US2057362A - Method of wadding cartridges - Google Patents

Description

Oct. 13, 1936. s. c. BOND METHOD OF WADDING CARTRIDGES Original Filed April 22, 1930 Sean s l C BOIZd/ Mahd W as Patented Oct. 13, 1936 Original application April 22, 1930, Serial No. 446,403., Divided and this application March 24, 1932, Serial No. 601,020. In Germany January 9, 1927 13 Claims.

My invention relates to improvements in cartridge wadding, and more particularly to the method of wadding cartridges. This application is a division of my application, Serial No. 446,403, filed April 22, 1930, which application is a continuation of my application, Serial No. 171,907, filed March 1, 1927.

It is the primary object of my invention to provide a cartridge wadding which has perfect initial sealing contact with the surrounding wall of the cartridge casing, which will maintain said sealing contact with the casing during its travel therein, and which will expand radially into complete peripheral sealing contact with the gun barrel as it leaves the shell casing and continue to maintain said peripheral sealing contact during its entire travel through the barrel.

It is a further object of my invention to provide an improved method of wadding cartridge shells which method provides perfect initial sealing of gas space, yet which does not bulge, distort, or swell the cartridge wall, as invariably happens when it is attempted to provide perfect initial sealing of the gas space with resilient wadding materials.

'It is a further object of my invention to provide a method of'wadding shot-gun shells and the like, which is cheap, and which provides uniformly perfect scaling in quantity production, even though there be considerable irregularity and variation in the size of the shell casings to be loaded.

Further objects and objects relating to details and economies of construction and operation will definitely appear from the detailed description to follow. In one instance, I accomplish the objects of my invention with the materials, means and procedure set forth in the following specification. My invention is clearly defined in the appended claims; Procedure, constituting a preferred embodiment of my invention, is illustrated diagrammatically in the accompanying drawing forming a part of this specification, in which:

Figure 1 is a view in cross-section of apparatus for installing a wad in the conventional cartridge shell, the plunger being shown in the position it, occupies prior to expanding the wad pellet;

I Fig. 2 is a similar view with the plunger shown in projected position and the Wad pellet extruded radiallyinto perfect sealing contact with the shell casing; and

,Fig. 3 is a view of the same apparatus, with the plunger shown in retracted position, the sealing having been completed.

Throughout the several views, the same reference numerals refer to the same parts.

Modern shot-gun cartridge casings have a metallic base with an inserted primer, and a cylindrical casing or shell which is usually of heavy paper treated to render it moisture-proof. The outer diameter of the shell is made somewhat smaller than the breech chamber of the gun in which it is to be used to allow for variance in manufacture and to facilitate its insertion and removal from the gun. When fired, the pressure from the powder gases immediately expands the shell into contact with the gun chamber effectively preventing gas leakage by way of the breech. As the function of the wad is to prevent gas leakage by way of the muzzle, it is essential not only that it maintain perfect sealing contact with the shell during shell expansion but also that it bridge and effect a seal while passing from shell to gun barrel.

I have found it to be of great importance that a plastic wad be used to separate the powder and shot charges and that such plastic wad be radially expanded into perfect gas sealing contact with the cartridge casing prior to firing. The importance of this initial seal appears to result from the fact that if the peripheral seal be initially imperfect, the gases leaking between the periphery of the wad and the cartridge casing prevent the radial expansion of the plastic wad to bridge the imperfection or gap during subsequent expansion of the powder gases and travel of the wad. The phenomenon appears to be much like that which has been experienced by nearly every person who has had occasion to use a cup piston type tire pump which has been in disuse for a considerable period of time. If the piston cup washer has shrunk slightly, so that a perfect initial seal is not provided, the device will not pump because the air escapes between the periphery of the cup washer and barrel. In such a case, pumping has a tendency to constrict the washer rather than to expand it. To restore the pump to usefulness, it is necessary to remove the cup leather from the barrel and spread it radially so that initial sealing contact be made with the barrel when the parts are reassembled. The cup leather then tends to expand radially when pumping pressure is placed upon the pump rod, and the greater the pressure built up in the compression chamber, the greater the peripheral sealing pressure.

