Patent GB-565226-A (GB)
Title: Improvements relating to aircraft propulsion plants
IPC: F02K5/02
Filed: 1943-04-27
Abstract: 565,226. Aircraft power plant. MERCIER, P. E. April 27, 1943, No. 6654. [Classes 7 (ii) and 7 (vi)] [Also in Group XXXIII] An aircraft propulsion plant includes an internal-combustion engine 1, Fig. 1, operating on a mixture of vaporized liquid fuel and air, the latter being derived partly from a compressor 5 driven by the engine and partly from an atmospheric air induction system which compressor and system both deliver to a mixing chamber communicating with the engine air intake. At low altitudes more air than is required by the engine is delivered by the compressor and this excess is directed to a rear propulsion nozzle. The power plant is mounted in a nacelle 3. The compressor 5 is supplied by an intake conduit 7, 6 and delivers through a conduit 8 having branches 9, 10, the former leading to a mixing chamber 19 and the latter to a rear propulsion nozzle 13 opening into a venturi 12. The rear nozzle includes a valve 14 movable axially to vary the nozzle area. The induced air conduit 23 also leads in the mixing chamber through a passage 27. The supply from the compressor is controllable by an axially-movable valve 15. In a modification, Fig. 2, the nozzle 17 is axially adjustable and the valve 15 fixed. The adjustment is effected from a belt pulley 20 rotatable by the pilot and acts through a screwed ring to vary both the induced air orifice 27 and the compressed air orifice 26 in inverse proportions. At moderately high altitudes the compressed air orifice is enlarged to increase the supply of compressed air and a still further increase is obtained from the increased engine revolutions obtainable through the decrease in air resistance. Some of the air flowing over the nacelle may pass through slots 28, 29 to the venturi 11 and, if desired, some of this air may pass through an engine-cooling radiator 31. In another modification, exhaust gases may be led to the rear propulsion unit through pipes 57, Fig. 5. The supply from the compressor to this nozzle is controlled by a valve 59 which may be operated through lever mechanism by the pilot or may be connected to the gas control lever of the engine. Alternatively, as shown in Fig. 5, the operation of the valve 59 may be automatic. In this case the valve 59 is connected through a lever 75 to a piston 82 working in a cylinder 81a supplied by compressed air or pressure oil from a line 91 controlled by a valve 88 actuated by a rod 89 having a pin-and-slot connection to a lever 92 pivoted at 78. This lever is actuated by a second lever P operated by a bellows 99 through rod 97. At low altitudes the bellows is contracted and the parts are in the Fig. 5 position, a spring 74 being effective to move the valve 59 forward to cause maximum orifice constriction. As altitude increases the expansion of the bellows causes the piston valve 88 to move to admit pressure fluid to cylinder 81a and withdraw the valve 59 so that more air can flow to the rear propulsion nozzle. The fluid-pressure cylinder 81a may be replaced by an electromagnetic device. A similar automatic control may in some cases be used for the valve 15 controlling the proportion of induced air to compressed air. For this purpose the nozzle 17, Fig. 9, is connected by a lever 75 to the piston of a cylinder 82a similar to that described above. In another modification, Fig. 4, the proportions of induced air 108 and compressor air 113 flowing to a mixing chamber 102, are varied by dampers 104, 105 controlled by a pair of intergeared wheels which may be actuated by a rack which is under either automatic or manual control.