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).
Proposals for reducing the effort required to operate the Phantom III gearbox.
| Identifier | ExFiles\Box 94\2\ scan0059 | |
| Date | 11th November 1936 | |
| ✓ 328 E.H. C. H.{Arthur M. Hanbury - Head Complaints} Robs. Rm.{William Robotham - Chief Engineer} RHC.{R. H. Coverley - Production Engineer} E/HDY.{William Hardy}1/HP.11.11.36. Phantom III Gearbox. We send herewith N.Sch's 4740, 4949 and 4951 showing proposals for the reduction of the effort required to operate the 2nd, 3rd and top gear change. N.Sch.4951 shows increased travel of the change gear lever knob. This is now the same for top and 3rd as for boxes with the isolated gear lever. The increase of travel is from 3.0 to 3.5". This is partly obtained by increasing the length* of the change gear lever by 1" from 13.0" to 14", and partly by a reduction of the length of the stirrup levers on the rocking shaft from 1.400 to 1.285. We also recommend that we use 9° cones for the top and 3rd speeds as shewn by N.Sch.4661. The reduction of effort made by these two changes should be 25%. N.Sch.4740 shows plungers with 45° angle of thrust, which we think should be tried as they reduce the end thrust due to friction, and will therefore make for an easy tooth engagement. Only six plungers can now be used as the sliding piece has to be to N.Sch.4896. N.Sch.4949 shows the use of an extra groove to free the cones as first shown by N.Sch. 4674 but now modified so as to be suitable for production. The cones in this case are 8°. The plungers and springs are as on N.Sch. 4740. This scheme also shows the stronger universal coupling ring G.84900 which we think should be incorporated. * THIS SHOULD NOT CAUSE ANY DIFFICULTY WITH THE ACCESS TO THE SEAT ETC AS THE LOWEST SEAT IS TO BE RAISED 1". E/HDY.{William Hardy} | ||