HIGH STRENGTH POLYMER-BASED CARTRIDGE CASING AND MANUFACTURING METHOD

• US 20120180688A1
• Filed: 01/13/2012
• Published: 07/19/2012
• Est. Priority Date: 01/14/2011
• Status: Active Grant

• Current Assignee: Pcp Tactical, LLC
• Original Assignee: Pcp Ammunition Company LLC
• Inventors: Padgett, Charles
• Granted Patent: US 8,443,730 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

A high strength polymer-based cartridge casing can include a first end having a mouth and a neck extending away from the mouth. Next, a shoulder extends below the neck and away from the first end. The cartridge can be have a frangible portion capable of being split upon discharge of a projectile. The shoulder can have unequal outside and inside shoulder angles. The casing can also include an insert having a rim at one end or a plurality of ribs extending longitudinally along a wall between the shoulder and the bottom of the cartridge and spaced radially from each other around a circumference of the wall. A projectile can be disposed in the mouth and a relief can be disposed on the neck near the mouth and projectile. The relief can form a gap between the neck and the projectile to receive an adhesive.

Claims

1. A high strength polymer-based cartridge casing inclosing a volume, comprising:

a first end having a mouth;

a neck extending away from the mouth;

a shoulder extending below the neck and away from the first end;

a projectile disposed in the mouth; and

a frangible portion disposed on the neck capable of being split upon discharge of the projectile;

wherein the split of the frangible portion prevents a second projectile from being disposed in the mouth.

2. The high strength polymer-based cartridge casing of claim 1, wherein the frangible portion is disposed on one of an inside and an outside of the casing.

3. The high strength polymer-based cartridge casing of claim 1, wherein the frangible portion extends to approximately the shoulder.

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

molding a component using a polymer, comprising;

a first end having a mouth; and

a second end opposite the first end;

molding a neck extending away from the mouth;

molding a shoulder extending below the neck and away from the first end; and

forming a frangible portion on the neck capable of being split.

5. The method of making a high strength polymer-based cartridge casing of claim 4, wherein the forming the frangible portion step comprises forming the frangible portion on at least one of an inside and an outside of the neck.

6. The method of making a high strength polymer-based cartridge casing of claim 4, wherein the forming the frangible portion step comprises forming the frangible portion approximately to the shoulder.

7. A high strength polymer-based cartridge casing enclosing a volume, comprising:

a first end having a mouth;

a neck extending away from the mouth;

a shoulder extending below the neck and away from the first end, comprising;

an outside shoulder sloped at an outside shoulder angle in relation to a center axis extending longitudinally along the cartridge and passing through a center of the mouth,

an inside shoulder sloped at an inside shoulder angle in relation to the center axis, and separated from the outside shoulder by a shoulder thickness,

wherein the outside shoulder angle and the inside shoulder angle are not equal, and

wherein the inside shoulder does not contact a base of a projectile disposed within the neck of the cartridge casing.

8. The high strength polymer-based cartridge casing of claim 7, wherein the inside shoulder angle is one of less than and greater than the outside shoulder angle.

9. The high strength polymer-based cartridge casing of claim 7, wherein the shoulder thickness is formed between the outer shoulder and the inner shoulder and

wherein the shoulder thickness varies along lengths of the inner and outer shoulders.

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

molding a component using a polymer, comprising;

a first end having a mouth; and

a second end opposite the first end;

molding a neck extending away from the mouth;

molding a shoulder extending below the neck and away from the first end, comprising the steps of;

forming an outside shoulder sloped at an outside shoulder angle in relation to a center axis extending longitudinally along the cartridge and passing through a center of the mouth,

forming an inside shoulder sloped at an inside shoulder angle in relation to the center axis, and separated from the outside shoulder by a shoulder thickness, and uniform over a circumference of the cartridge casing;

setting the outside shoulder angle to not equal the inside shoulder angle.

11. The method of making a high strength polymer-based cartridge casing of claim 10, wherein the setting step further comprises the step of setting the inside shoulder angle to be one of less than and greater than the outside shoulder angle.

12. The method of making a high strength polymer-based cartridge casing of claim 10, further comprising the step of forming the shoulder thickness between the outer shoulder and the inner shoulder, and wherein the forming the shoulder thickness step comprises the step of varying the shoulder thickness along lengths of the inner and outer shoulders.

13. 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.

14. The high strength polymer-based cartridge casing of claim 13, 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.

15. The high strength polymer-based cartridge casing of claim 13, wherein the lower bowl and the outer sheath compress against a portion of the overmolded area when under pressure.

16. 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;

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;

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.

17. 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;

a plurality of ribs extending longitudinally about a length of the wall and spaced radially from each other around a circumference of the wall; 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; and

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

18. The high strength polymer-based cartridge casing of claim 17, wherein the insert further comprises a ring formed on an inside of the overmolded area and extending into the hole of the lower component.

19. A high strength polymer-based cartridge casing inclosing a volume, comprising:

a first end having a mouth;

a neck extending away from the mouth;

a shoulder extending below the neck and away from the first end;

a projectile disposed in the mouth; and

a relief disposed on the neck proximate to the mouth;

wherein the relief forms a gap between the neck and the projectile, and

wherein the gap is configured to receive an adhesive.