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).
Speedometer drive gear ratio for the EAC.10 gearbox, comparing a sample Smith drive to the provided schematics.
| Identifier | WestWitteringFiles\R\October1927-December1927\ Scan116 | |
| Date | 1st December 1927 | |
| HS.{Lord Ernest Hives - Chair} FROM DA.{Bernard Day - Chassis Design} ORIGINAL DA{Bernard Day - Chassis Design}7/M1.12.27. EAC.10. GEARBOX - SPEEDOMETER DRIVE. X7310 X4367 X4308 (X108) 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} [Signature] | ||