Variable inside shoulder polymer cartridge

• US 8,869,702 B2
• Filed: 12/19/2012
• Issued: 10/28/2014
• Est. Priority Date: 01/14/2011
• Status: Active Grant

• Current Assignee: Pcp Tactical, LLC
• Original Assignee: Pcp Tactical, LLC
• Inventors: Padgett, Charles
• Primary Examiner(s): Hayes, Bret
• Assistant Examiner(s): MORGAN, DERRICK R
• Application Number:
  US13/720,430
• Publication Number:
  US 20140060372A1
• Time in Patent Office: 678 Days
• Field of Search: 102/430, 102/439, 102/440, 102/441, 102/464, 102/465, 102/466, 102/467
• US Class Current: 102/466
• 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 5/067 Mounting or locking missiles in cartridge cases F42B5/18 takes precedence
• 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

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. An inside of the shoulder can be shaped in at least one of a convex or concave shape. The shoulder can have unequal outside and inside shoulder angles. Further, the inside shoulder can be textured or coated.

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, and

a propellant chamber extending below the shoulder, opposite the neck;

wherein the shoulder comprises;

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 shaped concave, and separated from the outside shoulder by a shoulder thickness,

wherein the shoulder thickness varies along the length of the shoulder,

wherein the neck permits a base of a projectile to extend into the propellant chamber past at least a portion of the inside shoulder, and

wherein the neck comprises a uniform inside diameter from the mouth to the inside shoulder.

2. The high strength polymer-based cartridge casing of claim 1,

wherein the inside shoulder is sloped at an inside shoulder angle in relation to the center axis, and

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

3. The high strength polymer-based cartridge casing of claim 1, wherein the inside shoulder angle is one of less than and greater than the outside shoulder angle.

4. The high strength polymer-based cartridge casing of claim 1, wherein the inside shoulder comprises a texture.

5. 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 molding a propellant chamber extending below the shoulder, opposite the neck, wherein molding the shoulder comprises 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 which varies along the length of the shoulder, and uniform over a circumference of the cartridge casing; and

shaping the inside shoulder to a concave shape, and

wherein molding the neck includes the steps of;

forming the neck to allow a projectile to extend into the propellant chamber past a portion of the inside shoulder, and creating uniform inside diameter from the mouth to the inside shoulder.

6. The method of making a high strength polymer-based cartridge casing of claim 5, wherein the setting step further comprises the step of setting the outside shoulder angle to not equal the inside shoulder angle.

7. The method of making a high strength polymer-based cartridge casing of claim 6, 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.

8. The method of making a high strength polymer-based cartridge casing of claim 5, further comprising the step of forming a texture on the inner shoulder.

9. 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, and

a propellant chamber extending below the shoulder, opposite the neck;

wherein the shoulder comprises;

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 shaped convex, and separated from the outside shoulder by a shoulder thickness,

wherein the shoulder thickness varies along the length of the shoulder, wherein the neck permits a base of a projectile to extend into the propellant chamber past at least a portion of the inside shoulder.

10. The high strength polymer-based cartridge casing of claim 9,

wherein the inside shoulder is sloped at an inside shoulder angle in relation to the center axis, and

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

11. The high strength polymer-based cartridge casing of claim 9, wherein the inside shoulder angle is one of less than and greater than the outside shoulder angle.

12. The high strength polymer-based cartridge casing of claim 9, wherein the inside shoulder comprises a texture.

13. 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, comprising a inside neck wall and an outside neck wall;

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

molding a propellant chamber extending below the shoulder, opposite the neck,

wherein molding the shoulder comprises 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 which varies along the length of the shoulder, and uniform over a circumference of the cartridge casing; and

shaping the inside shoulder to a convex shape, and

wherein molding the neck includes the step of forming the neck to allow a projectile to extend into the propellant chamber past a portion of the inside shoulder.

14. The method of making a high strength polymer-based cartridge casing of claim 13, wherein the setting step further comprises the step of setting the outside shoulder angle to not equal the inside shoulder angle.

15. The method of making a high strength polymer-based cartridge casing of claim 14, 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.

16. The method of making a high strength polymer-based cartridge casing of claim 13, further comprising the step of forming a texture on the inner shoulder.