US3264997A - Propellant configurations for use in firearms - Google Patents

Description

H. E. MICHAEL 3,264,997 PROPELLANT CONFIGURATIONS FOR USE IN FIREARMS Aug. 9, 1966 Filed July 20, 1964 FEG.!.

H E WVENTOR. AROLD ICHAEL WW ATTORNEY United States atet ice

3,264,997 PROPELLANT CONFIGURATIONS FOR USE IN FIREARMS Harold E. Michael, 30714 Tarapaca Road, San Pedro, Calif. Filed July 20, 1964, Ser. No. 383,759 1 Claim. (Cl. 102-98) This invention relates to propellants as used in firearms such as revolvers, pistols, rifles, machine guns, and artillery.

Presently available firearm propellants are in the form of small particles of charge, each particle being in the form of a tubular section of relatively thick wall and of a length corresponding to approximately two to three times the diameter of the section. The configuration is designed to the provide a nearly constant burning area for each particle until the propellant particles are entirely consumed. For a given propellant composition and burning rate, the burning time is determined by the thickness of the tubular wall section of the propellant particles. The burning time is selected to obtain the maximum projectile velocity for the condition of projectile weight, bore and barrel length of the firearm, and propellant energy.

When propellant particles or grains of the foregoing configuration are loaded into a typical cartridge case, the volume occupied may contain sixty percent propellant and forty percent voids. As a consequence of this relatively low density of actual propellant in the cartridge, only a given energy can be packaged in a given sized cartridge.

With the foregoing in mind, it is accordingly a primary object of this invention to provide novel propellant configuration which result in an increase in the density of the propellant thereby enabling the size of the cartridge case required for a given weight of propellant to be decreased. As a consequence, certain economies in size and weight of the cartridge case and of cooperating equipment relating to the cartridge case can be effected.

Brieflly, this and other objects and advantages of this invention are attained by avoiding the use of hundreds of small particles or grains and instead providing the propellant charge initially as an integral solid mass in the shape of an enlarged cylinder which corresponds to the receiving portion of the shell so that if the charge were placed in the shell, there would be substantially no voids and thus one hundred percent filling of the shell by the propellant. However, without further modification, there would not be provided the necessary exposed surfaces to effect controlled burning of the propellant. Accordingly, and in accordance with various species of the present invention, the cylindrical charge portion after being shaped to be received within the interior receiving portion of the shell is cut in a manner to enable at least partial separation of the cylindrical shaped charge into small portions to take place thereby providing an increased burning area. In addition, the cylindrical shaped charge may be provided with at least one axial bore of small diameter running from one end of the cylindrical shape to the other to provide further burning area.

By means of the foregoing cuts and bore, the amount of voids may be reduced to 1cm than five percent of the volume occupied by the propellant without sacrificing the desired burning rates.

A better understanding of the invention will be had by referring to several embodiments thereof as illustrated in the accompanying drawings, in which:

FIGURE 1 illustrates an exploded view of a shell and charge configuration in accordance with one embodiment of this invention;

FIGURE 2 is a cross-section of the charge illustrated in FIGURE 1 looking in the direction of the arrows 22;

FIGURE 3 illustrates in partially exploded view an other embodiement of charge configuration in accordance with this invention;

FIGURE 4 is a cross view taken in the direction of the arrows 4-4 of FIGURE 3;

FIGURE 5 illustrates yet another charge configuration in accordance with this invention; and

FIGURE 6 is a cross-section looking in the direction of the arrows 6-6 of FIGURE 5.

Referring first to FIGURE 1, there is shown a firearm shell 10 of cylindrical configuration. Cooperating with this shell is a cylindrically shaped bulk charge 11 having a diameter and length corresponding to the interior receiving dimensions of the shell 10.

In accordance with the first embodiment of the invention illustrated in FIGURE 1, the cylindrical charge 11 is provided with a series of cuts extending generally normally to the axis of the cylindrical shaped charge to separate the charge into a plurality of discs such as indicated at 12. Also provided is a central bore 13 extending axially through the cylindrical configuration. By this arrangement, there results a series of stacked discs of propellant whose thickness is selected to permit the propellant to be consumed within the time required to produce the maximum energy to be tranferred to the projectile. Since each disc is provided with a hole as a consequence of the bore 13, there is defined an ignition passageway through the cylindrical shape when the primer is fired. As the combustion process progresses from the cylindrical surface of the ignition passageway in the form of the bore to the plane surfaces of each disc, the resulting gas pressure forces the discs to separate and thereby become distributed along the bore of the firearm as the propellant discs are consumed. Typically, the bore 13 may be about onefifth of the overall diameter in size and the discs may be of the order of .010 inch in thickness for hand held firearms.

