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 Ltd. concerning the trial and specifications of a 10-inch Semi-Centrifugal Clutch.
| Identifier | ExFiles\Box 129\4\ scan0164 | |
| Date | 8th March 1938 | |
| 1110 Rm{William Robotham - Chief Engineer}/NRC.{N. R. Chandler}8/AP. March 8th 1938. Messrs. Borg & Beck Ltd., Tachbrook Rd., LEAMINGTON SPA. For the attention of Mr. Barker. Dear Sirs, Re. 10" Semi-Centrifugal Clutch. We thank you for your favour of the 7th inst., enclosing drawing No.22,000. We would like to try one Experimentally on the Bentley, and would be glad if you will kindly send us one from stock, for which our official order will follow. (Please mark this clutch for the attention of the writer.) With reagrd to the Thrust Springs, we think that, in view of the centrifugal assistance provided at high speeds, it would be desirable to fit springs rather on the light side, we suggest a total thrust of about 1300 lbs, as we know that the 10-A-3 clutch is on the verge of slipping if Brown springs of about 145 lbs. are fitted, but we would be glad to have your views on this point, bearing in mind that at about this poundage, slipping only occurs at moderate and high R.P.M. and not at low. We would be interested to know if the 10" Long clutch uses the same series of springs as the 10" and 11"-A-3, as, on scaling the drawing, (as an approximate guide), the length appears to be about .100 less. We note the dimension from the face of the flywheel to the face of the fingers is 2" against 1-27/32 for the 10-A-3, but fortunately our operating mechanism would still provide a wear allowance of about 7/16" on the travel of the throw-out bearing, without alteration. continued | ||