US 3929074 A
A cartridge, fabricated from consumable material and having a rim which can be utilized to extract it should it fail to fire, is disclosed. A fuse train leading from the cartridge's initiator to the cartridge's rim is utilized to ignite a pyrotechnic train in the rim after the cartridge has been fired and thereby initiate consumption of the rim.
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Description (OCR text may contain errors)
United States atent [1 1 [111 3,929,074
San Miguel 1 Dec. 30, 1975  MEANS FOR THE ELIMINATION OF A 3,598,052 8/1971 Schwartz et a1. 102/43 P C R RI G RIM 3,670,649 6/1972 Hartlein et a1 1. 102/DlG. 1 3,749,023 7/1973 Kawaguchi et a1. 102/43 P  Inventor: Anthony San Miguel, Ridgecrest,
Cahf' Primary ExaminerSamuel W, Engle  Assignee: The United States of America as Assistant ExaminerC. T. Jordan represented by the Secretary of the Attorney, Agent, or FirmR. S. Sciascia; Roy Miller; Navy, Washington, DC. Lloyd E. K. Pohl  Filed: Apr. 5, 1974 21 Appl. No.: 458,253  ABSTRACT A cartridge, fabricated from consumable material and having a rim which can be utilized to extract it should it fail to fire, is disclosed. A fuse train leading from the cartridges initiator to the cartridges rim is utilized to ignite a pyrotechnic train in the rim after the cartridge has been fired and thereby initiate consumption of the  US. Cl 102/43 P; 102/38; 102/DIG. 1  Int. Cl. F423 5/30  Field of Search 102/43 P, 43 R, 38, DIG. l
 References Cited nm UNITED STATES PATENTS 3,348,484 10/1967 Grandy 102/38 3 Clam, 4 D'awmg F'gures US. Patent Dec. 30, 1975 3,929,074
13/2] f/ l I Fig. 4
MEANS FOR TI-IE ELIMINATION OF A CARTRIDGE RIM BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to consumable cartridges. More particularly, this invention relates to consumable cartridges which have rims and bases that are also consumable.
2. Description of the Prior Art The idea of utilizing consumable cartridges, i .e., cartridges which burn up when they are fired leaving nothing to remove from the gun barrel, has been with us for many years. Consumable cartridges are especially desirable for military applications because they are light weight, they eliminate the need for relatively expensive and rare material (brass), they deny the enemy material (the enemy often utilizes spent brass cartridges as reloads) and, in artillery applications they eliminate need for one man in the gun crew.
Prior art consumable cartridges have had one primary drawback in common. That drawback is the fact that they have. been rimless. A rimless cartridge is undesirable because, should it misfire (be a dud), there is no convenient way to remove the unfired cartridge from the gun barrel. In conventional guns, the cartridge rim is utilized in extraction and, if there is no rim present, it simply cannot be used. It is, therefore, and object of this invention to provide a consumable cartridge with a rim that is also consumable. It is also an object of this invention to provide a consumable rimmed cartridge wherein the rim and base are not consumed until after the cartridge has actually been fired.
SUMMARY OF THE INVENTION The present invention resides in a consumable cartridge which has a base and rim similar to that of a conventional brass cartridge. A fuse train leading from the cartridge initiator is utilized to ignite a consumable pyrotechnic train in the rim and insure consumption thereof after the cartridge has been fired.
BRIEF DESCRIPTION OF THE DRAWING FIG. 1 of the drawing is a cross sectional view of a consumable, rimmed cartridge according to this invention.
FIG. 2 is an elevational view of the base and rim of a cartridge according to this invention showing, in dashed lines, a suitable location for a pyrotechnic train in the rim.
FIG. 3 is similar to FIG. 2 with the exception that the dashed lines are utilized to show a configuration and location for the pyrotechnic train which is different from that of FIG. 2.
FIG. 4 is a cross sectional view similar to FIG. 1 with the exception that FIG. 4 shows a fuse train and pyrotechnic train in different locations.
DESCRIPTION OF THE PREFERRED EMBODIMENT Going first to FIG. 1 of the drawing, a cartridge according to this invention is indicated by the numeral 11. The cartridge has a consumable case 12 and consumable extractor rim 13. The cartridge has a base 14 comprising a sheet of consumable material with a center opening through which an igniter 15 for igniting powder 23 within the cartridge is inserted. The igniter 15 contains a pellet of explosive 16 adjacent to the base of the cartridge and a second pellet of explosive 17 immediately forward of and adjacent to pellet 16. A tube 18 with perforations 19 forms part of the igniter and is integrally attached to that portion of the igniter containing the explosive pellets and extends forward therefrom into the core of the cartridge. The portion of the igniter which contains the explosive pellets is retained in a rigid position by means of a center boss 20. A fuse train 21 taps the portion of the igniter holding explosive pellet 17 and extends therefrom into the rim 13. Fuse train 21 extends far enough into the rim so that, when initiated, it will, in turn, initiate a pyrotechnic train 22 which runs through the rim encircling the base. Naturally, if the entire cartridge is to be consumable, all parts, including those of the igniter, must be fabricated from consumable materials.
