A switch assembly (100, 200) is adapted to be disposed in a holding portion (50) of a hand-held device (10). The switch assembly (100, 200) includes first (110) and second (120) keys, first (115) and second (125) connecting portions, a switch element (130) and a plunger (140). The first and second keys are exposed on the surface of the holding portion and respectively disposed on the opposite sides thereof. The first and second connecting portions respectively connect the first and second keys and the holding portion. The first and second connecting portions are disposed for allowing the first key having a displacement toward the second key along their connecting direction. The switch element is located inside of the holding portion, and the first key has a first backside (111) toward the second key. The second key has a second backside (121) toward the first key. The plunger is adapted to press and activate the switch element through the displacement.

A modular contact element, designed to be mounted on a multiple contact switch (2), of the type that has a slider moving relative to a plurality of stationary electric contacts (4). The modular element (1) has one or more movable electric contacts (6) for selectively interacting with corresponding stationary contacts (4) to cause their respective external electric circuits to open and close in response to the motion of the slider (3). More in detail, at least one of the movable electric contacts (6) is associated to a support (7) which may be removably connected to the slider (3) by suitable connection means (8) to allow one or more movable contacts (6) to be mounted on and removed from the slider (3), to thereby change the opening and/or closing pattern of the electric circuits associated thereto.

A redundant switch includes a housing and an actuator movable in the housing in two opposing translational directions. A slide (16) is movable in the housing in the same two opposing directions as the actuator and is coupled to the actuator by two antagonistic springs (28a,28b) with clearance in both directions of movement. The switch also includes a latching track (18) with at least two latching notches, which are spaced from each other along the directions of movement. At least two switch units (26a,26b) are arranged one beside the other for simultaneous actuation by the slide. A latching cam (22) is movably guided on the slide perpendicular to its directions of translational movement and is urged towards the latching track by a compression spring. One of the latching notches in cooperation with the latching cam defines a rest position of the slide, in which the slide does not actuate the switch units. Another latching notch in cooperation with the latching cam defines an actuating position of the slide, in which the slide has actuated the switch units. The antagonistic springs (28a,28b) force the slide to move into the respective other position, when the latching cam slides over an apex between the latching notches.