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).
Improving an ignition timing device by reducing sleeve effort, noise, and specifying manufacturing tolerances.
| Identifier | ExFiles\Box 48\2\ Scan246 | |
| Date | 9th March 1925 | |
| - 2 - BY9/H. 9. 3. 25. The above matter is of the utmost importance to us, the facts of the case being that we have developed a device for advancing and retarding both the battery and magneto ignition by the same means and at the same rate, or any variable rate which may be required. We cannot, however, apply our scheme as advantageously as we wish to, unless we can reduce the effort required to operate the sleeve, and it appears to me that it is quite possible to reduce this effort by merely reducing the axial or endways pressure on the sleeve against its collar. Our further request to reduce the noise at the sleeve in operation seems to me possible of solution by accurately producing and grinding the parts so that the amount of slack which is very small indeed to permit of sleeve rotating without any particular friction, can be reduced to the minimum essential for its operation alone. It seems to me that this point is one of grinding to close limits so that we have say a positive clearance of .001 and a tolerance of .0005 up on the one piece and down on the other. Yours faithfully, M Harvey Bailey TECHNICAL PRODUCTION ENGINEER. FOR ROLLS ROYCE LIMITED. [Stamp: RECEIVED 9 MAR 1925] | ||