Patent GB-283537-A (GB)
Title: Improvements in carburettors
IPC: F02M37/02
Filed: 1927-06-24
Abstract: 283,537. Seignol, E. Jan. 13, 1927, [Convention date]. Spray carburettors. - The carburettors described, are of the type in which fuel for normal and slow running is raised from a closed tank by separate Venturis and the rich mixture produced is conveyed to a diffuser and suction passage of a secondary carburettor situated near the engine, where it is diluted with air. A carburettor a, Fig. 2, mounted on the fuel reservoir d at some distance from the engine, has two Venturi tubes 5, 13 of which 5 communicates by a pipe e with a chamber e<1> around the throat 1<a> of a diffuser 1 in the secondary carburettor, and 13 communicates through a pipe f with slow-running channels 12, 12a Fig. 3, leading to a hole in the edge of the throttle valve 4 in its closed position. The slowrunning duct is controlled by a valve 16 and has a permanent air inlet 17. The rich mixture passes to the interior of the diffuser through apertures e2 in the wall thereof. The lower end of the secondary carburettor is formed as a cylindrical casing 21a having an air inlet port 2a controlled by a sector shaped valve 21 to the spindle of which is secured a vane 24a adapted to move in a chamber 21d formed by partitions 21e, 21f. Suction is transmitted to the vane through port 34 and duct 33 and the movement of the vane is limited by the partition 21f and a stop 21g. The spindle 22 of the valve is loaded by a spiral spring 30 in a box 30a which may be rotated to adjust the tension of the spring. The back of the vane is open to atmosphere through an aperture 32 which may be provided with an adjusting device. The flow of mixture to the chamber e1 may be controlled by a valve 19, Fig. 4, actuated by a spindle carrying a tappet 20a adapted to engage a stop 20b, Fig. 3. The throat 6 of the Venturi 5 of the primary carburettor is in communication through tube 9 with a chamber 7 leading to the fuel reservoir d. This chamber is sealed by a plug 10 and serves to retain fuel to facilitate starting. The throat of the Venturi 13 communicates with the fuel reservoir through a tube 15 and calibrated aperture 13a, Fig. 2. Constancy in the supply of fuel is assured by hermetrically sealing the fuel reservoir at 18 and providing a tube g which descends nearly to the bottom of the reservoir and is open at its upper end h to the atmosphere. A conduit 13b, Fig. 2, connects the air space of of the reservoir d with the Venturi 13 and serves to create in the reservoir a depression sufficient to bring the tube g into action. To obviate loss of fuel through tubes 15, 9, g due to increases of pressure in the reservoir brought about by temperature variations, a safety valve i, Fig. 7, in the form of a light metallic disc may be fitted to the closure plug of the reservoir. The lift of the valve is limited by a perforated stop plate m secured by a plug o perforated at p. In a modification. Fig. 9 rich mixture is delivered througha pipe e, and the air inlet is controlled by a vane 21 carried by a pinion 24 engaging a rack 25 on a rod 26 secured to a spring-loaded piston 28 subject to atmospheric pressure through duct 32 and to suction through duct 33. In a modification, Figs. 11, 12 (not shown) the air valve is in the form of a vane mounted on the same spindle as a second vane subjected on one side to suction and on the other to atmospheric pressure. The means for conveying the rich mixture for normal and for slow running are the same as described with reference to Figs. 2, 3, 4. Specifications 265,905 and 273,339 are referred to. The Specification as open to inspection under Sect. 91 (3) (a) describes also a further modifi- .cation Figs. 11, 12, 14 (Cancelled) the air valve 21 being actuated by a vane 28a mounted on the valve spindle and subjected to suction through conduit 33, 33a. The closed position of the valve is limited by a stop 23 and a stop 35 which may be raised or lowered at will by a button 37 and pin-and-slot 38, 39 as shown in Fig. 14 (Cancelled) may be used to prevent the valve from opening in order to obtain a rich mixture at starting. It describes also a construction in which the piston arrangement of Fig. 9 is shown applied to a carburettor having a nozzle fed direct from a float-chamber. This subject-matter ,does not appear in the Specification as accepted.