Assembly unit for mounting in an opening in an assembly

The fitted unit (1) e.g. switch block has at least one cross bolt (9) for engaging behind a shoulder of an opening and at least one operating member (4) which can be fitted onto a stop in the opening. The operating member can be pressed into the housing (2) against a spring (6) and the bolt element which is mounted displaceable in the housing is connected kinematically to a slider (8) and can be moved behind the shoulder. The operating member and slider are connected to interacting slide elements (10, 12) which are mounted on alternate sides and form a slide drive for repeated operation of the bolt element. The housing can be pushed like a press button against the operating member which can be set on the stop .