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 a supplier regarding slipping clutches and the testing of spring poundage for 10' and 11' models.
| Identifier | ExFiles\Box 129\1\ scan0293 | |
| Date | 29th September 1937 | |
| C. Roy.{Sir Henry Royce} c. Hs{Lord Ernest Hives - Chair}/LS. [Handwritten in blue ink: X] [Handwritten in red pencil: 110] Rm{William Robotham - Chief Engineer}/NRC.{N. R. Chandler}17/MH.{M. Huckerby} Messrs. Borg & Beck Co. Ltd., Tachbrook Road, Leamington Spa, Warwicks. 29th. September 1937. Dear Sirs, Re 10" and 11" Clutches. With reference to the proposed change over to Thermoid facings, our final decision has been delayed by slipping clutches on several experimental cars to which plates with these facings had been fitted. At first we suspected oil, but on dismantling we found no trace of oil, or any other reason for the trouble, and we naturally assumed that the brown springs were up to their stated poundage, but on testing the springs we were surprised to find they only averaged 135.6 lbs., or 10% under 151, whereas in our letter Hs{Lord Ernest Hives - Chair}/Smth. of May 15th.1936, we particularly requested to keep the spring poundage between 151 and 155 on the 10" model. We next tested about 40 brown springs, none of which had been overheated, the condition of the paint being perfect, and they varied from 133 to 143 lbs. On packing out the springs by means of washers to provide a thrust of 151 to 155 lbs. the slip entirely disappears. We had intended fitting Thermoid plates to customer's cars, in cases of complaint, but it now appears that we will be faced with the extra cost of dismantling the pressure plate, testing the springs and replacing them by stronger ones when necessary, whereas had they been up to specified poundage there is no question of slip. Yours faithfully, for ROLLS-ROYCE. | ||