Background of the Invention
This invention relates to an apparatus to be installed on an automobile for preventing or extinguishing a fire thereon, and more particularly to such apparatus automatically operable to prevent or extinguish a fire which may break out in an automobile upon collision thereof with another automobile or a nearby building or other structure, or when the automobile has otherwise received a large impact thereon.
A large impact given to an automobile, whether by collision or otherwise, often causes damage to the fuel tank, fuel pipe or fuel pipe fitting thereof with a resultant leakage of vaporized gasoline therefrom. This vaporized gasoline is ignited and starts a fire in the automobile upon contacting an engine portion at an elevated temperature. Such a fire is very dangerous as it does not only burn the automobile, but may also often injure or even kill a person or persons in the automobile or cause damage to a nearby house or other structure. A fire is also started by ignition of such vaporized fuel due to the frictional heat generated upon collision. Sparks produced by short-circuiting of electrical equipment on an automobile also give rise to a fire. The inherent danger of a fire on an automobile is on the increase as the automobile is equipped with an increasing number of different electrical parts or devices, and also as it is equipped with an exhaust gas purifying system for operation at a high temperature.
Despite the obvious danger of a fire on an automobile, however, few countermeasures have been proposed with practical success in the past. That is apparently because it has been difficult to provide a fire fighting apparatus compactly designed for installation in a limited interior space available on an automobile and is automatically brought into sure and effective operation immediately on the occasion of collision or any other impact generating accident.
Summary of the Invention
It is an object of this invention to provide a fire fighting apparatus which is installed on an automobile and is automatically operable immediately on the occasion of collision or any other impact generating accident to surely and effectively prevent or extinguish a fire which may break out in the automobile upon such collision or accident.
It is another object of this invention to provide a fire fighting apparatus which is easy to install removably in an automobile portion in which a fire may often start upon collision of the automobile or occurrence of any other impact generating accident.
It is a further object of this invention to provide a fire fighting apparatus for an automobile which is compactly designed and yet owns a great fire fighting capability.
It is a still further object of this invention to provide a fire fighting apparatus for an automobile which is simple in construction and can be manufactured easily and inexpensively.
Other objects and advantages of this invention will become apparent from the following detailed description and the accompanying drawings.
Brief Description of the Drawings
FIG. 1 is a transverse sectional view of a preferred embodiment of this invention.
FIG. 2 is a sectional view taken along the line II--II of FIG. 1;
FIG. 3 is a diagrammatic side elevational view of an automobile illustrating one apparatus of the invention installed in the engine hood and another installed near the fuel tank; and
FIG. 4 is an enlarged view in plan of the apparatus installed in the engine hood.
Detailed Description
Referring to FIGS. 1 and 2 of the drawings, a fire fighting apparatus 1 according to a preferred embodiment of this invention comprises an outer container 2 and an inner container 3 housed in the outer container 2. The outer container 2 comprises a cylindrical portion 2c which is closed at the opposite ends thereof by a pair of end plates 2a and 2b. The outer container 2 may, as a whole, be made of steel or any other appropriate metal. The inner container 3 comprises a cylindrical portion 3c closed at the opposite ends thereof by a pair of end plates 3a and 3b. The inner container 3 may be made of glass or any other appropriate fragile material as a whole. Alternatively, only one end plate 3b or a portion thereof may be made of a fragile material for the reason to be later explained, while the remaining part of the inner container 3 is made of a durable material. It has been found practically preferable to employ a foil of a metal, such as aluminum, only in the central portion of the end plate 3b, while the remaining part of the inner container 3 is fabricated from a thicker sheet of the metal. In the event the inner container 3 is made of a plurality of different materials or with different thicknesses, joining may be accomplished by any appropriate known method, wherever necessary.
The inner container 3 is supported by a holding ring 4 which encircles the inner container 3 approximately in the middle of the cylindrical portion 3c. The holding ring 4 is made of a sheet of steel or any other appropriate metal having a width suitable for holding the inner container 3 in position, while the inner surface of the ring 4 closely contacts the outer surface 3d of the cylindrical portion 3c. A plurality of supporting bars 5 extend between the outer container 2 and the holding ring 4 and may be made of metal. The supporting bars 5 are provided radially relative to the outer container 2 in an equally spaced relationship, and one end of each bar 5 is joined by welding or otherwise to the inner surface 2d of the cylindrical portion 2c of the outer container 2, while the other end of each bar 5 is joined in a like manner to the outer surface 4a of the holding ring 4. The supporting bars 5 are all of the same length, so that the inner container 3 is supported in the outer container 2 in a coaxial relationship with the outer container 2 as shown in FIG. 2. One end plate 2a of the outer container 2 is formed with a relatively small opening in the center thereof, and the peripheral edge of this opening is bent outwardly to define a nozzle 6 at the outermost tapered end thereof. An outwardly tapered plug 7 is fitted in the nozzle defining portion of the end plate 2a and has a peripheral surface which is complementary to the inner surface of the nozzle defining portion, so that the plug 7 keeps the nozzle 6 closed under the normal situation. The plug 7 is made of rubber or any other suitable material that will allow the plug 7 to be easily broken to open the nozzle 6 when the internal pressure of the outer container 2 exceeds a predetermined level as will later be described in detail.
