Reduced energy cartridge

• US 5,492,063 A
• Filed: 10/31/1994
• Issued: 02/20/1996
• Est. Priority Date: 03/22/1990
• Status: Expired due to Term

• Current Assignee: General Dynamics Ordnance and Tactical Systems Incorporated (General Dynamics Corporation)
• Original Assignee: SNC Industrial Technologies Incorporated, SNC Industrial Technologies Incorporated /LES Technologies Industrielles SNC Incorporated
• Inventors: Dittrich, William A.
• Primary Examiner(s): TUDOR, HAROLD JAY
• Application Number:
  US08/331,969
• Time in Patent Office: 477 Days
• Field of Search: 102/430, 102/434, 102/439, 102/444, 102/445, 102/446, 102/447, 102/464, 102/466, 102/467, 102/469, 102/470, 102/472, 102/530, 102/531, 89/179, 89/14.5
• US Class Current: 102/430
• CPC Class Codes: F42B 14/064 Sabots enclosing the rear end of a kinetic energy projectile, i.e. having a closed disk shaped obturator base and petals extending forward from said base
• CPC Class Codes: F42B 5/02 Cartridges, i.e. cases with charge and missile

Abstract

A two part cartridge has a rearwardly recoiling inner piston and a choked orifice at its forward end to develop a blow-back thrust that will cycle a recoil operated automatic firearm. The piston itself may serve to contain propellant and preferably contains all propellant within the cartridge.

Claims

1. A cartridge for use in a recoil-operated, automatic cycling, firearm, said cartridge comprising:

(a) a cartridge case with a rearward cap end and a forward casing end and having an inner casing surface and

(b) an inner piston with a forward piston end extending into the cartridge case from the cap end for more than half of the length of said case, said piston being slideably contained within the cartridge case in contact with the inner casing surface in a sealed engagement which permits little gas flow therebetween, said piston carrying a primer at its rear end, adjacent to the cap end of the case;

(c) a flash tube contained centrally within the piston that communicates between the primer and the forward end of the piston;

(d) a transverse wall located forward of the forward end of the piston and substantially at the forward end of the cartridge case to create a closed space bounded by the piston, the case and said transverse wall;

(e) an orifice piercing said transverse wall to permit gases arising from within the cartridge case and the piston flash tube to pass outwardly from the forward end of the cartridge case while causing the piston to recoil under the build-up of gas pressure originating from the firing of the primer with sufficient force to cycle the firearm; and

(f) interengaging motion limiting portions provided respectively on the case and the piston in order to limit travel of the piston with respect to the cartridge case.

2. A cartridge as in claim 1 wherein the forward end of said piston extends substantially to and terminates at the transverse wall.

3. A cartridge as in claim 2 having propellant present within the case wherein substantially all of the propellant therein is contained within the piston.

4. A cartridge as in claim 1 comprising a propellant cavity located within the piston in communication with the flash tube to contain a quantity of propellant as a propellant chamber.

5. A cartridge as in claim 4 having substantially all the propellant in the cartridge present within the propellant cavity.

6. A cartridge as in claim 5 wherein said propellant cavity has a length to width ratio of between 1 to 1 up to 8 to 1.

7. A cartridge as in claim 1 comprising a recess located in the forward end of the case having said transverse wall as its rearward surface and a projectile positioned in such recess in front of said orifice.

8. A cartridge as in claim 1 wherein said interengaging motion limiting portions comprise interengaging stepped portions.

9. A cartridge as in claim 1 in combination with a firearm having a chamber with a forward end, the forward end of the case of the cartridge being seated on the forward end of the chamber before the firing of the primer.