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).
With diagrams showing six different designs for a plate, featuring variations in materials, slots, and corrugated centers.
| Identifier | ExFiles\Box 182\M21\ img009 | |
| Date | 8th September 1921 | |
| To HS.{Lord Ernest Hives - Chair} from R.{Sir Henry Royce} -2- R2/G7/9/21 Contd. which were reported to give great satisfaction. The sixth one is one in which the plate between the friction surface and the hub is corrugated, each having its own temperature and altering to its own diameter. R.{Sir Henry Royce} No1. FERODO ON STEEL No2. FERODO CARRIED ON STL. HUB No3. INVAR METAL AS USED FOR CLOCK PENDULUM ROD COEFFICIENT OF EXPANSION=O No 4. RADIAL SLOTS. No.5. SPIRAL SLOTS No.6 NO. OF CORRUGATIONS NOT NECESSARILY CORRECT CORRUGATED CENTRE. [Signature] 8/9/21 | ||