Abstract: This device comprises a pressure controller connected to the fluid source through a first calibrated aperture. This pressure controller controls a valve located on a by-pass circuit connected in parallel with the utilization circuit, and is provided with a second calibrated aperture for fluid discharge and with means for closing said second aperture when the pressure in the controller reaches a set value lower than the pressure required for actuating the by-pass valve. The use of this device is particularly suitable in supercharged engines.

Abstract: This device comprises a pressure controller connected to a fluid source through a first calibrated aperture. The pressure controller controls a valve located in a by-pass circuit connected in parallel with a utilization circuit, and is provided with a second calibrated aperture for fluid discharge and with means for closing said second aperture when the pressure in the controller reaches a set value lower than the pressure required for actuating the by-pass valve. The use of this device is particularly adapted for use in super-charged engines.

Abstract: A pump-injector assembly comprises a plunger slidable in a bore. The plunger has a first or upper position in which fuel is admitted into the lower part of the injector bore through an inlet port, and a second or lower position in which a tapered lower end of the plunger obturates fuel spray nozzles provided through the bottom of the bore. A recess is provided in the plunger wall and communicates with the bottom of the bore through a longitudinal passageway of the plunger. A ramp inclined to the plunger axis is formed by the upper edge of the recess and co-operates with a fuel outlet port located on the wall of the injector bore to control the beginning of the injection. Rotation of the plunger relative to this outlet port permits adjustment of the amount of injected fuel charge.

Abstract: This device comprises a manometric gauge connected to a fluid source through a first calibrated aperture. The manometric gauge controls a valve located in a by-pass circuit connected in parallel with a utilization circuit, and is provided with a second calibrated aperture for fluid discharge and with means for closing said second aperture when the pressure in the gauge reaches a set value lower than the pressure required for actuating the by-pass valve. The use of this device is particularly adapted for use in supercharged engines.

Abstract: This device comprises a body provided with a bore in which a plunger is slidably mounted, this plunger is movable between a lower position in which it obturates injection nozzles provided through the bottom of the bore, and an upper position where it is spaced from the bottom. Metering means comprise a feed groove provided in the piston wall and opening on the tapered end thereof, this groove having an upper edge inclined to the piston axis. This upper edge co-operates with a fuel inlet port. A similar groove is provided in the piston wall, this groove having an inclined upper edge co-operating with a fuel discharge port. Fuel metering is achieved by rotation of the plunger about its axis.

Abstract: A fuel pump-injector unitary assembly comprises a plunger slidable in a bore and provided with a longitudinal passage-way, in combination with a metering ring surrounding the plunger and housed in an annular chamber of the injector body. The plunger is movable into a first or upper postion in which fuel is admitted into the lower part of the injector bore through an inlet port, and a second or lower position in which the tapered lower end of the plunger obturates fuel spray nozzles provided at the bottom of the bore. Fuel metering results from the cooperation of an inclined ramp of the ring with a fuel discharge duct transversely extending through the plunger and connected with the longitudinal passage-way thereof. Relative rotation of the metering ring and of the plunger permits adjustment of the injected fuel charge.

Abstract: The invention provides a method comprising the detection of the operating conditions of the engine and, depending on these operating conditions, supplying the engine with air either from a static source or from an air compressor.When air is supplied to the engine from the static source the compression work of the compressor is kept at a minimum value, and shifting from one operating mode to the other is achieved within the shortest possible time interval.