GB233041A - Improvements in or relating to carbureters for internal combustion engines - Google Patents

Abstract

233,041. Stromberg Motor Devices Co., and Mock, F. C. Jan. 31, 1924. Spray carburettors.-To permit carburettors, and particularly those on aircraft, to work efficiently at different altitudes, air from the main intake may be drawn into the mixture conduit through a by-pass around the carburetting- chamber, said by-pass being controlled by a valve actuated by hand or by a barometric device, and the float chamber being at the same time subjected to the vacuum in the by-pass. The float chamber is preferably connected, in known manner, at both its upper and lower ends with the carburetting- chamber in order that the carbburettor may work in the upright or inverted position. The carburettor body, preferably of aluminium, is in two portions 23<1>, 24<1> meeting at 25<1> and the lower portion is provided with an air horn 151 and a choke tube 28', a by-pass to which is formed by a passage 165, Fig. 3, provided with a valve 167. A float 37<1> is connected to a lever 38<1>, Fig. 5, which actuates a valve 42<1> engaging a hard steel bushing 46<1> in a tubular member 45' inside a wire strainer 48<1> held, against vibration, by a spring 56<1>. The main fuel nozzle 29<1> is similar to that described in Specification 233,216 and has a tubular arm 78<1>, 79<1>, Fig. 4, with a calibrated nozzle 81<1> to admit air from a space 152 to a well 76<1>. The nozzle itself has a deflecting-flange 86<1> and discharge passages 87<1> in a conical head 88<1>. Fuel from the float chamber passes through conduit 153, Fig. 4, to a space 67<1> at the base of the nozzle, whence it passes through a calibrated orifice 66<1> in a plug 64<1> to a comparatively long and restricted passage 159, the purpose of which, in conjunction with air admitted to the main nozzle from the slow-running passage is to compensate for the tendency of the engine suction pulsations to produce an over-rich mixture at wideopen throttle position. The slow-running device is substantially similar to that described in Specification 233,217 and comprises a slow-running tube 92<1> with air inlets 161 and a calibrated passage 89<1> at its lower end which is in communication with the main nozzle passage through a conduit 85<1> and ducts 157. Air is admitted to the annular space 93<1> through a plug 94<1>. The slow-running mixture passes through the conduit 102<1> and through a plug 104 to an eccentrically-arranged outlet 170, the position of which relative to the throttle edge can be varied by rotating the plug by an arm 112<1> moving over a quadrant 113<1>. The valve 167, Fig. 3, in the by-pass 165 may be actuated bv hand or by a barometric device to serve as an altitude control, and a passage 176 in communication with the by-pass 165 communicates with the bottom of the float chamber through a duct 175, and with the top thereof through a port 172, Fig. 4, provided with a check valve 174, which closes this passage when the carburettor is inverted, suction then taking place through duct 175. An additional nozzle 177 provides for a fuel supply when the main nozzle 29' is inverted, each of these transmitting suction when the other is supplying fuel. The throttle-actuating arm engages through teeth an arm keyed to the spindle and carrying adjustable stops. Three of the carburettors are shown installed on a radial air-coolea engine.