Fluid injectors

Claim 1

In a rocket motor having fuel and oxidizer tanks pressurized by a gas source, propellant injection apparatus comprising: an annular housing the inner surface of which successively defines a combustion chamber, a first bore divergent from said combustion chamber, a second bore extending radially from said first bore and communicating with one of said fuel and oxidizer tanks, a third bore having a smaller diameter than said second bore, and a fourth bore convergent from said third bore and communicating with said gas source; a tubular post fixedly and coaxially disposed within said bores of said housing and having one end substantially even with the aft edge of said first bore, said post comprising a first cylindrical forward portion, a second aft portion disposed opposite the wall of said first bore and convergent relative thereto, and a third portion intermediate said first and second portions and having at least one port extending through the wall thereof, the end of said post remote from said combustion chamber communicating with the one of said fuel and oxidizer tanks not connected to said second bore; a partition fixedly attached to said post and extending across the interior thereof aft of said port therein; an annular pintle comprising a first cylindrical portion slidably engaged with the wall of said third bore and a second conical portion joined at its larger end to the forward end of said first portion and coaxial therewith, the aft end of said first portion of said pintle being tapered to form a first outwardly facing seating surface conforming with the wall of said first bore and a second inwardly facing seating surface conforming with said second portion of said post, said second portion of said pintle being disposed within said fourth bore and conforming with the wall thereof and its forward end being formed with an aperture the wall of which slidably engages said first portion of said post, the inner surface of said pintle between said second seating surface and the wall of said aperture being spaced from the surface of said post to define an annular space around said third portion of the latter, the length of said pintle being such that said second portion thereof is spaced from the wall of said fourth bore when said first and second seating surfaces are spaced from the wall of said first bore and said second portion of said post respectively, said pintle having a plurality of gas passages extending longitudinally through said first portion thereof and communicating with said combustion chamber and the space between the wall of said fourth bore and said second portion of said pintle; and means for moving said pintle longitudinally of said housing.