Abstract: A lock guard for use in connection with a lock assembly having a bolt action mechanism comprises a rigid plate bounded by upper and lower walls, the plate fitting against a side of the bolt mechanism, the side walls embracing and surround the top and bottom edges of the mechanism. A front panel embraces and covers a bolt plate to be engaged by the bolt. The guard prevents access to the lock mechanism and bolt plate. The lock assembly is of particular utility in connection with key lock units used in coin-operated pay telephones.

Abstract: A security interlock for the abutting portion of the upper and lower housing of coin-operated pay telephones comprise a pair of interlocking brackets positioned proximate the seam between the housing portions. A first bracket mounted to one housing has a leg portion which overlies the seam, while a second bracket mounted to the second housing portion overlies the first bracket.

Abstract: A protective cover for the coinbox-containing portion of pay telephones of generally box-like construction, comprises a front panel flanked by a pair of parallel, rearwardly-extending side walls to define a generally U-shaped construction. The construction closely abuts the front and side panels of the telephone. The front panel is adapted to be permanently fastened to the coinbox cover of the telephone, such as by welding, and has an entryway to the telephone coin return slot and an integral raised portion positioned to overlie the top portion of the coin return door plate of the telephone.

Abstract: A cover for a coin return relay assembly used in coin-operated telephones is formed of a tough, puncture-resistent material formed into a generally U-shaped barrier. The barrier is mounted on the relay such that it overlies the relay armature and coin return chute, preventing the insertion of probe-like instruments through the telephone box to contact such elements. The side walls of the cover are offset from the planes of the adjacent telephone housing walls, while the cover is mounted to the relay in a non-rigid manner to limit the ability of penetration therethrough.

Abstract: A protective cover for the coinbox-containing portion of pay telephones of generally box-like construction, comprises a front panel flanked by a pair of parallel, rearwardly-extending side walls to define a generally U-shaped construction. The construction closely abuts the front and side panels of the telephone. The front panel is adapted to be permanently fastened to the coinbox cover of the telephone, such as by welding, and has an entryway to the telephone coin return slot and an integral raised portion positioned to overlie the top portion of the coin return door plate of the telephone.