GB627046A - Improvements in or relating to carburetting apparatus for internal combustion engines - Google Patents

Abstract

627,046. Charge forming devices. CORTHALS, A. R. P. Dec. 11, 1945, No. 33419. Convention date, June 17, 1939. [Class 7 (iii)] A charge forming device comprises a vaporizing chamber for instantaneous evaporation of liquid fuel and a mixing chamber in which the evaporated fuel and air are mixed the vaporizing chamber communicating with a condenser which receives tepid fuel vapours and the vaporizing chamber communicates with the mixing chamber through a vapour admission needle valve the needle of which has an extension adapted to open a return valve for vapour which allows vapour flowing from the evaporator towards the mixing chamber to return to the condenser when the needle is in the closed position. In Fig. 1 air is drawn into an induction pipe 8 through a conical valve 24 and fuel vapour through a needle valve 10. The fuel vapour is formed in an evaporator 1. Fuel is supplied through a pipe 40 to. the evaporator and maintained at constant level by a float valve or the like, fuel vapour being formed by tubes 4, 5 heated by the exhaust gases of the engine. The evaporator communicates through a tube 6 with the induction pipe 8 through the needle valve 10. The seat of the valve communicates with the tube 6 through ports 91 of a valve chest 30. A tube 34 which communicates with the upper part of a tube 33 is concentrically mounted inside the tube 6 and connects the interior of the container with the valve 30. The valve 10 is prolonged axially by a pin 32 capable of opening a ball valve 31 when the needle valve is applied on its seat Thus fuel vapour in the tube 6 may penetrate through ports 91 through valve 31 and tube 33 to return to the evaporator. An opening 60 provides for communication between the right hand side (Fig. 1) of the evaporator and a condenser 35. A valve 36 allows the condenser 35 to be connected either to atmosphere or to the pipe 33. The valves 24 and 10 are controlled conjointly by a hand operated lever pivoted at 20. The lever controls a slotted member 18 which operates the fuel valve. A helical element 29 serves to create a whirling motion in the mixture of vapour and air. The needle valve may move against spring pressure in the event of a backfire. A modified construction of the evaporator is shown in Fig. 3. Fuel is supplied through a pipe 53 to a chamber 45 in which it is sprayed by a nozzle 48 on to tubes 47 heated by the engine exhaust gases. The vapour formed is further heated by tubes 49 before passing towards the induction pipe through a passage 51. A condenser 50 is provided. The chamber 45 is cylindrical and the exhaust gases follow a path indicated by the arrows. They heat successively the tubes 47 and 49. The Specification as open to inspection under Sect. 91 comprises also the following subjectmatter. Valves are provided in the induction pipe on opposite sides of the needle valve and these are operated by or simultaneously with the valves 10 and 24. When the valves 10 and 24 are closed the other valves open and one admits air to the induction pipe when the engine is being used as a brake in a vehicle and the other may admit water vapour from the radiator or heated air. In Fig. 6 (Cancelled) instead of the air and fuel vapour entering the induction passage in directions at right angles to one another they may both enter in the same direction. Air enters through a conical valve 61 and passes around the casing of the needle valve 59. The fuel vapour enters at permitted to escape through a conduit 67. In Fig. 5 (Cancelled) the air and fuel vapour enter in opposite directions into a housing which is connected to the induction passage by a port 58. In another arrangement the air valve comprises a rotatable sleeve around a conduit, the conduit having a port which is controlled by a port in the sleeve and the rotation of the sleeve lifts the needle valve by means of a rapid screw thread on an extension of the needle co-operating with a fixed nut. An arrangement in which there is an interconnection with a carburetter is very briefly described with reference to Fig. 2 (Cancelled), not shown. To permit the supply of additional air for slow running the air valve may have an axial bore in which is located the needle valve and an additional air valve upon an extension of the needle valve. The air valve may be hollow and contain the needle valve and the needle valve may be arranged to move against spring pressure in the event of a back fire. It is stated that the supply of fuel to the evaporator may be controlled by a ball valve opened by a hand control lever or by another needle valve actuated conjointly with the valves 10, 24. The fuel for the evaporator may be supplied by an injection pump and injector or by an electrical pump with intermittent delivery. A screen is fixed inside the evaporator. This subject-matter does not appear in the Specification as accepted.