Ammunition for recoilless weapons
United States Patent 2492279

My invention relates to improvements in ammunition for recoilless weapons, particularly fixed ammunition fired electrically in such weapons. In recoilless weapons of the type to be discussed, a proportion of the propellent gases is permitted to escape rearwardly of the weapon to eliminate...

Fowler, Kenneth R.
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Fowler, Kenneth R.
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F41A19/69; F42B5/05; F42B5/08
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My invention relates to improvements in ammunition for recoilless weapons, particularly fixed ammunition fired electrically in such weapons.

In recoilless weapons of the type to be discussed, a proportion of the propellent gases is permitted to escape rearwardly of the weapon to eliminate recoil of the same. Leakage of such gases not only diminishes the resultant effect of these gases but also causes corrosion of the finished surfaces of parts resulting in improper functioning of the same.

The principal object of my invention is to provide an insulating seal between the cartridge case walls and the electrical conducting means passing through the walls for firing the cartridge, said seal also being capable of withstanding the heat and pressure generated by the propellent gases.

The present invention can be used with recoilless weapons of the character disclosed in my application Serial No. 715,674, entitled "Recoilless weapons," filed December 12, 1947, in which is claimed the structure disclosed in this application but not claimed herein.

My invention will be more fully understood by reference to the accompanying drawings in which: Figure 1 is a longitudinal vertical section through the chamber, the breechblock and adjacent parts of a recoilless weapon, showing in elevation, a round of ammunition with its end broken away to show the construction thereof; Figure 2 is a vertical section through the breechblock at line 2-2 of Figure 1 showing the orifices at the rear of the weapon through which the propellent gases escape for counteracting the recoil of the weapon; Figure 3 is an enlarged partial sectional view taken through lines 3-3 of Figure 1; Figure 4 is an enlarged partial sectional view showing the spring-pressed plunger in engagement with the contact ring of the round of ammunition preparatory to firing the same.

Figure 1 discloses generally a recoilless weapon having a rifled barrel 1, a chamber 2, a breechblock 3, a locking sleeve 4 and a spring-pressed plunger device for electrically firing the round of fixed ammunition. The weapon is single loading and has the necessary mechanism, not shown, for aiming it. A breech mechanism, not shown, rotates the locking sleeve 4 to unlock and move the breechblock 3 away from the chamber 2 whereby a fired round of ammunition 5' can be removed from and a new one inserted into the chamber. By reverse 5 action of the breech mechanism, the breechblock 3 closes the chamber 2 preparatory to firing of the weapon.

To eliminate recoil in the weapon, the breech6 block 3 is provided with a plurality of inclined, tapered orifices 6 through which a proportion of the propellent gases are discharged from the cartridge case. The degree of inclination, the direction and the size of these orifices 6 are such that the reaction of the propellent gases passing through them will counteract the forces acting upon the weapon, such as the rotational forces created by the reaction between the rifling in the barrel and the moving projectile, and the longitudinal forces, caused by the reaction of the projectile when it is ejected from the cartridge case.

Further explanation of the operation of the recoilless weapon may be had by reference to my application Serial No. 715,674, filed December 12, 1947, entitled "Recoilless weapons." The round of ammunition 5' consists of the cartridge casing 7 rigidly secured, as by crimping, about the projectile 8 of any desired form and contains a propelling charge 8' adapted to be ignited by a primer, not shown, which is fired electrically in a manner to be described.

The rear end 10 of the cartridge case 7 is closed by a frangible cap 9 of cardboard, molded composition or other suitable material which, when the round is fired, is blown out by the propellent gases and disintegrated, permitting a portion of the propellent gases to escape rearwardly of the projectile and through the orifices 6 as heretofore explained. The cap 9 is anchored in place by the inturned flange 12' and sealed by wax 9' or other suitable substance.

Forwardly of the rear end 10 of the cartridge case 7, an annular rim I extends about and is rigidly secured to the cartridge case 7 by brazing or other similar means. The portion of the cartridge case 7, between its rear end 10 and rim II and indicated by reference numeral 12, is free to be expanded radially by the gases escaping to Sthe rear, for a purpose to be described.