In the cross-section view of FIGURE 2, the actual size of the bore 13 is greatly exaggerated for purposes of clarity.

FIGURE 3 illustrates another configuration in which a cylindrical charge 14 is provided with a spiral cut 15 extending generally towards the axis to define a general helical configuration for the charge as indicated in the exploded portion at 16. A bore 17 is provided as shown. This manner of cutting the charge provides the required burning surface area without increasing appreciably the volume percent of voids.

FIGURE 4 illustrates the appearance of the helical configuration when looking in the direction of the arrows 44 of FIGURE 3. Again, the central bore 17 provided in the charge has been exaggerated in size for purposes of clarity.

FIGURES 5 and 6 show yet a third embodiment of the invention wherein there is provided a cylindrical charge 18 having a plurality of cuts 19 and -20 extending in from diametrically opposite sides to define partial discs 21 which have their opposite diametrical ends alternately connected together. The cuts in every instance intersects a central bore 22 so that there is communication between the various burning surfaces.

In the embodiments of FIGURES 36, the axial distance between the various cuts would be of the order of .001 to .01 inch for hand held firearms and larger for field shells.

In the cross-section of FIGURE 6, there is shown a burning depressant coating 23 applied to the exterior burning surface of the cylindrical charge 18. Such a burning depressant may be desirable to provide further control over the burning rate and could of course be applied to 3 any of the embodiments of FIGURES 14 and on any of the exposed surfaces, either within the internal bore and/ or on the sidewalls defined by the cuts.

It is important in the various configurations described that the separated or partially connected disc-like sections resulting be easily separable in order to avoid errosive burning which would take place if the propellant surfaces could not separate easily.

Since the density of propellant within the shell has been greatly increased by the configurations described in FIG- URES 1-6, it is very important that the initial burning rate be held low compared to present practice in order that the bullet may be started down the barrel thus creating a gas expansion space for the more rapid burning that is to follow. This initial low burning rate is necessary in order to prevent the gas pressure from developing to such a high level that the resultant increased rate of combustion will generate gas at a faster rate than be can accommodated by the space behind the advancing bullet. This condition compounds itself and may result in damage or destruction of the gun breach.

This control of the burning, as stated, may be effected by the use of a burning depressant such as indicated at 23 in FIGURE 6. This burning depressant will hold the burning rate at a low value when first ignited but is removed as the burning progresses until the final burning is totally completed.

Also, the depressant may be applied only to the outer cylindrical surface of the various configurations illustrated in the drawings so that active burning initiates at the inner bore surfaces of the small bore passing axially through the cylindrical shape. As the burning progresses from the inside towards the exterior, the surface exposed to the flame is increased so that the desired increased rate of burning is automatically effected.

While only three basic configurations have been described in detail in the drawings, it should be understood that various further configurations may be effected without departing from the scope and spirit of this invention. The essential feature is that of providing an effectively solid cylinder of propellant which contains enough surface area to insure its complete burning within the required time and which distributes itself evenly along the bore while burning. Accordingly, the invention is not to be thought of as being restricted to the particular embodiments set forth merely for illustrative purposes.

What is claimed is:

A propellant configuration for use in a cylindrical firearm shell, comprising: a cylindrically shaped charge including an axially directed lbore extending therethrough, said charge having a plurality of lateral cuts extending generally normal to the longitudinal axis of said charge to intersect said bore at substantially right angles, said cuts initiated from opposite sides of said cylindrical charge in an alternate manner and extending completely through said bore and the major portion of the grain diameter to define closely adjacent disc portions alternately connected at their diametrically opposite ends, whereby said disc portions are at least partially separable to progressively increase the exposed burning area as the charge is progressively burned.

References Cited by the Examiner UNITED STATES PATENTS 660,567 10/1900 Gathmann 10298 660,568 10/1900 Gathmann 10298 716,768 12/1902 Scott 102-98 1,274,791 7/1918 Gerdom 10298 2,529,791 11/1950 Whitworth et a1 102--39 2,712,283 7/1955 Golden 10298 X 2,933,041 4/1960 Ambrose 102-98 3,048,112 8/1962 Shope 10298 BENJAMIN A. BORCHELT, Printary Examiner.

R. F. STAHL, Assistant Examiner.

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