Patent GB-554479-A (GB)
Title: Fire extinguishing apparatus employing carbon dioxide as the extinguishing medium
IPC: A62C99/00
Filed: 1942-01-05
Abstract: 554,479. Fire-extinguishing. CARDOX (GREAT BRITAIN), Ltd., (Cardox Corporation). Jan. 5, 1942, No. 159. [Class 47 (ii)] Fire extinguishing apparatus comprises pipe lines opening into enclosed spaces in a building and extending to the exterior of the building so that a portable container can be connected therewith. Manually operable control means connect any one of the lines to the external connection. A motor started by the flow of carbon dioxide through the pipe line controls means by which the flow may be discontinued after a predetermined time. Fire doors may be automatically closed. The gas may be pumped out after a predetermined interval. Suitable electric circuits for part manual and part automatic control are described. The building may have a control panel 23a on an external wall with a connection for a delivery pipe from a transportable tank. As shown, four pipes 30a each with a valve controlled by a hand-wheel 42a, lead to different rooms. Each room may have a heat sensitive device arranged in case of fire to actuate a signal adjacent its hand-wheel. When a fire occurs, the delivery pipe is coupled to the pipe 26a and the valve 42a of the pipe leading to the room in which is the fire, is opened. The pressure of gas in the pipe 26a moves a piston in a cylinder 171 and a contact arm 176 to close the circuit of an electric motor 180 rotating a disc 190 once a minute. Simultaneously solenoids are energized withdrawing pins releasing fire-doors isolating the various rooms. The disc has slots 193 spaced at 90 degrees and a slot 195, which come into line with lamps and apertures in the panel every 15 seconds and 60 seconds respectively. After a time dependent on the size of the room in which is the fire, the valve 42a is closed. After, say ten minutes a push button 186 is operated to close the circuit to a solenoid 85 withdrawing a latch and releasing a weight 81 and rotating a spindle 79 on which is a valve closing the pipe leading to the room. A second switch 187 is pressed to actuate similar mechanism to open a valve in an exhaust pipe leading from the room. A third switch 188 starts a blower to exhaust the carbon-dioxide from the room to permit inspection. In a modification, a separate timing mechanism is provided for each room, a number of cams 94 being secured to a shaft 90 driven by an electric motor energised when the carbon dioxide flows along the inlet pipe. Each of these pipes is normally closed by a plate 116 pivoted at 119 and moving with a mercury switch 123 which, on being brought to the horizontal position closes the circuit to its timing motor. Thereafter the cam shaft 90 is turned causing cams thereon to actuate mercury switches 104 to close circuits in solenoids in succession, these, respectively, closing the fire door of the room concerned, cutting off the flow of carbon dioxide after a predetermined time, closing the valve in the inlet pipe and opening the valve in the outlet pipe after a second predetermined time, and closing the circuit of a blower to exhaust the gas, the last cam stopping the timing motor at one complete rotation of the cam-shaft. Specifications 519,789, 548,441, [Group XXIX] and 556,978, also are referred to.