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).
Alteration report discussing brake troubles and potential improvements to the servo system.
| Identifier | ExFiles\Box 41\1\ Scan107 | |
| Date | 24th May 1929 | |
| Sg{Arthur F. Sidgreaves - MD} c. Hs.{Lord Ernest Hives - Chair} 13681 BY11/G.24.5.29. R.R.A.I. - ALTERATION REPORTS. Referring to Sg{Arthur F. Sidgreaves - MD}19/E.17.5.29. amd OY.4 of the 6th inst., I have discussed this matter with the people concerned at Derby, but cannot find that we have any trouble along the lines indicated in OY's memo. They have put forward on previous occasions certain proposals to attain a similar end, but although at the time they considered the proposals were effective apparently further use has demonstrated that the trouble had not been over-come. In view of the fact that they appear to have troubles which we do not, although we note they refer to English cars running in American and say that they have similar defects, we are inclined to consider that either:- (a) The conditions under which the brakes are being continually used are different from those in this country OR (b) That the manufacture of the servo parts calls for an improvement. We are of the opinion that the introduction of the hardened balls between the cam faces of the brake application levers will certainly eliminate any variation at this point which might occur, and increase the efficiency of the system, but we should have placed the increase in efficiency at somewhere round 20%, and cannot quite follow their suggestion that they find an 80% increase. An increase of the nature of the figures quoted viz. 80% would indicate very serious cross binding on the working parts, which of course would cause very great irregularities in brake characteristics in the absence of the suggested balls for transmitting the load between the cam faces. Our opinion at Derby is that we do not know of any reason for making a serious change of this nature, particularly as such a gain of efficiency of 80% could not be introduced without a re-proportioning of brake levers and load distribution. BY.{R.W. Bailey - Chief Engineer} Br | ||