Base Insert for Polymer Ammunition Cartridges

• US 20140373744A1
• Filed: 09/10/2014
• Published: 12/25/2014
• Est. Priority Date: 07/30/2010
• Status: Active Grant

• Current Assignee: Pcp Tactical, LLC
• Original Assignee: Pcp Tactical, LLC
• Inventors: PADGETT, Charles, WILEY, Sy
• Granted Patent: US 9,599,443 B2
• Time in Patent Office: Days
• US Class Current: 102/466
• CPC Class Codes: B29C 65/72 by combined operations or combined techniques, e.g. welding and stitching
• CPC Class Codes: B29C 69/001 a shaping technique combined with cutting, e.g. in parts or slices combined with rearranging and joining the cut parts for reinforced material B29C70/545; B29C49/4278, B29C51/268 take precedence
• CPC Class Codes: B29K 2096/00 Use of specified macromolecular materials not provided for in a single one of main groups B29K2001/00 - B29K2095/00, as moulding material
• CPC Class Codes: B29L 2031/7772 Cartridges
• CPC Class Codes: F42B 3/24 Cartridge closures or seals top closures for shotgun ammunition cartridges F42B7/12
• 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 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 19/083 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
• CPC Class Codes: F42C 19/10 Percussion caps

Abstract

An insert for a high strength polymer-based cartridge casing can include an outside, an inside formed within the insert, and a back end disposed at a rear of the cartridge casing. The back end includes a rim and groove disposed around the outside of the insert and a primer pocket disposed inside the back end. Also included is a front end, opposite the back end, having an overmolded area disposed around the outside of the insert above the primer pocket and a basin, having a depth, formed inside the overmolded area. A flash hole can be included inside the insert and communicating between the primer pocket and the basin. The flash hole has a perimeter and a ring disposed around the perimeter of the flash hole, including a height starting at a bottom of the basin, disposed toward the front end, and less than the depth of the basin.

Claims

1. An insert for a high strength polymer-based cartridge casing comprising:

an outside;

an inside formed within the insert;

a back end disposed at a rear of the cartridge casing, comprising;

a rim and groove disposed around the outside of the insert; and

a primer pocket disposed inside the back end;

a front end, opposite the back end, comprising;

an overmolded area disposed around the outside of the insert above the primer pocket; and

a basin, having a depth, formed inside the overmolded area;

a flash hole, inside the insert and communicating between the primer pocket and basin, comprising a perimeter; and

a ring disposed around the perimeter of the flash hole, comprising a height starting at a bottom of the basin, disposed toward the front end, and less than the depth of the basin.

2. The insert of claim 1, wherein the overmolded area comprises a ridge.

3. The insert of claim 2, wherein the ridge comprises one or more keys.

4. The insert of claim 3, wherein the keys are flat surfaces on the ridge.

5. The insert of claim 1, wherein the overmolded area comprises knurling.

6. The insert of claim 1, wherein the groove and the rim are dimensioned to a size dictated by a caliber of a projectile loaded in the cartridge casing.

7. The insert of claim 1, further comprising a belt disposed on the outside of the insert and between the overmolded area and groove.

8. The insert of claim 1, further comprising a radiused portion at the front end of the insert and inside the overmolded area.

9. A high strength polymer-based cartridge casing comprising:

an upper component, molded from a polymer, comprising;

a first end having a mouth;

at least a wall between the first end and a second end of the upper component opposite the first end; and

an overlap portion extending from the wall near the second end;

a lower component, molded from a polymer, comprising;

a tapered portion that engages the overlap portion to join the upper and the lower components;

an outer sheath disposed opposite the tapered portion; and

a lower bowl disposed between the tapered portion and the outer sheath having a hole therethrough;

an insert comprising;

a rim disposed at one end of the insert;

an overmolded area formed opposite the rim and engaging the outer sheath to join the insert to the lower component, and

a ring formed on an inside of the overmolded area and extending into the hole of the lower component.

10. The high strength polymer-based cartridge casing of claim 9, wherein the insert further comprises:

a ridge formed on the overmolded area; and

a key formed on the ridge;

wherein both the ridge and the key engage the outer sheath, and wherein the key comprises at least one of a flat portion, a raised portion, or dimples.

11. The high strength polymer-based cartridge casing of claim 9, wherein the lower bowl and the outer sheath compress against a portion of the overmolded area when under pressure.

12. A method of making a high strength polymer-based cartridge casing comprising the steps of:

machining an insert having a primer pocket, a flash hole, a ring, and an overmolded area; and

molding a lower component using a polymer comprising the steps of;

molding the polymer over the overmolded area of the insert; and

stopping the polymer at the ring.

13. The method of claim 12, further comprising the steps of:

molding an upper component using a polymer, comprising;

a first end having a mouth; and

a second end opposite the first end; and

bonding the lower component to the upper component at the second end.