UNIT OF CONTACT CROSS-PIECES OF ELECTROMAGNETIC SWITCHING DEVICE Russian patent published in 2001 - IPC

FIELD: electrical engineering. SUBSTANCE: invention can be employed in design of contactors and starters. Unit of contact cross-pieces of electromagnetic switching device is made of two symmetrical hollow parts joined by contact spring in zone of supporting part and mobile bridge contacts ( in at least some of these contacts each hollow part of cross-piece carries protrusion and has window located in its bearing surface and contact spring is positioned in hollow parts and is fixed by bosses ). Contact bridge is put on bearing surface of cross-piece. Mobile bridge contact units have contact bridges with contact straps containing silver and clamp that has jumper and free ends located in mentioned above windows. Clamp is coupled to contact spring and contact bridge and is placed in space of cross- piece with upward orientation of free ends. Contact spring is positioned on internal surface of jumper of clamp. Characteristic feature of invention is that at least part of contact straps containing silver of some of mobile bridge contact units has variable cross-section within limits of one quarter of their height on side of contact surface and at least one strap containing silver has bevel of contact surface. Area of horizontal projection of it is 15% as minimum of total area of horizontal projection of contact strap. EFFECT: increased mechanical and switching wear resistance, reduced usage of silver with provision of required service life and switching wear resistance. 3 cl, 13 dwg