Nozzled mortar ignition system for improved performance

Patent metadata

Field	Value
Publication number	US-9249759-B1
Application number	US-201213599261-A
Country	US
Kind code	B1
Filing date	Aug 30, 2012
Priority date	Aug 30, 2012
Publication date	Feb 2, 2016
Grant date	Feb 2, 2016

Abstract

A mortar system includes a launch unit that comprises a mortar ignition cartridge provided with a flashtube. The flashtube incorporates a ring-like nozzle that is positioned within the flashtube, which acts to restrain the motion of the black powder pellets as well as to choke the flow of the resultant combustion products. The nozzle separates the flashtube into two compartments: a flashtube venting chamber and a pellet combustion chamber. The mortar ignition cartridge combustion chamber acts as the product-gas venting area of the flashtube. The combustion of the black powder pellets essentially takes place in the pellet combustion chamber. The present design modification improves the overall performance of the mortar system.

First claim

What is claimed is:

1. A mortar projectile ( 55 ) having a mortar ignition cartridge ( 65 ) comprising a bed of loose powder propellant ( 250 ) and wherein the propellant is ignited through a percussion primer ( 205 ) striking a firing pin ( 210 ), leading to activation of a launch unit ( 50 ) secured within said mortar ignition cartridge, and wherein said launch unit comprises:
a flashtube ( 100 ), whose pressure is sealed by an end steel pin ( 255 );
a ceramic nozzle ( 200 ) that divides the flashtube into two compartments: a pellet combustion chamber ( 305 ) and a flashtube venting chamber ( 270 );
wherein the pellet combustion chamber contains pellets ( 222 ) that generate combustion products after being struck by the firing pin;
wherein the nozzle acts as a quasi-solid boundary to flashtube venting chamber pressure disturbances for choking the flow of pellet combustion products toward the flashtube venting chamber; and
wherein the flashtube venting chamber acts as a product-gas forming area and includes a plurality of vent holes ( 230 ) that allow at least some of the combustion products to escape outside the flashtube and to impinge on, and ignite said propellant.

2. The mortar projectile according to claim 1 , wherein the nozzle is inserted within the flashtube against a shoulder ( 300 ) that prevents the nozzle from sliding into the flashtube.

3. The mortar projectile according to claim 2 , wherein the nozzle has a ring-like, circular configuration.

4. The mortar projectile according to claim 2 , wherein the nozzle is generally cylindrically shaped.

5. The mortar projectile according to claim 4 , wherein the nozzle includes a central orifice.

6. A mortar having a mortar ignition cartridge comprising a bed of propellant and wherein said propellant is ignited through action of a launch unit secured within said mortar ignition cartridge and wherein said launch unit comprises:
a flashtube;
a nozzle that divides the flashtube into two compartments: a pellet combustion chamber and a flashtube venting chamber;
wherein the pellet combustion chamber contains pellets that generate combustion products;
wherein the nozzle acts as a quasi-solid boundary to flashtube venting chamber pressure disturbances for choking the flow of the combustion products toward the flashtube venting chamber; and
wherein the flashtube venting chamber acts as a product-gas forming area and includes a plurality of vent holes that allow at least some of the combustion products to escape outside the flashtube and to impinge on, and ignite said propellant.

7. The mortar according to claim 6 , wherein the nozzle is inserted within the flashtube against a shoulder that prevents the nozzle from sliding into the flashtube.

8. The mortar according to claim 7 , wherein the nozzle has a ring-like, circular configuration.

9. The mortar according to claim 8 , wherein the nozzle is generally cylindrically shaped.

10. The mortar according to claim 9 , wherein the nozzle includes a central orifice.

11. The mortar according to claim 10 , wherein the nozzle is made of an integral piece of metal.

12. The mortar according to claim 10 , wherein the nozzle is made from a ceramic material.

Assignees

• Einstein Sandor I
• Chiu Donald S
• Colletti Alexander
• Us Army

Inventors

• Einstein Sandor I
• Chiu Donald S
• Colletti Alexander

Classifications

• F42C19/0826 Primary

  comprising an elongated perforated tube, i.e. flame tube, for the transmission of the initial energy to the propellant charge, e.g. used for artillery shells and kinetic energy penetrators · CPC title

• F42C19/0819

  Primers or igniters for the initiation of rocket motors, i.e. pyrotechnical aspects thereof · CPC title

• F42C19/02

  Fuze bodies; Fuze housings · CPC title

• F02K9/97 Primary

  Rocket nozzles (thrust or thrust vector control F02K9/80) · CPC title

• F42C19/0807

  characterised by the particular configuration of the transmission channels from the priming energy source to the charge to be ignited, e.g. multiple channels, nozzles, diaphragms or filters · CPC title