Patent ID: 6845605

Claim:
An ignitor for use with a rocket engine to provide hypergolic fluid directly to a combustion chamber, said ignitor comprising: a cartridge having a length and a cavity there along; a first and second end cap at first and second ends of the cartridge; an ignitor inlet located in the first end cap and an ignitor outlet located in the second end cap; a piston assembly moveable between a first position and a discharged position along the length of the cartridge within the cavity; a first and a second rupture disc assembly located internally within the ignitor; a supply of hypergolic fluid located within the cavity between the piston assembly and the ignitor outlet, wherein movement of the piston assembly from the first position to the discharged position expels at least some of the supply of hypergolic fluid out of the ignitor outlet; and at least one purge groove located along an interior surface of the cartridge cavity, wherein said piston assembly is in the discharged position, said purge groove provides a conduit for flow around the piston assembly from the ignitor inlet to the ignitor outlet.