US-20260126277-A1 - POLYMERIC CARTRIDGE ASSEMBLY

US20260126277A1US 20260126277 A1US20260126277 A1US 20260126277A1US-20260126277-A1

Abstract

A polymeric cartridge subassembly for use in medium caliber weaponry, comprising a metallic base having a rearward surface, an open forward surface, and a coupling element therebetween. A polymeric casing is mated with the base coupling element via a coupling end, and includes a forward end opening, an opposite end, and a middle body portion therebetween. The forward end opening is adapted to receive a projectile, and the coupling end has an outer diameter less than that of the middle body portion to facilitate mating with the base coupling element. The polymeric casing is formed from a graphene-reinforced polymer matrix composite which is light-weight; producing necessary ballistics for medium caliber ammunition without deformation of the polymeric casing after firing.

Inventors

Vincent Battaglia

Assignees

Vincent Battaglia

Dates

Publication Date: 20260507
Application Date: 20241030

Claims (20)

1 . A polymeric cartridge subassembly for use in medium caliber weaponry, comprising: a metallic base having a rearward surface, an open forward surface, and a coupling element therebetween, the rearward surface including a primer recess for receiving a primer, the primer recess having an opening extending into an interior portion of the subassembly forming a combustion chamber; a polymeric casing having a forward end opening, an opposite end, a middle body portion therebetween, and a shoulder portion for couplable engagement with the metallic base open forward surface such that a ledge member of the metallic base receives the casing opposite end during subassembly, the forward end opening adapted to receive a projectile, the opposite end forming a coupling end sized to and being mated with the base coupling element; and a retaining insert received within a combustion chamber of the polymeric casing, the retaining insert ensuring engagement between the polymeric casing and the metallic base.
2 . The polymeric cartridge subassembly of claim 1 , wherein the graphene-reinforced polymer matrix composite is formed from a thermoplastic selected from the group consisting of: high density polyethylene, polyethylene terephthalate, polystyrene, polyamide 6-6, polysulfone, polyphenylene sulfide, and polyether-ether-ketone.
3 . The polymeric cartridge subassembly of claim 1 , wherein the polymeric casing formed from a graphene-reinforced polymer matrix composite.
4 . The polymeric cartridge subassembly of claim 1 wherein said retaining insert comprises a bottom surface having an approximately central primer port opening.
5 . The polymeric cartridge subassembly of claim 1 wherein said retaining insert includes a contoured region for mating with said base, and a cylindrical extension member having a first diameter and extending from said contoured region terminating in an undulation and rim end, wherein said rim end having a second diameter greater than said first diameter.
6 . The polymeric cartridge subassembly of claim 1 , wherein the base includes a plurality of apertures disposed around an arch length of the base and in communication with the combustion chamber of the polymeric casing, and a mechanical fastening member received in each of the plurality of apertures forming a compression assembly between the polymeric casing, the metallic base, and the retaining insert.
7 . The polymeric cartridge subassembly of claim 6 wherein said retaining insert includes one or more openings for communication with said plurality of apertures on said base, such that said complementary apertures are disposed around an arch length of the base and in communication with the combustion chamber of the polymeric casing.
8 . The polymeric cartridge subassembly of claim 7 , including a mechanical fastening member received in at least one of said plurality of apertures on said base, forming a compression assembly between the polymeric casing, the metallic base, and the retaining insert.
9 . The polymeric cartridge subassembly of claim 1 wherein the forward end opening includes at least one protrusion on an interior surface and extending radially inwards towards the polymeric casing.
10 . The polymeric cartridge subassembly of claim 9 , wherein the at least one protrusion comprises an Acme thread pattern and a tear perf at a root of the Acme thread pattern.
11 . The polymeric cartridge subassembly of claim 1 , wherein the subassembly comprises a medium caliber ammunition subassembly for use with medium handheld, crew-served, ground, platform, and aircraft mounted weapons.
12 . A polymeric cartridge subassembly for use in medium caliber weaponry, comprising: a metallic base having a rearward surface, an open forward surface, and a coupling element therebetween, the rearward surface including a primer recess for receiving a primer, the primer recess having an opening extending into an interior portion of the base; a polymeric casing having a forward end opening, an opposite end, and a middle body portion therebetween, the forward end opening adapted to receive a projectile, the coupling end sized to and being mated with the base coupling element, and wherein the polymeric casing includes a shoulder portion for couplable engagement with the metallic base forward surface such that a ledge member of the metallic base receives the casing opposite end during subassembly; and a retaining insert received within a combustion chamber of the polymeric casing, the retaining insert ensuring engagement between the polymeric casing and the metallic base, wherein said retaining insert includes a contoured region for mating with said base, and a cylindrical extension member having a first diameter and extending from said contoured region terminating in an undulation and rim end, wherein said rim end having a second diameter greater than said first diameter.
13 . The polymeric cartridge subassembly of claim 12 , wherein the polymeric casing is formed from a graphene-reinforced polymer matrix composite.
14 . The polymeric cartridge subassembly of claim 13 , wherein the graphene-reinforced polymer matrix composite comprises 35% graphite in 65% polyether-ether-ketone (PEEK) polymer that has been fully exfoliated.
15 . The polymeric cartridge subassembly of claim 13 , wherein the graphene-reinforced polymer matrix composite comprises 20% graphite in 80% polyphenylene sulfide (PPS) that has been fully exfoliated.
16 . The polymeric cartridge subassembly of claim 13 , wherein the graphene-reinforced polymer matrix composite is formed from a thermoplastic selected from the group consisting of: high density polyethylene, polyethylene terephthalate, polystyrene, polyamide 6-6, polysulfone, polyphenylene sulfide, and polyether-ether-ketone.
