Fire extinguisher

Abstract

The specification discloses a fire extinguisher comprising a fire extinguishing substance located in a closed container. A small amount of explosive charge is employed primarily for opening the container wall in the presence of high temperatures to allow the fire extinguishing substance to pass out of the container. In the preferred embodiment, the wall has weakened portions selectively formed to facilitate rupturing to form an opening in the wall without fragmentation. The small amount of explosive charge is located in the container in close proximity to the wall in the vicinity of the weakened portions for rupturing the wall at the weakened portions to form an opening therethrough. In addition, a heat sensitive fuse or firetrain is provided for actuating the explosive charge in the presence of heat above an undesired level. In one embodiment, a secondary explosive charge is located in the fire extinguishing substance and spaced from the small amount of explosive charge and which is actuated by the fuse or firetrain after the small amount of explosive charge is actuated to force the fire extinguishing substance outward through the opening formed by the small amount of explosive charge. The fuse or firetrain comprises a metallic wire having a high thermal conductivity, a fast burning substance located around the wire, a confining cover comprising wires spirally wrapped around the fast burning substance, a nylon yarn counter wrapped, as added hoop compression, and a water-proof layer of highly flammable material deposited on and throughout the confining cover.

Description

BACKGROUND OF THE INVENTION

This invention relates to a fire extinguisher employing an explosive charge for releasing fire extinguishing substance from a container and in addition to a fast burning and effective fuse or firetrain for use actuating the charge.

Fire extinguishers have been built or proposed comprising a scored container wall having located therein a fire extinguishing powder with a single explosive charge embedded in the powder and which is ignited by a heat sensitive fuse to rupture the scored container wall and force the powder outward into the surrounding environment. Unless the explosive charge is relatively large, problems have been observed to occur in that the explosive force tends at random to rupture one portion or the other of the container wall leaving a large amount of powder in the container. This is due in part to the fact that the scoring of the container wall may not be the same on all sides and hence certain sides may be more weakened than the others. The explosive force will seek the path of least resistance, through the powder, and the portion of the wall in this path will be ruptured and possibly fragmented, dispersing only a small portion of the powder in a random direction with the balance of the powder being tightly packed in the other side of the container. Improved rupture and dispersion of the powder may be obtained if the centered or embedded explosive charge is made relatively large, however, this presents safety problems particularly if the fire extinguisher is to be used indoors.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide an arrangement for effectively opening the wall of a fire extinguisher container in the presence of undesired temperatures to allow a fire extinguishing substance to pass out of the container.

It is a further object of the present invention to provide an effective and practical non-fragmenting fire extinguisher employing an explosive charge for forming an opening or openings through the wall of a container for the purpose of releasing a fire extinguishing substance and which has a high factor of reliability or repeatability in forming the opening or openings where desired and further which does not require a large explosive charge to form the opening or openings.

It is a further object of the present invention to provide a fast burning, easily ignitable, and effective fuse or firetrain for use for actuating an explosive charge used in a fire extinguisher.

In the preferred embodiment, the fire extinguisher comprises a closed container having a fire extinguishing substance located therein. The wall of the container has weakened portions selectively formed to facilitate rupturing to form an opening in the wall without fragmentation. A small amount of explosive charge is located in the container at a position outward from the center of the fire extinguishing substance and in close proximity to the wall in the vicinity of the weakened portions for rupturing the wall at the weakened portions to form an opening therethrough to allow the fire extinguishing material to pass out of the container. In addition, a heat sensitive fuse or firetrain is provided for actuating the explosive charge in the presence of heat above an undesired level.

In one embodiment, a magnet is attached to the container to allow the container to be attached in place to a metallic object.

In a further embodiment, the fire extinguisher comprises a secondary explosive charge located or embedded in the fire extinguishing substance and spaced from the small amount of explosive charge. The fuse or firetrain extends from the exterior of the container to the small amount of explosive charge and to the secondary explosive charge to allow the small amount of explosive charge to be actuated by delayed action to force the fire extinguishing substance outward through the opening.

