GB1347489A - Actuating devices for fire extinguishers - Google Patents

Abstract

1347489 Pressurised fire extinguishers WALLOP INDUSTRIES Ltd 11 Aug 1971 [12 Aug 1970] 38951/70 Heading A5A A container 1 of pressurised fire extinguishant has outlet 5 sealed by frangible head 6 which is arranged to be shattered by plunger 21 of piston 24 when the latter is propelled along cylinder 23 by ignition of propellant charge 33. Adaptor 7 threaded on neck 2 of container 1 is formed with axial hole 9 and further hole 14 in its side wall. Bore 9 opens out into threaded bore 10 and houses pointed outlet tube 11, which is retained therein by threaded bush 13 and deformable ring 12. Threaded side bore 14 engages threaded portion 15 of housing 16, portion 15 terminating in projecting boss 19 having axial bore 20 for sliding plunger 21. Shear pin 22 passing through boss 19 and plunger 21 normally retains the latter in retracted position. At its rear end bore 20 opens into cylinder 23 in which piston 24, integrally formed with plunger 21, is movable. The rear end of 24 is formed as combustion chamber 26, and radial and axial vents 27, 28 are provided for the combustion gases. Threaded bore 29 in housing 16 engages screw-threaded cartridge unit 30 which has central bore 32 at the leading end of which propellant charge 33 is located and retained by closing disc 34. Fuse head 35 is connected to electric cables 36 which pass through potting 37 and sleeve 38 and form part of a manually or automatically energised circuit, e.g. employing a thermocouple. The electric igniter 35/36 may be replaced by percussion ignition if required.