Abstract: By forming a plurality of false void zones in a lock housing in association with the tumbler release channel, a combination lock construction is attained which virtually eliminates the ability of trained individuals to gain unwanted access to the lock. Preferably, the combination lock housing also incorporates a plurality of non-releasing open or void zones or slots formed in association with the lock release groove for each rotatable tumbler sleeve. In this way, the desired false click is provided for each rotatable dial in order to thwart unwanted opening of the combination lock of this invention. Furthermore, the lock construction of the present invention is constructed with the interior chambers thereof virtually sealed from ambient surroundings, thereby preventing unwanted contamination from entering the interior of the lock and the rotating components thereof. In this way, degradation by contamination is virtually eliminated.

Abstract: Combination locks employ dial-driven rotary elements for controlling the position of a locking member between locking and unlocking positions by peripheral cooperating of the respective elements with the locking member. Each rotary element is formed in a manner whereby no audible sound or difference in feel is produced during rotation of the element when the on-combination setting of the element is reached. This reduces the possibility that the lock may be picked.