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).
Specification sheet for alternative armature springs for an S.S. motor, including poundage and rate data.
| Identifier | ExFiles\Box 64\2\ scan0216 | |
| Date | 20th November 1928 | |
| X 7625B BY/RD7/ML.20.11.28. To RHC.{R. H. Coverley - Production Engineer} [Obscured] C. EFC. ARMATURE SPRING FOR S.S. MOTOR. Please put in hand two each of the following springs which are alternative to D.71719:- D.71931 - Spring. D.71932 - " D.71933 - " These springs will give poundages as follows:- ARMATURE AT REST. IN GEAR. RATE. D.71931. 3.4 lbs. 10½ lbs. 9.8 lbs/in. D.71932. 3.58 " 13¼ " 13.8 " D.71933. 4.43 " 14½ " 14 " 2 Blueprints of each herewith. BY/RD. | ||