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).
Suspension spring deflection, buffer clearance, and camber for models EAC.7 and EAC.10.
| Identifier | ExFiles\Box 16\7\ Scan069 | |
| Date | 21th May 1928 | |
| BY.{R.W. Bailey - Chief Engineer} from Hs{Lord Ernest Hives - Chair}/Rm{William Robotham - Chief Engineer} c. to BY/HEB.{H. Biraben} 47410 Hs{Lord Ernest Hives - Chair}/Rm{William Robotham - Chief Engineer}1/LG21.5.28. SUSPENSION - STANDARD, EAC.7., & EAC.10. 47410 Thank you for the spring and frame details EAC.7. and 10. The deflection under normal load of EAC.7. front springs is 13% greater than present standard. Therefore the equivalent buffer clearance should be 13% > standard, or 1.75 + .23" = 1.98". Therefore we should like to know if we can take .250 off the present EAC.7. buffers without causing a foul; it will be remembered that we have already taken .5" off these buffers. With reference to EAC.10. These springs have 9.7% greater deflection under normal load than standard. Therefore their correct buffer clearance is 1.75 + .175 = 1.92". Will you please let us know if there is any objection at present to cutting .5" off EAC.10 buffers. If not, we can reduce the free camber of the spring by .33" making it say 2.950". We cannot quite understand why, with three front springs whose rating differs as much as 13%, the buffer clearance is specified in each case as 1.75". Actually this is the absolute minimum that can be used with the strongest of these springs i.e., the present standard. Possibly WW. increased the buffer size and expected us to make the necessary alteration in clearance. Will you please let us have a sketch of the buffers originally specified with EAC.7. and EAC.10 so that we can see how they compare with standard. Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} | ||