ELECTROMAGNETIC SWITCHING DEVICE Russian patent published in 2001 - IPC

FIELD: electrical engineering. SUBSTANCE: invention is related to low-voltage equipment and can be used in design of contactors and starters. Electromagnetic switching device has frame, core with pull-in coil, armature installed in casing, shock absorbers placed between casing and surface of armature, units of contact cross-pieces joined to casing by means of common axle, mobile bridge contact units coming in the form of contact bridges with straps containing silver put on contact cross-pieces, block with immobile contact units with straps containing silver put on it and return springs. Salient feature of invention is that electromagnetic switching device is equipped with additional shock absorbers and contact straps containing silver of at least part of mobile bridge units and/or of immobile contact units have variable cross-section within limits of quarter of their height on side of contact surface and one strap containing silver as minimum has bevel of its contact surface. Area of horizontal projection of it is 15% as minimum of total area of horizontal projection of contact strap. Technical result provided by invention lies in design of switching device with higher mechanical and switching wear resistance requiring reduced usage of silver to ensure needed service life of device, of structural materials, less labor input in manufacture of parts and units thanks to adaptability of structure to manufacture. Easy access to contact straps of mobile bridge and immobile contacts and coil of device is provided when maintenance is conducted during operation. EFFECT: increased mechanical and switching wear resistance and easy access to contacts and coil during maintenance. 16 cl, 11 dwg