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 concerning the despatch and testing of two modified R.V.60 thermostats, including a data table of their thrust measurements.
| Identifier | ExFiles\Box 39\4\ Scan180 | |
| Date | 14th October 1930 | |
| TELEPHONE: EAST 0149. S. SMITH & SONS (MOTOR ACCESSORIES) LTD., BIRMINGHAM WORKS. HEAD OFFICE: CRICKLEWOOD WORKS, LONDON, N.W.2. Reply to:- 173-177, CLIFTON ROAD, ASTON, BIRMINGHAM. OUR REF. FGE/ELG. YOURS 14th Oct., 1930. Messrs. Rolls Royce Ltd., Nightingale Rd., DERBY. For the attention of Mr. Robotham. Dear Sirs, We are despatching under separate cover two of the R.V.60 Thermostats, the filling of which has been modified from the standard to suit your condition. The thrust developed by both of these is less than that of the standard instrument; for identification purposes an "A" and "B" respectively is scratched on the bottom of the case. The following are the differences:- Temperature Degrees Cent: Standard. T H R U S T. "A" "B" 20 Minus 32 Minus 40 Minus 40 30 " 27½ " 35 " 36 40 " 20½ " 28 " 30 50 " 11½ " 18 " 24 60 Plus 1 " 7 " 16 70 " 16 Plus 9 " 5 80 " 38 " 29 Plus 8 90 " 66 " 60 " 25 100 " 99 " 94 " 47 With reference to the above, measurements of pull and thrust are taken when the bellow is at a position corresponding to 6 m/m travel from the bottom of the stroke: the maximum thrust i.e. at commencement of stroke will of course be greater than the above figures. We think it probable that the "A" will suit your purpose, as it is considerably weaker at 75 degrees than the standard, and at the same time it exerts more pull for closing the shutters. We are continuing experiments with a view to arriving at a filling which will come between "A" and "B". Continued:- | ||