Patent GB-207252-A (GB)
Title: Improvements in and relating to carburettors
IPC: F02M9/133
Filed: 1922-08-21
Abstract: 207,252. Winslow, C. A. Aug. 21, 1922. Spray carburettors. - A rotatable conical throttle valve works over two conical seats one having mixture ports and the other fuel orifices which are controlled simultaneously, the fuel supply being independently adjustable; means are provided for holding the automatic air valve closed or limiting its movement; a separate duct for slow running is provided, and the top of the float chamber may be in communication with the suction passage to serve, together with the control of the automatic air valve, as an altitude control. An annular fuel nozzle 19, Fig. 1<a>, has fuel orifices 39 and is arranged coaxially with a conical seating 25 formed as a partition between the vaporizing and mixing chambers and provided with mixture ports 28. The throttle valve, of the form shown in Figs. 1<c> and 13, has faces 29, 40, 41 to engage the seats 25, 37<a>, 38, and instead of being in one piece may be in three portions 29<b>, 29<c>, 29d, Figs. 8, 9, and 10, the last being the spindle portion and carrying two pins 29<g>, which enter the other portions and ensure that all rotate as one piece. The mixture and fuel-control portions, however, are forced against their respective seats by a spring in the recess 29i. The nozzle has an annular fuel chamber 20, Fig. 1<a>, which communicates with the fuel chamber 21 through a duct 21a. Filtering screens are provided between the chamber 21 and the float chamber and between the float chamber and the supply pipe. The fuel orifices 30 are formed in a tubular part 36 and their outlets may be independently controlled by a rotatable screwed sleeve 37 provided with a circular rack 44 actuated by a worm 42. The automatic air valve 59, Fig. 1<a> is mounted out of centre on a spindle 60 so that it tends to close against a shoulder 61 by gravity. The lower and heavier wing of the valve is ported at 63 and provided with an automatic relief valve 62 for use in the event of a back fire. The valve may be held closed at starting, or its opening limited or aided according to atmospheric conditions or altitude, by the mechanism shown in Fig. 2, in which a part 65 secured to the valve spindle carries arms 66, 67 adapted to engage a stop 69 carried by a ring 68 mounted loosely on the spindle and actuated by the driver through a flexible cable 70. 72. The stop may comprise a yielding portion 75 which limits the opening movement of the valve. In a modification of this mechanism, the ring 68 is toothed and actuated by a straight rack. The movement of the throttle valve is limited bv adjustable stops in the path of its actuating lever. For slow running, fuel is supplied through a duct 90, Fig. 1<a>, air being admitted to the duct from the air chamber 23 through a valve-controlled port 87, the mixture passing to the engine through ducts 92, 93, Fig. 13, in the upper throttle spindle 91. Thus this by-pass is cut out when the throttle is opened. A further altitude control consists in connecting the space above the fuel in the float chamber with the suction passage by a duct 94, 95, Fig. 2, open to the atmosphere at 100 and regulated by a screw valve 97. Helical or straight ribs facilitate mixing.