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).
Test results and diagrams comparing standard and improved slow-speed servo types.
| Identifier | ExFiles\Box 73\1\ scan0150 | |
| Date | 17th April 1924 | |
| TESTS ON SLOW SPEED SERVO - STANDARD OR IMPROVED TYPE. First Table: | Eqvt. pedal pressure. | Torque put in to servo. | Torque output due to servo. | | Total torque output (servo T + T put in). | | |---|---|---:|---:|---:|---:| | | | Increasing loads. | Decreasing loads. | Increasing loads. | Decreasing loads. | | 46.5 | 217.5 | 792.5 | 932.5 | 1010 | 1150 | | 78.7 | 367.5 | 1179.5 | 1322.5 | 1547 | 1690 | | 111.0 | 517.5 | 1352.5 | 1389.5 | 1870 | 1907 | | 143.0 | 667.5 | 1492.5 | 1522.5 | 2160 | 2190 | | 175.0 | 817.5 | 1592.5 | 1592.2 | 2410 | 2410 | The following figures give the ratio pull from serv / pull to servo for the previous and standard, or improved type servo. Diagrams: PREVIOUS TYPE 45° THD. Labels: P, Q TO EQUALIZER, 4.175, 2.2= IMPROVED TYPE. 55° THD. Labels: P, Q. TO EQUALIZER, 4.175, 2.8= Second Table: | Eqvt. pedal pressure. | Ratio Q/P | | |---|---:|---:| | | Previous Type. | Improved type. | | 46.5 | 1.35 | 3.12 | | 78.7 | 1.20 | 2.83 | | 111.0 | 1.12 | 2.43 | | 143.0 | 1.03 | 2.17 | | 175.0 | 0.99 | 1.98 | | ||