ELECTRIC SWITCHING DEVICE

摘要

An electric switching device for fast closing of a high current comprises one movable contact element (4) and one fixed contact element (5), which form a sliding contact. A spring member (2) operates the first contact element (4). During the closing movement, the first contact element completes an acceleration phase (t1), during which the spring force stored in the spring member (2) by clamping is transformed into kinetic energy of the movable contact element. Then follows a movement phase (t2-t1), during which the movable contact element moves towards the closed position at constant speed. The spring member (2) comprises a freely journalled torsion-spring rod, one end of which is fixed to an operating arm (3) which is freely rotatable between a first support (7) and a second support (8). The contact element (4) is fixed to the second end of the torsion-spring rod, the torsion-spring rod being clamped by rotating the contact element in the opening direction with the operating arm against the first support. The fixed contact element (5) comprises a plurality of contact fingers (14) as well as a plurality of spring fingers (17). The contact fingers are made of a first electrically conducting material with good electrical conductivity. The spring fingers (17) are made of a second conducting material with a high yield point and designed so as to have an essentially higher resonance frequency than the contact fingers. The spring fingers are adapted to rapidly resume a contact position after a deflection excited transversely of the closing direction.