Method of making ammunition having a two-piece primer insert

Patent metadata

Field	Value
Publication number	US-9523563-B1
Application number	US-201615065486-A
Country	US
Kind code	B1
Filing date	Mar 9, 2016
Priority date	Mar 9, 2016
Publication date	Dec 20, 2016
Grant date	Dec 20, 2016

Abstract

The present invention teaches methods of making ammunition having a polymer cartridge casing overmolding a primer inserts made by joining 2 or more primer sections.

First claim

What is claimed is:

1. A method of making polymer ammunition having a two piece primer insert comprising by the steps of:
providing a two piece primer insert comprising: an upper primer insert portion comprising an upper primer bottom surface, an upper primer aperture through the upper primer bottom surface; a substantially cylindrical coupling element extending away from the upper primer bottom surface, and an interior surface inside the substantially cylindrical coupling element; a lower primer insert portion comprising a lower primer bottom surface opposite a lower primer top surface, a primer recess in the lower primer top surface that extends toward the lower primer bottom surface and the primer recess adapted to fit a primer, a lower primer aperture through the lower primer bottom surface, and a flange that extends circumferentially about an outer edge of the lower primer top bottom surface, wherein the flange is adapted to receive a polymer overmolding; and an insert joint that links the upper primer bottom surface and the lower primer bottom surface to align the lower primer aperture with the upper primer aperture and forming the two piece primer insert;
providing a primer flash hole aperture extending through the lower primer aperture and the upper primer aperture;
providing a first polymer composition for molding the polymer ammunition cartridge;
molding from the first polymer composition a substantially cylindrical polymeric middle body having the two piece primer insert at a first end and a substantially cylindrical polymeric coupling region at a second end, wherein the first polymer composition extends over an outer surface of the two piece primer insert over the flange and the first polymer composition extends over the interior surface of the substantially cylindrical coupling element and into the primer flash hole aperture, wherein the first polymer composition extends from the substantially cylindrical polymeric coupling region into the primer flash hole aperture;
forming a substantially cylindrical polymeric bullet-end component from a second polymer composition comprising a bullet aperture opposite a polymeric bullet-end coupling that mates to the substantially cylindrical coupling region;
coupling the substantially cylindrical coupling region to the polymeric bullet-end coupling to form a propellant chamber that extends from the primer flash hole aperture to the bullet aperture;
inserting a primer into the primer recess, wherein the primer is in operable communication with the propellant chamber through the primer flash hole aperture;
at least partially filling the propellant chamber with a propellant; and
frictionally fitting a projectile in the bullet aperture, wherein the propellant chamber is enclosed at one end by the primer and the projectile at the other end.

2. The method of claim 1 , wherein the insert joint is threaded, riveted, locked, friction fitted, coined, snap fitted, chemical bonded, chemical welded, soldered, smelted, sintered, adhesive bonded, laser welded, ultrasonic welded, friction spot welded, or friction stir welded.

3. The method of claim 1 , wherein the upper primer insert portion, the lower primer insert portion or both are formed independently by metal injection molding, polymer injection molding, stamping, milling, molding, machining, punching, fine blanking, smelting, or any other method that will form insert portions that may be joined together to form a primer insert.

4. The method of claim 1 , wherein the upper primer insert portion, the lower primer insert portion or both independently comprise a polymer, a metal, an alloy, or a ceramic alloy.

5. The method of claim 4 , wherein the upper primer insert portion and the lower primer insert portion comprise the same material or different materials.

6. The method of claim 1 , wherein the upper primer insert portion comprises a polymer, a metal, an alloy, or a ceramic alloy and the lower primer insert portion comprises a different polymer, metal, alloy, or ceramic alloy.

7. The method of claim 1 , wherein the upper primer insert portion and the lower primer insert portion comprise steel, nickel, chromium, copper, carbon, iron, stainless steel or brass.

8. The method of claim 1 , further comprising a flash hole groove that extends circumferentially about the upper primer aperture or the lower primer aperture.

9. The method of claim 1 , wherein the first polymer composition, the second polymer composition or both independently comprise a nylon polymer.

