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).
And comparing various design schemes for fuel gauges and their components.
| Identifier | ExFiles\Box 75\2\ scan0074 | |
| Date | 3rd August 1920 | |
| Contd. -2- Dal/CB3.8.20. arrangement. So that a man's gauge indicating two gallons would be a warning to him that he must fill up again. We think it would be very nice if we could avoid the use of these wells as they make so many lumps on the tank. X.3882. The following are particulars of the drawings sent: "N" scheme 262, 263 & 273 are schemes for Mr. Barrington's suggestion of a direct reading instrument with a glass spy hole. These schemes were drawn before we knew how exacting the Octroi requirements were, and the marking of the scales may require modification in consequence. The principal points about these schemes are - (1) To make a joint between the glass and the retaining cover. "N" scheme 262 shews a joint made by a cork washer and a ground cone. "N" scheme 363 by two ground cones with a springs load. "N" scheme 273 by a ground cone and a spring diaphram. We have also considered a flat grass plate and indicated the arrangement as an alternative scheme on "N" scheme 262. We have discussed the question of the glass of these spy holes with the Derby Glass Co., and have arranged the glass to suit their suggestions. (2) It is considered desirable to provide a cover to prevent the spy hole becoming scratched by mud thrown over it. There are several suggestions for covers shewn on these drawings. "N" scheme 363 ad 373 making use of a spring lock, while "N" schem 262 shews a cover which tends to spring back into place. (3) The method of mounting the float and scale on its supporting bearings, and the method of mounting the whole instrument in the tank. There are five alternative schemes shewn on these drawings. We are disposed ourselves to prefer "N" scheme 262 in general, except that the method of retaining the bushes by washers rivetted to the spindles shewn on "N" scheme 273 seems better than the screwed bush. "N" scheme 518 is a magnetic indicator and is designed so that it can be completely erected outside the tank and pushed in without fastening up inside the tank. magnetic "N" scheme 519 is another gauge of which the arrangement shewn in Fig. 1 and Fig. 3 can be erected Contd. | ||