GB522530A - Improvements in fire extinguishing systems - Google Patents

Abstract

522,530. Fire - extinguishing ; valves. AMERICAN - LAFRANCE - FOAMITE CORPORATION. Dec. 12, 1938, No. 36232. Convention date, Dec. 11, 1937. [Class 47 (ii)] [Also in Group XXIX] In a fire-extinguishing system, particularly for aircraft. a source of compressed gas is connected to more than one point of danger through a selector valve, a single manual control member serving, through two distinct operations, both to operate the valve and to cause discharge of gas from the source. As shown, a cylinder 1 of carbon-dioxide, having a cutter operable by mechanism in a head 2, is connected by a pipe 5 to a valve 6 from which extend pipes 7, 8 leading to the engine compartments and a ,pipe 9 leading to a safety vent. The head 2, Fig. 9, comprises a wedge member 35 adapted to be moved by a cable 32 so as to operate a lever 38 which bears directly on the cutter 4. The pipe 9 leads to a vent 10, Fig. 8, arranged beneath the fuselage and fitted with diaphragms 12, 13 adapted to rupture in the event of a serious leakage of gas from the cylinder, so as to permit safe escape of the gas to the atmosphere and to provide an indication of such escape. The .selector valve comprises a body 6, Fig. 5, a cover 14 which, with the body, provides a valve chamber, and a non-metallic valve disc 17 carried by a stem 18. The disc 17 has. a port 24 adapted to register with any one of the passages 7 - 9, and a slot or recess 23 which co-operates with a nipple 22 of the pipe 5 in order to restrict the movements of the disc. The valve is fitted with an index plate 28, Fig. 7, with indicia corresponding to the pipes 7-9, and the stem 18 has a pointer 29 which also serves as a handle. A further handle 30 slidable on the squared end of the stem is connected to the cable 32, so that a pull on the handle 30 serves to actuate the cutter 4. A catch 40, however, prevents axial movement of the handle 30 until the stem has been turned to a position in which the valve disc will pass gas to one of the danger points 7 or 8. In the inoperative position of the. apparatus, the valve disc connects the pipes 5 and 9, and the handle 30 cannot be moved to actuate the cutter.