METHOD OF MAKING LIGHTWEIGHT POLYMER AMMUNITION

• US 20160033246A1
• Filed: 08/04/2015
• Published: 02/04/2016
• Est. Priority Date: 11/10/2010
• Status: Active Grant

• Current Assignee: Velocity Holdings LLC (Centerpoint Energy Incorporated)
• Original Assignee: True Velocity, Inc.
• Inventors: Burrow, Lonnie
• Granted Patent: US 9,441,930 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B22F 1/108 Mixtures obtained by warm mixing
• CPC Class Codes: B22F 2998/10 Processes characterised by the sequence of their steps
• CPC Class Codes: B22F 3/004 Filling molds with powder feeding material to presses in general B30B15/302
• CPC Class Codes: B22F 3/10 Sintering only
• CPC Class Codes: B22F 3/1021 Removal of binder or filler removal of binder from ceramics C04B35/638
• CPC Class Codes: B22F 3/1025 not by heating only
• CPC Class Codes: B22F 3/225 by injection molding
• CPC Class Codes: B22F 5/00 Manufacture of workpieces or articles from metallic powder characterised by the special shape of the product
• CPC Class Codes: B22F 5/06 of threaded articles, e.g. nuts
• CPC Class Codes: B22F 9/04 starting from solid material, e.g. by crushing, grinding or milling C22C1/1084 takes precedence; crushing, grinding or milling, in general, see the relevant subclasses, e.g. B02C
• CPC Class Codes: C04B 35/64 Burning or sintering processes C04B33/32 takes precedence ; powder metallurgy B22F
• CPC Class Codes: C22C 1/0458 Alloys based on titanium, zirconium or hafnium
• CPC Class Codes: C22C 14/00 Alloys based on titanium
• CPC Class Codes: C22C 33/0257 characterised by the range of the alloying elements
• CPC Class Codes: C22C 33/0285 with Cr, Co, or Ni having a minimum content higher than 5%
• CPC Class Codes: C22C 38/02 containing silicon
• CPC Class Codes: C22C 38/04 containing manganese
• CPC Class Codes: C22C 38/18 containing chromium
• CPC Class Codes: C22C 38/42 with copper
• CPC Class Codes: C22C 38/44 with molybdenum or tungsten
• CPC Class Codes: C22C 38/48 : with niobium or tantalum
• CPC Class Codes: C22C 38/58 : with more than 1.5% by weight of manganese
• CPC Class Codes: F42B 33/00 : Manufacture of ammunition; Dismantling of ammunition; Apparatus therefor F42B5/188 takes precedence; manufacturing processes for hollow charges F42B1/036; manufacture of blasting cartridge initiators F42B3/195
• CPC Class Codes: F42B 33/001 : Devices or processes for assembling ammunition, cartridges or cartridge elements from parts
• CPC Class Codes: F42B 33/02 : Filling cartridges, missiles, or fuzes; Inserting propellant or explosive charges F42B33/004 takes precedence
• CPC Class Codes: F42B 33/04 : Fitting or extracting primers in or from fuzes or charges F42B33/004 takes precedence
• CPC Class Codes: F42B 5/02 : Cartridges, i.e. cases with charge and missile
• CPC Class Codes: F42B 5/025 : characterised by the dimension of the case or the missile
• 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
• CPC Class Codes: F42B 5/313 : all elements made of plastics
• CPC Class Codes: F42C 19/0807 : characterised by the particular configuration of the transmission channels from the priming energy source to the charge to be ignited, e.g. multiple channels, nozzles, diaphragms or filters
• CPC Class Codes: F42C 19/0823 : Primers or igniters for the initiation or the propellant charge in a cartridged ammunition primers for caseless ammunition F42C19/085
• CPC Class Codes: F42C 19/083 : 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

Abstract

One embodiment of the present invention provides a method of making a polymeric ammunition cartridge having a substantially cylindrical metal primer insert, a substantially cylindrical polymeric middle body coupled to a substantially cylindrical open-ended polymeric bullet-end component.

Claims

1. A method of making a polymeric ammunition cartridge having a substantially cylindrical metal primer insert comprising the steps of:

providing a substantially cylindrical insert comprising a top surface opposite a bottom surface and a substantially cylindrical coupling element that extends from the bottom surface to form a circumferential surface, a primer recess in the top surface that extends toward the bottom surface, a primer flash hole aperture positioned in the primer recess to extend through the bottom surface, and a flange that extends circumferentially about an outer edge of the top surface;

forming a substantially cylindrical polymeric middle body comprising the steps of overmolding a polymer composition over the substantially cylindrical insert by molding the polymer composition over the substantially cylindrical coupling element, over the circumferential surface and into the primer flash hole aperture to form a primer flash hole, forming a substantially cylindrical polymeric middle body extending from the substantially cylindrical insert, and forming a substantially cylindrical polymeric coupling end at the end of the substantially cylindrical polymeric middle body;

forming a substantially cylindrical open-ended polymeric bullet-end component comprising the steps of forming a polymeric bullet-end coupling component opposite a bullet-end aperture from a second polymer composition, wherein the polymeric bullet-end coupling component mates to the substantially cylindrical polymeric coupling end; and

adhering the polymeric bullet-end coupling component mates to the substantially cylindrical polymeric coupling end to form a propellant chamber having a bullet-end aperture opposite a primer flash hole.

