GB420182A - Electric circuit breaking apparatus - Google Patents

Abstract

420,182. Arc-rupturing in switches. ELLIS, G. B., 70, Chancery Lane, London.- (Metropolitan Device Corporation ; 1250, Atlantic Avenue, Brooklyn, New York, U.S.A.) July 10, 1933, No. 19502. [Class 38 (v)] Protective arrangements.- Circuit-breaking apparatus comprises a relay-operated switch 7, which is shunted by a light fuse 5 at which circuit is broken, and is in series with a heavy fuse 6 for instantly disconnecting short-circuits. The switch 7 may have three series or parallel breaks, and may be responsive to overload or reverse current or energy. The heavy fuse is rated at at least 10 per cent above, but is preferably of ten times, the normal current capacity of the circuit. Fig. 3 shows a construction in which the fuse 6 is in three parallel parts in a block 18, each being connected to appropriate contacts 16 which are separable from fixed contacts 15 by raising the barrier 19 for replacement of the fuses. An insulating, box-like barrier 21 normally has its flanges 23 resting on the leads 17, but, on blowing of the fuses, drops down and covers the holes in block 18. The light fuse 5, Figs. 7 and 9, is in three parts, only one of which is in use at a time. Three barriers 33 carry the fuses and are released one after another as required, by a solenoid and latch 37 to fall into the circuitclosing position shown in Fig. 7 The fixed contacts 30 are connected to leads 28 by connectors 29 and are separated by barriers 36. The relay-, or mechanically-operated switch has a similar latch arrangement 50, 51 (Fig. 10) for tripping closed, and can be opened by the handle 49 separating bridge contact 46 from contacts 45. Spring-urged arcing barriers 53 enter recesses 55 when the contacts separate, and are pressed back by cams 57, 58 automatically when the contacts are being closed. The fuses may be any or all of the character disclosed in Specification 393,951.