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).
Magazine article detailing the features of the 'Convac' carburettor and the 'Bijou Reliance' horn.
| Identifier | ExFiles\Box 122\4\ scan0021 | |
| Date | 7th March 1914 | |
| The AUTO MOTOR JOURNAL MARCH 7, 1914. the “vacuum tube” so that the air pressure in the float chamber rises and a correspondingly greater quantity of fuel passes through the jet opening. The area of the air-valve and jet opening is so calculated as to produce a rich mixture for slow running while at all other speeds the proportions of air and fuel are such as to produce highest efficiency, i.e., a maximum of engine power with a minimum consumption of fuel. No less interesting is the design of the float-chamber, also shown in section. It will be seen that the needle-valve is controlled by a hinged lever which carries a movable weight. By moving this weight further outwards or inwards, more or less pressure is required to lift the lever and close the needle-valve. Any variation in the level of the fuel can thus be effected by simply moving the weight one way or another; i.e., inwards to lower the level, outwards to raise it. Nowadays with the many grades of spirit in use this is a convenience, the importance of which can hardly be exaggerated. A series of experiments, both in the laboratory and on the road, have convinced the designer that his theories are well confirmed by results obtained in practice. Especially, we are told, is this the case as far as low consumption at high speed is concerned, and we are informed that on a run of some 200 miles, at an average speed of over 30 m.p.h., the consumption of fuel (Benzole) worked out at over 35 m.p.g. with a 15 h.p. Talbot car. A few private users, who have had the carburettor fitted as an experiment, speak highly of it, so that the result of a contemplated official trial is looked forward to with confidence by the manufacturers of the carburettor. Finally the design and general arrangement of the “Convac” carburettor is such as to make it readily adaptable to any car. The float-chamber, for instance may be fixed on either side of the main body, so that it can be fitted to almost any engine without difficulty while every essential part of the carburettor can be got at from above, as is clearly demonstrated in our illustration. The movements of the air-valve can be followed by means of an indicator needle rising and falling with it, which is visible through a glass window in a cap on the top of the carburettor. [Image Caption] A.J. Left to right: “Convac” carburettor complete; interior of the dash-pot or suction chamber; regulating valve with indicator needle; lid{A. J. Lidsey} of float chamber. Notice the vent hole at the top. “Auto.” (Yellow Cover) Copyright. NEW HORN FOR LIGHT CARS AND CYCLECARS IN the AUTO. for January 18th, 1913, a description was given of a new horn which had just been put on the market by the Reliance Motor Horn Co., Ltd., of 89, Great Portland Street, London, W. This horn, which may be described as being of the hand operated mechanical type, has given such satisfaction during the time it has been on the market, that the manufacturers have been induced to produce another and smaller model which has been specially designed to meet the requirements of the owners of light cars and cyclecars. As we have pointed out on other occasions, it is of great importance—if appearance is considered at all—that the fittings should be in keeping with the vehicle. For the small cars which are now so popular, small accessories are required, but it is essential that although small, they must not interfere with their efficiency. The “Bijou Reliance” horn, the new model in question, meets this requirement in every way. It is, in fact, a replica in miniature of the larger model. The same method of operation and sound-production—which, we understand, has proved entirely satisfactory—is retained, as well as the general shape of the instrument itself. In view of the description previously referred to, it is unnecessary to describe the instrument in detail, but for those who do not know the horn, it may be said that the warning sound is produced by pulling a ratchet lever, thus causing a toothed wheel to impinge against a diaphragm, the vibrations of which produce the sound. The principal advantages of this horn are, firstly, its extreme simplicity, and secondly, the “bark” emitted is by no means objectionable, for although it is penetrating it does not rasp the nerves like some do. The price of the “Bijou,” with nickel plated finish, is £2 2s. [Image Caption] Bijou Reliance The “Bijou” Reliance horn for light cars and cyclecars. “Auto.” Copyright. [Stamped on right margin] RR 68 (25cm) (DB{Donald Bastow - Suspensions} 925 8-5-25) J.H.D. | ||