In a shot-gun cartridge, a poor or defective seal not only results in loss of velocity, but, if such leakage be concentrated at any point about the periphery of the wad, it seriously disturbs apparatus for carrying out my method, there is shown a base I0, having one or more bores I I, through which a conventional shot-gun shell !2 is disposed and backed against swelling or other distortion. Within cartridge 12, there is shown a charge of powder l3, and upon this charge of powder is placed a. disc M of paper or similar material. Upon the disc M is laid a pellet or similar mass of plastic material I5, such as a mixture of cork, paraffin and asphaltum, the asphaltum being the major constituent, preferably of the grade known as Texaco No. 14, having a melting point, by the ball and ring method, of approximately 300 F. Such a mixture of cork, paraffin and asphaltum is plastic in nature, the cork particles serving solely to absorb the initial peak pressures developed by modern fast burning powders. On top of the pellet of plastic material is placed a second disc of paper 46. A plunger ll, having a foot l8 telescoped within its lower portion and normally urged downwardly by a spring (not shown) is alined with bore H of the base member ID, and fits snugly within the cartridge shell l2. Means (not shown) are provided for pressing the plunger I! downwardly and causing the plunger foot l8 to bear upon the disc is, radially expanding the pellet of plastic material outwardly into perfect sealing contact with the shell casing 12. As shown in Fig. 2, disc [4 separates the plastic material of the wad l5, thus formed, from the powder charge l3. It will be noted, as shown in Fig. 2, that the plunger portion ll comes down into contact with the disc l6 and, with the plunger foot l8, provides pressure across the entire top surface of the disc I6. I have found that in wadding the powder charge of a twelve-gauge shell with a pellet composed by weight of approximately eight parts of Texaco No.14 asphaltum, two parts paraflin and five and one-half parts granulated cork capable of passing through fifteen-thirty screens, a plunger pressure of 185 lbs. will effect the perfect initial sealing contact desired. After the pellet or rough wad l has been thus expanded or extruded radially into perfect peripheral sealing contact with the wall of the cartridge shell l2, the plunger portions I I and I8 are retracted, as shown in Fig. 3, and the usual shot charge (not shown) is loaded upon disc IS. The conventional pasteboard wad (not shown) is then placed upon the shot charge and the shell is crimped over in the usual manner. The plastic pellet 15, once expanded into the form of a wad having perfect sealing contact with the shell l2, by reason of its plastic nature remains in contact, and has no tendency either to withdraw from the shell wall or to expand and swell the shell wall after the shell is removed from the loading base It].

With the present composition, however, the wads need not be individually formed at a time prior to the loading of the shell, it being possible to feed proper quantities of the composition directly into the shell on top of the powder and by means of a suitable plunger compress the same therein so that the wad is formed in situ in the cartridge. Where this procedure is followed, good results may also be obtained by mixing one and one tenth parts of the granulated cork with one part paraflin and adding to this mixture one part of a composite mixture comp-rising eight parts of asphalt and two parts paraffin. Best results, when forming the wad in situ, may be obtained by separating the wad material from the powder and the shot by the insertion of two small paper discs.

While I have disclosed as an application of my invention the wadding of shot gun shells with a plastic composition consisting primarily of asphaltum with a small admixture of paraffin as a lubricant and granulated cork as a shock absorber, it is to be understood that wads may be similarly formed of pure asphaltum or other truly plastic, substantially non-resilient compositions. I am aware that cartridge shells have been wadded with punched or otherwise preformed wads of plastic material, but I have found by actual tests extending over a protracted period that shells equipped with such wads are little or no better, ballistically, than shells using pre-cut felt, paper or cork wads. On the other hand, shells in which the powder sealing wads are formed in situ, that is, by expanding the wad material into complete sealing contact within the shell casing, have been found markedly uniform in velocity and pattern and far superior, ballistically, to shells provided with pre-formed wads of either plastic or resilient materials. I have also found that perfection of seal may be aided, in the case of some plastic materials, by the application of heat, thereby causing the material to flow more readily and permit the use of lower plunger pressures. Other changes within the scope of this invention will also appear to those skilled in the art. I therefore claim my invention broadly as indicated by the appended claims.

What I claim is:

1. The method of wadding the powder space of a cartridge shell which comprises charging the cartridge casing with the required amount of powder, placing a pellet of plastic wad material in the shell casing above the powder charge, and applying pressure upon the top surface of said plastic pellet until said pellet has been extruded radially into complete circumferential sealing contact with the inner surface of said casing.