10. The method of claim 1 , wherein the first polymer composition, the second polymer composition or both independently comprise between about 10 and about 70 wt % glass fiber fillers, mineral fillers, or mixtures thereof.

11. The method of claim 1 , wherein the first polymer composition, the second polymer composition or both independently comprise polyurethane prepolymer, cellulose, fluoro-polymer, ethylene inter-polymer alloy elastomer, ethylene vinyl acetate, nylon, polyether imide, polyester elastomer, polyester sulfone, polyphenyl amide, polypropylene, polyvinylidene fluoride or thermoset polyurea elastomer, acrylics, homopolymers, acetates, copolymers, acrylonitrile-butadinen-styrene, thermoplastic fluoro polymers, inomers, polyamides, polyamide-imides, polyacrylates, polyatherketones, polyaryl-sulfones, polybenzimidazoles, polycarbonates, polybutylene, terephthalates, polyether imides, polyether sulfones, thermoplastic polyimides, thermoplastic polyurethanes, polyphenylene sulfides, polyethylene, polypropylene, polysulfones, polyvinylchlorides, styrene acrylonitriles, polystyrenes, polyphenylene, ether blends, styrene maleic anhydrides, polycarbonates, allyls, aminos, cyanates, epoxies, phenolics, unsaturated polyesters, bismaleimides, polyurethanes, silicones, vinylesters, urethane hybrids, polyphenylsulfones, copolymers of polyphenylsulfones with polyethersulfones or polysulfones, copolymers of poly-phenylsulfones with siloxanes, blends of polyphenylsulfones with polysiloxanes, poly(etherimide-siloxane) copolymers, blends of polyetherimides and polysiloxanes, and blends of polyetherimides and poly(etherimide-siloxane) copolymers.

12. The method of claim 1 , wherein the bullet aperture comprises one or more cannelures formed on an inner circumferential surface of the bullet aperture.

13. The method of claim 1 , wherein the bullet aperture accepts a .221, .223, .243, .25-06, .264, .270, .300, .308, .338, .30-30, .30-06, .45-70 or .50-90, 50 caliber, 45 caliber, 380 caliber or 38 caliber, 5.56 mm, 6 mm, 7 mm, 7.62 mm, 8 mm, 9 mm, 10 mm, 12.7 mm, 14.5 mm, 14.7 mm, 20 mm, 25 mm, 30 mm, 40 mm, 57 mm, 60 mm, 75 mm, 76 mm, 81 mm, 90 mm, 100 mm, 105 mm, 106 mm, 115 mm, 120 mm, 122 mm, 125 mm, 130 mm, 152 mm, 155 mm, 165 mm, 175 mm, 203 mm or 460 mm, 4.2 inch or 8 inch projectile.

14. The method of claim 1 , wherein the projectile has a frustoconical shaped nose.

15. A method of making a polymer ammunition having a two piece primer insert comprising by the steps of:
forming the two piece primer insert comprising the steps of:
forming an upper primer insert portion comprising an upper primer bottom surface, an upper primer aperture through the upper primer bottom surface; a substantially cylindrical coupling element extending away from the upper primer bottom surface, and an interior surface inside the substantially cylindrical coupling element;
forming a lower primer insert portion comprising a lower primer bottom surface opposite a lower primer top surface, a primer recess in the lower primer top surface that extends toward the lower primer bottom surface and the primer recess adap

Assignees

• True Velocity Inc

Inventors

• Burrow Lonnie

Classifications

• F42B33/04

  Fitting or extracting primers in or from fuzes or charges {(F42B33/004 takes precedence)} · CPC title

• F42C19/083 Primary

  characterised by the shape and configuration of the base element embedded in the cartridge bottom, e.g. the housing for the squib or percussion cap · CPC title

• F42B5/30

  of plastics {, i.e. the cartridge-case tube is of plastics} · CPC title

• F42B5/313 Primary

  all elements made of plastics · CPC title

• F42B33/001

  Devices or processes for assembling ammunition, cartridges or cartridge elements from parts · CPC title