GB808772A - Improvements to circuit breakers with magnetic blow-out - Google Patents

Abstract

808,772. Arc-rupturing in switches; air-blast switches. ETABLISSEMENTS MERLIN & GERIN. Feb. 23, 1956 [Feb. 25, 1955; July 26, 1955], No. 5606/56. Class 38 (5). In a switch having an are horn 16 and a magnetic blow-out coil 13 connected to a fixed contact 22 and a second arc horn 17 associated with a main moving contact 23, an auxiliary movable contact 29 remains electrically connected with the horn 17 when the contact 23 is in the closed position and during its opening movement until the arc is extinguished, the contact 29 then being disconnected by, and during the final movement of, the main moving contact 23. The auxiliary contact 29 co-operates with a fixed contact clip 18 and is pivoted on a member 27 fixed on the moving contact arm 24. When the switch is opened, the contact 29 slides downwardly in the clip 18 so that by the time the contact arm 24 abuts a stop 30 on the contact 29, the contact 29 has been moved to a position in which it is clear of a fixed stop 33. From this position the contact 29 is pivoted away by the moving arm. When the switch is closed, the arm 24 and the contact 29 move together until the contact 29 engages in the clip 18 and abuts a fixed stop 32, the further movement of the arm 24 then resulting in the contact 29 being thrust up between the stops 32, 33. As shown, a blow coil 35 may be connected between the horn 17 and the contact clip 18. An auxiliary moving contact 29 may be provided on both sides of the contact arm 24. Figs. 6 and 7 (not shown) illustrate an arrangement in which a bellows is mounted between the contact arm 24 and the auxiliary contact 29, the bellows providing an air-blast during the opening period in which relative motion occurs between the arm 24 and contact 29.