear chamber,
• a stack of annular locking plates disposed rotatably in said front chamber of said inner shell, each of said locking plates having an inner periphery that confines a central hole, said central holes of said locking plates defining cooperatively an axial key hole of said lock core unit,
• an annular drive plate disposed in said front chamber between said locking plates and said rear chamber of said inner shell, said drive plate having an inner periphery that confines a key passage hole registered with said central hole of said locking plates, and an outer periphery formed with a radial outward drive member that is bent to extend axially into said rear chamber, and
• a latch actuator having a connecting portion inserted into said receiving space via said rear end portion and further extending into said rear chamber of said inner shell, and an actuating portion that extends from said connecting portion out of said rear chamber, said connecting portion being coupled with said inner shell for co-rotation therewith, said connecting portion having a front end face extending in a transverse direction relative to said key hole, a tubular wall extending from said front end face in a direction toward said front chamber and confining a key insert hole that is registered with said central holes of said locking plates and said key passage hole of said drive plate, and a cam projection extending radially and outwardly from said tubular wall, said cam projection being formed with two planar surfaces at two radial sides of said key insert hole, said front end face, said tubular wall and said planar surfaces of said cam projection cooperatively defining an arc groove, said drive member of said drive plate extending into said arc groove in such a manner that rotation of said drive plate together with said locking plates upon insertion of a correct key into said key hole and said key passage hole will result in movement of said drive member in said arc groove and in abutment of said drive member with one of said planar surfaces to move said latch actuator together with said inner shell between locking and unlocking positions relative to said lock shell.