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 supplier S. Smith & Sons discussing the manufacture and design of a spring-loaded thermostat.
| Identifier | ExFiles\Box 156\1\ scan0091 | |
| Date | 15th May 1935 | |
| X4508 Exptl. Dept. Hs {Lord Ernest Hives - Chair} /Std.1/KW. 15th May, 1935. Your Ref: E.6.FGE/MM. Messrs. S. Smith & Sons (M.A.) Ltd., Cricklewood Works, London, N.W.2. Re Thermostats E.86612. Dear Sirs, We thank you for your prompt reply of the 10th inst. and note that you say you are able to manufacture a thermostat of the required type. However, you mention in your letter that you may have some difficulty in securing a range of 7 degrees with the expansion which we specify (.250") unless you adopt an external loading of the thermostat (e.g. a spring). This is the whole crux of the matter and is the reason for our letter to you. We realise that our requirements could more easily be met by employing a spring loaded thermostat, having been informed of this fact by the firm which at present supplies us with thermostats of this type; but since this would necessitate a change in design we are anxious to know whether you can produce a thermostat as specified. (We would agree to the detail alterations which you suggest, i.e., modified screw plug and spanner flats on external boss) as a practical production proposition, since the above-mentioned firm are unable to do so. (One of our objections to a spring loaded thermostat is that the valve would close instead of open if the bellows were accidentally punctured). We should like your estimate of the price of such a thermostat as supplied for production. If you are able to produce such a thermostat we should like you to send us a sample - we will send you an official order for same on receipt of your reply to this letter. | ||