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).
Secret technical memo with annotated diagrams detailing further views on a servo design.
| Identifier | Morton\M20.1\ img017 | |
| Date | 1st April 1924 | |
| To E.{Mr Elliott - Chief Engineer} & ST.{Capt. P. R. Strong} FROM R.{Sir Henry Royce} S E C R E T. R3/M14. 4. 24. Copy to CJ. DA.{Bernard Day - Chassis Design} HS.{Lord Ernest Hives - Chair} RS.{Sir Henry Royce's Secretary} BM. E.{Mr Elliott - Chief Engineer} A.{Mr Adams} C. SERVO. 19910 Further to my notes on EAC. servo. In the hurry of catching the post I did not get to the best for this design. The following are further views:- (1) We must have nothing that is likely to bind up the release, therefore pedal lever and its boss and the central pressure bolt should not have friction created by superimposed parts. (2) Inner ball bearing should be thus: This can be arranged for friction-less rotary and end motion. No groove so as to move freely endwise. Central pressure bolt might be 5/8 dia. Bearing on cross bar should be near con. rods as possible. These are good dia. & small face fit will control if no force to twist. Do not require large face area because of stickiness. Serrations to keep bolt & control ratchet lock washer from turning whose steps are now only .020 high. These must not be superimposed. This is screwed washer but may not be necessary. 3 or 4 bolts only or set screws here: locked plate washers. 2 or 3 driving pins only. Clear to prevent binding by uneven driving by pins. Short cylindrical fit will do, does not move under load but must not be likely to bind when pressed upwards by con. rod, therefore rod opposite bearing. When lifting these levers can be bound by up themselves but not one another. Three little springs in tunnels or 1 spring from round wire to fit over boss. (1) | ||