GB217079A - Improvements in or relating to sprinkler systems - Google Patents

Abstract

217,079. Jackson, W. J. Mellersh-, (General Fire Extinguisher Co.). July 25, 1923. Sprinklers, automatic. - Dry-pipe sprinkler systems are so constructed that the dry-pipe valve is caused to open upon any drop of pressure to a predetermined extent or upon a slight quick drop of pressure not necessarily reaching the predetermined extent. A pressure-sensitive device subject on one side to the pressure in a chamber communicating with the dry pipe by a restricted opening operates a valve to admit fluid under pressure to the chamber 10 between the air valves 5 and the water valve 7 of a differential type valve. On the opening of a sprinkler the pressure in pipe 40 and bellows 38 falls quickly, but the, pressure in bellows 39 in communication with the dry pipe by an air chamber 12, chamber 31, and pipe 13 falls slowly owing to the restricted orifice 14 in the chamber 31; the bellows thus move a bar 42, and a weighted lever 19<1> which opens a valve 18<1> by a finger 21. In this way the chamber 16<1> which is connected to the water supply pipe 4 by a pipe 17<1> is put into communication with the chamber 10 by a pipe 15<1>. In a modification in which air pressure is supplied to the chamber 10 the pipe 17<1> connects the chamber 16<1> to the air pipe 2 and the weighted lever 19<1>, operating the valve 18<1>, is moved by a, plunger and a rubber diaphragm. supported by a perforated plate in communication with the air chamber 12 on one side, its other side being subject to the pressure in chamber 16<1>. The chamber 31 is provided with a strainer 37 to prevent the orifice 14 from being choked. An open drip attachment 11 which normally maintains atmospheric pressure in the chamber 10 is closed by pressure. Reference has been directed by the Comptroller to Specification 221,602.