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 Dunlop Rubber Co. Ltd. discussing the properties and specifications for rubber engine mountings.
| Identifier | ExFiles\Box 65\4\ scan0092 | |
| Date | 29th September 1928 | |
| X8005 DUNLOP RUBBER CO.,LTD. TELEGRAPHIC ADDRESS: "DUNLOPS, PHONE, BIRMINGHAM". TELEPHONE: BIRMINGHAM CENTRAL 4108 P.B.E. 25 LINES EXTENSION No. YOUR REF: OUR REF: Technical Director's Office. FORT DUNLOP ERDINGTON BIRMINGHAM 29th Sept. 1928. Messrs. Rolls Royce Ltd. DERBY. For the attention of W.A. Robotham Esq. Dear Sirs: RUBBER ENGINE MOUNTING. With regard to our discussion with Mr. Robotham on the 24th. We have been considering this matter further as promised, and we are endeavouring to provide a mixing which while giving a closely similar load deflection curve, will at the same time give a lower stretch. As you kindly promised to consider any recommendations which we could make to you in connection with the future use of these mountings, we would bring before your notice the following points. 1. Could you consider giving the blocks a lower set up if possible, than .150" which was given to the samples in question? 2. To reconsider the possibilities of using a slightly harder mix. Your agreement to this would make the obtaining of a lower set rather easier. 3. To give the block an initial permanent set before using it. In this way a lower set during use should be obtained. On the question of the coefficient of expansion of the rubber packing ring, you will remember that Mr. Jones advised you that the expansion of this material is approximately 4.7 x 10-6, which is about twice as high as the coefficient of expansion for aluminium - this figure was given from memory, but it now appears that this should be altered to 4.7 x 10-5. Yours faithfully, For THE DUNLOP RUBBER CO. LTD. W Bond Technical Director's Office. | ||