Deadbolt lock

A lock configured for installation on a door which separates an interior space from an exterior space, the door having oppositely facing inner and outer panels, the inner panel, when the door is closed, faces the interior space while the outer panel faces the exterior space, said lock cooperating with a deadbolt operable by a knob accessible in the interior space and by a key, accessible in the exterior space, wherein with said deadbolt installed in the door, said deadbolt is caused to selectively lock and unlock the door from the interior space by operation of the knob accessible in the interior space and from the exterior space by operation of the key accessible in the exterior space, wherein the lock comprises:

• an elongated track adapted to be attached to the inner panel of the door and comprising an underside surface facing the inner panel of the door when the track is attached to the inner panel, a slider disposed in said track, said slider having a flat leading edge, said slider being slidable from i) an inoperative position in which said slider is spaced apart the knob and allows the knob to turn, to ii) an operative position in which said leading edge is in contact with a corresponding surface of the knob and prevents the knob from turning;
• and immobilizing means for selectively immobilizing said slider in said operative position and in said inoperative position, wherein said immobilizing means is a spring-activated ball-locking pin comprising a spring and a ball, wherein when inserted into openings of said track and said slider corresponding to said operative position and said inoperative position of said slider, the pin holds the slider in place in the track by engagement of said ball with the underside surface of the track until a force, opposed to the bias of said spring, is applied to extract said pin from said openings, allowing the slider to be slid in the track, and wherein said slider comprises a flat bar having the flat leading edge that is generally perpendicular to the directions in which said slider slides in said track.