Patent GB-367107-A (GB)
Title: Improvements in or relating to automatic fire extinguishing apparatus
IPC: A62C35/60
Filed: 1931-01-02
Abstract: 367,107. Fire-extinguishing sprinklers. AUTOMATIC SPRINKLER CO. OF AMERICA, Standard Bank Building, Cleveland, Ohio, U.S.A.-(Assignees of Hamilton, J. R. ; c/o Automatic Sprinkler Co. of America, Standard Bank Building, Cleveland, Ohio, U.S.A.) Jan. 2, 1931, No. 231. Convention date, Jan. 4, 1930. [Class 47 (ii).] Relates to a sprinkler system wherein the distributing pipes 12, 69, 10 are normally charged with a non-freezing fire-extinguishing liquid contained in a tank 14 and wherein a chemical mixing apparatus 20 comes into operation automatically to provide a main supply of extinguishing liquid as the initial supply becomes exhausted ; and consists in detail improvements in such a system. The mixing apparatus is brought into action by a suction impulse transmitted from a suction chamber 16 which is connected to the tank 14 by restricted passages 17, 18, Fig. 4, to the main pipe 12 by a connection 19, and to the lower chamber 24 of a diaphragm casing 21 by a pipe 24<1>. The space 23 above the diaphragm 22 is connected by a pipe 25 to a casing 59 associated with the mixing apparatus. The latter comprises the tank 20 charged with soda solution, and a casing 28, Fig. 3, housing a cylinder 27 divided by a partition 32 into two chambers 33, 34 for acid. The chamber 34 is formed by a cup member 31 in which the cylinder 27 stands loosely, leaving an annular space 34<1>. The chambers 33, 34 respectively communicate with the tank 20 by a tube 38 and bell 39, and a tube 35 and bell 37. The chambers communicate by a tube 41 and a restricted vent 46, the tube 41 opening from a well 43 in the partition 32. When charging the chambers with acid, acid is poured into the chamber 33 until it reaches the top of the tube 41, when it overflows into the chamber 34. A weight 47 pivoted in the chamber 33 is supported by a latch lever 49 and a rod 54 pivoted in flexible packing 57. The outer end of the rod enters an opening in a stem 62 secured to a diaphragm 60 arranged in the casing 59 and held upwardly by a spring 64. The pipe 25 opens into the space below the diaphragm. When a sprinkler head 11 opens, the fall of liquid in the tank 14 transmits a suction impulse from the diaphragm 22 to the diaphragm 60. The stem 62 falls, releasing the rod 54 from the latch lever 49, and allowing the weight 47 to fall. This drives acid from the chamber 33 to the tank 20. The resulting reaction forces liquid into the main pipe 12, and gas pressure is built up in the chamber 34. When the reaction is finished, pressure falls in the tank 20. The excess pressure in chamber 34 then drives acid through the tube 35 into the tank 20. This process is repeated until the acid in chamber 34 is exhausted. The tank 14 is arranged horizontally, so that the pressure head of the liquid does not vary much during the early operation of the sprinklers. Check valves are arranged in the connections between the main pipe 12 and the distributing pipes 69, to prevent any air that may have been trapped in the system during initial charging from delaying the action of the suction device.