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 Borg & Beck Co. Ltd. discussing test results for 10' clutch thrust springs.
| Identifier | ExFiles\Box 129\4\ scan0027 | |
| Date | 26th October 1937 | |
| 111D c. By.{R.W. Bailey - Chief Engineer} c. Hs{Lord Ernest Hives - Chair}/LS. RM{William Robotham - Chief Engineer}/NRC.{N. R. Chandler}3/MH.{M. Huckerby} Messrs. Borg & Beck Co. Ltd., Tachbrook Road, Leamington Spa, Warwicks. 26th. October 1937. Dear Sirs, Re 10" Clutch Thrust Springs. We thank you for your letter TS/HTB/LK{L. King} of 11th. inst., and have re-tested the 6 springs brought back by Mr. Armitage, and our tests agree within half a pound of the original tests, our mean readings being 4 lbs. or 2 1/2% lighter than yours. According to your own test figures these springs average 141.7 lbs. or 6.1% under 151 lbs. We have recently tested the springs of two new and unused clutches, one showed a mean of 150.5 lbs. per spring, to which we can take no exception, but the other showed only 140.9 lbs. mean, and a few brown springs showed under 130 lbs. Experience with Thermoid facings indicates that, to insure freedom from slip, the springs should be not less than 150 lbs, and if we felt satisfied that the springs on customer's cars were up to this poundage, we could go ahead with changing over to Thermoid at our works and service depots, but, since we know that some of the clutches in question have springs very much under the above poundage, it will be necessary for us to dismantle each assembly, test the springs and replace as necessary, and in addition to the cost of the springs, there is the labour cost to consider, also there is the question as | ||