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).
Necessity and application of a clutch brake with the introduction of synchromesh gearboxes.
| Identifier | ExFiles\Box 13\7\ 07-page120 | |
| Date | 7th May 1932 | |
| Handwritten: X7480, x3310, Sg{Arthur F. Sidgreaves - MD}3/Ell.5.32, x7310, x7310 Faded Header: To E.{Mr Elliott - Chief Engineer} From SM. re Chromesh. To Wor.{Arthur Wormald - General Works Manager} Hs.{Lord Ernest Hives - Chair} The Brake. Sg.{Arthur F. Sidgreaves - MD} from E.{Mr Elliott - Chief Engineer} c. Wor.{Arthur Wormald - General Works Manager} Hs.{Lord Ernest Hives - Chair} E.1/HP.7.5.32. Referring to E.1/HP.7.5.32, it is correct that we have not used a clutch brake on the 20/25, it is something which we rather regret and I think we must be very, very careful before we drop the clutch brake on the P.II re Synchromesh - Sg.{Arthur F. Sidgreaves - MD}13/E.6.5.32. Whilst the introduction of synchromesh renders a clutch brake unnecessary on several gears, it still seems to be very necessary to enable one to get a gear in the first. We do not use a clutch brake on the 20/25 and on P.II we propose dropping the brake when synchromesh is used, especially with a P.II and rest. The only way in which the brake could be of use in the latter case would be in speeding up the change from 1st to 2nd (since the remaining changes up are all synchro) and also in initially engaging a gear with car standing, supposing clutch was sticking. A number of complaints - if we turned out a car on which one had to wait a long time before being able to engage a gear from a standing start, and it would be quite hopeless and an undesirable condition, especially in these days of traffic stops, if we had to put up with any delay in bringing the clutch to rest greater than that which exists at the present time. Is it not possible with E.{Mr Elliott - Chief Engineer} Synchromesh to arrange for the clutch brake to be operative from neutral to first or second and, say, from first to second. If, as I gather from your memo., this is the only other change when it would be of use. I think Hs.{Lord Ernest Hives - Chair} should conduct an experiment on one or two of his cars such as that referred to above and let us have his views. Sg.{Arthur F. Sidgreaves - MD} | ||