GB566248A - An improvement in or relating to fire-fighting systems or appliances - Google Patents

Abstract

566,248. Fire-extinguishing. NUSWIFT ENGINEERING CO., Ltd., and HENSHAW, T. A. May 22, 1943, No. 8166. [Class 47 (ii)] A gaseous or liquid fire - extinguishing medium under pressure is confined by a valve which is held in operative position in an undistorted condition by fusible metal, so that in normal temperature conditions the fusible metal is not required to withstand the whole pressure of the medium. As shown in Fig. 1, a discharge head b with discharge nozzle c is screwed to a spigot a<2> on a fitting a adapted to be secured by a spigot a into a delivery pipe or outlet opening of a container for pressure medium. A metal plug member d with circumferentially spaced spring leaves d<1> is secured by a metal plug f which spreads the leaves d<1> to seat in an annular recess or depression e in the bore a<3> of the fitting a, and the plug f is normally retained in this position by fusible metal run between the plug and the leaves d<1>. The plug f or the fitting a in the vicinity of the recess e is heated by passage of current through a resistance wire, and, when the fusible metal melts, the pressure medium forces the plug axially, by causing the leaves d' to be forced inwardly out of the recess e, into a chamber bl in the head b. In a modification, Fig. 2, leaves j<1>, provided on an outlet passage j for the medium, are bent inwardly over the solid plug member d and normally retained in this position by fusible metal. Fig. 3 shows a further modification where a series of loose leaves m are held in an annular recess j<2> or in a series of spaced recesses and held in place by fusible metal to normally hold a valve or plug d in closure position in a passage j.