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).
Modification of Bentley clutches by replacing black springs with green ones to correct excessive pedal pressure.
| Identifier | ExFiles\Box 85\2\ scan0357 | |
| Date | 29th June 1938 | |
| To RHC.{R. H. Coverley - Production Engineer} c. to IA. c. to Roy{Sir Henry Royce}/MS. c. to G/Mt. 212 Rm{William Robotham - Chief Engineer}/NRC.{N. R. Chandler}18/JH,29.6.38. CLUTCH BENTLEY. The present stock of 10" Borg & Beck clutches have Black springs, and these give a higher thrust poundage than was anticipated last November when the matter was discussed, resulting in excessive pedal pressure. We have arranged with Borg & Beck to reduce the poundage by replacing three of the Black springs by Green springs. Please do not fit any more clutches with all nine black springs. There are 2 clutches with Brown springs in Dept. 126, and one in Central Stores, these are O.K. for immediate use. Will C.C. please arrange to send 93 clutches now in Central Stores to Leamington by lorry (visiting Coventry) tomorrow to be modified by replacing three of the Black springs by Green ones. Borg & Beck have promised by 'phone to return 10 or 12 the following day. In the meanwhile, if there is any risk of a hold up in production, we have enough green springs in Exptl. Dept. to modify 9 clutches immediately. The balance of the clutches with all Black springs in Works and Test Dept. can be sent to Leamington for modification next week. Attached is copy of our letter of 29th. to Borg & Beck which clearly explains the reason for this change and also why the Black springs were decided upon. Actually the new combination of 6 Black and 3 Brown springs in each clutch provides the correct poundage which would have been the case if the Brown springs were up to their nominal poundage. Rm{William Robotham - Chief Engineer}/NRC.{N. R. Chandler} | ||