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 changes to the specifications and manufacture of rubber blocks.
| Identifier | ExFiles\Box 45\2\ Scan230 | |
| Date | 14th February 1930 | |
| X4050 DUNLOP RUBBER CO.,LTD. TELEGRAPHIC ADDRESS: 'DUNLOPS PHONE BIRMINGHAM' TELEPHONE: BIRMINGHAM CENTRAL 4108 P.B.E. 25 LINES EXTENSION No. 339. YOUR REF: OUR REF: LEM/NGH.2. FORT DUNLOP ERDINGTON BIRMINGHAM 14. 2. 30. W.A.Robotham Esq., Experimental Dept., Messrs. Rolls-Royce Ltd., D E R B Y. Dear Sir, Further to your letter HS{Lord Ernest Hives - Chair}/RM{William Robotham - Chief Engineer}1/MJ. of the 13th inst. the change which you suggest in reducing the free length of the blocks from 1.250" to 1.175" will cause considerable delay as it will be necessary for us to make an entirely new mould for the purpose. Your letter does not state whether you still require a rating of 400 lbs at the working length of 1". If this is so, a rubber will be required intermediate between the two types ordered under your order No.99198, one of which was to have a deflection of .175" and the other .200" under a load of 400 lbs. starting with a free length of 1.250". One way out of the difficulty with regard to free length would be for us to grind down blocks from 1.250" to 1.175", but I take it that this method would not fulfil your present requirements. With reference to the last paragraph in your letter. We can understand that the permanent set of these blocks after a period of running at a working length of 1" might be considerable, but in the experiments which we have made to produce suitable rubber for these buffers, we have always endeavoured to keep the permanent set to the irreducible minimum, and if you have any difficulty in this connection, the only thing we can suggest is that a larger cross-sectional area should be employed to give a considerably lower load per unit area. Cont'd.{John DeLooze - Company Secretary} .......... | ||