17 . The polymeric cartridge subassembly of claim 12 , wherein the base includes a plurality of apertures disposed around an arch length of the base and in communication with the combustion chamber of the polymeric casing, and a mechanical fastening member received in each of the plurality of apertures forming a compression assembly between the polymeric casing, the metallic base, and the retaining insert.
18 . A method of assembling a polymeric cartridge for use in medium caliber weaponry, the method comprising the steps of: securing a coupling end of a polymeric casing to a coupling element of a metallic base such that the coupling element encapsulates an interior combustion chamber of the polymeric casing, and the base includes a plurality of apertures disposed around an arch length of the base and in communication with the combustion chamber of the polymeric casing; inserting a primer into a primer recess of the base; inserting a propellant charge within the combustion chamber; and seating a projectile onto a forward end opening of the polymeric casing to encapsulate the combustion chamber, wherein the polymeric casing is formed from a graphene-reinforced polymer matrix composite; inserting a retaining insert within the combustion chamber.
19 . The method of claim 18 , further comprising the steps of: securing a mechanical fastening member within each of a plurality of apertures disposed on an arch length of the base such that the mechanical fastening member is received by the retaining stamping and the base; and forming a compression assembly between the casing, the base, and the retaining insert.
20 . The method of claim 18 , wherein the forward end opening includes at least one protrusion on an interior surface to ensure a contact point with the projectile and a predetermined cartridge overall length elevation during assembly.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates in general to the field of ammunition, and more specifically to a polymeric ammunition cartridge casing for use with medium caliber ammunition. 2. Description of the Related Art Medium Caliber Ammunition (hereinafter, “MCA”) includes 20 mm, 25 mm, 30 mm, and 40 mm Armor-Piercing (AP), High-Explosive (HE), smoke, illumination, training, and antipersonnel cartridges, and is designed to defeat light armor, materiel, and personnel targets. Generally, medium caliber weapons utilizing MCA are installed on military aircraft, helicopters, main battle tanks, infantry fighting vehicles, armored personnel carriers, and the like. In order to achieve necessary projectile velocities, prior art MCA casings are constructed of metals and metal alloys, such as aluminum metal, copper, aluminum alloy, and the like. Current 20 mm and 30 mm MCA case manufacturing entails manufacturing processes that are equipment intensive as well as expensive. The manufacturing processes include forging and draw form stamping for the creation of MCA within steel or aluminum cases. Additional machining or trimming operations are also necessitated to complete the ammunition case. As a result, bottlenecks and/or shortages can arise during the operation of traditional manufacturing processes. These shortages are often amplified due to limitations on manufacturing capacity or the availability of raw material. FIG. 1 depicts a cross-sectional view of a prior art MCA case. The geometry of the internal base of current MCA casings (such as 30×113 mm MCA casings) often stems from constraints in the manufacturing process, including a needed forging profile to achieve appropriate cartridge density or transfer material for an external feature. In order to produce velocities required for proper ballistic operation of the MCA, there is a heavy dependency on the quantity of the propellant charge. This, as a result, creates further issues with manufacturing bottlenecking and/or shortages within the MCA supply chain. In addition, current MCA casings constructed of lighter weight metals, such as aluminum, are often mass-intensive when considering a complete payload. By way of example, a complete 30×113 mm medium caliber round will have a mass on the order of 340 g (0.75 lbs), resulting in strain on the equipment housing the complete payload which decreases battle efficiency and increases military resource consumption. In U.S. Pat. No. 11,479,653 issued to Rutgers, The State University of New Jersey on Oct. 25, 2022, titled “USE OF GRAPHENE-POLYMER COMPOSITES TO IMPROVE BARRIER RESISTANCE OF POLYMERS TO LIQUID AND GAS PERMEANTS,” a packaging material is taught that uses a graphene-reinforced polymer matrix composite (G-PMC). The G-PMC is produced using a plastic material comprising graphene nano-flakes which produces improved barrier property, mechanical properties, and durability. Like other polymers, G-PMCs possess a number of desirable physical properties, are lightweight, and inexpensive. Therefore, it would be desirous to achieve an MCA casing of reduced mass, while also increasing the performance, velocity, and burn rate efficiency of produced from MCA casings. It would further be desirable to employ a parallel manufacturing process that is scalable for the entire inventory of MCA cases of all sizes and neck types to facilitate integration into existing manufacturing facilities. SUMMARY OF THE INVENTION Bearing in mind the problems and deficiencies of the prior art, it is therefore an object of the present invention to provide MCA casings of decreased mass. It is another object of the present invention to raise performance, velocity, and burn rate efficiency produced from MCA casings. A further object of the invention is to provide a parallel manufacturing process that is scalable for the entire inventory of MCA casings of all sizes and neck types to facilitate integration into existing manufacturing facilities. Still other objects and advantages of the invention will in part be obvious and will in part be apparent from the specification. The above and other objects, which will be apparent to those skilled in the art, are achieved in the present invention which is directed to a polymeric cartridge subassembly for use in medium caliber weaponry. The subassembly comprises a metallic base having a rearward surface, an open forward surface, and a coupling element therebetween. The rearward surface includes a primer recess for receiving a primer, the primer recess having an opening extending into an interior portion of the subassembly forming a combustion chamber. A polymeric casing is securable to the metallic base and includes a forward end opening, an opposite end, and a middle body portion therebetween. The forward end opening may be adapted to receive a projectile, the opposite end forming a coupling end sized to and being mated with the base coupling element. The polymeric c