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).
Forces and deflection issues in the foot brake linkage and servo system.
| Identifier | ExFiles\Box 121\1\ scan0254 | |
| Date | 19th April 1940 | |
| 1029 To Ev.{Ivan Evernden - coachwork} c. to Rm{William Robotham - Chief Engineer}/HH. Rm{William Robotham - Chief Engineer}/MHR.{M. H. Rigby}20/JH.19.4.40. I have noticed that on the drawing PL.98 of the L.H. foot brake linkage, the forces at the cam levers instead of neutralising each other as on all previous arrangements now both tend to pull the servo backwards in the same direction as the pull on the rod to the pressure plate. We have noticed on 4.B.50 that the deflection of the gearbox due to the pull on the pressure plate is very appreciable and besides more than doubling this effect, there will be a considerable bending stress on the servo motor which of course has no support at its outer end. Short of using a reversing lever in front of the servo to make the pedal give a forward pull on the servo, the only way to get over this difficulty seems to be to go back to a torsional shaft. Rm{William Robotham - Chief Engineer}/M.H.Rigby. | ||