Abstract: A direct dial combination lock having tumblers which are cammed in reciprocating movement by rotation of a driver and which, once set, are disengaged by shifting the driver axially. Each tumbler has an internal cam track that is operated on by rotation of the driver to establish a reciprocating or back and forth tumbler motion. Gates presented on the respective tumblers receive individual combs that are movable as a set toward the tumblers in a direction perpendicular to the direction of tumbler back and forth movement. The combs are scrambled for greater manipulation resistance, and their positions relative to one another are changeable without opening the lock, to change the combination.