Abstract: A nozzle for atomizing fuel for combustion in a gas turbine engine. During normal operation of the engine, the nozzle uses a portion of the air supplied to the combustion chamber by the engine compressor to atomize fuel flowing through the nozzle. During start-up and low power operation of the engine when flow of engine air through the nozzle would otherwise be of insufficient velocity to cause good atomization of the fuel, additional air from a separate external source is introduced at high velocity into the nozzle in the manner of an ejector. The additional air imparts high velocity to the engine air within the nozzle so that the air from both sources acts on the fuel at the nozzle discharge orifice at high velocity to effect good atomization and spray pattern of the fuel. The nozzle is designed in such a manner as to cause no significant restriction of engine air flow through the nozzle under high power operation of the engine when the external air source is shut off.

Abstract: A welded joint between two telescoped and threaded together inner and outer parts of an assembly wherein the joint may be cut apart to permit unthreading of the one part from the other and for their subsequent reuse after repair or cleaning of the assembly. The inner part has an external thread and has a cylindrical portion between the external thread and the welded joint for expanding any inwardly projecting burr that may be formed on the outer part during the cutting operation so that the burr may pass over the external threads without damaging the same when the parts are unthreaded from each other. The invention is particularly adaptable for use with fuel injection nozzles but has use in other applications where welded together threaded parts are subject to disassembly and reuse.