GB141738A - Improvements in or relating to automatic sprinkler systems - Google Patents

Abstract

141,738. Lewis, L. M. April 16, 1919, [Convention date]. Sprinklers, automatic. - Relates to alarm-controlling apparatus for automatic sprinkler systems, of the type comprising an alarm check valve and means to allow for the escape of small quantities of water, thus preventing false alarms due to leakage, water hammer, &c. A passage 31 from the auxiliary valve of the alarm check valve 15 leads to a passage 30, pipes 45, 91, a restricted nozzle 93, Fig. 2, the hollow stem 76, 73 of a control valve 77, a fitting 64, a pipe 63, and past a normally open valve 58 to a drain pipe 62. The control valve 77 is normally held closed by the pressure of liquid in a supply pipe 94 acting upon the upper side of a diaphragm 71. When the alarm valve is operated by the opening of one or more sprinkler heads, the increased pressure in the pipes 45, 91, acting on a diaphragm 52 against the action of a spring 61, closes the drain valve 58. Pressure in a chamber 68 on the lower side of the diaphragm 71 then increases, until the control valve 77 opens and allows liquid to flow from the pipe 94 to a pipe 95 leading to the alarm. The auxiliary valve controlling the inlet to the passage 31, Figs. 1 and 4, is situated at the side of the main check valve 15 on a line passing through the centre of the valve 15 parallel to the axis of the pivot 21. The auxiliary valve consists of a disk which is lifted from its seat, on the opening of the valve 15 to a predetermined extent, by a flanged sleeve in which it is mounted and which is carried by a cross arm 36; this arm 36 is engaged by a lug 25 on the valve 15, and is secured to arms 41 turning about the pivot 21.