Vacuum switch coaxial contact arrangement for arc extinction - relies for anode spot inhibition upon unequal anode and cathode contact potential differences w.r.t. anode centre

摘要

The contact pieces (1,2) aligned with the same axis (3) carry at their respective ends plane contact portions (4, 5) which take up the cathode and anode roots of the arc (6,7) struck when the circuit is broken. The edge of the contact portion (4) associated with the contact piece (1) which acts as the anode has a greater potential difference than the corresp. edge of the portion (5) associated with the cathode contact piece (2), w.r.t. the centre of the anode. ADVANTAGE - Circuit-breaking arc contraction and anode spot formation are avoided without recourse to auxiliary magnetic field prodn. devices.