GB529846A - Improvements relating to liquid immersed circuit breakers having arc extinguishing provision - Google Patents

Abstract

529,846. Liquid-blast switches. FLURSCHEIM, C. H.. and METROPOLITAN-VICKERS ELECTRICAL CO., Ltd. May 25, 1939, No. 15555. [Class 38 (v)] The contacts of a liquidimmersed switch are disposed adjacent arc - constraining surfaces forming a corner along which the arc is drawn and the conductors leading to the contacts are arranged to force the arc electrodynamically into the corner, one or more cross-jet passages being provided for leading the liquid across the arc. The invention is applicable to the arrangements described in Specifications 506,857 and 525,622 in which series isolators are provided. In Fig. 1, a series of bridging-members 6 .. 8 .. are provided on an insulating operating rod 3 and carry at each end a contact 19 co-operating with a contact 18, the latter being interconnected by U.shaped members 16 so that all the breaks are in series. In the original drawing, six bridging-members 6 &c. are shown. A shield 21 is mounted on the supporting board 1 which is apertured at 20 to provide a cross-jet passage against each contact 18, and are-resistant side plates 22 are mounted adjacent to each shield. The jet may be produced by the arc, by another arc, or by a piston associated with rod 3. The flux due to the limbs 17 of members 16 forces the arcs into the corners against the passages 20 and where an arc lies parallel to the long part of the member 16, the repulsive effect of the oppositely-flowing currents produces the same result. The board 1 may be mounted as a partition in a horizontal insulating cylinder with the larger, contact - containing compartment below, and a barrier running the length of the cylinder and at right-angles to the board so as to separate the apertures 20 on the two sides of the board. The cylinder may however be vertically arranged or at any other angle. In Fig. 3, a conventional oil switch is shown with a container 33, 34 mounted on each lead-in insulator, each container having two bridging members 35, 36 interconnecting contacts 37, 39, and 41, 42, respectively. Contacts 37 are connected to the respective lead-in conductors, contacts 39, 41 are connected to conductors 40, and contacts 42 are connected to contacts 43 which are engaged by the bridge-member 44 before the latter closes the other contacts by means of the lift-rods 46. Each container comprises an apertured base-board analogous to 1 in Fig. 1, and a cover member, Fig. 4 (not shown). The Provisional Specification refers also to jet passages in opposite walls of the oil-chamber, so that the blasts are oppositely-directed, and also to two jets at right-angles.