The fuse or firetrain comprises a metallic wire having a high thermal conductivity, a first burning substance located around the wire, cover means wrapped around said fast burning substance to provide strength for said fuse and to hold said fast burning substance in place, and a water-proof layer of highly flammable material deposited on said cover means. In one aspect, the cover means comprises thin metallic wires spirally wrapped around the fast burning substance with a nylon yarn counter wrapping to bind these wires in place and provide a foundation for the water-proof layer of highly flammable cover material.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a fire extinguisher attached to the top of a vent-a-hood of a cooking stove;

FIG. 2 is an enlarged partial cross sectional view of the fire extinguisher of FIG. 1 illustrating a thin lyaer of explosive charge deposited on the interior of its bottom wall for rupturing scored portions of the wall when the charge is ignited;

FIG. 3 is a bottom view of the fire extinguisher of FIG. 2 illustrating scored lines on its bottom end;

FIG. 4 is an enlarged cross sectional view of FIG. 3 taken through the lines 4--4 thereof illustrating scored lines;

FIG. 5 is an enlarged partial cross sectional view of the container of FIG. 2 illustrating the double seam connecting the bottom end and the side walls;

FIG. 6 illustrates the fire extinguisher of FIGS. 2 and 3 after its explosive charge has been ignited and its rupturable segments forced outward to form openings through the bottom end to allow its fire extinguishing powder to fall out for fire extinguishing purposes;

FIG. 7 illustrates a ferrule and a push on friction nut for holding the fuse in place;

FIG. 8 is an enlarged partial cross sectional view of the bottom end of the fire extinguisher illustrating an embodiment for minimizing the amount of explosive charge required for rupturing the bottom wall of the fire extinguisher for releasing its powder;

FIG. 9 is a view of the bottom end of the embodiment of FIG. 8 as seen from the inside of the fire extinguisher;

FIG. 10 is a partial cross sectional view of another embodiment of the fire extinguisher employing a secondary charge embedded in the fire extinguishing powder;

FIG. 11 is a partial cross sectional view of a fire extinguisher of the type illustrated in FIG. 10 but having a dome shape;

FIG. 12 is a bottom view of the fire extinguisher of FIG. 11;

FIG. 13 illustrates the fire extinguisher of FIGS. 11 and 12 after its explosive charge has been ignited and its rupturable segments forced outward to form openings;

FIG. 14 illustrates an enlarged and partial cross sectional view of the fuse or firetrain employed in the fire extinguishers of FIGS. 1-13;

FIG. 15 is a cross sectional view of FIG. 14 taken through the line 15--15 thereof;

FIG. 16 is an enlarged cross sectional view of another embodiment of the fire extinguisher wherein its wall is formed of a material capable of being disintegrated by the explosive charge when exploded;

FIG. 17 illustrates a further embodiment wherein the walls of the container are formed of a highly flammable material; and

FIG. 18 illustrates a portion of a container wall of an embodiment wherein the container wall is layered having an inner sandwiched layer formed of a highly flammable, self-oxidizing material or an explosive material.

DETAILED DESCRIPTION OF THE DRAWINGS

Referring now to FIGS. 1-7, the fire extinguisher illustrated therein is identified by reference numeral 11 and comprises a container 13 formed by a cup-shaped member 15 having a lower lid 17 sealed to the lower end 15a of the member 15 by a double seam illustrated in FIG. 5. Located within the container is a fire extinguishing substance 19, preferably a fire extinguishing powder which may be of the A.B.C. type or for example, of the B.C. type. As is well known, the A.B.C. type is formed of about 90% monoammonium phosphate with about 10 percent silicones and other materials (silica, ground mica) added to keep it free flowing to protect it from moisture. The B.C. type is about 90-94 percent sodium bicarbonate. The balance of the material is stearates or silicones and other materials added to keep it free flowing and to protect the sodium bicarbonate from moisture.

The top 15b of the container 13 has a magnet 21 attached thereto to allow the extinguisher to be attached to a metallic object and hung with its bottom end 17 downward. When used as illustrated in FIG. 1, the fire extinguisher will be attached to the top of a vent-a-hood of a stove for protection against grease fires. The magnet 21 is encased in a case 23 which is movably attached to the container 13 by a ring 25. This ring is inserted through loop 23a of the case 23 and through aperture 27 formed member 29 attached to the top end 15b of the container 13.

