Abstract: A grooved contact roller is movable in a housing between two switching poions determined by an elastic positioning element which defines an intermediate position in which the contact roller is in a state of unstable equilibrium. The positioning element is engaged in the groove of the roller and the latter is disposed flat against the bottom of the housing. A slidable cover for the housing constitutes an actuating member for the switch and has a journal which extends toward the bottom of the housing and is engaged with clearance in a central aperture of the roller.

Abstract: The switch has two metal contact strips projecting upwardly from the bottom all of the housing and connected to two pins which extend out of the housing. A rectilinear slideway parallel to the end wall contains a slide of electrically insulating material which is movable in the slideway between a first position and a second position. The slideway has an aperture in the region of the contact strips and the slide has a cavity which contains a freely rotatable contact roller and has confronting lateral surfaces which urge the roller to a position for interconnecting the contact strips in said first position of the slide and an inoperative position of rest in said second position of the slide. A spring wire supported in the slide biases the roller out of the cavity toward the contact strips.