Blank cartridge

• US 20090211482A1
• Filed: 05/08/2006
• Published: 08/27/2009
• Est. Priority Date: 05/10/2005
• Status: Active Grant

• Current Assignee: UTM Limited
• Original Assignee: UTM IP Limited
• Inventors: Saxby, Michael Ernest
• Granted Patent: US 7,814,836 B2
• Time in Patent Office: Days
• US Class Current: 102/430
• CPC Class Codes: F42B 8/04 Blank cartridges, i.e. primed cartridges without projectile but containing an explosive or combustible powder charge

Abstract

A blank cartridge (1) comprises a cartridge casing (2) with a first primer (18); a piston (9) with a head (10) and an arm (11); and an expansion chamber located between said primer (18) and the head of the piston (10), wherein, following detonation of the primer, the piston slidably displaces substantially within the casing (2) of said cartridge (1).

Claims

1-6. -6. (canceled)

7. A blank cartridge comprising:

a cartridge casing with a first primer;

a piston with a head and an arm; and

an expansion chamber located between said primer and the head of the piston;

wherein, following detonation of the primer, the piston slidably displaces substantially within the casing of said cartridge; and

wherein, prior to firing, the front of the cartridge forms between the casing and the piston a recessed portion;

whereby the front of the casing can fit around a projection formed in the breech of a gun and, following detonation, during expansion, the piston'"'"'s arm abuts against the projection to tend to oust the cartridge from the breech.

8. A cartridge according to claim 7, wherein the expansion chamber forms a substantially closed chamber between the casing and the piston where the piston head incorporates a seal to prevent the propellant gases from the explosion of the first primer escaping the expansion chamber.

9. A cartridge according to claim 7, wherein the piston incorporates a second primer and a channel extending from the second primer through the arm of the piston;

and the expansion chamber incorporates a projectile which is projected, following detonation, by the explosion of the first primer onto the second primer.

10. A gun barrel shaped and configured to accommodate a cartridge according to claim 7.