Ammunition and explosives – Igniting devices and systems – Arming devices
Reexamination Certificate
2002-09-26
2003-07-08
Nelson, Peter A. (Department: 3641)
Ammunition and explosives
Igniting devices and systems
Arming devices
C102S229000, C102S230000, C102S254000
Reexamination Certificate
active
06588343
ABSTRACT:
STATEMENT OF GOVERNMENT INTEREST
The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without payment of any royalties thereon or therefor.
BACKGROUND
The present invention relates to an igniter system for a flare. More specifically, but without limitation, the present invention relates to an igniter system for an aerial flare.
Aerial flares are used for a variety of applications, including, but not limited to, illumination, signaling, marking, decoys, military countermeasures, and the like. A flare is typically defined, but without limitation, as a pyrotechnic device designed to produce illumination or a luminous signal. Due to the important nature of their uses, aerial flares require a high degree of reliability in their ignition systems. The flare must not prematurely ignite, which can cause damage to the platform from which the flare is being released (a platform can be, for instance, but without limitation, a stand, an aircraft, a ship, a submarine, a land vehicle, or the like.) The flare must also have consistent ejection velocities.
The flare and its igniter must be in a constant state of readiness, and when the flare ignition system is placed in the “armed” mode, ignition must be certain. Nevertheless, the flare cannot be carried on a vehicle/aircraft or transported in an armed mode at all times. The flare must be capable of being transported with the ignition in a “safe” mode in which ignition is impossible.
In operation, typically a military flare or countermeasure is dispensed from a flare dispenser using an impulse cartridge. Upon initiation of the impulse cartridge, the internal payload (the igniter system) begins to exit from the case. The hot particles from the impulse cartridge travel through a hole and ignite an ignition pellet. An interrupt or slider separates the pellet and flare grain (i.e. the illuminant or pyrotechnic material.) As the ignition system departs from the flare case the interrupt or slider is removed from between the ignition pellet and flare grain, allowing the flare grain to be ignited by the pellet, and thus illuminating the flare.
Despite the various safe and armed igniter designs in use, premature ignitions continue to happen. The cause of most of these premature ignitions is hot gases from the impulse cartridge around the flare piston and igniter, which directly ignite the flare grain, pyrotechnic material or illuminant. Besides the chance of premature ignition, blow of impulse cartridge gases causes a reduction in the flare grain exit velocity. Many flare igniters do not adequately center the payload/igniter to prevent impulse cartridge gas blow around the piston, which can cause a premature ignition or reduction in flare velocity. This is especially important in military applications, such as countermeasures or decoys, because in today's combat environment, some missiles use forward motion of an aircraft to discriminate between the signature of an aircraft and the signature of a decoy flare or countermeasure. Therefore, to be an effective countermeasure or decoy, the flare must be capable of keeping up with the speed of the aircraft, thus any reduction of flare velocity or a premature ignition would render a countermeasure or decoy ineffective against these types of missiles.
Certain igniters also have a tendency to ignite the flare grain prior to exiting the flare dispenser and/or prior to exiting the case (a type of premature ignition). This could cause damage to the dispenser and the platform.
Information relevant to address these problems can be found in U.S. Pat. No. 5,561,259 and U.S. Statutory Invention Registration Number H1603. However, each of these references, as well as other uncited references, suffers from one or more of the following disadvantages: the igniter does not adequately center the payload or igniter to prevent impulse cartridge gas blow by around the piston; at times the igniter causes unwanted premature grain ignitions; and causes inconsistent ejection velocity of the grain.
For the foregoing reasons, there is a need for an igniter system for a flare.
SUMMARY
The instant invention is directed to an igniter system for a flare that satisfies the needs enumerated above and below.
The present invention is directed to an igniter system for a flare that includes a housing, a slider assembly, and a piston assembly. The housing has two ignition portals for holding ignition pellets. The slider assembly is disposed within the housing, and includes two sliders and a spring. Each slider corresponds to an ignition portal, and the two sliders communicate with the spring. The slider assembly has an armed position and a safe position. The armed position has the sliders not covering the ignition portals and allowing conflagrant communication between the ignition pellets and flare grain, while the safe position has the sliders covering the ignition portals and not allowing conflagrant communication between the ignition pellets and flare grain. The piston assembly communicates with the housing and communicates with the inside of the flare case to contain gases generated by the impulse cartridge. This provides the pressure needed to eject the igniter/grain assembly from the flare case. Upon exiting the case, the slider assembly moves to armed position. The ignition pellets, ignited by hot particles from the impulse cartridge, communicate with the grain through the ignition portals to ignite the flare grain.
It is an object of the invention to provide an igniter system for a flare that prevents and minimizes premature ignition of a flare and substantially assures that the flare grain is completely exited from their outer case before ignition.
It is an object of the invention to provide an igniter system for a flare that ensures rapid reliable ignition as soon as the flare grain exits the flare case.
It is an object of the invention to provide an igniter system for a flare that adequately centers the payload/igniter to prevent impulse cartridge gas blow by around the piston.
It is an object of the invention to provide an igniter system for a flare that has consistent ejection velocities, and can be effectively used in flares that act as countermeasures or decoys.
It is an object of the invention to provide an igniter system for a flare that is efficient, simple and an inexpensive safe-arm device for a flare.
It is an object of the invention to provide an igniter system for a flare that does not ignite flare grain prior to exiting the flare dispenser and the flare case.
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Glut Mark O.
Nelson Peter A.
The United States of America as represented by the Secretary of
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