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).
Improvement in or relating to Carburettors for Internal Combustion Engines.
| Identifier | ExFiles\Box 1\7\ B001_X15 20 46 50 59-page286 | |
| Date | 11th June 1917 | |
| 2 118,861 rods or stays so that the parts can be taken apart speedily and easily and also reassembled. By constructing the spring valve as proposed by this invention, and provid-ing for a supply of air as stated, a stronger and more reliable spring can be employed and also the movable bell can be made heavier and of more sub-stantial construction. By providing a control valve in the fuel-supply conduit and allowing a little air to enter, the liquid in the nozzle can always be maintained at a proper level thus ensuring a sufficient supply under all conditions of engine running. Referring now to the accompanying drawings. Figure 1 is a sectional elevation and Figure 2 a section of a carburettor embodying the present invention. A is the expansion chamber, B is the float chamber, C is the air inlet control valve, D is the valve controlling the petrol supply, E is the throttle, F are the securing stays or rods, G is the air inlet and H the petrol inlet. The expansion chamber, as hitherto, comprises an outer tubular casing A¹ lined with gauze a between which and the casing itself is conveniently placed an absorbent lining, and an inner tube A² which is covered inside and outside with gauze a and conveniently also with absorbent material. The movable bell A³ is placed intermediate of the tubes A¹ A² and has its lower end resting normally on a conical seating j at the lower end of the base piece J of the apparatus and at its upper end has an inverted conical cover or end piece A⁶ which projects conveniently a short distance into the inner tube A². The gauze nozzle A⁴ up which the petrol is drawn is fitted into the supply pipe or tube A⁵ which communicates at its lower end with the conduit H lead-ing from the float chamber B. The air control valve C is in the form of a conical wire coil which encircles the tube A⁵ and projects into the inner tube A² of the expansion chamber. This coil according to the present invention is so constructed that there is a free or open air passage C at all times between the tube A⁵ and the convolutions of the coil. By this arrangement it is not necessary for the suction of the engine to expand or separate the convolutions of the coil before a supply of air when the tube A⁵ to take up the petrol from the nozzle A⁴. A supply of air when the engine suction is not strong enough to expand the coil is thus ensured and a more substantial spring can be employed than when there has been no free air opening through the spring as hitherto and it has been necessary for the engine suction to be strong enough to expand the spring coil before any air can enter. The lower or narrow end of the coil is attached to a boss or curb C² of a ring C¹ which is conveniently secured and clamped in a position between the lower end of the inner tube A² and a seating formed on the base piece J of the apparatus. The conical coil C may be inverted so that its narrow end with space c between it and the nozzle tube may be uppermost. According to this invention also, as above stated, the supply of petrol from the float chamber B to the conduit H leading to the nozzle is controlled by a screw down valve D formed on the end of a stem or rod D¹ to fit a valve seating in the conduit H and in this stem is a longitudinal slit D² open at its upper end to the atmosphere so that the level of the liquid in the tube A⁵ is main-tained equal to that of the float chamber at all times when the engine is running. The valve D is controlled by a lever D³ which can be set for any size of open-ing of the valve required and readily secured by a pin D⁴ which passes into one of a series of holes d in a plate on the end of the bearing sleeve in which the stem D¹ works. d¹ is a spring which locks the lever in its adjusted position. The upward movement of the bell is controlled by a ring A⁷ which acts as a stop and is secured to the upper end cover E¹ of the apparatus in which the throttle E is mounted. 118,861 3 In order that the apparatus may be taken apart readily and as readily assembled, the lower end of the outer tube A¹ fits into an annular groove j¹ in the base J and its upper end fits into a similar groove in the cover E¹. The lower end of the inner tube A² fits into an opening in the base J.{Mr Johnson W.M.} The cover E¹ and the base J are secured together and to the outer tube A¹ by four or other convenient number of rods or stays F which are pivotally connected to the base J at f². At their upper ends these rods are screw threaded; they pass into open ended lugs e on the cover E¹ and are furnished with clamping nuts F¹. By unscrewing these nuts the rods can be released and turned down so that the cover E¹ can be removed, then the outer tube A¹ and the bell A³ and inner tube A². The rods F in place of being outside the apparatus as shewn may be situated within the outer tube A¹ of the expansion chamber A and act as guides for the bell A³ which will be provided with lugs or the like to embrace the rods. Having now particularly described and ascertained the nature of our said invention and in what manner the same is to be performed, we declare that what we claim is:— 1. In a carburettor such as described the combination with an expansion chamber which expands towards the induction pipe from the inlet for the fuel mixture and to which air is supplied by a single opening of a spring-coil valve in the air supply inlet through which valve there is a free air passage when the coil is not expanded substantially as and for the purpose described. 2. In a carburettor such as described the combination with an expansion chamber which expands towards the induction pipe from the inlet for the fuel mixture and a movable bell in the chamber of a fuel-supply control valve to the fuel conduit and an air supply control valve comprising a spring through which there is a passage for free air substantially as and for the purpose described. 3. A carburettor such as described having an expansion chamber compris-ing an outer tubular member A¹ detachably secured to a base J and an end cover E¹ and an inner tubular member A² detachably fitted in the base J, a movable bell A³ located intermediate the tubes A¹ A² and securing rods F pivotally connected to the base J and engaging with lugs on the cover E¹ sub-stantially as described. 4. A carburettor for an internal combustion or explosion engine or motor having its parts constructed arranged and combined to operate substantially as described or illustrated in the accompanying drawings and for the purpose stated. Dated this 11th day of June, 1917. WM. J.{Mr Johnson W.M.} DOW, Agent for the Applicants. Redhill: Printed for His Majesty's Stationery Office, by Love & Malcomson, Ltd.—1918. | ||