Patent GB-463294-A (GB)
Title: Improvements in carburetters for internal combustion engines
IPC: F02M17/26
Filed: 1936-05-11
Abstract: 463,294. Spray carburetters; vaporizers. ERICSSON, H. E. T. May 11, 1936, Nos. 13289 and 13290. Convention dates, May 10, 1935 and April 30, 1936. [Class 7 (iii)] Fuel is first subjected to a vaporizing action, without preceding mechanical subdivision, by being spread as a film over the surface of a body heated by the exhaust gases, and.suction air, not yet mixed with atomized fuel is passed over the film while taking up fuel in the vapour phase whereafter the unvaporized heated fuel in divided or atomized condition is supplied to the vapour - air mixture obtained through the vaporization. Light or heavy fuel is supplied selectively from float chambers 30, 31 past valves controlled by a rod 40 to a channel 15 whence fuel for idling may flow past a valve 18 to a passage 19 and a chamber 13 to which fuel for normal running is supplied past an adjusting valve 16 to a central bore in a sleeve 12 communicating by stepped apertures 11 with the chamber 13. The ports 11 are controlled by a piston rod 10 coupled to the throttle valve 8. From the chamber 13, fuel is drawn through channels 14 to the surface of a neck formed on a heating member 1 through passages 2 in which the exhaust gases are conducted in an amount which may be controlled by a damper. A film of fuel is drawn upwards over the vaporizer 1 and in part vaporized, the vapour-air mixture so formed dragging the unvaporized part off a sharp edge 5 formed at the top of the vaporizer 1. Venturis 22, 6 are disposed opposite the channels 14 and edge 5 respectively. During idling, the Venturi 22 is restricted by a conical obturator 24, adapted to be raised by suction during normal running, against the tension of a spring 25 ; whereupon it divides the air stream into portions directed towards the vaporizer and the outer wall of the body respectively. This construction may be adapted to a downdraught carburetter. In a modification, the exhaust gases flow around the heating element 41 and through valvecontrolled passages 52 within it. The air and fuel pass down a central passage 42, Fig. 6, the former being divided by a tubular member 127 to compel a small portion thereof to traverse spiral grooves on the inner wall of the passage, these grooves lengthening the heating path of the fuel. Unvaporized fuel is drawn off the edge 129 of the element 41 or off a sharpened edge 130 in the induction manifold, waste fuel being drained away through a port 131. Fuel is supplied selectively from either of two float chambers 70, 71, Fig. 9, according to the setting of valves 78 controlled through rods 80 by a hand lever 122, the fuel flowing upward around the rods 80 into the chambers 89 of needle valves 88 to chambers 92 or 93 each housing a ported sleeve 96, 97 controlled by a piston 98, 99. The pistons are connected through a common cross-member 101 to a rod 102 linked to the throttle valve 47. The ports in the sleeves 96, 97 lead past the pistons to a common chamber 100 communicating through a central bore in a downward extension 64 of a casting 69 with six tubular fuel nozzles 45. The upper edges of these nozzles engage the surface of a Venturi 44 to prevent air from interfering with the discharge of fuel on to the Venturi, the fuel flowing therefrom into an extension 46 of the heating element 41. Fuel for idling is drawn from the chambers 89 past adjusting valves to a common passage leading to the chamber 100. In the case of marine engines, the cooling water may traverse pockets in the sides of the exhaust pipe adjacent the vaporizer 41.