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).
Differences between various Phantom steering box worm gears.
| Identifier | ExFiles\Box 67\4\ scan0143 | |
| Date | 10th July 1926 | |
| To CWB. from Hs.{Lord Ernest Hives - Chair} (8450) Hsl/LG10.7.26. PHANTOM STEERING. X8450 With reference to CWBlA/8.7.26. There should be no difficulty in distinguishing the .720 worm from the .940 worm or the 1.125 because the steering box of the .720 is considerably larger than that containing either of the other two. Once the two types of steering box have been seen together there is no chance of any difficulty in distinguishing them. 1.125 and the .940 have the same size steering box. If however the cover of the box is removed and the steering wheel rotated until the worm is visible, it will be observed that on the .940 worm there are a number of grooves cut in order to distribute the oil; the 1.125 worm has no grooves. With reference to the number of complete turns from full lock to full lock, these are approximately :- 1.125 worm = 1 3/4 turns. .940 " = 2 " .720 " = 2 1/4 " It will be observed that these are not in the ratio of the leads, the leverage of the steering box elsewhere differing. Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} Attached is a blue print shewing details for fitting the 1500 lbs. spring. F.74422 | ||