Patent GB-418887-A (GB)
Title: Improvements in carburettors
IPC: F02M1/04
Filed: 1934-01-30
Abstract: 418,887. Spray carburetters. SOC. ANON. SOLEX, 190, Avenue de Neuilly, Neuilly-sur-Seine, France. Jan. 30, 1934, No. 3113. Convention date, March 11, 1933. [Class 7 (iii).] An auxiliary carburetter is provided for starting and running when cold, and is adapted to be brought into and put out of action by a thermally sensitive device subjected to the temperature existing in the auxiliary carburetter itself, which temperature is dependent upon the running condition of the engine. The principal carburetter has a float chamber 1 feeding a main nozzle 3 as well as an idling nozzle 2 delivering through a duct 14 adjacent a throttle valve 6. The auxiliary carburetter comprises a nozzle 7 discharging into a chamber 8 which communicates with the induction passage beyond the throttle through a duct 10. In all but one construction, this duct is adapted to be controlled by a valve 13 actuated by a thermallysensitive device 12 located in the chamber 8 and subjected to the temperature of the air supplied through a pipe 9 coiled around or within the exhaust pipe and provided, if desired, with a small cold air inlet 9‹. To ensure the maintenance in the chamber 8 of a temperature sufficient to keep the capsule expanded when the valve 13 is closed, a small pipe 14 connects the chamber with the main mixing chamber, and through this pipe a current of the heated air is drawn. In a modification, Fig. 2, (not shown) the valve 13 is attached to a piston immersed in a liquid the viscosity of which varies with temperature, as described in Specification 336,678, [Class 7 (iii)]. In Fig. 3, the capsule is replaced by a thermally-sensitive strip 12 which is protected from excessive temperature by providing at the lower end of the strip a valve 18 which is closed at the same time as the valve 13, and is perforated to permit of air being drawn from the pipe 9 through the pipe 14. In Fig. 4, the thermally-sensitive device 12 actuates a needle valve 23 controlling a supplementary orifice 22 for feeding a well 21 supplying the nozzle 7. The well is normally fed through a calibrated orifice 20 as described in Specifications 357,310, 389,735, and 420,715. In modifications, Figs. 5, 6 (not shown) the thermally-sensitive device controls the communication of the upper part of the well, feeding the nozzle 7, with the atmosphere. In a further modification, Fig. 7 (not shown) the device shown in Fig. 1 is applied to a carburetter as described in Specification 420,715 in order to enrich the mixture at unusually low temperatures. In a still further modification, Fig. 8, the flow of fuel to the auxiliary carburetter nozzle 7 is controlled according to vapour pressure as described in Specification 280,879, [Class 135]. The thermally-sensitive element 12 takes the form of an inverted tube 26, with bulbous upper end, dips into fuel at constant level in a chamber 27. Within this tube is a perforated pipe 31 feeding a space 21 into which the nozzle 7 dips. Increase of temperature in chamber 8 increases the vapour pressure and forces down the level in the tube 26 so that fewer orifices are available for supply of fuel. Specifications 381,982 and 397,093 also are referred to.