From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Copy of an 'Automotive Industries' article detailing the development of a Wheeler-Schebler carburetor.
| Identifier | ExFiles\Box 122\4\ scan0014 | |
| Date | 9th November 1934 | |
| COPY FROM "AUTOMOTIVE INDUSTRIES DECEMBER 27, 1930. WHEELER-SCHEBLER DEVELOPS CARBURETOR ------------------------------------ The accelerating device is of the dwell type continuing to discharge for a definite length of time. ------------------------------------ The Wheeler-Schebler Carburetor Co., Indianapolis, Ind., has developed a new Model T Carburetor in a 1 1/2 in. size which is an improvement on the Model T made in 1930. Several drawings of the new model are shown herewith. The body castings are made of cast iron, with a parkerized and stained finish. Metering parts, the accelerating device etc. are made of yellow brass, and the outside levers, links etc., are made of stamped steel and heavily cadmium plated. All bearings, and particularly those of the throttle shaft, choke shaft and float arm, are made of liberal size for long life. This carburetor has a fixed venturi A and a main nozzle B from which the metered fuel is discharged into the air stream passing up the venturi. When set for idling, the metered fuel is drawn up the idling tube C and discharged into the throttle barrel in the idling hole above the closed throttle disk. As the throttle disk D is opened, metered fuel is discharged from the lower idling hole in addition to that from the upper hole, and as the throttle disk is opened still farther, the main nozzle delivers additional fuel. The main nozzle is air-bled and the proper sizing of the air-bleed passage-ways, venturi etc., determines the mixture and pressure-drop characteristics. Metering of the fuel delivered by the main nozzle is controlled by the metering pin E and metering pin orifice F, the metering pin in turn being operated by a suction-controlled metering-pin piston G.{Mr Griffiths - Chief Accountant / Mr Gnapp} The metering pin has a two-diameter portion, one being of the proper size for controlling the economy mixture and the other for controlling the power mixture. Piston G is actuated by a spring, and the suction above the throttle (there being a hole from the top of the cylinder into the throttle barrel) in such a manner that when the engine is lightly loaded and the manifold suction is high, piston G is lifted and the metering pin is held in the "economy" position. When the load on the engine is increased and the suction in the manifold decreases, the piston drops (and with it the metering pin) to the "power" position. | ||