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).
Technical discussion on spring specifications, including poundage, camber, and part numbering.
Identifier | ExFiles\Box 154a\4\ scan0031 | |
Date | 1st January 1937 | |
- 2 - EY.5/G.1.1.37. (3). Simplification of the spring drawing is purely imaginary, in any case it does not affect the springs. Spring Specification. (a). We must have a type number, we cannot revert to a long discursive description of the spring features to distinguish the type. (b). The piece number confuses nobody, and is the only number we quote on the identification plate. The reported confusion does not exist in fact. (c). A lubrication number is not called for on the drawing or identification, it was only used when the lubrication was added in the first place when it was obviously a necessity. (4). We always specify the springs to the poundages which are actually current at the time the springs are ordered. Is it suggested we make a wild guess or blindly go on ordering springs to an original poundage when bodies have gone up as much as 1 1/2 to 2 cwts. on the average. (5). We have no objection to issue an instruction to our Works that gives the actual poundage the specifica- tion of the body demands and give the Works a limit of ± 50 lbs., and I have instructed that this shall be done in future. (6). We see no reason for limiting the free camber to ± .100 it will only increase Firths difficulties. We specify a certain camber when loaded, and give Firths as much as ± 40 lbs. There is no need to put a limit on poundage, and again on position of eye by deflection. (7). It is not reasonable to quote a limit of ± 50 lbs. on springs so divergent as :- (a). Bentley front of 750 poundage. " " rear " 950 " (b). Phantom lll rear of 1400 poundage. The different numbers of plates and plate thicknesses call for variations in limits. | ||