Referring to FIG. 3, the bottom lid 17 has grooves or scored lines 31a-36a selectively formed on one side thereof to facilitate breaking or rupturing of the bottom end into separate tear-open segments 31-36 without fragmentation to form openings 31b-36b only in the bottom end or bottom wall portion when the free ends of the segments are forced outward to allow the fire extinguishing powder to fall or pass outward from the container onto the fire. Although the scoring is illustrated on the outside surface of the lid 17, preferably it will be on the inside surface thereof.

The explosive charge for rupturing the bottom end along the weakened or scored lines for forcing the free ends of the segments outward comprises a small amount of explosive charge 41 deposited on the inside of the lid 17. In the embodiment of FIG. 2, the charge 41 is deposited as a thin layer in the area defined by the dotted circle 43, as seen in FIG. 3. Extending through the lid 17 and to the explosive layer 41 is a heat sensitive fuse or firetrain 51. As illustrated, the fuse 51 is held in place by a ferrule 53 and a push on friction nut 55. The fuse 51 ignites when the temperature outside of the fire extinguisher reaches a certain level to explode the charge 41. When this occurs, the force of the explosion ruptures the scored or weakened lines and forces the tear open segments 31-36 outward to form the openings 31b-36b. In addition, the force of the charge pushes the fire extinguishing powder upward in the container, loosening any caking. The fire extinguishing powder then gently falls out of the can by gravitational force to extinguish any fire below which may be in a frying pan, for example. The non-erupting portions 17a of the lid 17 control the flow so that the powder does not fall out in one lump, which might splash grease from the frying pan, but gently trickles out for about 10 seconds, in one embodiment. Thus in the embodiment of FIGS. 1-7, the fire extinguishing powder is not dispersed too widely but only on the flame area below the fire extinguisher.

Since the explosive charge 41 is located in close proximity to the grooves or weakened lines formed in the lid 17, the charge will form the openings where desired when ignited with a high degree of reliability thereby insuring proper release of the fire extinguishing powder. Moreover, the amount of explosive charge required is small, thereby reducing dangers or hazards which may be otherwise present if a large amount of charge were employed. For ease of assembly, the fuse or firetrain 51 is inserted in place through the lid and the explosive charge applied onto the interior side of the lid 17 before it is attached to the member 15.

Instead of depositing a thin layer of explosive charge on the inside of the lid 17, within the full area defined by dotted line 43, a small amount of explosive charge may be deposited on the inside of the lid 17 concentrated closely around the fuse 51, in effect to form a ball of more concentrated charge. Such a ball of charge having a diameter of about one fourth of an inch has been found to be sufficient to force the tear open segments outward when exploded even though it is not directly opposite the scored lines defining the tear open segments. The use of a small ball of charge has advantages over the thin layer of charge in that increased brisance is obtainable with less explosive material.

Referring now to FIGS. 8 and 9, there will be described another embodiment for minimizing the amount of explosive charge required for forcing the tear open segments 31-36 outward to form the desired openings for releasing the powder from the fire extinguisher. As shown in FIG. 9, scoring is done on the inside surface of the lid to define the segments 31-36. In this embodiment, a small plate 61 is held in place on the inside of the lid 17 by eyelets 63 and 65 which also hold the fuse in place. A plurality of pockets 67 are formed in the plate by punching portions 62 inwardly with the openings 67a facing the axis of the plate 61. As illustrated, the pockets are located next to the free corners or free ends of the rupturable segments 31-36. The pockets are filled with an explosive charge 69 which also is deposited on the plate 61 forming a firetrain 71 leading to the fuse 51. When the fuse or firetrain 51 is ignited, the firetrain 71 is ignited which in turn ignites and explodes the charge 69 in the pockets to rupture the lid at the scored lines and force the segments 31-36 outward forming the desired openings to allow the powder to fall outward. In this embodiment, the portions 62 forming the pockets reflect the force of the explosion occurring in the pockets outward to increase the amount of force applied to force the segments 31-61 individually outward to form the desired openings.

Preferably the container formed by member 15 and lid 17 are formed of this aluminum. In one embodiment, the container has a diameter of about 3 inches and a height of about 2 inches. The lid is attached to the member 15 by way of a double seam since this manner of attachment can be done rapidly and economically and in addition, provides a water-proof seal for the powder in the container.

In the embodiments of FIGS. 1-9, the purpose of the explosive charge 41 and 69 is to act solely on the container wall to form an opening or openings without forcing the bulk of the powder out of the container. After the opening or openings have been formed, the fire extinguishing powder then is allowed to fall out by the force of gravity.

