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).
The design and feasibility of a small, thick glass window for a gauge, mentioning a ball cock scheme.
| Identifier | ExFiles\Box 75\2\ scan0054 | |
| Date | 3rd February 1920 | |
| Contd. -2- Bn{W.O. Bentley / Mr Barrington}10/W3.2.20. could be made very small and very thick. We think it should be possible to make a perfectly safe permanent joint with a glass window say, 1" in diameter and .2" thick, the edges of which are formed spherically and ground into a copper or perhaps lead seat and held in place by a ring or union nut. Alternatively the window could be a lens with one side spherical rising to a maximum thickness in the centre of say .4". If we could make a job of such a window a fairly simple type of gauge is then available by using the Ball Cock scheme mounted somewhat as in the design sent through but with the Fulcrum located two or three inches from the back of the tank and the Ball Cock arm extended to the rear and carrying a moving dial with a cylinderical surface which rolls by the little window situated in the centre of the rear of the tank. We show this diagrammatically on the attached sketch. We think it would be worth while preparing sketches of such a window to see if we could make a practical success of it and it is our intention to get the Derby Crown Glass Company to make us a sample window. You will note that the moving dial renders it unnecessary to use a large window and this perhaps makes the scheme possible. It would have the advantage of giving us very accurate reading particularly when we use the side filler. We think it may be desirable to use a cover for the window, not because we are afraid of breakage but to avoid it being covered with dirt and to avoid the continual cleaning which would in time scratch the surface of the window. The slight matting of the outside surface combined with the thick glass would render it impossible to read the figures. Do you think it is worth proceeding with preliminary designs of this suggestion? Bn.{W.O. Bentley / Mr Barrington} | ||