Push-button operated bipolar faulty current protective switch

A push-button operated bipolar faulty current protective switch having two fixed contacts and two movable contacts, said fixed contacts co-operating with said movable contacts, and an electromagnetic tripping device which is actuated in dependence of a faulty current, such a circuit breaker comprising a switching bar, a bell crank made of electrically insulating material, a spring biased push-button, said push-button being rigidly connected to the switching bar, said bell crank including first and second leg members, said first leg member being arranged transversely of the switching bar so that it is freely pivotable thereon and displaceable axially thereof, said second leg member being arranged parallel to said switching bar, a cross member of an insulating material, said cross member having an abutment and being arranged on said second leg member and pivotally mounted about an axis substantially parallel to said switching bar and being provided at each of its ends with one of said movable contacts, said switching bar including a drive member, said drive member being adapted to engage said abutment on said second leg member in the switched off condition of said bell crank, a stop member, said stop member being adapted to maintain said bell crank at an angle to said switching bar in the switched off condition of said bell crank, so that it can be moved to the switched on condition, said electromagnetic tripping device including an armature provided with a protuberance, a spring, said protuberance being adapted to maintain said bell crank in its switched on condition against the bias of said spring.