US1886407A - Pyrotechnic device - Google Patents

Description

Nov. 8, E932. K. KQHN 1,886,407

PYROTECHNIG DEVICE Original Filed July 25, 1929 Patented 'Nov. 8, 1932 KOBY K'OHN, OF NEW YORK, N. Y., ASSIGNOR TO CHATHAMI SPECIALTY CORPORATION, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK PYROTECHNIC DEVICE Application filed July 25, 1929, Serial This invention relates to pyrotechnic devices and particularly to the cases or containers used for holding the pyrotechnic compound whether it be explosive or of some other nature.

It is a general object of the present invention to provide a novel and improved form of pyrotechnic and casing therefor.

One of the features of the invention comprises the uses of a molded casing or container for the pyrotechnic compound.

Another feature of the invention comprises the use of a molded casing for a. pyrotechnic compound in which the fuse for igniting the compound is molded through the wall of the casing.

Still another feature of the invention comprises the use of a molded casing for a pyrotechnic compound together with a gas-tight envelope of electro-deposited material.

Still another feature of the invention resides in the use of a bitumen casing for the confinement of the pyrotechnic compound used in such fireworks as are ignited by means of a fuse.

Other and further important features and objects of the invention, in addition to those enumerated above, will be evident to those skilled in the art upon a consideration of the accompanying drawing and following speci-V fication wherein are disclosed several exemplary embodiments of the invention with the understanding that such changes may be made therein as fall within the scope of the appended claims without departing from the spiritof the invention.

In said drawing:

Figur-e 1 is a longitudinal section through a firework constructed according to the present invention;

Figure 2 is a similar view through a modified form of the invention; and

Figure 3 is a perspective View of the device of Fig. 2.

In the manufacture of most pyrotechnic devices, suchl for instance as firecrackers, rockets, bombs, and the like, it has been cus' tomary to form the outer casing, which confines the gases upon explosion and finally disrupts, from tubes of pasteboard or papery No. 380,998. Renewed April e, 1932.

usually formed by wrapping a number of turns of paper coated with adhesive on a mandrel. When these forms of containers arerused, some means must be provided to plug the ends, and often difficulty is encountered, and mis-fires occur because the plugs become loosened and blow out with merely a puff. vWith certain types of fireworks the blowing-out of ar plug is extremely dangerous where the firework is intendedl to be held in the hand.v Paper is expensive, and the manufacture of the casings involves considerable manual labor. Likewise the casings are hygroscopic and subjectfthe powder to spoilage by .conducting moisture thereto. The present invention lcontemplates the molding of the casing or container for the pyrotechnic compound of a water-proof material in order to obviate those dilculties enumerated above and others which will be evident to those cognizant with the manufacture of pyrotechnics. y

Referring now to the drawing, there are disclosed two embodiments of what is commonly known as a firecracker,cannon cracker, or salute, the only differences in the twoA `embodiinents being in the shape of the casing. Firecrackers are used as illustrative embodiments of the invention because of their simplicity and ease of explanation, but the invention is in no sense limited to these particular articles.

The flrecracker of Figure 1 has a main body portion 10 provided with a cavity 11 for the reception of the pyrotechnic compound or explosive 12. The cavity is closed by a cap or plug 13, and the fuse 14 is provided passing from the outside to the inside of the casing to ignite the compound, and finally the gas-tio'ht protective coating 15 is applied over the whole casing and a portion of the fuse as at 16.

The main casing 10 is formed of molded material whereby large numbers of the casings can be simultaneously formed by machinery. It is preferable to mold the casing from a bitumen, such for instance as a high or low carbon pitch, which may or may not have incorporated therein such fillers and fibrous strengtheners as fullers earth and its equivalents and asbestos or similar fibrous material. For a complete description of the material and fillers, reference may be had to my Patent No. 1,672,460, for toy torpedoes, issued June 5, 1928, which discloses the compositions of materials from which casings of this type may be made and illustrates a possible embodiment of mechanism for molding.

The cap or closure 13 is preferably molded from the same material7 and after the casing is loaded, the cap is placed in position and Secured either by the application of heat which melts the two parts into a unit or by the use of a solvent or adhesive which produce substantially the same effect. The fuse4 14 of any conventional form preferably has some portion of the casing molded around it, conveniently the plug or cap as shown, where a boss 17 is provided for additional adhesion to the fuse, but it will be evident that the fuse could equally as well be extended through any of the walls of the main casing and particularly the narrow septum 18 between the main cavity 11 and the open-end` cavity 19 which is provided merely to give the iirecracker sulfiicient length for good appearance without providing too large a capacity for explosion or too great a quantity of casing material.