2. The method of claim 1, wherein the substantially cylindrical open-ended polymeric bullet-end component comprises a shoulder positioned between the substantially cylindrical polymeric bullet-end and the bullet-end aperture and a neck positioned between the shoulder and the bullet-end aperture.

3. The method of claim 1, wherein the substantially cylindrical open-ended polymeric bullet-end component, substantially cylindrical polymeric middle body or both are formed from a ductile polymer.

4. The method of claim 1, wherein the substantially cylindrical open-ended polymeric bullet-end component is formed from a less ductile polymer than the substantially cylindrical polymeric middle body.

5. The method of claim 1, wherein the substantially cylindrical open-ended polymeric bullet-end component, substantially cylindrical polymeric middle body or both comprise a nylon polymer.

6. The method of claim 1, wherein the substantially cylindrical open-ended polymeric bullet-end component, substantially cylindrical polymeric middle body or both are formed from a fiber-reinforced polymeric composite.

7. The method of claim 6, wherein the fiber-reinforced polymeric composite contains between about 10 and about 70 wt % glass fiber fillers, mineral fillers, or mixtures thereof.

8. The method of claim 1, wherein the polymeric bullet-end coupling component mates is welded or bonded to the substantially cylindrical polymeric coupling end.

9. The method of claim 1, wherein bullet-end aperture is welded or bonded to the bullet.

10. The method of claim 1, wherein the bullet-end aperture is crimped to the bullet.

11. The method of claim 1, wherein a bullet is adhesively fitted to the bullet-end aperture.

12. The method of claim 1, wherein the bullet-end aperture comprises one or more cannelures that interlocks with the bullet.

13. The method of claim 2, wherein the neck comprises one or more cannelures that interlocks with the bullet.

14. The method of claim 1, wherein the forward opening end comprises one, two, three, or more annular rings that mate with one, two, three, or more corresponding annular grooves positioned on the bullet.

15. The method of claim 1, wherein the polymer composition and the second polymer composition independently comprise a polymers selected from the group consisting of 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.

16. The method of claim 1, wherein the substantially cylindrical open-ended polymeric bullet-end component comprises a neck with a plurality of internal structures for supporting a bullet.

17. The method of claim 1, wherein the substantially cylindrical coupling element is a male coupling element with a straight skirt interlock surface that tapers to a smaller diameter at the forward portion on the skirt tip to mate with a female coupling element of the substantially cylindrical polymeric coupling end.

18. The method of claim 1, further comprising a diffuser positioned in the primer recess in contact with the primer and comprising a diffuser flash hole aligned with the primer flash hole.

19. A method of making a polymeric ammunition having a substantially cylindrical metal primer insert comprising the steps of:

providing a substantially cylindrical insert comprising a top surface opposite a bottom surface and a substantially cylindrical coupling element that extends from the bottom surface to form a circumferential surface, a primer recess in the top surface that extends toward the bottom surface, a primer flash hole aperture positioned in the primer recess to extend through the bottom surface, and a flange that extends circumferentially about an outer edge of the top surface;

forming a substantially cylindrical polymeric middle body comprising the steps of overmolding a polymer composition over the substantially cylindrical insert by molding the polymer composition over the substantially cylindrical coupling element, over the circumferential surface and into the primer flash hole aperture to form a primer flash hole, forming a substantially cylindrical polymeric middle body extending from the substantially cylindrical insert, and forming a substantially cylindrical polymeric coupling end at the end of the substantially cylindrical polymeric middle body;

forming a substantially cylindrical open-ended polymeric bullet-end component comprising the steps of forming a polymeric bullet-end coupling component opposite a bullet-end aperture from a second polymer composition, wherein the polymeric bullet-end coupling component mates to the substantially cylindrical polymeric coupling end;

adhering the polymeric bullet-end coupling component mates to the substantially cylindrical polymeric coupling end to form a propellant chamber having a bullet-end aperture opposite a primer flash hole;

inserting a primer inserted into the primer flash hole aperture;

at least partially filling the propellant chamber with a propellant; and

frictionally fitting a bullet in the bullet-end aperture, wherein the primer, the propellant and the bullet form a sealed propellant chamber.