GB1140444A - Improvements in gas blast electric circuit breakers - Google Patents

Abstract

1,140,444. Gas blast switches. ALLMANNA SVENSKA ELEKTRISKA A.B. 31 May, 1966 [1 June, 1965], No. 24165/66. Heading H1N. A gas blast switch (not shown) is controlled by a valve 11, 12 at high potential operated through an insulating rod 7 by an operating means at earth potential, the rod 7 being maintained in tension by the force of compressed gas in a supporting insulator column 4 upon pistons 8, 9 at the top and bottom of the rod. The combined area of piston 9 and valve member 12 is greater than the area of piston 8 so that with the space 14 vented there is a resultant force downwards to keep valve 12 closed. To open, the switch space 14 is filled with the compressed air; since piston 8 is of greater area than valve member 12 the rod 7 moves upwards opening valve 12 to pass compressed air from reservoir 1 through conduit 2 to the operating mechanism (not shown). The switch and operating mechanism may be inside tank 1. In a modification (Fig. 2, not shown) rod (7) is coupled to the valves (11, 12) by a lever (18); the relative sizes of piston (8) and valve (12) can then be different. In another modification (Fig. 3, not shown) the rod (7) operates a valve (19) which vents conduit (2) to open the switch. The space 14 may be normally filled with compressed air the rod 7 being held down by a permanent magnet (23) (Fig. 4, not shown) which may be demagnetized by a coil or have its flux shunted to release the armature (22) to open the contacts. Several series connected switches may be operated simultaneously by a linkage (24, 25) (Fig. 5, not shown) coupling together the lower ends of rods 7. The operating rod may be directly connected to the blast valve (not shown).