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).
Secret internal memorandum discussing improvements and alternatives for the clutch for EAC's models.
| Identifier | ExFiles\Box 22\1\ Scan127 | |
| Date | 4th March 1924 | |
| 4214 To HS.{Lord Ernest Hives - Chair} ST.{Capt. P. R. Strong} RG.{Mr Rowledge} } E.{Mr Elliott - Chief Engineer} DA.{Bernard Day - Chassis Design} } S E C R E T. R7/M4.3.24. CLUTCH FOR EAC'S. c. to CJ.Wor.{Arthur Wormald - General Works Manager}PN.{Mr Northey}BY. X.9480 X.4244 X.9580 X.4214 Some slight improvements are needed in this before we can turn it over for production. When Gos.11. was made we sent many alternatives to try, but assume very few were tested. We therefore again send Derby Lec.1836 - a clutch made with a ferodo disc. I believe these are in use, but even if we were to prefer it we should want much experience before we could put it in the hands of customers unless it was a remarkable improvement, and in long use by others. I do not remember seeing particulars of driven member of Hispano, which clutch I thought good to handle. Have they a drive member with less inertia than our thin plate, and have they a clutch brake? The clutch on PN{Mr Northey}'s car did stop with me but took a long time and we had to press it well out. If it does not stop it must be rubbing on the ferodo faces (possibly gravity) because there is only the one ball bearing to turn it, and several to stop it including a pair of oily gears. Supposing it is gravity could we arrange an end screw so as to just support it against a set-up spring? Goshawk 11. is on serrations so that there is only the weight of the revolving disc to gravitate against the ferodo surface. Could the same gravitating force be used to let it float against a stationary ferodo surface of a small dia. set by hand so as to touch and clutch wear would take it away? This scheme the clutch would stop more quickly going up a steep hill which would be good, and is a very gentle clutch brake that would do no harm. I personally hate an extremely quick stopping clutch by means of a vigorous clutch brake, because it is not a free clutch when out. Herein is enough to give you something to arrange and to test temporarily and permanently if any good is found. If it is necessary to still further reduce the inertia and if - (1) we cannot make a thinner steel plate, (2) we have no other metal, (3) we do not like the ferodo disc, and that bringing it to rest by the means herein suggested is not enough, can we reduce the dia. of the plate, and use increased spring pressure. Naturally this is not a good idea but is given as a possibility. How do we compare for inertia with others? Are we not now much better than 40/50? contd:- | ||