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 to Dunlop Rim & Wheel Co. Ltd. about loose spokes on a Phantom III 5' rim, proposing a design modification to the rim's base.
| Identifier | ExFiles\Box 159\1\ scan0286 | |
| Date | 15th June 1937 | |
| c Rm{William Robotham - Chief Engineer}/grys. 1370 15th. June 1937. BY.8/G.{Mr Griffiths - Chief Accountant / Mr Gnapp} ------- Messrs. Dunlop Rim & Wheel Co. Ltd., Foleshill, COVENTRY. For the attention of Mr. Sharp. ------------------------------ Dear Sirs, Phantom 111 - Re: 5" Type of Rim. --------------------------------- As the result of running one of our cars in France with this type of rim we find as previously explained to you by our Experimental Department, that the spokes are slightly loose in the wheel. In looking at the drawing it occurs to me that the possible cause of the trouble is the flat base to the rim, the spokes being fairly close to the centre of this flat base, with the result that the base takes up a slight permanent set as the result of the pull of the spokes. In the original type of rim the base of the rim of the wheel was curved, and had the effect of supporting the metal right up to the point at which the spoke was secured, whereas in the flat base type it is obvious that the necessary rigidity is in the vertical edges, and the wide space between these vertical supports and the point at which the spoke is attached gives you a weak bridge effect, and one would expect under such conditions to find the spokes working loose. A modification to the shape of the base of the rim would be very much more effective than increasing the gauge of the material from the point of view of removing this defect. I would like to have an opportunity of discussing this matter with you, particularly as we have obviously had to hold up the introduction of this rim in view of the fault which has developed. Yours Faithfully, FOR ROLLS-ROYCE LIMITED. (Signature) TECHNICAL PRODUCTION ENGINEER. | ||