In the preferred embodiment, the explosive charges 41 and 69 are a primary or initiating type of exposive in that it does not require confinement or enclosure to develop brisance. Examples of this type of explosive are mercury fluminate, lead azide, nitrosoguanidine, lead styphnate, double salts of lead styphnate as with nitroaminotetrazole, or with lead hypophosphite, or with lead propionate, lead picrate, or its double salts, lead dinitroresorcinate, diazodinitrophenol, tetracene, mono-basic lead dinitrobenzoate, di-basic lead dinitrobenzoate, double salt of lead trinitroresorcinate, basic salts of tetrazole and basic lead salts of nitrotetrazole, nitrotetrazole, salts of mercury nitrotetrazole, salts of silver nitrotetrazole, acid copper salt of C-nitrotetrazole, silver and mercury azides, or combinations of explosives such as picric acid and silver azide or diazodinitrophenol primed with lead azide alone or with the addition of lead styphnate or tetrazene or with diazodinitrophenol as the primary explosive, tetryl, the lead salts of picric acid and trinitroresorcinal, m-nitrophenyldiazonium perchlorate, nitrogen sulfide, copper acetylide, fulminating gold, the tartarates and oxalates of mercury and silver, fulminate of silver, cadmium azide, cuprous azide, thallium azide, cadmium fulminate, copper fulminate, thallium fulminate, sodium fulminate, potassium fulminate, cobalt azide, barium azide, calcium azide, strontium azide, nickel azide, manganese azide, lithium azide, mercurous azide, zinc azide, etc. For further information on primary or initiating explosives, reference is made to The Chemistry of Powder and Explosives by Dr. Tenney L. Davis, John Wiley and Sons, Inc., New York 1943, pages 2 and 3. A suitable binder is mixed with the explosive used and a protective coating such as nitrocellulose may be applied to protect it environmentally. The binder may be gum arabic, karaya gum, gum tragacanth, guar gum, locust bean gum, arabinogalactan derived from locust bean gum, glucose, gum yacca (red gum), or the following may be used alone or in combinations of two or more: methyl cellulose, hydroxyethyl cellulose, carboxymethyl cellulose, dextrin, polyvinyl-pyrrolidone, linear high molecular weight poly (ethylene oxide), polyvinyl alcohol, and ureaformaldehyde or melamine-formaldehyde polymers, as well as shellac, rosin, calcium resinate and ester gum, all of which are more or less commonly used explosive binders.

Referring now to FIG. 10, there will be described another embodiment of the fire extinguisher which is similar to that of FIGS. 1-9 except that it has embedded in the fire extinguishing powder 19, a secondary charge identified at 81. The container is similar to that of FIG. 1 in that it is formed of a cup shaped member 83 having a lid 85 sealed to the side walls by a double seam. The lid 85 forms the top of the fire extinguisher while the other end 87 forms the bottom thereof. Formed in the bottom end 87 are scored lines similar to that disclosed in FIG. 3 forming a plurality of rupturable segments 31-36. In addition, the side walls have scored lines 89 formed to provide rupturable but non-fragmenting segments 91. Deposited on the inside of the bottom 87 and on the inside of the side wall 86 is a thin layer of explosive charge 93. Both charges 81 and 93 may be formed of the same material as charges 41 and 69 described previously. However, since the explosive charge 81 is housed in a paper container, explosives such as black powder, flash powder commonly used in firecrackers and similarly used explosives may be effectively used for the charge 81. The explosive charge 81 is housed in a paper container 94 which is held centered within the powder 19 by member 95 which may be a polyethylene, closed cell, sponge material. Member 95 also may be formed metal or cardboard. As illustrated, the charge 81 is spaced from the primary charge 93 in that the container 94 has a lower insert 96 providing a space 97 between the secondary charge 81 and the primary charge 93. The upper end of the container also has an insert 101 which spaces the charge 81 from the upper end of the container. The fuse 51 extends through the primary charge 93 and to the secondary charge 81. In operation, when the fuse 51 is ignited, the primary charge 93 will be actuated initially to force the segments 31-36 and 91 outward to form openings in the container wall. The explosion of the primary charge 93 also drives the powder 19 tightly around container 94 housing the secondary charge 81. Since the secondary charge is spaced from the primary charge, its ignition will be delayed subsequent to the ignition of the primary charge. As the fire extinguishing powder starts moving into the vacuum caused by the primary charge, the secondary charge is exploded by the fuse thus taking advantage of the reflex phenomena. The secondary charge then widely disperses the powder through the openings formed.

