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).
Letter to Hoffmann Manufacturing Co. Ltd. regarding the results of an overload test on steering rollers.
| Identifier | ExFiles\Box 153\1\ scan0285 | |
| Date | 26th April 1939 | |
| c. Roy.{Sir Henry Royce} c. By.{R.W. Bailey - Chief Engineer} 1350 Experimental Dept. Rm{William Robotham - Chief Engineer}/PJH.3/MH.{M. Huckerby} 26th. April, 1939. The Hoffmann Manufacturing Co. Ltd., Chelmsford, ESSEX. For the attention of C.H.Smith, Esq. Dear Sirs, we are returning to you under separate cover 11 steering rollers which have indented badly on the external V track under 100% overload test. The position appears to be that with the core of the material in good condition, i.e. soft, some indentation will always occur at loads exceeding the normal maximum and that the amount of indentation will naturally vary with the depth of the case. According to case depth measurements we have made on some other indented rollers, the amount of indentation on the samples we have sent to you corresponds to a case of 0.030 or less. This we consider to be too thin. You will notice that the indentation varies round the circumference. This suggests eccentric setting up before grinding and corresponding variation of case depth. Our measurements so far indicate that rollers marked 'R.R.' and carburised by ourselves have cases of 0.040 or over, although these also vary round the circumference. We should be glad to hear the results of any measurements you make on the samples, and we assume that if you agree with us that the cases are thin, that you will credit us with the value of these rollers. | ||