US2328491A - Bomb comprising a compressed mass of fire extinguishing powder - Google Patents

Description

Aug. 31, 1943. E. PUCHNER BOMB COMPRISING A COMPRESSED MASS OF FIRE EXTINGUISHING POWDER Filed July 18, 1939 Patented Aug. 31, 1943 CUMPEISING A COMPRESSED MASS F EXTINGUISHING POWDER Erwin Puchner, Rome, Italy; vested in the Alien Property Custodian Application July 18, 1939, Serial No. 285,146 In Italy July 29, 1938 Claims. (01. 169-28) The invention relates to fire extinguishing bombs or grenades having fire extinguishing material arranged around an explosive charge which when exploded is adapted to distribute or spread the fire extinguishing material over the fire to be subdued.

Devices of this nature have heretofore comprised a casing for the fire extinguishing material and have generally possessed the defect that they distribute the extinguishing material in an uneven manner. The present invention has for an object the provision of a fire extinguishing bomb in which the extinguishing material is more uniformly spread on explosion of the bomb than in prior devices of this character. Another object is to provide a fire extinguishing bomb in which the extinguishing material is not encased but consists of a solid mass formed by pressing together a powdery substance having fire extin-- guishing properties. A further object of the invention resides in the provision of a fire extinguishing bomb of a type which employs a relatively small explosive charge.

With these and other objects in view which may be incident to the improvements herein described, the invention consists in the parts and combinations to be hereinafter set forth and claimed with the understanding that the several necessary elements comprising the invention may be varied in construction, proportion and arrangement without departing from the spirit of the invention or exceeding the scope of the appended claims. Y

Briefly, the invention contemplates carrying these objects into practical effect by a construction which makes use of fire extinguishing material that is moulded into a mass or body of desired shape, the body being formed with a bore passing therethrough. This body is fixedly mounted on a handle which extends into the bore for part of the length of the bore. An explosive charge is carried in that portion of the bore which is unoccupied by the handle and means leading from the charge to the exterior of the body are employed for firing or igniting the charge. Ignition of the explosive pulverizes the body of fire extinguishing material and spreads it around the vicinity of the fire.

The invention is carried out with fire extinguishing material in the form of small particles which possess an inherent ability to cohere to each other and which resist relative displacement due to surface friction. Moulding of the body is effected without the use of a binder, such as cement, which solidifies. Instead, a volatile moistening agent is employed for binding purposes. By these practices, a shaped body of fire extinguishing material is provided which is well. able to withstand external shocks and blows encountered in ordinary handling of the bomb prior to its use. At the same time, however, there is provided a body which is easily pulverized by small internal forces which can be developed on the firing of a small quantity of a quick burning explosive located within the body.

In regard to the explosive, a major factor influencing its selection is its ability to rapidly detonate. That is to say, a quick burning explosive is required as a slow burning explosive will cause the fire extinguishing body to shatter in large pieces rather than to pulverize. Secondary factors involved in the choice of an explosive are the power it develops and the quantity required. From the standpoint of a compact device it is desirable to keep the quantity of the charge relatively small and the use of a fast burning explosive permits the accomplishment of this aim, such an explosive when employed in small quantities producing sufficient power to pulverize the fire extinguishing body.

In order to make the invention more clearly understood there is set forth in the accompanying drawing means for carrying the same into practical effect.

In the drawing:

Figure 1 is a sectional elevation of the fire extinguishing bomb with a part of the handle shown in full.

Figure 2 is a perspective view of the device.

Figure 3 is a plan View of the bomb.

Figures 4 and 5 show various details of the device in elevation.

As shown in Figure 1 the bomb comprises a handle I having a hole 25 extending therethrough adjacent one end thereof for a carrying cord or lanyard 24. Slipped onto the handle and fixed thereto is a hollow member 2 which provides support means for the moulded or pressed body ll formed of fire extinguishing material. Hollow member 2 has a base or seat portion t which seats on the end of the handle most distant from the cord 24. An opening is provided in the base t for a central rod or tube ii which extends there through and which is screwed or otherwise secured to the handle. In case the member 6 is a tube, its free end is closed by a rubber plug H or the like.

The body I! is moulded with a central bore or channel i therein so that the body may be slipped onto the rod or tube 6. By providing the seat surface of base 4 with ribs and the seat surface [8 of the body I! with corresponding depressions a firm bearing is provided which aids in preventing relative rotative movement between the body I! and the handle. Prior to placing the body 11 on the rod 8 and against the end 4 of handle I, the rod and the free end of the handle is smeared with a highly viscous cement of suitable character which assists in securing an explosive charge within the bore 1 of body IT.

