Patent Application
20080087446
The accompanying drawings illustrate the invention. In such drawings:
As shown in the drawings for purposes of illustration, the present invention relates to a self-activated fire extinguisher primarily for use as a Christmas tree ornament or decoration.
The self-activating fire extinguisher 10 consists of a plastic pressure vessel 14 that can be molded or configured in a variety of shapes such as spherical or cylindrical. The pressure vessel 14 may or may not be painted or decorated with an external facade to suit various usage requirements, i.e., as a Christmas decoration. The pressure vessel 14 includes mounting tabs 11 integrally molded onto the surface.
The pressure vessel 14 is capable of housing a variety of fire suppressant agents such as a liquid, a powder, or combinations of both. Such fire suppressant agents include Purple K Powder or any bicarbonate compound in a water solution. The fire suppressant agent may also include Envirogel or any halocarbon compound. The pressure vessel 14 also contains a pressurized gas to ensure that the fire suppressant agents are under sufficient pressure to be ejected from the fire extinguisher 10 when it is activated. The pressurized gas preferably comprises nitrogen at a pressure of 20-30 psig. Other inert gases may be used at similar pressures. The primary purpose of the pressurized gas is to eject the fire suppressant agents in a timely manner.
The pressure vessel 14 includes an outlet passageway 16. A metal boss 13 is embedded into the pressure vessel 14 around the outlet passageway 16. A plug or fitting 18 is positioned within the outlet passageway 16 and seals the pressure vessel 14 with a metallic or polymer seal 20. The seal 20 may comprise a tin plated soft copper washer, O-ring or other similar device mounted against a sealing surface 21 on the fitting 18.
One or more tubes 22 may be mounted on the fitting 18 to provide access to the pressure vessel 14 through the outlet passageway 16. The tubes 22 are brazed 23 to the fitting both internally and externally. The tubes 22 may be of different lengths and/or diameters to provide for different patterns of fire suppressant agent to be discharged from the fire extinguisher 10.
The ends of the tubes 22 farthest from the pressure vessel 14 include a valve mechanism 24 and a temperature sensor 26. The valve mechanism 24 allows for the contents of the pressure vessel 14 to be discharged into the designated fire zone. The valve 24 is spot welded, brazed or threaded onto the end of the tubes 22. The temperature sensor 26 comprises a fusible alloy that maintains the valve in a closed position for a normally charged fire extinguisher 10. The temperature sensor 26 is a specially formulated metal alloy that softens and melts at a precise temperature or temperature range. Preferably that temperature or temperature range approximates the temperature which the intended fire to be extinguished would likely burn. In the preferred embodiment this temperature range is between 225° F. and 235° F. Upon exposure to heat and/or flame the temperature sensor 26 will soften and/or melt, thereby allowing the pressure inside the pressure vessel 14 to open the valve. The pressure in the fire extinguisher 10 will force the fire suppressant agent to discharge into the fire zone, i.e., the direction in which the tubes 22 are pointing. A conical plug 28 may be positioned within the valve to allow the fire suppressant agent to discharge in a uniform 360° pattern. Where multiple tubes 22 are used, each tube may include a temperature sensor 26 with a melting point different from temperature sensors 26 in other tubes 22. Further, each tube 22 may include a conical plug 28 with a slightly different shape from the conical plugs 28 used in other tubes 22 to create differing discharge patterns.
One or more of the tubes 22 may include a capillary tube 30 for charging the pressure vessel 14 with fire suppressant agent and/or pressurized gas. The capillary tube 30 is preferably brazed to the tube to create a seal. Once the pressure vessel 14 is charged, the capillary tube 30 subsequently hermetically seals the fire extinguisher 10.
Although several different embodiments of the present invention have been illustrated and described in detail, various modifications may be made without departing from the spirit and scope of the invention. Accordingly, the invention is not to be limited, except as by the appended claims.