The whole casing 10 and part of the fuse is covered with the coating 15 of electro-deposited material, preferably some metal such as copper, but obviously non-metallic material may be used. In order to provide a conducting surface on the pitch so that electro-deposition may be accomplished, the surface l0 is sprayed, coated, or otherwise treated with quick-acting and quick-drying solvent or some adhesive material so that it can be dipped in, rolled in, or sprayed with a powdered conductor such as plumbago, bronze, or aluminum powder. A portion of the fuse 1s likewise treated, and the article can then be suspended by the fuse in an electro-depositing bath and coated with a suitable thickness of the metal, say from .003 to .005 of an inch. Various teXtures of coating by electrodeposition are possible in accordance with the current density and the ingredients of the bath, and it is contemplated that the coating in the present instance be extremely tough and resistant to tearing. It may be mentioned here that the adhesive material used to attach the metallic or conductive coating is water-proof so that-when it is applied to the fuse, it protects the fuse against the liquid of the bath.

It is preferred that the material from' which the casing 10 is molded be a high carbon pitch so that the resultant product is quite brittle or frangible. This insures that upon the explosion of the material in the cavity 11, the casing will be blown inte small bits to protect by-standers against flying particles of any size. Furthermore, the inciting point of this pitch should be such that the heat of explosion will at least partially melt these particles so that they are more or less inert and will not fly so far nor have sharp edges to injure those nearby. This'V melting action is assisted by the fact that the deposited coating is gas-tight and of considerable strength so that it momentarily holds, the gases of explosion until they become" strong enough to rupture this coating, and during this momentary holding, the heat of the explosion is transferred to the particles of the casing 10 to produce the result mentioned.

It is obvious that the easing lOrmay be made of a pitch which when hardened hasgreat tenacityand is not brittle. This characteristic may be enhanced by the use of fillers and fibrous strengthening materials.

In this case the container may havesuffi'cient i strength to resist the expanding gases from the explosion so Vthat the outer coating can be dispensed with and a suliiciently loud repo-rt obtained with but a singley layered casing. It is believed, however, that better rer sults are obtained by using the innery layer of bituminous material of considerable frangibility and the tough gas-tight coatingV of electro-deposited material. This electro-de'- posited material. gives a pleasing appearance to the article and adds considerably to theV 'l sales value.

For the sake of novelty, the salute or firecracker may be made spherical, as shown in Figure 2, where the main casing 20 is 'pro-V vided with a suitable cavity 21 containing the explosive compound 22. They cavity 'is closed or plugged with the closure member 23 through which passes the fuse 24'.' rTheE whole is coated with a suitable de osit 25.

One of the main advantages o this form.A

of casing is that it can be molded in multiple unit automatically, and the whole group ofobvious that the expanding gases will first disrupt the casing and coating at this weakened portion where both are perforated.y It has been found that this results in tearing but The fuse, therefore, produces a comparatively small opening in the coat--V ing through which the gases issue to produce the report. This small opening prevents, to

a great extent, the dispersion' ofthe fragments, of the molded casing which'a'r'e driven ian to the opposite side of the coating or envelope from the issuing gases so that in most cases there are substantially no iiying fragments, and the remains of the pyrotechnic usually stay on the ground substantially at the place where the explosion was effected. It will thus be seen that the present invention as applied to firecrackers in particular adds materially to the safety thereof.

Having thus described the invention, what is claimed as new and desired to be secured by Letters Patent is:

l. A firework comprising in combination, a frangible container, an explosive composition completely encased in said container, a gas vtight covering of high tensile strength surrounding said container and a fuse extending through said container and covering.

2. A firework comprising in combination, a molded container, an explosive encased in said container, an electro deposited coating on said container and a fuse passing' through said container and said coating and having its inner end in cooperative relation with said explosive.

3. A new article of manufacture comprising in combination, a molded container having avcavity for explosive and a fuse through a wall of said container and entering said cavity, the material of said container being molded about the fuse.

4. A firework casing composed of an inner layer of molded material, an outer layer of gas tight material and a fuse, both the inner and outer layers being formed about the fuse.

5. A firecracker casing composed of a molded bitumen and an electro deposited outer coating.

6. A firework casing composed of a molded bitumen and having a wall of said casin molded around a fuse.

7. firework casing composed of a molded bitumen, an elec-tro deposited outer coating and a fuse, said bitumen and outer coating being adherent to said fuse.

8. A rework comprising in combination, a pyrotechnic composition, a totally enveloping container of heat softened moldable material, and a fuse, a wall of said container being molded around said fuse.

9. A rework comprising in combination, a pyrotechnic composition, a totally enveloping container of heat softened moldable ma'- terial, a fuse extending through a wall of said container, and a deposited coating covering a portion of the fuse and container.

10. In a firecracker, in combination, a container, an explosive in said container, a fuse passing through the wall of said container, said container being formed of such material that the parts thereof resulting from the explosion of the explosive are at least partially melted by the heat of the explosion and an electro deposited coating surrounding said container.

11. A firework comprising in combination, a molded container, an explosive encased in said container, an electro deposited coating on said container and a fuse passing through said container and said coating and having its inner end in cooperative relation with said explosive, said coating being initially weakened by the passage of the fuse and the container being reinforced surrounding the opening for the fuse.

l2. A recracker having an explosive container formed of a layer of frangible material and a contiguous layer of electro deposited matter.

13. A plug for a fire work comprising a fuse and a mass of heat softened material molded around an intermediate portion of said fuse.

In testimony whereof I hereunto afiix my signature.

KOBY KOI-IN.

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