The embodiment of FIG. 10 has a number of useful applications, for example, it may be used in the attics of homes for providing fire protection. It may be attached to the rafters with a nail, hook, or staple inserted through the ring 25.

The embodiment of FIGS. 11 and 12 is similar to that of FIG. 10 except that the container is dome shaped and the scored lines 103 forming the tear open segments 105 are continuous. In the embodiment of FIG. 10, the primary charge 93 is deposited on the sides, as well as on the bottom of the container. In the embodiments of FIGS. 11 and 12, however, the primary charge may be deposited on the inside of the rounded bottom end as illustrated or a small amount of explosive charge may be deposited on the inside of the bottom concentrated around the fuse or firetrain 51 in effect balling the charge so as to increase the brisance. A charge of lead styphnate having a diameter of about one half of an inch has been found to be sufficient in force to open the segments outward when exploded even though the charge is not opposite the scored tear open segments.

Referring not to FIGS. 14 and 15, there will be described the fuse or firetrain 51 which is a fast burning, highly flammable, water-proof and explosion-proof fuse. In addition, it is readily ignited by a low temperature flame or an ambient temperature of approximately 310.degree.F. In the preferred embodiment, the fuse or primary firetrain 51 comprises a thin copper wire 121 heavily coated with a fast burning substance or material 123 which may comprise 2-3 micron size fine silicon powder for the fuel ranging from 30 to 60 percent (40 percent preferred), and lead peroxide (PbO.sub.2) ranging from 30 to 60 percent (58 percent preferred) as the oxidizer plus 0.5 to 10 percent (20 percent preferred) fine zinc powder to add to the heat and vigor of the burning. Acetone wetted cellulose nitrate may be used to bind these materials together. The ratios of this formulation may be varied to produce different burning rates and this formulation is extremely stable. Wrapped around the material 123 is a protective covering comprising five spirally wrapped wires 125 to prevent the fuse from being extinguished or destroyed by the substance 123 when ignited or by the explosive charge of the fire extinguisher before the fuse can effectively perform its function. This is particularly important in the embodiments of FIGS. 10-13 wherein the fuse is employed to ignite the secondary charge after the primary charge is exploded. Also spirally wrapped around the wire 121 in a counter direction is a nylon yarn illustrated at 127 for providing additional protection. Deposited on the yarn 127 and hence on the cover and cut ends is a coating 129 of nitrocellulose for environmental protection and which also provides high flammability. The purpose of the wire 121 is to provide support for the fuse firetrain or fuse material and assist its continuity of burning since the wire 121 has a high thermal conductivity. It is noted that the ends of the fuse are cut at an oblique angle of about 45.degree.relative to the axis of the fuse to provide a sharp pointed tip to allow the highly flammable coating 129 to ignite easily and to provide a large surface exposure on the end to facilitate ignition of the fuse material 123 by the burning of the highly flammable coating 129 whereby the fuse may be readily and reliably ignited by a low temperature flame. In one embodiment, the wire 121 has a diameter of 16 mils while the wrapped wire 125 has a diameter of 8 mils and is formed of galvanized soft iron. The total diameter of the fuse is 0.068 of an inch. Its burn rate was three forth of an inch in 227 milliseconds.

Although the preferred fuse or firetrain employed is that disclosed in FIG. 14, it is to be understood that other types of fuses may be employed. For example, the fuse may be common black powder preferably fine meal size powder, prepared as what is commonly known in pyrotechnics as a black match and utilized in the tube provided by the eyelet 65 of FIG. 8 as a quick match (see the lower portion of page 67, reference 21 of The Chemistry of Powder and Explosives, by Tenney L. Davis, volume 1). Also, a regular commerically available fusing may be used, if desired.

