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).
Technical memo discussing a provisional patent and design improvements for carburettors, including a sketch.
| Identifier | ExFiles\Box 15\6\ Scan067 | |
| Date | 30th November 1927 | |
| BY.{R.W. Bailey - Chief Engineer} from E.{Mr Elliott - Chief Engineer} C. to BJ. Hs.{Lord Ernest Hives - Chair} BY/HW. 7124 E1/M30.11.27. PROVISIONAL PATENTS - CARBURETTERS. X.8080 X.728 X.3933 Referring to BY9/G22.11.27., the specification No.222901 does not cover the suggested improvement in E1/M29.10.27. The latter is a new arrangement of the expanding type of carb., the choke tube being fixed, and a tulip shaped restrictor being drawn downwards or outwards by automatic means. In this form of carburetter it is the choke tube that is moved generally and this has a number of objections. The carburetter cannot have an unobstructed vertical gas-way. The sliding bearing of the choke is of large dia. and has appreciable friction. It creates leakage and gets jammed by drawing in dust. These difficulties and disadvantages either disappear or are considerably minimised when the choke remains fixed and the restrictor is moved as in sketch. It is best used in conjunction with an annular petrol feed through the chokes. A dashpot is provided attached directly to the tulip to damp out the effect of rebounding pressure waves from the induction pipe. The air valve could be made to operate directly from a position immediately beneath the restrictor. Regarding your 2nd. para, this idea is to make an expanding carb., the opening of which is controlled by a centrifugal governor driven by the engine and is hence a function of the speed. With such a carb. we could arrange for an depression desired at any speed. The depression in the carb. could be lower at max. speed than when pulling hard slowly if required. In our particular case it happens that we have a means ready to hand in our governor controlled oil relay for such a purpose. It should be understood that this has nothing to do with the carb. throttle valve which is operated as usual from the accelerator pedal or the throttle governor. The speed governor contd :- AIR PISTON OIL DASH POT | ||