The rim 1 is provided with an annular groove 13 containing a micarta layer 14, or other suitable insulating material. An annular metallic contact ring 15 is secured in the layer 14 and 5o sunk below the radial surfaces of the ring II, clearly shown in Figure 3. The ring 15 is adapted to be engaged by a spring-pressed pin 16 of the device 5, at all angular positions of the cartridge case 7, the pin 16 being connected to an outside 5 electrical source. The rim II and a wall of the cartridge case 7 are provided with aligned radial openings 17 and 18, respectively.

A hollow cylindrical plug 19 extends through these openings and is securely fastened to the inside of the cartridge case by brazing 19' or other suitable means. The plug 19 has a cylindrical recess 20 within which a cylindrical piston 21, formed of copper or other suitable deformable material, is inserted and insulated from the walls of the recess 20 by a micarta lining 22 or similar material. The plug 19 is also provided at one end with an aperture and at the other end with a tapered recess 20'.

A short insulated electrical lead 23, having one of its ends bared and packed with lead foil against the metallic ring 15 to form a good electrical contact therewith passes through the opening 24 and has its other end bared and imbedded in the copper piston 21. Another insulated electrical lead 24' having one of its ends bared and imbedded in the copper piston 21, is connected to a primer, not shown. An insulated lead 25 from the primer is grounded to the cartridge case at 26 to complete the electrical circuit. The copper piston 21 with its insulating lining 22 has a drive fit within the recess 20. The space between the walls of the flared recess 20' and the electrical lead 24' is sealed with wax 27 or similar plastic substance to exclude moisture from entering the cartridge case.

During operation of the weapon, the breechblock 3 is opened, a round of ammunition having the improvement just described is rammed into the gun chamber 2 and the breechblock 3 is then closed and locked preparatory to firing.

The gun chamber 2 does not house the complete length -of the cartridge case I but only that forward portion up to and including the annular rim 11, leaving the remaining portion 12 rearwardly of the rim 11 to be engaged by the breechblock 3.

To fire the round -of ammunition, electric current from any suitable outside source is carried by the spring-pressed pin 1I6 to the annular contact metallic ring 15, and then through the lead 23, the copper piston 21 and the lead 24' to the primer, not shown, returning through the grounded lead 25.

Upon firing the round of ammunition, the propellent gases will shoot the projectile 8 forwardly through the gun barrel in the usual manner and at the same time force out the cap 9 disintegrating the same, thereby allowing a portion of the propellent gases to escape rearwardly through the orifices .6 to counteract the recoil of the weapon as already explained. .Simultaneously with this action, the propellent .gases will also expand radially the cylindrical portion 12 of the cartridge case I against the breechblock 3 to seal off any leakage of the propellent gases between the abutting faces 28 and 29 of the breechblock 3 and the gun chamber 2, respectively, and through the device 5, thus protecting these parts from damage.

The piston 21, will also be forced by the gases against the seat 25' in the recess 20 and be deformed, thereby preventing leakage of said gases through the joint between the cartridge case and the electrical wiring.

Through the use of the expanding portion 12 and the gas-tight seal for the electrical wiring, I completely and effectively utilize the propellent gases both to propel the projectile and to counteract recoil of the weapon, losing none of the gases prior to extraction of its energy through undesirable leakage.

It will be obvious to those skilled in the art that various modifications may be made in the construction described herein without departing from the spirit and scope of my invention.

I claim: In an electrically fired round of fixed ammunition having a casing and a rearwardly disposed annular flange thereon adapted to seat between the chamber and breech block of a gun into which the round is loaded, means for conducting current from an insulated conductor on said gun to the interior of said round to fire same, said means serving also to obturate explosive gases, said last means comprising an annular conducting ring set into said annular flange but insulated therefrom, a passage through said flange and casing from said ring to the interior of said -asing, and insulated conducting means in said passage leading from said ring to said interior, said conducting means including an enlarged-partially deformable cylindrical plug of relatively soft metal in said passage constructed and arranged to be forced against a portion of said passage by explosive gases to prevent leakage of such -gases through said passage the portion of the passage against which the plug is forced under pressure being a conically tapered reduced shoulder in said passage.


REFERENCES -CITED 50 The following references are of record in the file of this patent: UNITED STATES PATENTS Number 520,116 1,084,745 1,108,717 1,263,763 Name Date Mason ---------- May 22, 1894 Lindsay ----..- Jan. 20, 1914 Davis ------------- Aug. 25, 1914 Hasting ----------- Apr. 23, 1916