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).
Testing and performance of different clutch servo springs.
| Identifier | ExFiles\Box 93\3\ scan0355 | |
| Date | 18th August 1937 | |
| To By.{R.W. Bailey - Chief Engineer} from Rm{William Robotham - Chief Engineer}/NRC.{N. R. Chandler} 312 Rm{William Robotham - Chief Engineer}/NRC.{N. R. Chandler}3/AP.18.8.37 Re. P.III. Clutch Servo. The square section servo spring F.89637 has been tested and only shows 60 lbs. at 1.700 deflection against 75 lbs. called for on the drawing. The original round section spring shows 77 lbs. at 1.7 deflection. When tried on a present production chassis with R.R. plate and shorter pedal travel, the action was not satisfactory, and even when the stronger round section spring was tried, very little useful assistance was given. A new square section spring of rating equal to the old round one would be satisfactory with increased travel and cushion plate, but not on the present standard chassis, for which a new lay-out of forces would be necessary. In view of the fact that the cushion plate will so soon be standard, we suggest that the servo spring should not be fitted on Production will we have tried one on a Production chassis with cusnion plate but shorter pedal travel. Rm{William Robotham - Chief Engineer}/NRC.{N. R. Chandler} | ||