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).
Design modifications for a pull rod fork, differential box, equalising shafts, and other components.
| Identifier | WestWitteringFiles\F\March1921\ Scan11 | |
| Date | 7th March 1921 | |
| To DA.{Bernard Day - Chassis Design} from E.{Mr Elliott - Chief Engineer} -2- E7/07/3/21 Contd. (6) The fork shown on N.715 at the top of the blueprint for the pull rod should have the shoulders narrowed, as previously mentioned, and the hexagon on the stem for holding it while the lock nut is tightened, should be deleted. Mr. Royce thinks that for the latter purpose a spanner can be used on the jaws. (7) The differential box should be reduced in size until the bevel teeth are .3 long instead of .450. This should reduce the diameter of the box by about .3, and a little more might be gained by making the die-cast cover a closer fit round the bevels, and avoiding some of the internal features. The central lever should be in sheet metal .125" thick, and should engage deeply with the two ends of the pinion shaft. No washers should be used behind the pinions. (8) The brackets for the equalising shafts should be cast in bronze for the few that are required, and the clamping bolt bosses should be altered as previously described, for the brake lever bosses. Mr. Royce thinks that spring washers and castellated nuts should not both be required for the bracket clamping bolts. (9) The equalising shafts should be reduced in diameter where they enter the supporting brackets, and the supporting brackets should be bushed with blind ended bushes having central holes for lubrication. (10) The locking collars on the foot brake equalising shaft should be of the split type with biting-in bolt as used on "Goshawk II" pedal gear shaft. (11) The differential box sheet metal levers should not be bushed at the end, but special narrow forks should be made having screwed shanks, and attached by turnbuckles to the pull rods. (12) The equalising shaft supporting brackets should be tapered in the plan view towards the root, as Mr.Royce thinks they appear too weak near the cross member. The width at this point should be increased to .5 or .6 E.{Mr Elliott - Chief Engineer} | ||