When a cartridge according to this invention is fired in the conventional manner (by a firing pin striking the igniter and initiating explosive pellet 16), explosive pellet 16 initiates explosive pellet 17 which, in turn, blasts heat and flame forward through tube 18 and perforations 19 to initiate powder in the cartridge. The initiated powder, in turn, expells a projectile (not shown) from the forward end of the cartridge.
Heat from the initiated powder is sufficient to initiate comsumation of the relatively thin cartridge case 12 and of devices within the cartridge such as igniter 15 and tube 18 of the igniter. I-Ieat from the initiated powder is not, however, sufficient to initiate complete consumation of the rim which is remote from (not in contact with) the powder.
To ignite the rim, the fuse train 21 and pyrotechnic train 22 are utilized.
To insert train 21 into the cartridge, that portion of igniter 15 which contains explosive pellet 17 is tapped with an opening just large enough to hold the train snugly and the train is inserted into the opening in a manner whereby its end is from about 1/32 to /a inch away from the explosive pellet. The other end of the train is imbedded in the rim of the cartridge adjacent to the pyrotechnic train 22 which runs therethrough as shown in the drawing.
When a cartridge according to this invention is fired, initiation of the forward explosive pellet initiates fuse train 21 which, in turn, initiates ignition oi pyrotechnic train 22. Initiation of pyrotechnic train 22 insures consumption of rim 13.
A cartridge of the present invention has an advantage over prior art consumable cartridges because, should a cartridge fail to fire, no consumation reaction is initiated and the rim is available to remove the dud from the gun chamber.
FIG. 2 of the drawing is an elevational view of base 14 with integrally attached rim 13 encircling it an: igniter 15 inserted through it. Dashed lines are utilizer to indicate where pyrotechnic train 22 runs through the rim. The inner dashed line, in addition to correspond ing with the inner circumference of the pyrotechnii train corresponds approximately with where the oute circumference of case 12, which is integrally attache to the base and rim, extends forward.
FIG. 3 shows another configuration for pyrotechni train 22 in which, rather than merely being embeddei in the rim as in FIG. 2, the pyrotechnic train is in th configuration of a helix which runs essentially through out the base as well as the rim.
Other pyrotechnic train configurations could be used in lieu of those depicted in FIGS. 2 and 3. For example, a pie shaped or wedge shaped configuration could be used or the train could even be run randomly through the base and rim. The function of the pyrotechnic train is to insure burning of the rim which is remote from the powder in the cartridge and is not easily ignited. The configuration of the pyrotechnic train is of importance only insofar as it insures that the train will perform its function.
FIG. 4 is a cross sectional view similar to that of FIG. 1 with the exceptions that the pyrotechnic train is shown with a concentric ring configuration like that of FIG. 3 and the fuse train, rather than being embedded in the rim, is embedded in the base so that its end is adjacent to the pyrotechnic train.
Cartridges according to the present invention can be fabricated from any of several suitable consumable materials. In tests, polysulfone with ammonium perchlorate oxidizer embedded has been used but any consumable, propellant type material comprising an oxidizer and fuel and having enough tensile strength to withstand the stresses and strains to which a cartridge is ordinarily subjected could be used. In a like manner, almost any pyrotechnic train can be used to ignite the 4 rim and almost any fuse train can be utilized to ignite the pyrotechnic train. For example, the pyrotechnic train could be a highly exothermic explosive such as RDX and the fuse train could be magnesium-Teflon.
Cartridges according to this invention may be easily fabricated by those skilled in the art using existing techniques.
What is claimed is: l. A consumable cartridge comprising: a case member; a base member closing one end of the case member and encircled by a rim; an igniter inserted through the base member into the interior of the cartridge; and a fuse train and a pyrotechnic train in combination connecting the igniter and the base to insure consumption of the base and rim when the igniter is iniatiated.
2. Apparatus according to claim 1 wherein said pyrotechnic train is embedded in the base in the form of a helix.
3. Apparatus according to claim 1 wherein said pyrotechnic train is embedded in the rim only.