GB1224762A - Carburettor - Google Patents

Abstract

1,224,762. Spray carburetters. K. LOHNER. May 30, 1968 [May 31, 1967], No.26029/68. Heading F1B. In a constant suction type carburetter the fuel needle 4, Fig. 1 controls a fuel orifice 11 opening into a preliminary chamber 5 which opens into the space below the piston 2, air being supplied into chamber 5 from a chamber 8 through a duct or ducts 9 to disperse the fuel. Air is supplied from chamber 8 to a slot 30 to detach fuel from the surface 1b, a sharp edge 31 assisting the detachment. The chamber 8 is connected to the inlet through a passage 7 and the passages 9 may be arranged to cause swirling in the chamber 5. The needle 4 may be provided with sharp-edged recesses to prevent fuel sticking thereon. In Fig.3 a passage 16 feeding air to a slot 16a on the downstream portion of the surface into which the chamber 5 opens to detach any fuel film forming thereon, is connected to chamber 19 which is in connection with chamber 8 through a valve 17 which is open during normal running but closed by contact of the piston 2 with the stem 18 during idling. The float chamber may be connected to the carburetter suction space through a passage 21, Fig. 5, and the pressure in the float chamber controlled by a valve 37a actuated by the throttle valve 20 or by a suction actuated diaphragm. In Fig.7 (not shown), the needle (4<SP>11</SP>) projects downwardly from the jet (11) and is connected to the piston (2) by linkage (46), (45). The passage beneath the piston 2 at idling may be reduced by projections (47) in the bridge (1b), Fig.8A (not shown) mating with corresponding recesses (48) in the piston. In Fig.4 the undersurface of the piston 2<SP>1</SP> ends in a sharp fueldetaching edge 32 and detaching of any fuel film thereon is also assisted by air supplied through passage 34 to an orifice adjacent the edge 32. The passage 34 is closed at idling by a pin 36 projecting into a recess 35 which intersects the bore 34.