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).
Calculations and modifications for Phantom valve springs.
| Identifier | ExFiles\Box 66a\2\ scan0066 | |
| Date | 24th February 1928 | |
| E.{Mr Elliott - Chief Engineer} c. Hs.{Lord Ernest Hives - Chair} 48060 BY/Cgh{W Clough}6/G.24.2.28. PHANTOM VALVE SPRINGS. ---------------------- With reference to E2/M21.2.28. it has been proved that after the springs have been coiled and each end coil laid flat that only 1/6th of the thickness of the wire is ground away at/each end, consequently we find it necessary to calculate/the choc-a-bloc length from the actual number of working coils plus 1 2/3rds. Based on this the total coil clearances for the inner and outer springs respectively, as shown on LeC.2479 are .137 and .082" instead of .217" and .201". The Experimental Dept. found that the clearance for the outer spring viz. .082" was insufficient, therefore the bottom spring washer was lowered .075" giving a total coil clearance of .157". We attach sheet giving a complete set of figures for the original inner and outer springs, also for the revised outer spring, in accordance with the above. BY/Cgh.{W Clough} | ||