US3026803A - Cartridge case - Google Patents

Description

March 27, 1962 D. METZGER 3,026,803

CARTRIDGE CASE Filed June 2, 1959 Fig.

Dan/'e/ Me/zger 1N VENTOR.

The present invention generally relates to an improved and novel cartridge case which may be constructed in any caliber and either center fire or rim fire and involves certain safety features as well as a more effective cartridge case.

In present day construction, conventional cartridge cases quite often'malfunction due to what is commonly referred to as primer blow bac The shoulder which abuts the inner end of the primer so constricts the passage between the primer and the main portion of the shell that the forces created by the primer force the primer back out of the shell thus causing the cylinder of the gun to jam and preventing rapid fire. This condition is normally termed primer blow back and this is especially troublesome in firing wax projectiles by using the primer as the projecting force. Therefore, it is the primary object of the present invention to provide a cartridge case in which there is a very small shoulder for engaging the inner end of the primer thus leaving the hole at the inner end of the primer at the maximum diameter or size for reducing the restriction and reducing the tendency of the primer to blow back from the cartridge.

Another object of the present invention is to provide a cartridge case constructed of plastic in which the shoulder which limits the insection of the primer melts away when the primer is fired thereby preventing reuse of the cartridge since the primer will not be held in the primer hole if the shoulder is missing thereby providing a safety feature since a new cartridge must be used each time.

A further object of the present invention is to provide a plastic cartridge case which will be extremely inexpensive to manufacture and will be a throw away item in that once it has been fired, it cannot be used and will be thrown away although the thin shoulder concept may be employed in brass cartridges using regular powder and lead projectiles.

Another important object of the present invention is to provide a cartridge case constructed of plastic in which the entrance to the primer area is chamfered or tapered to assist the primer when it is being forced in place which construction enables the primer to be placed in firing po* sition just by using thumb pressure which is an inexpensive way for the individual to apply primers and it is further impossible to apply enough force to the primer with your thumb to set it off thereby providing another safety feature for those whose load their own cartridges.

Still another feature of the present invention is the provision of a cartridge case in which the primer hole is provided with serrations which, due to their plastic construction, are sufiiciently resilient that they move outwardly when the primer is forced into the primer hole and thus securely grip the primer in position which also enables the primer to be inserted by thumb pressure and once the primer is in place, the serrations grip the primer to prevent primer blow back.

Other objects of the present invention will reside in its extreme simplicity of construction, ease of loading the case by hand and its inexpensive cost to enable the cartridges to be thrown away after one use.

These together with other objects and advantages which will become subsequently apparent reside in the details of construction and operation as more fully hereinafter Patented Mar. 27, 1962 described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout, and in which:

FIGURE 1 is a perspective view of the cartridge case of the present invention;

FIGURE 2 is a vertical sectional view taken substantially upon the plane passing along section line 22 of FIGURE 1 illustrating the details of construction of the case; and

FIGURE 3 is a bottom plan view of the cartridge case taken substantially upon reference line 3-3 of FIG- URE 2.

Referring now specifically to the drawings, the numeral 10 generally designates the cartridge case of the present invention which includes a cylindrical wall 12 having a peripheral flange 14 at the bottom edge thereof together with a projectile (not shown) forming the nose of the wall 12. The flange 14 is the usual construction for reception in the breech of a gun such as in the cylinder of a revolver and which will be associated with an extractor or ejector for operation in the usual manner.

The end of the wall 12 having the flange 14 thereon is thickened into substantially an annular body 16 having an arcuate curved upper surface 18 defining an opening 20 at the upper end of the primer hole 22. A peripheral downwardly facing shoulder 24 is provided which forms an abutment for the primer (not shown). The lower end of the primer hole 22 is tapered or outwardly chamfered as indicated by numeral 26 for forming a guide to assist the primer (not shown) when inserting the primer into the primer hole 22. Also, the primer hole 22 is provided with a plurality of longitudinal serrations 28 therein for gripping engagement with the primer (not shown) when inserted into the primer hole 22 into abutting engagement with the shoulder 24.

While dimensions may vary as to the caliber, the following dimensions have been found suitable for a 45 caliber cartridge. The over-all length is 1.030 inches, the thickness of the wall 12 tapering from .030 adjacent the body 16 to the outer end of .025 inch thickness. The serrations are .005 inch deep and the inside diameter of the serrations is .210 inch. The inside diameter of the opening 20 is .170 inch while the shoulder is .125 inch in diametrical distance. The outside diameter of the outer end of the wall 12 is .475 while the outside diameter adjacent the body or at the body is .476 inch and the joint between the curve 18 and the wall 12 is rounded to a .060 inch radius and the chamfer or taper is substantially 45.

Thus, when the primer is forced into the primer hole, the chamfer will assist the guiding of the primer into the primer hole and the serrations will resiliently be forced outwardly for enabling thumb pressure to place the primer in position thereby assuring that suflicient pressure will not be placed on the primer to set 01f the primer or fire the primer thereby providing a safety factor. When the primer is fired and the wax projectile or some other type of projectile is projected from the cylindrical wall 12, the shoulder 24 will be melted 01f thereby preventing reuse of the cartridge, since the primer would then fall into the interior of the cartridge if forced into the primer hole.

The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described and accordingly all suitable modifications and equivalents may be resorted to, falling within the scope of the invention as claimed.

What is claimed as new is as follows:

A cartridge case comprising an elongated cylindrical wall, a flange at the lower end of said wall projecting out- 3 wardly peripherally thereof, a thickened body portion at the flange end of said wall with the wall having substantially a constant outside diameter from the flange to the opposite end, said thickened body portion having a smoothly curved convex inner surface extending inwardly and defining an orifice spaced from the flange end of the cartridge, a primer hole formed in 'the'fiange end of the cartridge and communicating with said orifice, said primer hole having a diameter slightly larger than the orifice thereby providing a longitudinally outwardly facing shoulder for limiting the insertion of aprimer into the primer hole, the diametrical distance of the shoulder being relatively small in relation to'the diametrical distance of the orifice thereby forming but very little restriction of flow of gases from the primer into the cylindrical wall of the cart-ridge, said curved inner surface of the thickened body portion being continuous to said shoulder thereby defining a relatively thin lip forming said shoulder, said cartridge case being constructed of plastic material whereby the thin lip forming the shoulder will melt when the primer is fired thereby preventing reuse of the cartridge case, said primer hole being chamfered at the outer end and provided with 4 a plurality of longitudinal serrations for grippingly engaging a smooth surface primer when forced therein and enabling the primer to be forced in the primer hole with only finger pressure exerted thereby preventing pressure on the primer duringinsertion thereof from firing the same and securely gripping the primer to prevent primer blow back when the primer is fired, said serrations including a plurality of longitudinal ridges and depressions formed in the wall of the primer hole, the peaks of the ridges being substantially in alignment with the inner edge of the shoulder with the bottoms of the depressions spaced slightly radially outwardly from the inner edge of the shoulders thus further reducing the area of the lip actually engaging the primer when inserted into the primer hole.

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