Since the fuse 51 has a core 121 formed of copper wire, it may employed to actuate the fire extinguisher remotely by applying electrical current through the fuse for remote ignition thereof. This application is particularly useful, for example, in the embodiments of FIGS. 10-12. Referring to FIG. 10, for example, two separate electrical leads may be attached to the outside end of the fuse end 51 at spaced positions such that when an electrical current is applied through the leads, the wires in the fuse will heat to a point where the fuse 51 will ignite to actuate the primary explosive charge and the secondary charge. In the alternative, the fuse 51 may be looped in a hairpin manner into the primary and secondary charges. Electrical leads then may be attached to the two ends of the fuse extending from the casement or housing of the fire extinguisher. The fire extinguisher will be able to automatically release its fire extinguishing powder in the presence of heat from a fire or may be actuated remotely to release its powder by closing an electrical switch to pass an electrical current through the fuse 51 for ignition.

Referring now to FIGS. 16-18, there will be described other embodiments of the fire extinguisher. In FIG. 16, the fire extinguisher illustratted is the same as that disclosed in FIG. 2, except that the lid 17 has a central aperture formed therethrough which is covered by a circular disc 137 of a material capable of being disintegrated by the explosive charge 41 to form an opening in the bottom of the container 13 when exploded, thereby allowing the fire extinguishing powder to fall out of the container by gravitational force onto the fire below. The disc 137 in one embodiment, may be formed of a thin sheet of fiber board sealed to the lid portion 17. The fuse 51 is attached to the disc 137, as illustrated.

Referring to FIG. 17, the container 141 is domed shaped and has located therein the fire extinguishing powder. All or a portion of the wall of the container is formed of a highly flammable material such as nitrocellulose plastic. Thus the container in the presence of heat above an undesired level will ignite and rapidly burn through to free the fire extinguishing powder and allow it to fall by gravitational force onto the fire below. In this embodiment, the container 141 has fusing means consisting of projections shaped as small points 143 formed of nitrocellulose or other fusing material randomly attached over the area of the container. The burning rate of such a container may be increased by adding to the nitrocellulose material, when in a liquid state, oxidizing agents (5 to 50 percent by weight) such as barium nitrate and lead peroxide. These are the preferred oxidizing agents, however, others may be used, such as sodium nitrate, potassium chlorate, potassium perchlorate, potassium permangmate, ammonium nitrate, ammonium perchlorate, barium peroxide, strontium peroxide, lead monoxide, or ferric oxide. A fuel component also may be added generally to the extent of 5-25 by weight and which may comprise as one example, one or more finely powdered metals, metal alloy, or other combustible elements or compounds such as aluminum, magnesium, zirconium, titanium, iron, antimony sulfide, lead hypophosphite, or lead thiocyanate. In addition, the highly flammable material from which the container wall is constructed may be chemically treated paper such as paper treated with an oxidizing agent such as potassium chlorate, potassium perchlorate, barium nitrate, etc., as disclosed above.

Referring to the embodiment of FIG. 18, all or a portion of the wall of the container is formed of an inner layer 151 sandwiched in between two other layers 153 and 155. The layer 151 may be formed of the highly flammable material mentioned above while the layers 153 and 155 are also combustible and may be formed for example, of paper. As an alternative, the layer 151 may be an explosive layer, layers 153 and 155 being formed of a material which will disintegrate when the charge layer 151 is exploded. In this embodiment, the charge of layer 151 may be the primary or initiating charge mentioned above while the layer 153 and 155 may be formed of thin fiber board. As illustrated in FIG. 18, the fuse 51 extends through the outer layer 155 to the inner layer 151 for igniting or actuating this layer in the presence of heat to release the fire extinguishing powder.

Claims

I claim:

1. A fire extinguisher comprising:

a closed container,

a fire extinguishing substance located in said container,

force producing means located in close proximity to a given portion of the wall of said container for use primarily for opening only said given portion of said container wall when actuated, and

heat sensitive means for actuating said force producing means in the presence of heat above an undesired level to form said opening to allow said fire extinguishing substance to pass out of said container,

said heat sensitive means comprising:

a metallic wire having a high thermal conductivity,

a fast burning substance located around said wire,

cover means wrapped around said substance to provide strength for said heat sensitive means and to hold said substance in place, and

a water-proof layer of highly flammable material deposited on said cover means.

2. The fire extinguisher of claim 1 comprising:

means coupled to a top end of said container for hanging said container from a desired object,

said force producing means being located at the bottom end of said container for forming said opening in the bottom of said container when actuated to allow said fire extinguishing substance to fall out of said container through said opening, when formed, by the force of gravity.