The opposite end plate 2b of the outer container 2 is formed in the center thereof with a similar opening which defines an outwardly extending tubular projection 8 in a coaxial relationship with the inner container 3. A plunger 9 is received in the bore 8a of the tubular projection 8. The plunger 9 may be made of metal or any other appropriate rigid material and includes a relatively elongate stem portion 9c having a circular cross section complementary to the bore 8a. The stem portion 9c includes a pointed inner end 9b facing the end plate 3b of the inner container 3 and projecting into the outer container 2. The outer end of the stem portion 9c extends outwardly from the outer end 14 of the tubular projection 8 and terminates in a flange or head portion 9a having a large diameter relative to the stem portion 9c. The tubular projection 8 of the outer container 2 has a pair of diametrically oppositely formed holes having an equal small diameter approximately in the middle thereof. The stem portion 9c of the plunger 9 is formed approximately in the middle thereof with a diametrically extending hole of a diameter which is substantially equal to that of the holes provided in the tubular projection 8. The hole in the stem portion 9c is aligned with the holes in the tubular projection 8. A shear pin 10 extends through the holes provided in the tubular projection 8 and the stem portion 9c. Under the normal situation, the shear pin 10 maintains the plunger 9 in its retracted position as shown in FIG. 1 in which the pointed end 9b is spaced apart from the end wall 3b of the inner container 3. The flange 9a of the plunger 9 is spaced from the outer end 14 of the tubular projection 8 to such an extent that the pointed end 9b of the plunger 9 can pierce the end plate 3b of the inner container 3 upon sliding displacement of the plunger 9 into the outer container 2 when an impact resulting from collision of the automobile or a like cause is applied onto the flange 9a and the shear pin 10 is broken.
The outer container 2 contains a foamable fire extinguishing composition alternatively, either in the form of powder or liquid. If the composition 11 is liquid, an appropriate seal is provided between the nozzle 6 and the plug 7 and between the tubular projection 8 and the plunger 9 in any known manner to prevent the composition 11 from leaking out of the outer container 2. The composition 11 may be selected from any fire extinguishing chemical readily available on the market if it can extinguish a fire caused by combustion of gasoline. For example, the composition 11 may be prepared from sodium bicarbonate if a powder form is preferred, or alterantively, carbon tetrachloride may be used if a liquid form is preferred. The inner container 3 contains a high pressure gas, such as carbon dioxide and nitrogen. The inner container 3 is wholly or partially made of a fragile material as mentioned before, but is required to withstand the high pressure of the gas contained therein and remain a totally closed structure until the end plate 3b is broken by the plunger 9. It is thus preferable to make the central portion of the end plate 3b of an aluminum foil to permit the plunger 9 to easily break through the end plate 3b, while the remaining part of the inner container 3 is made of a thicker material.
The outer container 2 is encircled by an annular band 13 closely contacting the outer surface of the outer container 2 approximately in the middle of the cylindrical portion 2c. The band 13 may be made of metal and provides means for removably mounting the apparatus 1 in any desired location on the automobile. Mounting of the apparatus 1 by the band 13 may be accomplished in any known manner and no further explanation will be required in connection therewith. It is, however, essential to install the apparatus in a location or locations where a fire is more likely to start than in any other locations upon leakage of fuel as the result of collision or application of any large impact against the automobile. It is preferable to install one unit of the apparatus 1 in the engine hood and another unit near the fuel tank as shown in FIGS. 3 and 4. It is also necessary to position the apparatus 1 in a posture which permits quick response of the plunger 9 upon collision of the automobile. More particularly, the flange portion 9a of the plunger 9 must be directed in a direction in which an impact applied to the automobile upon collision thereof or otherwise is easily transmitted to the flange portion 9a by deformation of a portion of the automobile body and contact thereof with the flange portion 9a to cause displacement of the plunger 9 into piercing contact with the end plate 3b of the inner container 3.
Upon collision of the automobile, the impact applied to the automobile body acts upon the flange portion 9a of the plunger 9. The plunger 9 breaks the shear pin 10 and plunges into the outer container 2. The pointed end 9b of the plunger 9 strikes against the adjacent end plate 3b of the inner container 3 and breaks therethrough. The gas gets out of the inner container 3 into the outer container 2 and the composition 11 in the outer container 2 is foamed. The foamed composition 11 breaks the plug 7 and is discharged through the nozzle 6 to prevent a fire or extinguish a fire if any has already started.
Although only one plunger 9 has been described and shown, it is possible to provide a plurality of differently directed plungers so that any one of the plungers may be actuated in whichever direction an impact is applied to the automobile and transmitted to the apparatus 1. Likewise, it is possible to provide the outer container 2 with a plurality of nozzles for discharging the composition 11 in a plurality of different directions. In the event a plurality of plungers are provided, it will be understood that the inner container 3 must be made of a fragile material in its entirety. It will also be easy for any person skilled in the art to operationally associate the plunger 9 with an accelerometer which measures the acceleration of the automobile upon its collision and causes the plunger to break through the adjacent wall of the inner container 3 when the acceleration has exceeded a predetermined level.
While the invention has been described with reference to a preferred embodiment thereof, it will be understood that modifications or variations may be easily made by those skilled in the art without departing from the scope of the invention which is defined by the appended claims.