GB413751A - Improvements in or relating to oil-immersed electric circuit-breakers - Google Patents

Abstract

413,751. Oil break switches. REYROLLE & CO., Ltd., A., Hebburn-on- Tyne, and CHRISTIE, J., 4, Sidecliff Road, Sunderland. Jan. 26, 1933, No. 2492. [Class 38 (v).] Arc-rupturing devices ; contacts.-An oil switch has main fixed contacts co-operating with a movable main bridging contact, and fixed arcing contacts co-operating with movable ones adjacent the ends of an oil-filled chamber carried by the bridge-contact, so that pressure generated by the arc at one set of arcing contacts is utilized to drive the oil in the chamber against the arc formed at the other set. In Figs. 1 and 3, fixed main contacts A, B co-operate with the shaped upper surface of a tubular, metal bridge F, which forms the pressure-chamber and is apertured at each end to admit the fixed arcing contacts D, E cooperating with contacts D<1>, E<1> in extensions of the bridge F. The tube F is closed at F<2> and the contact D is shorter than E so that the first arc is formed between D, D<1> and produces the oil-blast for the arc formed subsequently at E, E<1>.The exhaust takes place through a passage shaped to form a flared nozzle by means of baffle plates G which taper outwardly (Fig. 3) and are interleaved with thinner baffles G<1>, which may either extend across the full width of the tube or have slots of different width from that of the plates G. Alternatively, a deflecting block may be inserted in the lower part of the tube-opening, Fig. 4 (not shown), or the tube may be closed at both ends and the contact E provided with a hollow bore with an aperture that is uncovered at a certain stage in the opening movement, Fig. 5 (not shown). Contacts D, E could be made of the same length and E<1> have an extension E<5> (Fig. 3) to ensure the prior breaking. The arrangement is stated to be adapted to existing breakers and to be free from repulsive forces during closure. In Figs. 6 and 8, the fixed arcing contacts are duplicated at each end, as at P, P<1>, Q<1>, and co-operate with contacts M<2> to provide two parallel-connected paths, each in its own chamber, as K<1>. By arranging for the blasts from the chambers to exhaust in opposite directions, reactions due to the blasts are compensated. The chambers as K<1> are formed by means of insulating side plates J, J and a partition J<2>, insulating plates J<3>, J', a central metal bridge L, and mutually-insulated metal plates M, one for each chamber. The parts of the structure are secured by bolts J<5>, with insulating sleeves J<5> to insulate the plates M, and the chamber ends are constituted by insulating closure plates K<2> and baffles K<3> at the exhaust end, Fig. 8.