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).
Modification to speedometer cables to create a deliberate weak point to prevent gearbox damage.
| Identifier | ExFiles\Box 151\2\ scan0125 | |
| Date | 27th December 1933 | |
| X4698 LES To BT. {Capt. J. S. Burt - Engineer} from HDY. {William Hardy} HDY. {William Hardy} 2/MP.27.12.33. c. Wdr. E. {Mr Elliott - Chief Engineer} Hs. {Lord Ernest Hives - Chair} De. RHC. {R. H. Coverley - Production Engineer} Speedometer Cables for Cars with Controlled Dampers. ----------------- The Experimental Department have requested that means be provided to prevent a seized speedometer cable from causing failure of the square shaft in the gearbox and so throwing the damper control out of action. We suggest a reduction of the diameter of the cable end as shown on N. Sch. 3923 herewith. The diameter we show gives 80% of the strength of the square. It should be ascertained experimentally that the reduced section will fail before any other part of the drive. HDY. {William Hardy} | ||