Contactor having self-protection means against the effect of the forces of repulsion between the contacts

A contactor comprising:

• a. first and second conductive substantially flat stationary contact carriers symetrically arranged about an axis of symmetry and extending substantially at right angles with said axis of symmetry and first and second stationary contacts mounted on the first and second conductive stationary contact carriers respectively;
• b. a movable insulating contact holder mounted for translation along the said axis of symmetry;
• c. a U-shaped magnetic member having first and second legs and a groove between said first and second legs, said groove having a bottom, said U-shaped magnetic member being rigidly connected to the contact holder and forming a permanently open magnetic circuit;
• d. a magnetic armature resiliently coupled to the contact holder and a permanently open air gap located between the said armature and the said U-shaped magnetic member;
• e. a bridging conductive movable contact carrier resiliently coupled to said contact holder and having a central blade which is substantially at right angles with the stationary contact carriers, said blade extending substantially at right angles to the said axis with first and second portions symmetrically arranged with respect to the said axis and first and second movable contacts rigidly coupled to the said first and second portions respectively, the said stationary contact carriers having means for generating electrodynamic blow off forces on the said movable contact carrier, said blade engaging the said groove, whereby the magnetic flux developed in the U-shaped member when overload current flows through the central blade crosses the said groove thereby generating electrodynamic forces forcing the movable contact carrier towards the bottom of the groove and the movable contacts against the stationary contacts;
• and
• f. means for exerting on the contact holder a pulling force parallel to the said axis for carrying the said movable contacts into and out of engagement with the stationary contacts.