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 S. Smith & Sons regarding design issues and suggested modifications for an oil valve thermostat's bellows.
| Identifier | ExFiles\Box 39\4\ Scan274 | |
| Date | 5th September 1932 | |
| C O P Y. S. SMITH & SONS, (MOTOR ACCESSORIES) LTD., 26/33, COX STREET, BIRMINGHAM. Ref. FGE/MM. 5th September, 1932. Messrs. Rolls-Royce Ltd., DERBY. Dear Sirs, FOR THE ATTENTION OF MR. H.{Arthur M. Hanbury - Head Complaints} ROYCE. OIL VALVE THERMOSTATS. With reference to the above instrument, we have experimented with the one which you returned with a view to making it operate at the lowest possible temperature. We find however, that the lowest temperature at which it will close the oil valve against a load of 3½ lbs per sq. inch is 45° Centigrade, and as we are using a spirit of the lowest possible boiling point, we are afraid that we cannot hold out any hopes of reducing this to the required figure unless the design is modified. The trouble is that the bellows is so short and the area so small that most of the pressure in the Thermostat is expended in overcoming the spring of the bellows. It is our opinion that the bellows should be at least twice as long as at present in order to obtain the necessary flexibility and we think it possible that your design of the casing might possibly allow of modification to accommodate this length of bellows, alternatively a greater diameter of bellows might be used, our next size being 26 m/m.{Mr Moon / Mr Moore} Awaiting your instructions in this matter. Yours faithfully, P.P. S. Smith & Sons (Motor Accessories) Ltd., (Sgd) F.E. Eckford. | ||