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).
Slack and wear issues related to the Phantom III hand brake lever's key and keyway fitting.
| Identifier | ExFiles\Box 92\4\ scan0340 | |
| Date | 9th June 1937 | |
| To RHC.{R. H. Coverley - Production Engineer} from Rm{William Robotham - Chief Engineer}/AFM.{Anthony F. Martindale} c. HFS. c. W. c. Da.{Bernard Day - Chassis Design} c. Hdy.{William Hardy} c. By.{R.W. Bailey - Chief Engineer} c. Mx.{John H Maddocks - Chief Proving Officer} 306 RM{William Robotham - Chief Engineer}/AFM.{Anthony F. Martindale}19/AP.9.6.37 PHANTOM III. HAND BRAKE LEVER. The Ph.III. hand brake lever is keyed to a shaft which is its fulcrum, and to the same shaft is also keyed the lever operating the brakes. On some of the cars in the Test there is slack between keys and keyways resulting in lost movement of the shoes for a given travel of the H.B. lever. The cars in the Repair are rather worse. On 33-EX. in the Experimental Dept. the slack amounts to .025" at the end of the H.B. lever (approx. .018" slack in the keys) while on 32-AX. which has just been prepared for a 10,000 miles test the slack is .075" or .022" in the keys. The duty the keys have to do is really too great for their size and some deformation of the metal takes place in course of time. At the same time careful fitting of the keys and adequate tightening of the pinch bolt in the first instance should minimize the wear. The keys should be a tight fit on the driving surfaces, and not tight on the ends of the keys, as we noticed in one instance. Will you please see that the standard of fitting of this part is as high as possible, in order to save trouble in the future. Rm{William Robotham - Chief Engineer}/AFM.{Anthony F. Martindale} | ||