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 from F.H.R. to Claude Johnson regarding the design and materials for a new worm and wheel back axle.
| Identifier | ExFiles\Box 2\6\ B002_X 140 141 157-page214 | |
| Date | 15th June 1912 | |
| T.C. Mr Warwald X/141 COPY. Beacon Hotel, Hindhead, Surrey. 15th June 1912. Mr Claude Johnson from F.H.R. With reference to new worm and wheel for our new back axle. As it is probably fairly easy to obtain or produce a straight worm, and as there are some doubts as to whether the straight worm is preferable to the Hindley worm, I shall be glad if Mr Bailey will ascertain what type of worm is used by the London General Omnibus Co. If they use a straight worm, I recommend that we have made a pair of gears of the ratios of 3.3. to 1 and the angle of obliquity of either 25 degs. or 30 degs. These would be excellent for comparing with those we have already made. Perhaps at the same time we could find out if the London General Omnibus Co. used any special metal for their bronze wheel as I had suggested the use of a bronze with a fair percentage of lead, which I should like to be tested, but I am afraid that for a good comparative test it would be advisable to stick to exactly the same metal as we used with the other two worms we are testing. The firm which has had much experience, in fact more experience than anyone, with worm drives, is Dennis & Co. of Guildford, who use a worm drive for small cars, and for heavy motor vehicles. I think the practice of the London General Omnibus Co. to be particularly based upon the practice | ||