Abstract: The downstream portion of the diverging part of the nozzle of the rocket engine is extended by an ejectable diffuser which, downstream from the zone where it is connected to the diverging part, presents a zone of smaller cross-section that acts during a first stage of flight in the presence of significant outside pressure to recompress the flow of hot gases and to prevent a flow separation from appearing along with the wall of the diverging part. The ejectable diffuser may have a streamlined throat which constitutes the zone of smaller cross-section.

Abstract: A constant-stroke, variable by-pass, plunger-type, jerk pump for injecting fuel-oil into a working cylinder of an internal combustion engine, wherein the plunger comprises a passage-way opening at one end thereof into the working chamber of said plunger and adapted to communicate at its other end with at least one duct connected to the fuel supply and opening into the pump cylinder housing said plunger to temporarily cut off the fuel discharged from said chamber to the fuel injector during the upward stroke of the plunger towards its top dead center, the first fuel discharge phase enabling the fuel to be pre-injected into the engine cylinder whereas the second fuel discharge phase provides for the main injection of fuel thereinto.