Lightweight cartridge case

• US 8,156,870 B2
• Filed: 06/12/2008
• Issued: 04/17/2012
• Est. Priority Date: 06/12/2008
• Status: Active Grant

• Current Assignee: United States Of America As Represented By The Secretary Of The Army (Government of the United States of America)
• Original Assignee: The United States Of America As Represented By The Secretary Of The Army
• Inventors: South, Joseph T.
• Primary Examiner(s): BERGIN, JAMES S
• Application Number:
  US12/137,989
• Publication Number:
  US 20090314178A1
• Time in Patent Office: 1,405 Days
• Field of Search: 102/464, 102/468, 102/469, 102/470, 102/204, 102/465, 102/466, 102/467, 102/472
• US Class Current: 102/469
• CPC Class Codes: F42B 33/04 Fitting or extracting primers in or from fuzes or charges F42B33/004 takes precedence
• CPC Class Codes: F42B 5/26 Cartridge cases F42B5/18 takes precedence ; manufacturing of cartridge cases B21K21/04
• CPC Class Codes: F42B 5/28 of metal , i.e. the cartridge-case tube is of metal
• CPC Class Codes: F42B 5/30 of plastics , i.e. the cartridge-case tube is of plastics
• CPC Class Codes: F42B 5/307 formed by assembling several elements

Abstract

Disclosed is an ammunition cartridge case that includes a sleeve, a base fixedly attached to the sleeve and a fiber reinforced polymer composite annulus that is at least partially within the base. In certain embodiments, the sleeve and the base are formed partly or entirely from a metal, for example steel or stainless steel. The base has a central aperture that affords for the annulus ring to fit within. The annulus is dimensioned such that it fits securely within the central aperture of the base and has a center aperture wherein a primer can be located. The annulus ring contains a volume of composite fibers ranging from 10 to 90 volume percent. The annulus isolates the primer from the cartridge case and thereby prevents galvanic corrosion between the primer and case. In addition, a metallic foil can be present between the annulus and the cartridge case in order to assure proper securement of the annulus therewithin.

Claims

1. A cartridge case, comprising:

a sleeve, said sleeve having a mouth end and a base end, said mouth end operable to accept a projectile;

a base fixedly joined to said base end of said sleeve, said base having a central aperture; and

a fiber reinforced polymer composite annulus at least partially disposed within said central aperture, said fiber reinforced polymer composite annulus defined by an outer sidewall, an inner sidewall, a top end, a bottom end and a central aperture that affords a location for a primer to be located therewithin.

2. The cartridge case of claim 1, wherein said sleeve is a metallic sleeve or a metal sleeve and said base is a metallic base or a metal base.

3. The cartridge case of claim 1, wherein said sleeve is a steel sleeve and said base is a steel base.

4. The cartridge case of claim 1, wherein, said annulus has a center aperture and further comprising a primer at least partially within said center aperture of said annulus ring.

5. The cartridge case of claim 4, wherein said annulus isolates said primer from said cartridge case.

6. The cartridge case of claim 4, further comprising a metallic foil between said annulus and said base.

7. The cartridge case of claim 6, wherein said metallic foil is selected from a group consisting of copper foil, stainless steel foil, aluminum foil, aluminum alloy foil, titanium foil and titanium foil.

8. The cartridge case of claim 1, wherein said annulus contains a volume of composite fibers ranging from about 10 to about 90 percent.

9. The cartridge case of claim 8, wherein said composite fibers are glass fibers.

10. The cartridge case of claim 8, wherein said composite fibers are polymeric fibers.

11. The cartridge case of claim 8, wherein said composite fibers are selected from the group consisting of polyurethane, polyepoxy, poly(vinyl ester), polyphenol polybenzoxazole, polyamide, polyethylene, ultra high molecular weight polyethylene, M5 synthetic, poly-paraphenylene terephthalamide, polymetaphenylene isophtalamide, polyamide imide, copolyimide, and combinations thereof.

12. The cartridge case of claim 8, wherein said composite fibers have an orientation selected from the group consisting of hoop, axial, and a combination thereof.

13. The cartridge case of claim 8, wherein said composite fibers are carbon fibers.

14. The cartridge case of claim 13, wherein said carbon fibers are selected from the group consisting of short chopped carbon fibers, aligned continuous carbon fibers, woven carbon fibers, non-woven carbon fibers and combinations thereof.

15. The cartridge case of claim 1, wherein said annulus has a matrix made from a plastic, said plastic selected from the group consisting of thermoplastic polymers and thermosetting polymers.

16. The cartridge case of claim 1, wherein said annulus is made from a composite formed by pressure-assisted infusion of a flowable polymer into a dry fabric.

17. A cartridge case, comprising:

a metallic sleeve, said sleeve having a mouth end and a base end, said mouth end operable to accept a projectile;

a metallic base extending from and integral with said base end of said sleeve, said base having a central aperture;

a fiber reinforced polymer composite annulus at least partially disposed within said central aperture, said annulus having an outer sidewall, an inner sidewall, a top end, a bottom end and a center aperture; and

a primer at least partially within said center aperture of said annulus.

18. The cartridge case of claim 17 further comprising an adhesive intermediate between said annulus and at least one of said metallic base and said primer.

19. The cartridge case of claim 17, wherein said annulus contains a volume of composite fibers ranging from about 10 to about 90 percent.

20. A cartridge case, comprising:

a steel sleeve, said sleeve having a mouth end and a base end, said mouth end operable to accept a projectile;

a steel base extending from and integral with said base end of said sleeve, said base having a central aperture and an extraction groove;

a fiber reinforced polymer composite annulus at least partially within said central aperture, said annulus having an outer sidewall, an inner sidewall, a top end, a bottom end and a center aperture wherein the fiber reinforced polymer composite annulus comprises a volume of composite fibers ranging from about 10 to about 90 percent; and

a primer at least partially within said center aperture of said annulus, said primer isolated from said steel base by said annulus.