GB1395355A - Carburetor - Google Patents

Abstract

1395355 Spray carburetters J M J DE PONTAC 21 June 1972 [30 June 1971] 29122/72 Heading F1B The flow of fuel from a float chamber 2 to a fuel chamber 4, which communicates with the induction passage Venturi 3 through ducts 5, is controlled by a needle 35, coupled to an air-flow responsive valve 45 in the induction passage, and the pressure difference between the float and fuel chambers. The chamber 2 is subject to the pressure in the inlet 28' through a tube (43), Fig. 1 (not shown), and the chamber 4 is subject to the pressure at the carburetter inlet through a flowpath regulated by a bellows 51 subject to the inlet pressure and a control member 22 positioned is aligned recesses in first and second plates 14 and 15 of the carburetter. The tube 30 containing the bellows 51 is connected to an intake pipe supplying the inlet 28' and the valve 49 operated by the bellows controls the cross-sectional area of a calibrated opening in a disc 48. The member 22 is rotatable by a cable to close the flow-path to the chamber 4, through a recess 29 in the plate 15 and an opening 25 in the plate 14, for starting and partially close the flow-path when an associated enzyme is cold. To reduce the fuel flow on over-running a valve 54 subject to the pressure downstream of the carburetter throttle valve via a passage 60 connects the recess 29 to the chamber 2 by uncovering an opening 19. The chamber 4 is also connected to the inlet 28' through a tube 40 under the control of a valve 64 and a cylindrical valve 68. The valve 68 closes the flow-path from the tube 40 when the throttle valve is opened rapidly, the rod 72 coupled to the air valve 45 raising the valve 68 until sufficient fuel has flowed from the chamber 2 through the restricted passage 74 to permit the valve to move downwardly relative to the piston 77. The diaphragm 62 of the valve 64 is subject through a passage 66a to the pressure at an induction passage port 67 which is upstream of the throttle valve only when the throttle valve is closed or partially closed. The valve 64 opens the opening 32 in the flow-path in a range of throttle valve positions between idling and full load at which the valve 64 is closed. The carburetter may be supplied with air by a compressor (103), Fig. 8 (not shown), driven by an electric motor (104) which energized when the accelerator pedal (107) is depressed beyond a certain extent.