Patent ID: 7235751

Claim:
An electric device comprising an electric switch having a plurality of contact members arranged in series to form a plurality of breaking points arranged in series, at least one of the contact members at each breaking point being movable, and drive means arranged to actuate each movable contact member, which drive means is arranged to effect simultaneous movement of the movable contact members so that simultaneous breaking is achieved at all the breaking points, wherein a commutation circuit is connected in parallel with the electric switch, each contact member constitutes a part of a contact element, which contact elements are arranged in series, a contact surface of each contact element abutting each immediately adjacent contact element, which contact surfaces are substantially flat and parallel, each contact element comprises at least one conducting part and at least one insulating part, the contact elements are divided into a first and a second group of contact elements, so arranged that every second contact element beginning with the first contact element belongs to the first group and every other contact element belongs to the second group, the contact elements of the first group and the contact elements of the second group are arranged movable in relation to each other in planes parallel with the contact surfaces, between a first position in which conducting part(s) of each contact element is/are in contact with conducting part(s) of immediately adjacent contact elements, and a second position in which the conducting part(s) of the first group of contact elements is/are exposed only to the insulating part(s) of immediately adjacent contact elements in the second group, and in that the drive means is arranged to effect a relative movement of the contact elements between said first and second positions.