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).
The testing and implementation of Thermoid faced cushion plates for the Phantom III clutch.
| Identifier | ExFiles\Box 93\3\ scan0353 | |
| Date | 17th August 1937 | |
| To Sg.{Arthur F. Sidgreaves - MD} c.c. to Hs.{Lord Ernest Hives - Chair} c.c. to By.{R.W. Bailey - Chief Engineer} c.c. to RHC.{R. H. Coverley - Production Engineer} 312 Rm{William Robotham - Chief Engineer}/NRC.{N. R. Chandler}15/JH.17.8.37. re Phantom III Clutch. A Thermoid faced cushion plate has now run over 11,000 miles on 32-EX and all reports have been entirely satisfactory; another has now completed 11,000 miles in America without trouble. Similar plates are running on three experimental cars, and 21 have already been fitted to customers cars, the first of these has been running since May 26th, and in no case has any further complaint been received. The delivery position of the 100 on order from Borg & Beck is now such we can commence to fit them on production at once. With regard to replacements on customers cars, we are at present fitting complete new cushion plates, as above, in cases of complaint, but we have under consideration a scheme for fitting Thermoid segments to the existing R.R. clutch plates, and this would effect a very big saving in cost, as the whole of the existing plate would be used, the facings only being changed from Ferodo No. 6 to Thermoid. A plate of this description has been running in 33-EX since July 27th, and has done 1021 miles including 500 starts in a day. So far it is promising but sufficient experience with it has not yet been obtained to justify standardisation for replacements especially in respect to the possible risk of the segments bursting during a high gear change. Spinning tests are being arranged. With regard to the clutch pedal servo spring, this is now satisfactory in conjunction with the cushion plate and increased pedal travel, as on 32-EX and 33-EX, but as recently tried on a production chassis with a standard R.R. plate and old pedal travel, the action is not so satisfactory, and will require further development, and schemes to overcome the difficulty are already in hand. Rm{William Robotham - Chief Engineer}/NRC.{N. R. Chandler} | ||