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).
The gear ratio of a Smith speedometer drive being incompatible with the 1 to 1 ratio designed for the EAC.10 gearbox.
| Identifier | ExFiles\Box 51\3\ Scan017 | |
| Date | 1st December 1927 | |
| tu367 Hs. {Lord Ernest Hives - Chair} from DA. {Bernard Day - Chassis Design} DA {Bernard Day - Chassis Design} 7/MM.12.27. EAC.10 GEARBOX - SPEEDOMETER DRIVE. X.7310 X.4308 X.1087 X.4367 On the sample Smith double drive for a speedometer and screen wiper which has been sent to us we notice that there is a speeding up ratio much more than 1 to 1. In the schemes of the EAC.10 gearbox which we have recently sent you we have only provided for a ratio of 1 to 1. We are not quite certain that this speeding up ratio on the Smith gear is for, but it may be in connection with the Smith speedometer. If the 1 to 1 ratio we have sent you is not suitable for the combination of an A.T. speedometer and a Smith wiper will you please make any necessary alterations. It will be noticed that we have provided a slightly slower speed than hitherto. We assume that you can get a speedometer suitable for this speed. DA. {Bernard Day - Chassis Design} | ||