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).
Destructive tests comparing the resistance to 'burning out' of a fabric-on-driven-plate clutch versus a standard clutch.
| Identifier | ExFiles\Box 13\7\ 07-page056 | |
| Date | 30th August 1930 | |
| To A.{Mr Adams} From He/Sm. c. to SS.{S. Smith} HOT. c. to De. E.{Mr Elliott - Chief Engineer} c. to RY. X7305 He/Sm.6/MJ.30.8.30. X7480 X7305- 41/80 CLUTCH TESTS. We carried out some tests to determine the relative resistance to "burning out" of the clutch with the fabric on the driven plate and the standard clutch. The tests were obviously carried too far, as any driver who used the car under these conditions would undoubtedly have been asphyxiated by the fumes from the clutch lining. However, we were out to test to destruction. It is difficult to ensure that each clutch had the same heat units per min. put through it, and we should say that in this test the standard clutch was not quite so severely dealt with as the new type. The results show that the clutch lining definitely has an easier time when mounted on the driven plate. The lining of the standard clutch after this test had all the nature burst out of the material whereas the other clutch was not so bad. The outstanding trouble encountered was that the pressure springs on the "fabric on the driven plate" clutch all took a permanent set due to the increased heat transmitted to them. This set was such that the clutch would hardly drive the car. We think that the simplest procedure is to insulate these springs with a thin Ferodo packing such as | ||