The fire extinguishing body I! may be given a general spherical or ball like contour as shown in the drawing and is formed by moulding fire extinguishing material of the kind already described into the desired shape.

The explosive charge is placed within a separate small tube 8 of copper, zinc, Celluloid, or the like, which is closed at one end. This explosive, for instance, nitropentaerythrite l4, after introduction into the tube 8 is subjected to a slight tamping. Then a priming substance for example nitroglycerin, indicated by the reference numeral I5, is introduced into the tube on top of the explosive l4. Thin tinfoil is placed over the'priming substance l and a small tube of asbestos l3 carrying a match I2 is inserted Within the tube 8. The upper end of tube 8 is closed. by

a thin air-tight water-proof membrane I ii of varnish or nitrocellulose. The explosive as thus prepared is then placed within the'free. part of the bore 1 after the wall of the said bore has been lubricated with water or milk in the event that there is a close fit between the channel and the tube 8. in place by applying a highly viscous cement to the wall of the bore 1. The latter practice has the advantage that it prevents the explosive charge from being unduly removed from the body I1.

It may be noted that the portion of the bore 1 most distant from the handle of the bomb is of a funnel shape. Bands N3 of a material which is capable of spontaneous ignition at ordinary flame temperatures are located within the funnel portion of thebore l and are connected to the priming charge to provide a firing means Ior the bomb. Material coated with readily inflammable varnish may be used for the bands iii. In

this manner, firing means are provided which operate either at a predetermined temperature or when brought into contact with a fiame.

The means for securing the fire extinguishing body l1 onto the handle 2 of the bomb comprises a wire ring or cage member 25 which is placed over and which engages the exterior of the body I? at a portion thereof located away from the handle I. If'desired, the fire extinguishing body I? may be provided with fiat portions in its surface on which the ring 26 is adapted to seat. 'A closing disc 5 is suitably secured to the end of the hollow member 2 most distant from the body I! and serves as a stifiener for the hollow memher 2 and also as a support for anchorage means However, the tube 8 may be cemented 32 which carry hooks 33. Tensionlng members 2'! of wire, in the form of loops, are each passed around the ring 26 as indicated at 28 and each has a portion 30 engaged with a -hook 3. Grooves 20 are formed in the exterior of the body I! adjacent the ring member 28, each groove providing a guideway for a separate tension member 21. Tensioning oi the members 21 is effected by varying the diameter of a. wire adjusting member 29 which surrounds the members 21 at a position between the hooks 33 and the body I1.

The fire extinguishing body I I is coated with a suitable waterproofing agent. In order to provide the priming substance against damage a cap 22 is detachably secured over the funnel shaped end of the bore 1 of the body l1. By the use of a cord or handle 23 secured to the cap 22, the latter may be readily removed. A plurality of openings 3! are provided in the cap so that the bomb will not be inoperative even though the cap remains in place. Under normal operation the cap is removed prior to throwing the bomb, by means of the handle I, onto or in the vicinity of a fire.

From the foregoing it will be appreciated that the aims and objects of the invention have been accomplished in that a simple and efiective fire extinguishing device has been provided.

Having described the invention, the following is claimed:

1. A fire extinguishing bomb comprising a.

caseless moulded mass of the extinguishing powder, an explosive charge located in said mass and a firing match for said charge having communication with the exterior of said bomb.

2. A fire extinguishing bomb comprising a caseless moulded mass of an extinguishing powder, a handle upon which said mass is mounted, said handle entering partially into said mass, an explosive charge located at substantially the center of said mass and a firing match for said charge having communication with the exterior of said bomb.

3. A fire extinguishing bomb as set forth in claim 2 in which said handle is secured to said mass by means of a binding.

4. A process for constructing a fire extinguishing bomb comprising moulding an extinguishing powdery mass into a suitable shape with an easily volatile binding means, then inserting an explosive charge into said mass and covering the exterior surface of said mass with a varnish which does not penetrate into said mass and is impermeable.

5. A fire extinguishing bomb comprising a caseless moulded mass of an extinguishing powder, a handle upon which said mass is mounted, said handle having a supporting surface to which said mass is secured by a binder, said mass having a bore therein and an explosive charge located in said groove- ERWIN PUCHNER.

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