GB1282569A - Improvements relating to gas blast interrupters - Google Patents

Abstract

1282569 Gas blast circuit breakers ASSOCIATED ELECTRICAL INDUSTRIES Ltd 10 March 1970 [23 Dec 1968] 61032/68 Heading H1N A gas blast interrupter comprises hollow contact assemblies 5 and 7 with associated exhaust valves 17 and 67, the first of which is housed within contact assembly 5. Assembly 5 comprises a slidable tubular contact 9 having a nozzle 13 communicating with a discharge port 15 by means of the exhaust valve 17. This valve comprises a slidable piston 19 mounted on the contact member 9 which has ports 23, 25 communicating with chambers 21, 27 respectively. Piston 29 controls the discharge port 15 being biased towards the closed position by spring 31. Contact assembly 7 comprises a slidable tubular contact 33 connected by webs 37 to tubular operating member 39 biased to the closed contact position by spring 41. Piston 43 at one end of the member 39 is slidably mounted within a chamber 45 having ports 47 and 49 controlled by pistons 43 and 51 respectively. The exhaust valve 67 comprises a piston 71, biased to its closed position by spring 77 and controlling the ports 79, 83 and 85. Duct 59 connects port 49 with a port 63, the latter of which is controlled by a slide valve 61 operated by a push rod 69. When the push rod 69 is moved downwards from the position shown, compressed air from chamber 45 passes to the lower face of the piston 71, opening the exhaust valve 67 and allowing contact 33 to move back into its housing 35. Contact 9 follows the contact 33 initially due to a pressure differential across the piston 19, which then opens port 15 allowing the compressed air within contact 9 to be released. The gas blast occurs on the separation of the two contacts which allows compressed air in the housing 1 to pass through the nozzles 13 and out through exhaust ports 15 and 79. Reclosing the contacts is achieved by pushing the rod 69 upwards thus linking chamber 45 with the high pressure air in the column 3, thus enabling spring 41 to reclose the contacts.