Changeable combination lock for desk drawers and the like

A combination lock for receptacles such as desk drawers and the like, comprising a lock case having a vertical rear wall and a front face plate secured to the lock case, a horizontal shaft journaled in said case adjacent and parallel to said front face plate, a set of plural rotatable combination dial wheel assemblies disposed in axially spaced coaxial relation along said shaft, said wheel assemblies each comprising an outer annular dial wheel and an inner hub extending therethrough selectively intercoupled at plural relative angular position with respect to said dial wheel, a movable fence rearwardly adjacent said dial assemblies having a locking projection extending rearwardly therefrom and locking and unlocking positions, means on said hubs coactive with said fence for restraining the latter at said locking position and releasing the fence to unlocking position, said hubs being slidably and rotatably journaled on said shaft in endwise abutting stacked relation, means at one end of the stack of hubs biasing them to a first axial position interlocking them against angular displacement relative to their respective dial wheels, means for releasing the hubs from their dial wheels at a second axial position of the hubs, a change and operating lever having a portion abutting the other end of said stack, means journalling said change lever on said shaft for angular movement about the shaft axis over an arcuate range between upper and lower vertically spaced angular positions, a slidable bolt member guided for vertical movement adjacent said rear wall between a projected position and a retracted position, the bolt member having a first slot receiving a rearward end portion of said change and operating lever therein for movement of the bolt member by the lever between said projected and retracted positions and having a second slot for receiving the locking projection of said fence therein only at the projected position of said bolt member to lock the latter at said projected position when the fence occupies its locking position, said front face plate having dial wheel openings therein through which portions of the dial wheels project forwardly for exposing portions thereof to observation and hand manipulation and having a shaped vertically extending guide slot through which a front portion of the change and operating lever extends accommodating lever movement its said vertically spaced angular positions disposing the bolt member at its projected and retracted positions and said guide slot having a lateral extension at one end thereof accommodating a limited extent of lateral angular movement of the lever about its end portion in said first slot to shift the lever axially along said shaft to force said hubs from said first axial position to said second axial position.