Abstract: Vessel provided with at least one water jet propulsion unit consisting of a casing containing, between an intake (3) tangential to the hull (2) and a rear water outlet (4), a duct (5) upstream of the propulsion device, an impeller (6), fixed flow-correction guide vanes (7) and a tail cone (8) carried by the blades which with the casing (9) form the tail pipe (10). The cross section of the tail pipe (10) varies but within narrow limits between the vanes (7) and the outlet (4) by virtue of a number of gas injection slots situated in the area of the trailing edges of the vanes (7) and connected by a circuit to a supply of compressed gas (16). The gas supply circuit includes an external annular chamber (14) formed within the casing and the shroud surrounding the vanes (7) and connected to the injection slots (25, 26, 29). Of application to vessels requiring very high thrusts.

Abstract: In an internal combustion engine having controlled ignition, apparatus for controlling injection of the fuel so as to greatly increase the advance with the load on the engine, and a precombustion chamber into which emerge both the fuel injector and the controlled ignition device, adjacent elementary chambers formed at least in the cylinder head, the lower face of the cylinder head extending between the elementary chambers and the upper face of the piston forming an impelling surface surrounding the prechamber, the inlets into the main combustion chamber and prechamber opening into the impelling surface without throttle between the prechamber and the main chamber during the complete cycle of the piston.