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).
Letter to Borg & Beck Ltd. discussing experiments on clutch plates and requesting new samples for testing.
| Identifier | ExFiles\Box 129\3\ scan0318 | |
| Date | 25th June 1936 | |
| X1110 Exptl. Dept. Hs{Lord Ernest Hives - Chair}/Smth.6/KW. 25th June, 1936. Messrs. Borg & Beck Ltd., Tachbrook Road, Leamington Spa. For the attention of Mr. Barker. Dear Sirs, From the experiments we have done up to date, Ferodo "No.6" seems to give an excellent take-up on the Bentley clutch, and we think we ought to pursue this development. Its disadvantage is that it requires a slightly higher thrust spring load than F.F.1. as its /u is .32 as against .35. We have done whirling tests on a "No.6" lined 10" plate, however, and find that, if the material is hot, it spreads off the rivets at 4,800 r.p.m. in a similar manner to the Phantom III. We should like you therefore to make us two plates in which the inner rivets are made common to both facings, one with the standard thickness of facings and the other with .165" facings. The rivet heads should be .032" countersunk as in the Ph.III plate. If you have any objection to the thicker facings on the grounds that the clutch will not accommodate them, you will no doubt let us know. We are passing you an order for these. The sample of English made "Hycoe" is now to hand. It appears to be identical with the American variety, but we will do whirling tests on the built up plate when it arrives. We still think it worth while to try a Ph.III plate made of a different gauge steel, to determine whether or not the rate of the cushioning has any effect on the take up. We believe you have in hand a .048" thick plate, and would like you to try to make a .072" one also. Yours faithfully, | ||