COMPOSITE METAL CARTRIDGE CASE

• US 3,659,528 A
• Filed: 12/24/1969
• Issued: 05/02/1972
• Est. Priority Date: 12/24/1969
• Status: Expired due to Term

• Current Assignee: Teuvo Santala
• Original Assignee: Teuvo Santala
• Inventors: Santala, Teuvo
• Primary Examiner(s): Stahl, Robert F.
• Application Number:
  US04/887,956
• Time in Patent Office: 860 Days
• Field of Search: 102/43,43F,38 29/1.3
• US Class Current: 102/468
• CPC Class Codes: F42B 5/28 of metal , i.e. the cartridge-case tube is of metal

Abstract

An ammunition cartridge cause is shown to comprise a deep, openended cup having a base of substantial thickness, having a relatively thin, generally cylindrical wall upstanding from the base and having an annular, peripheral, extraction groove formed in the base, the base having a recess which opens oppositely of the open cup end for receiving a primer cup therein. The cartridge case if formed of a composite metal laminate material having a core metal layer sandwiched between and metallurgically bonded to outer layers of other metal materials. The core metal layer of the laminate material extends as a core throughout the wall of the cup and the base of the cup and is disposed within the cup base to surround the bottom and lateral walls of the primer cup recess to provide adequate case strength in the primer cup area. The core material is arranged within the cup base so that the core material is completely covered by the outer layer material of the laminate at the location of the cartridge extraction groove.

Claims

1. A cartridge case comprising an open-ended cup having a base of selected thickness and having a relatively thinner, generally cylindrical wall upstanding from said base, said case being formed of a composite metal laminate material having metal core layer means of steel sandwiched between and metallurgically bonded to outer metal layer means one of which is disposed as an exterior surface layer of said case and one of which is disposed as an inner surface layer of said case, said exterior surface layer means being of selected thickness around said cylindrical wall and having relatively thicker portions thereof disposed around the periphery of said base and across the bottom of said base, said exterior surface layer means having an annular groove in one of said relatively thicker portions thereof extending around the periphery of said base, said exterior surface layer means having a recess in one of said relatively thicker portions thereof extending into the bottom of said base, said recess having lateral and bottom walls and having an open end facing away from said cup, said core layer means of said laminate material extending as a core throughout said cylindrical cup wall and extending into said base between portions of said groove and recess, said core layer means being disposed in spaced, surrounding relation to bottom and lateral wall portions of said base recess, said case having a passage therein extending from the bottom of said base recess through said laminate material into said cup.

2. A cartridge case as set forth in claim 1 wherein said core layer means within said base is spaced from said base groove.

3. A cartridge case as set forth in claim 2 wherein said cartridge case laminate material has a central core layer of low carbon steel sandwiched between and metallurgically bonded to outer metal layers of aluminum alloy.

4. A cartridge case as set forth in claim 3 wherein said aluminum alloy has a nominal composition, by weight, of 5.1-6.1 percent zinc, 2.1-2.9 percent magnesium, 1.2-2.0 percent copper, 0.18-0.40 percent chromium and the balance aluminum.

5. A cartridge case as set forth in claim 1 wherein said core layer of steel comprises a layer of low carbon steel which is sandwiched between and metallurgically bonded to outer metal layers of cartridge brass.

6. A cartridge case as set forth in claim 1 wherein said core layer of steel comprises a layer of low carbon steel which is sandwiched between and metallurgically bonded to outer metal layers of cartridge brass and aluminum alloy respectively.

7. A cartridge case as set forth in claim 6 wherein said aluminum alloy has a nominal composition, by weight, of 4.7-5.5 percent magnesium, 0.50-1.00 percent manganese, 0.05-0.20 percent chromium and the balance iron.

8. A cartridge case comprising an open-ended cup having a base of selected thickness, having a relatively thinner wall upstanding from said base and having an annular, peripheral groove formed in said base, said base having a recess which opens oppositely of said open cup end and having a passage connecting said recess with the inside of said cup, said case being formed of a composite metal laminate material having a core layer of low carbon steel having a nominal composition, by weight, of 0.08 percent (max.) carbon, 0.25-0.45 percent manganese, 0.040 percent (max.) phosphorous, 0.050 percent (max.) sulfur, and the balance iron, said core layer being sandwiched between and metallurgically bonded to outer metal layers of aluminum alloy having a nominal composition, by weight, of 5.1-6.1 percent zinc, 2.1-2.9 percent magnesium, 1.2-2.0 percent copper, 0.18-0.40 chromium, and the balance aluminum, said core layer extending as a core throughout said cup base and wall and being disposed within said base to surround bottom and lateral wall portions of said base recess.

9. A cartridge case as set forth in claim 8 wherein said core layer of steel has a thickness comprising approximately 15 percent of the total thickness of said composite material.