2. The method of wadding the powder space of a cartridge shell which comprises charging the cartridge casing with the required amount of powder, placing a disc of paper or the like flatly upon the top surface of said powder charge, placing a mass of plastic wad material in the shell casing above said disc, placing a second disc above said plastic mass, and applying pressure upon the top surface of said last-mentioned disc until the voids between said discs and shell casing are displaced and the plastic mass has been radially flowed into complete circumferential sealing contact with the inner surface of said casing.

3. The method of wadding the powder space of a cartridge shell which comprises placing the shell in a snugly fitting sleeve, charging the cartridge casing with the required amount of powder, placing a pellet of plastic wad material in the shell casing above the powder charge, applying pressure upon the top surface of said plastic pellet until said pellet has been extruded radially into complete circumferential sealing contact with the inner surface of said casing, and

removing said shell from said snugly fitting sleeve.

after the pressure upon said pellet has been relieved.

4. The method of wadding the powder space of a cartridge shell which comprises charging the cartridge casing with the required amount of powder, placing a disc of paper or the like flatly upon the top surface of said powder charge, heating and placing a mass of plastic wad material in the shell casing above said disc, placing a second disc above said plastic mass, and applying pressure upon the top surface of said last-mentioned disc while said plastic mass is still warm to flow said plastic mass into complete circumferential sealing contact with the inner surface of said casing.

5. The method of wadding the powder space of a cartridge shelhwhichcomprises charging the cartridge casing with the required amount of, powder, placing above said powder charge a pellet composed essentially of asphaltum having a ball and ring melting point of approximately 300 Fahrenheit, and applying a pressure of several hundred pounds to the square inch upon said pellet to expand said pellet radiallyinto perfect peripheral sealing contact with the inner surface of said casing.

6. The method of wadding the powder space of a cartridge shell which comprises charging the cartridge casing with the required amount of powder, placing said shell in a snugly fitting sleeve, placing above said powder charge a pellet composed essentially of asphaltum having a ball and ring melting point of approximately 300 F., applying a pressure of several hundred pounds per square inch upon said pellet to expand said pellet radially into perfect peripheral sealing contact with the inner surface of said casing, and removing said shell from said snugly fitting sleeve after the pressure upon said pellet has been relieved.

7. The method of wadding the powder space of a shot-gun cartridge which comprises forming a pellet of plastic material smaller in diameter than the inside diameter of the cartridge casing, placing said pellet above the powder charge, and applying pressure to the exposed surface of the pellet thereby causing it to flow radially across the top surface of the powder charge and completely and permanently contact peripherally with the inside surface of the cartridge casing.

8. The method of wadding the powder space of a shot-gun cartridge which comprises placing upon the powder charge a thin disc of substantially the same diameter as the inside diameter of the cartridge casing, forming a pellet of plastic material smaller in diameter than the inside diameter of the cartridge casing, placing said pellet above the said disc, placing a second nonadhesive disc above said pellet, and applying pressure upon the second disc thereby causing the material of the pellet to flow between said discs into perfect and permanent peripheral sealing contact with the inside surface of the cartridge casing which is adjacent said discs.

9. In the art of loading cartridge shells, the method comprising, charging the shell with the required amount of powder, placing plastic wad material in the shell and forming said material into gasimpervious contact with the shell. r

10. In the art of loading cartridge shells, the method comprising, charging the shell with the required amount of powder, placing plastic wad material in the shell, forming said material into a wad within the shell and causing radial flow of portions of said wad material into sealing contact with the inner surface of the shell casing.

11. In the art of loading shot shells, the method comprising, charging the shell with the required amount of powder, placing plastic wad material in the shell, and applying pressure upon the top surface of said material to condense it and cause radial flow thereof into sealing contact with the inner surface of the shell casing.

12. In the art of loading cartridges, the method comprising charging the cartridge with the required amount of powder, placing plastic wad material in the cartridge, and forming said wad material in situ into a gas impervious body and simultaneously expanding the peripheral portions thereof into sealing contact with the.

inner surface of the cartridge casing.

13. In the art of loading cartridges, the method comprising charging the cartridge with the required amount of powder, placing plastic wad material in the cartridge, said wad material being composed of a mixture of plastic material and a resilient material, and the former material being present in greater proportion by weight than the latter; and forming said wad material in situ into a gas impervious body and simultaneously expanding the peripheral portions thereof into sealing contact with the inner surface of the cartridge casing.

SAMUEL C. BOND.

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