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 from The British Thermostat Co. Ltd. discussing the specifications of thermostat part number E.86612.
| Identifier | ExFiles\Box 156\1\ scan0083 | |
| Date | 7th May 1935 | |
| Steadman Telephone: SUNBURY 456 (4 LINES). Codes: BENTLEY'S, WESTERN UNION. Telegrams & Cables: THERMOSTAT, SUNBURY COMMON. FBI INCORPORATED BY ROYAL CHARTER MEMBERS OF THE NATIONAL UNION OF MANUFACTURERS THE BRITISH THERMOSTAT CO., LTD. Makers of Scientific Instruments. DIRECTORS: M. {Mr Moon / Mr Moore} PAYNE. W. A. {Mr Adams} PAYNE. J. {Mr Johnson W.M.} E. {Mr Elliott - Chief Engineer} SHERLOCK. L. S. SWINNERTON-DYER. TEDDINGTON WORKS. Windmill Road, Sunbury, Middlesex. W.M.H/GN: May 7th, 1935. Your Ref: Hs {Lord Ernest Hives - Chair} /Std.20/KW: Messrs. Rolls-Royce Limited. DERBY. Dear Sirs, Thermostats - Part No. E.86612. We must apologise for the delay in replying to your letter of April 24th. Dealing with your points in turn - (a). The minimum length of bellows which we consider suitable for a temperature range of 7°C (75°C to 82°C) is 2" in the cold or contracted condition. Such a bellows can be relied upon to give at least 5/16" lift over this range. (b). The normal temperature range, taking the average of the various types of instrument which we are manufacturing, is 11°C. between opening and full open temperatures. We note that it is in order for the thermostat to open fully at a lower temperature than 82°C. providing that the opening temperature is correct. If it is inconvenient for you to arrange for the position of the valve head to be adjustable on the spindle the lower plate of the bellows may be provided with a screwed | ||