3. The fire extinguisher of claim 2 wherein:

the wall of said container has weakened portions selectively formed to facilitate rupturing to form an opening in said wall without fragmentation,

said force producing means being located in close proximity to said weakened portions for rupturing said wall at said weakened portions to form an opening therethrough to allow said fire extinguishing material to pass out of said container.

4. A fire extinguisher comprising:

a closed container,

a fire extinguishing substance located in said container,

a small amount of explosive charge located only at a position outward from the center of said fire extinguishing substance in close proximity to the wall of said container for forming an opening in the container wall when exploded without forcing the bulk of said fire extinguishing substance out of said container, and

heat sensitive means for actuating said explosive charge in the presence of heat above an undesired level to form said opening to allow said fire extinguishing substance to pass out of said container,

said explosive charge being characterized as capable of developing brisance without confinement.

5. The fire extinguisher of claim 4 comprising:

means coupled to a top end of said container for hanging said container from a desired object,

said explosive charge being located at the bottom end of said container for forming said opening in the bottom of said container when actuated to allow said fire extinguishing substance to fall out of said container through said opening, when formed, by the force of gravity.

6. The fire extinguisher of claim 4 wherein:

said explosive charge is deposited on the wall of said container.

7. The fire extinguisher of claim 4 wherein:

the interior zone of said fire extinguishing substance is free of explosive.

8. A fire extinguisher comprising:

a closed container,

a fire extinguishing substance located in said container,

a small amount of explosive charge located in said container for use primarily for opening the container wall,

said explosive charge being located in close proximity to a given portion of the wall of said container for forming an opening only through said given portion,

heat sensitive means for actuating said small amount of explosive charge in the presence of heat above an undesired level to form said opening to allow said fire extinguishing substance to pass out of said container, and

a secondary explosive charge located in said fire extinguishing substance and spaced from said small amount of explosive charge,

said heat sensitive means extending from the exterior of said container to said small amount of explosive and to said secondary explosive charge to allow said small amount of explosive to be actuated initially to form an opening through said container and then to allow said secondary explosive charge to be actuated to force said fire extinguishing substance outward through said opening.

9. The fire extinguisher of claim 8 wherein said small amount of explosive is deposited on the interior of the wall of said container.

10. The fire extinguisher of claim 8 wherein:

the wall of said container has weakened portions selectively formed to facilitate rupturing to form an opening in said wall without fragmentation,

said small amount of explosive charge being located in close proximity to said weakened portions for rupturing said wall at said weakened portions to form an opening therethrough to allow said fire extinguishing material to pass out of said container.

11. The fire extinguisher of claim 8 wherein said given portion of the wall of said container next to which said explosive charge is located is formed of a material capable of being disintegrated by said explosive charge when exploded to form said opening.

12. A fire extinguisher comprising:

a closed container,

a fire extinguishing substance located in said container,

a small amount of explosive charge located in said container in close proximity to the wall thereof for forming an opening in said container wall when exploded to allow said fire extinguishing material to pass out of said container, and

heat sensitive means for actuating said explosive charge in the presence of heat above an undesired level,

said explosive being characterized as a primary initiating explosive capable of developing brisance without confinement.

13. The fire extinguisher of claim 12 wherein said small amount of explosive is located only next to said wall and the interior zone of said fire extinguishing substance is free of explosive.

14. The fire extinguisher of claim 12 wherein said small amount of explosive is deposited on the interior of said wall.

15. The fire extinguisher of claim 12 wherein said explosive charge is selected from the class consisting of mercury fulminate, lead azide, nitrosoguanidine, lead styphnate, double salts of lead styphnate as with nitroaminotetrazole, or with lead hypophosphite, or with lead propionate, lead picrate, or its double salts, lead dinitroresorcinate, diazodinitrophenol, tetracene, mono-basic lead dinitrobenzoate, di-basic lead dinitrobenzoate, double salt of lead trinitroresorcinate, basic salts of tetrazole and basic lead salts of nitrotetrazole, nitrotetrazole, salts of mercury nitrotetrazole, salts of silver nitrotetrazole, acid copper salt of C-nitrotetrazole, silver and mercury azides, or combinations of explosives such as picric acid and silver azide or diazodinitrophenol primed with lead azide alone or with the addition of lead styphnate or tetrazene or with diazodinitrophenol as the primary explosive, tetryl, the lead salts of picric acid and trinitroresorcinal, m-nitrophenyldiazonium perchlorate, nitrogen sulfide, copper acetylide, fulminating gold, the tartarates and oxalates of mercury and silver, fulminate of silver, cadmium azide, cuprous azide, thallium azide, cadmium fulminate, copper fulminate, thallium fulminate, sodium fulminate, potassium fulminate, cobalt azide, barium azide, calcium azide, strontium azide, nickel azide, manganese azide, lithium azide, mercurous azide, zinc azide, etc.

