Piston/rocket projectile with separable casing

1. A projectile for use with a launcher system having a barrel comprising:

a projectile body having a combustion chamber for propellant, a piston moveable in one direction to ignite the propellant in the combustion chamber and in an opposite direction to protrude out of a base of the projectile as a result of ignition of propellant in the combustion chamber, and vents for expulsion of combustion products from the ignition of propellant out of the projectile base after initial movement of the piston;

a casing secured to the base of the projectile body enclosing the piston and vents prior to the ignition of propellant; and

a separable joint between the casing and the base of the projectile body, wherein, upon ignition of propellant in the combustion chamber by movement of the piston in the one direction, the piston is forced in the opposite direction and causes the separable joint to separate, leaving the casing in the barrel such that after the piston completes exertion of propulsion force against the casing, combustion products of the ignition of propellant are expelled through the vents out of a lower end of the projectile and solid combustion byproducts from the ignition of the propellant are collected in the casing.

2. The projectile of claim 1 wherein the separable joint comprises a flange in one of the casing or projectile base secured in a groove in the other of the casing or projectile base, the flange being shearable upon a predetermined force to separate the casing from the projectile body upon ignition of propellant in the combustion chamber and extension of the piston out of the projectile base.

3. The projectile of claim 1 wherein the separable joint comprises a reverse or conical joint flange between the casing and projectile base, the flange being separable upon a predetermined force to separate the casing from the projectile body upon ignition of propellant in the combustion chamber and extension of the piston out of the projectile base.

4. The projectile of claim 1 wherein the propellant in the combustion chamber is ignited by a mechanically-initiated primer.

5. A method of launching a projectile from a launcher system having a barrel and a breech comprising:

providing a projectile body having a combustion chamber for propellant, a piston moveable in one direction to ignite the propellant in the combustion chamber and in an opposite direction to protrude out of a base of the projectile as a result of ignition of propellant in the combustion chamber, and vents for expulsion of combustion products from the ignition of propellant out of the projectile base after initial movement of the piston;

providing a casing secured to the base of the projectile body by a separable joint between the casing and the projectile body base, the casing enclosing the piston and vents prior to the ignition of propellant;

moving the piston in the one direction to ignite propellant in the combustion chamber, causing the piston to be forced in the opposite direction and causing the joint to separate, thereby leaving the casing in the barrel such that after the piston completes exertion of propulsion force against the casing, combustion products of the ignition of propellant are expelled through the vents out of a lower end of the projectile and solid combustion products from the ignition of propellant are collected in the casing.

6. The method of claim 5 wherein the separable joint in the casing is separated upon a predetermined force by the piston to separate the casing from the projectile body upon ignition of propellant in the combustion chamber and extension of the piston out of the projectile base.

7. The method of claim 5 wherein the separable joint comprises a flange in one of the casing or projectile base secured in a groove in the other of the casing or projectile base, and wherein the flange is sheared upon a predetermined force by the piston to separate the casing from the projectile body upon ignition of propellant in the combustion chamber and extension of the piston out of the projectile base.

8. The method of claim 5 wherein the separable joint comprises a reverse or conical joint flange between the casing and projectile base, the flange being separable upon a predetermined force to separate the casing from the projectile body upon ignition of propellant in the combustion chamber and extension of the piston out of the projectile base.

9. The method of claim 5 wherein the propellant in the combustion chamber is ignited by a mechanically-initiated primer.

10. A projectile for use with a launcher system having a barrel comprising:

a projectile body having a combustion chamber for propellant, a piston moveable to protrude out of a base of the projectile as a result of ignition of propellant in the combustion chamber, and vents for expulsion of combustion products from the ignition of propellant out of the projectile base after initial movement of the piston, the vents being formed in part by walls of an inner surface of the projectile body and in part by an outer surface of the piston; and

a casing secured to the base of the projectile body by a joint between the casing and the base of the projectile body, the casing enclosing the piston and vents prior to the ignition of propellant,

wherein, upon ignition of propellant in the combustion chamber the piston exerts a propulsive force against the casing and, the piston moves such that the vents are exposed before the piston reaches a limit of travel within the projectile body, whereupon combustion products of the ignition of propellant are expelled through the vents out of the lower end of the projectile.

11. The projectile of claim 10 wherein the vents are non-circular in cross-section and are extruded into an inner surface of the projectile body.

12. The projectile of claim 10 wherein the propellant in the combustion chamber is ignited electrically.

13. The projectile of claim 12 further including a gel-type propellant in the combustion chamber and an electrode extending into the gel-type propellant in the combustion chamber for ignition of propellant.

14. The projectile of claim 10 wherein the propellant in the combustion chamber is ignited by a mechanically-initiated primer.

15. A projectile for use with a launcher system having a barrel comprising:

a projectile body formed of an electrically non-conductive material having a combustion chamber for propellant, the combustion chamber having a gel-type propellant therein and an electrode extending through the projectile body and into the combustion chamber for electrically igniting the gel-type propellant, a piston moveable to extend out a base of the projectile as a result of ignition of said gel-type propellant in the combustion chamber, and vents for expulsion of combustion products from the ignition of the gel-type propellant out of the projectile base after initial movement of the piston;

a non-electrically conductive layer between the gel-type propellant and the end of the chamber opposite the piston, the non-electrically conductive layer covering at least a portion of a width of the combustion chamber, said non-electrically conductive layer having an opening therein through which extends the electrode; and

an electrically conductive layer covering at least a portion of the width of the combustion chamber, said electrically conductive layer disposed between the non-electrically conductive layer and the gel-type propellant in electrical contact with an end of the electrode, wherein, upon ignition of the gel-type propellant by the electrode and electrically conductive layer in the combustion chamber, the piston is forced outward from the lower end of the projectile and subsequently combustion products of the ignition of the gel-type propellant are expelled through the vents out of the lower end of the projectile.

16. The projectile of claim 15 wherein the non-electrically conductive layer covers the entire width of the combustion chamber.

17. The projectile of claim 16 wherein the non-electrically conductive layer includes projections extending along side walls of the combustion chamber.

18. The projectile of claim 15 wherein the electrically conductive layer covers the entire width of the combustion chamber.

19. The projectile of claim 18 wherein the electrically conductive layer has a projection extending therefrom in contact with the end of the electrode.