The design, function, and fixing of indicators and petrol filters.
| Identifier | ExFiles\Box 154\3\ scan0116 | |
| Date | 11th August 1920 | |
| contd. -2- 3. Indicator. The type of gauge sent is intended to work with the needle pivot horizontal, vertical or inclined at any angle. The pivot is pointed and the socket on the needle is also pointed so that it has no great friction surface when touching the glass. This actual gauge is used in all positions by the makers. The reason why an outer bracket is used on the Marmon is that there the faces of the instruments are not glazed but the whole instrument holder on the board is covered by a large sheet of glass after assembling the instruments. Naturally it would not be possible to insure the small end play desirable on the needle with this construction unless an outer bearing were provided for the needle. The position of the indicator face shewn on our A.522 is inclined at about 30°. Horizontal faces will not do because of rusting the needle. A blue print of the dial is enclosed. One can read accurately to a gallon, which is quite as near as one needs to read. There is the advantage in having a 180° dial, that if the radium paint on the needle becomes dull there is never any doubt as to which way it is pointing. We do not know whether the needle ever "hops" through 180° on these gauges, as happened on the original gauge on 4.EX, but see in case this should happen the half circle scale is an advantage. 4. Petrol Filter. The small size of the hand hole was an error in design. What was intended, and is now being done, is shown in A.522 enclosed. This shows the flange between bosses milled away. This is only a temporary arrangement to use up existing castings. The castings will be modified later. With this arrangement it is quite easy to get one's hand in. 5. Fixing of Indicators. We agree that this might be "smoothed up", but consider the ring and screws are a very good method of making an air and gas-tight joint. contd:- N.R. 235A (100) (T.00) H'S (S.H) 159 (11-8-20) G. {Mr Griffiths - Chief Accountant / Mr Gnapp} 2800 | ||
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).