Cam switch formed by modular units

A cam switch formed by modular units comprising an operating member provided with a rotary coupling shank, a trip unit housing a trip mechanism operatively connected to the coupling shank;

• a number of pack-aligned switching units contiguously fixed to said trip unit and each provided with contact means comprising fixed and movable contacts, the latter being movable, in opposition to the action exerted by counter-springs, from a closure position in which the movable contacts come in contact with the fixed contacts and a break condition in which the movable contacts are spaced apart from the fixed contacts;
• a drive shaft operatively connected to said trip mechanism and provided with a rotating motion by said coupling shank, in order to cause the translation of said movable contacts through cams associated therewith;
• a terminal closure element fixed to one of said switching units opposite the trip unit and rotatably supporting the drive shaft at one free end thereof;
• the trip unit, switching units and terminal closure element forming each a modular unit, and being engageable with and disengageable from each other by restrained fixing, wherein each of said switching units comprises a casing with first housings, each first housing having one of said fixed contacts forcibly inserted therein, as well as second housings each accommodating an envelope, said envelope containing one of said counter-springs, one of said movable contacts and a tappet member, said tappet member operable by one of said cams to bring the movable contact from a closure condition to a break condition, said movable contact coming out of the envelope from either side thereof so that it overlaps the fixed contacts with its opposed ends.