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).
Letter to S. Smith & Sons Ltd. outlining a scheme for a new thermostat design.
| Identifier | ExFiles\Box 156\2\ scan0271 | |
| Date | 19th August 1939 | |
| 1328 EXPERIMENTAL DEPARTMENT. Rm{William Robotham - Chief Engineer}/Ed.{J. L. Edwards}7/JH. 19th. August, 1939. S.Smith & Sons Ltd., Cricklewood Works, LONDON.N.W.2. For the attention of Mr. Grose. Dear Sirs, Many thanks for your letter of the 17th. instant, and we are enclosing a very rough sketch of a scheme which we think might work. Needless to remark it is by no means essential that this should be rigidly adhered to, if you consider it could be improved by modification. The general idea is as follows - When the temperature reaches 95 - 98°C the bellows expands sufficiently to close the needle valve, giving a sealed system. The pressure will then rise to 12 - 15 lbs/sq.in. and the outer valve lifts off its rubber seating against the loading of the bellows and the spring. We are not sure whether the loads due to bellows and steam pressure make this scheme practicable, but by suitable design of bellows and seat area we imagine a satisfactory arrangement could be reached. The essential points in this design are the two depths marked as shown, but the top dimensions may be modified to ± 0.25" if necessary. We should prefer the sizes shown however. Naturally simplicity and cheapness are also extremely important, and if possible prices should be comparable with our engine thermostats. Yours faithfully, FOR ROLLS-ROYCE LTD. | ||