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).
Addition of a clutch brake to synchro-mesh gearboxes.
| Identifier | ExFiles\Box 13\7\ 07-page121 | |
| Date | 11th May 1932 | |
| Y7480 To Sg.{Arthur F. Sidgreaves - MD} From Hs.{Lord Ernest Hives - Chair} c. to E.{Mr Elliott - Chief Engineer} c. to Wor.{Arthur Wormald - General Works Manager} c. to PM. Hs.{Lord Ernest Hives - Chair}4/WJ.11.5.32. SYNCHRO MESH AND CLUTCH BRAKE. X7310 Replying to Sg.{Arthur F. Sidgreaves - MD}3/E11.5.32. All cars both 25 HP. and P.11 which have been fitted with the synchro-mesh gearbox, have never been run with the clutch brake. There has never been any comment as regards the clutch stopping, and there has never been any difficulty. The addition of the clutch brake is definitely going to add to our difficulties on the P.11 synchro mesh and at the present time the only prospect we see of a satisfactory P.11 gearbox is by reducing the drag to the minimum by using a lower oil level. This will be all discounted if we have to fit a clutch brake. There is always one very easy way of stopping the clutch on the synchro mesh box, that is, if you move the gear lever slightly in the direction of either top or third you will engage the synchro mesh cones which will immediately stop the clutch and allow any gear to be put in. We agree that this is not altogether desirable or what we expect should be done, but it means that a car with a synchro mesh box in which the clutch does not stop is in a much better position than a car without the synchro mesh box in which the clutch does not stop. Another point with a synchro mesh box is that we have two pairs of continuous gear running round in the box always which create a certain amount of drag in the oil which does provide more tendency for the clutch to stop than on a standard box. We sincerely hope we shall not be forced into a clutch brake, and we do not believe we shall find it necessary. Hs.{Lord Ernest Hives - Chair} | ||