Patent GB-535461-A (GB)
Title: Improvements in or relating to electric high voltage air circuit breakers
IPC: H01H71/68
Filed: 1940-03-01
Abstract: 535,461. Automatic circuit-breakers. WESTINGHOUSE ELECTRIC INTERNATIONAL CO. March 1, 1940, No. 3874. Convention date, March 11, 1939. [Class 38 (v)] An air-break, h.v. circuit-breaker has contacts mounted on insulators extending perpendicularly from a vertical base, a closing solenoid also extending with its axis vertically from the base, releasable and resettable trip-free mechanism beyond the outer end of the solenoid, and an insulating mechanical connection between the mechanism and contacts, all parts of the operating means being spaced from the contact-region by a distance sufficient to prevent transfer of power therebetween. The base of a 3-pole breaker may be a single metal or insulating plate, but, as shown, comprises angle-section side members 9 and cross-bars 11 carrying a plate 13, which is apertured to receive the terminal studs 17 and supports insulators 29 on which are blocks 33, 35 supporting the main fixed contacts 37. Block 33 has a pair of lugs 53 which are slotted to receive pins on a channel-like platform 39 carrying an intermediate contact 41 and arcing contact 43, springs 45, 47 and stops acting to tilt the platform so that the circuit is finally broken at 43. The companion contacts are carried on a partly channellike arm 57 and comprise a spring-urged main bridging block 61 and intermediate and arcing contacts 69, 71, all interconnected by flexible lead 73. The contacts of the individual poles are separated by insulating barriers 23 and the contacts as a whole are separated by insulating barrier 24 from the operating mechanism 16 which is carried by a U-shaped frame 77, 81 on a transverse plate 15 on the flanges of members 9. An operating-lever 97, which can be moved by handle or by a link 103 and closing- solenoid 83, is pivoted at 99 together with an actuating lever 95, to which lever 97 transmits closing movement and holding force by a roller 109 on the latter engaging a latch 111 pivoted at 112 between the parallel plates forming lever 95. The end of 111 normally is retained by a shoulder 119 on a limb 117 of a latch 113 pivoted at 115 to lever 95 and having a long arm 121 which is engageable, throughout the closing movement, by a trip lever 143 pivoted at 135 and operable by a trip coil 87 or manually by the fingerpiece 141. The parts 95, 97 are retained in the closed position by the roller 109 engaging a latch 133, also pivoted at 135. This latch is deflected by a surface. 140 of the descending lever 95 when tripping occurs, whereby the member 97 is released and moved by spring 131 to a position in which roller 109 clears the tailpiece 121 and the members 95, 97 are again latched together at 109, 111 ready for reclosure. Lever 95 is pivoted at 155 to arms 153 on a steel tie bar 151, which carries an anchoring bar 172 for the upper ends of the opening springs 101, their lower ends being anchored to frame 77. The arms 57 are each connected to the tie bar 151. by bolts 159 threaded adjustably into clawlike inserts 165 embedded in insulators 161, and by conical inserts 169 threadedly engaged by bolts 171 passing through the bar 151, the arrangement being such that the insulators are subjected to compressive stresses only. The opening movement of bar 151 is arrested by stops 176 which are adjustable for determining the separation of the contacts. Arc-rupturing devices.-An electromagnetic blow-out for each pole of the circuit comprises a core 183 and side plates 181 sheathed in insulating material 182, and is fixed to the frame by a high-voltage insulator 203 and an anglebracket 211 to which the plates 181 are screwed at 215. The plates 181 also bear on, preferably insulating, blocks 205 screwed to the ends 187 of a two-part winding 185, the other ends of which are secured together to a knife contact 191 engageable by a pair of finger contacts 193 on the inner arc horn 177 on the shoot, so allowing the shoot to be horizontally withdrawn. For this purpose, the sides of the shoot are recessed at 217, Fig. 1, to engage the plates 181 and the cover 219 has screws 221 engaging the latter. The shoot may also have spaced arccooling and deionizing plates. The arc horn 177 may alternatively be fixed to the base, in which case contacts 191, 193 are not required.