16. The fire extinguisher of claim 12 comprising:

a secondary explosive charge located in said fire extinguishing substance and spaced from said small amount of explosive charge,

said heat sensitive means extends from the exterior of said container to said small amount of explosive and to said secondary explosive charge to allow said small amount of explosive to be actuated intially to form an opening through said container and then to allow said secondary explosive charge to be actuated to force said fire extinguishing substance outward through said opening.

17. The fire extinguisher of claim 12 wherein:

the wall of said container has weakened portions selectively formed to facilitate rupturing to form an opening in said wall without fragmentation,

said small amount of explosive charge being located in close proximity of said weakened portions for rupturing said wall at said weakened portions to form an opening therethrough to allow said fire extinguishing material to pass out of said container.

18. The fire extinguisher of claim 17 comprising:

a secondary explosive charge located in said fire extinguishing substance and spaced from said small amount of explosive charge,

said heat sensitive means extends from the exterior of said container to said small amount of explosive and to said secondary explosive charge to allow said small amount of explosive charge to be actuated initially to form an opening through said container and then to allow said secondary explosive charge to be actuated to force said fire extinguishing substance outward through said opening.

19. The heat sensitive means of claim 1 wherein said cover means comprises thin metallic wires.

20. A heat sensitive fuse for igniting an explosive charge comprising:

a metallic wire having a high thermal conductivity,

a fast burning substance located around said wire,

cover means wrapped around said substance to provide strength for said fuse and to hold said substance in place, and

a water-proof layer of highly flammable material deposited on said cover means.

21. The fuse of claim 20 wherein said cover means comprises a wrapping of thin metallic wires.

22. The fuse of claim 21 wherein its end to be exposed to sense for undesired temperatures is cut at an angle relative to the axis thereof to form an end with a pointed tip and a relatively large surface area,

said water-proof layer of highly flammable material being deposited on the cut end of said fuse.

23. A fire extinguisher comprising:

a closed container,

a fire extinguishing substance located in said container,

said container having a bottom end and a top end,

a magnet coupled to said top end to allow said container to be attached in place to a metallic object to locate said bottom end in a downward direction,

said bottom end having weakened portions selectively formed to facilitate rupturing to form an opening in said bottom end without fragmentation,

a small amount of primary initiating explosive charge located in said container, only in the vicinity of said weakened portions for rupturing said bottom end at said weakened portions to form an opening therethrough to allow said fire extinguishing material to fall out of said container, and

heat sensitive fuse means for igniting said explosive charge in the presence of heat above an undesired level.

24. The fire extinguisher of claim 23 wherein said container is formed by a cup shaped member having a lid attached thereto by a double seam.

25. A fire extinguisher comprising:

a closed conatiner,

a dry fire extinguishing substance located in said container,

means coupled to said container for attaching said container to an object,

at least a portion of the wall of said container comprising a layer of highly combustible material sandwiched between two layers of combustible material, and

ignitable fuse means extending from the outside to said layer of highly combustible material for igniting said layer of highly combustible material and hence said two layers of combustible material in the presence of an undesired high temperature for rapidly removing at least a portion of the wall of said container from its confining position for allowing the passage of said fire extinguishing substance out of said container.

26. A fire extinguisher comprising:

a closed container,

a dry fire extinguishing substance located in said container,

means coupled to said container for attaching said container to an object,

said fire extinguisher container wall being formed at least in part of an explosive material,

said explosive material is sandwiched between two layers capable of being disintegrated when said explosive material is exploded, and

fuse means for actuating said explosive material in the presence of undesirable high temperatures.