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 from Cambridge Instrument Company clarifying the use of their Vibrograph for measuring crankshaft vibrations.
| Identifier | ExFiles\Box 175\4\ img158 | |
| Date | 10th November 1933 | |
| X3987 TELEGRAMS: UNIPHOTO, KNIGHTS, LONDON. CODES: A.B.C. (5TH AND 6TH EDITIONS); WESTERN UNION: BENTLEY'S. TELEPHONE SLOANE 9146 (3 LINES). CAMBRIDGE INSTRUMENT COMPANY, LIMITED, MANUFACTURERS OF MECHANICAL & ELECTRICAL INSTRUMENTS OF PRECISION. [LOGO] REGD. TRADE MARK. WORKS: LONDON AND CAMBRIDGE. HEAD OFFICE AND SHOWROOMS: 45, GROSVENOR PLACE, LONDON, S.W.1. YOUR REF...........Hs{Lord Ernest Hives - Chair}/Gry.{Shadwell Grylls}5/KT. IN REPLY PLEASE QUOTE....FW/JS{Mr Johnson's Secretary} 10th November, 1933. HS{Lord Ernest Hives - Chair} Messrs. Rolls-Royce Ltd., Experimental Dept., DERBY. GRY{Shadwell Grylls} Dear Sirs, Your letter of November 8th, addressed to our Mr. Mason at Cambridge, has been passed on to us by him for reply. As we informed you in our letter of October 24th, at the speeds you mention our instrument will simply act as a Vibrograph and will record the actual displacements. If the instrument is used on the right range, the style will not come against the stop and no damage will be done to the instrument because the stops are fitted to prevent any damage occurring. There is no need for you have any doubt on this point. With regard to the crankshaft vibrations, we should like to know a little more clearly what is the exact meaning of this sentence. Are the lateral vibrations of the nose of the crankshaft longitudinal or transverse to the axis of rotation of the engine? If longitudinal we can neglect them, but if they are transverse they will upset the belt drive and it is doubtful if any. Torsiograph could be used directly on any part of the crankshaft near the nose. The instrument must be driven from a concentric pulley or piece of concentric shaft near a bearing where true circular rotation can be | ||