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).
Overload testing on four different fixing models to determine their margin of safety.
| Identifier | ExFiles\Box 179b\1\ img288 | |
| Date | 28th January 1933 guessed | |
| (2) Knowing the maximum load that ought to fall upon this fixing we ought to make the test I suggested recently, of over-loading, to see the margin of safety, and also the relative merits of say 4 models, as follows: (1) Plain grip with good nut and tight fit. (2) Parallel serrations split. (3) Parallel serrations pressed solid. (4) Square shaft. I fear (4) may move slightly before one feels the benefit of the square. Examine after 100,000 reversals of load, and increase the loading until the result of movement can be seen. You will remember that I suggested we could mount the damper body on the flanged end of a strong shaft, and slightly rotate the shaft by an eccentric, screwing down the relief valve spring to give any desired overloading. R.{Sir Henry Royce} | ||