Sash lock for a sash window

A sash lock for a sash window assembly, the sash window assembly including an upper sash window and a lower sash window, each of the sash windows mounted within opposed guide rails on a master frame, wherein at least one of the sash windows is slidable within the frame relative to the other sash window, the sash lock comprising:

• a keeper for mounting on a style of one of the sash windows, the keeper including a keeper surface;
• and
• a locking assembly for mounting on an adjacent style of the other of the sash windows, the locking assembly including:
• a housing having a hole;
• an actuator arm having a shaft;
• a cam having a cam surface for engaging the keeper surface;
• and
• a shaft extending through the housing hole and operably coupled to the cam, the shaft and the housing arranged to cooperatively limit rotational travel of the arm with respect to the housing;
• the shaft and the hole have corresponding circumferential surfaces;
• the shaft has a shaft projection extending from its circumferential surface;
• and
• the hole has two spaced hole projections on its circumferential surface, wherein the shaft projection engages one of the hole projections to define an unlocked position and engages the other hole projection to define a locked position.