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 Hardy Spicer & Co. regarding the design specifics of a component's inner cone and lock nut angle.
| Identifier | ExFiles\Box 159\7\ scan0185 | |
| Date | 24th February 1938 | |
| MANUFACTURERS OF HARDY SPICER UNIVERSAL JOINTS & PROPELLOR SHAFTS. MANUFACTURERS OF GENUINE HARDY FLEXIBLE COUPLINGS. MANUFACTURERS OF BRITISH BOUND BROOK OIL-LESS BEARINGS. MANUFACTURERS OF COMPO OIL-RETAINING BEARINGS. Hardy Spicer HARDY SPICER & CO., LIMITED. REGISTERED OFFICE & WORKS - BIRCH ROAD, WITTON, BIRMINGHAM 6, ENG. LONDON OFFICE - 54, ST. {Capt. P. R. Strong} THOMAS STREET, LONDON, S.E.1. TELEPHONE - HOP. 0703. TELEGRAMS AND CABLES: "AUTOJOINTS, BIRMINGHAM" CODE: BENTLEY'S PHRAZE. TELEPHONE: BIRCHFIELDS - 4504/9. 6 LINES. Our Ref......JAD.MW Your Ref...R..Gry. {Shadwell Grylls} .7/AP 1375 ? 24th February, 1938. Rolls Royce Limited. D E R B Y. Dear Mr.Erylls, I understand your question quite well and I have definite views in connection with it. I think it is possible to cure your criticism of it in its present size, although actually the indications are that the pressure or load on the Inner Cone is too high for it to stand up. It could also be made larger at the driving end and decreasing at the Inner end. I will take an early opportunity of seeing you so that my views may be more definitely given. The 10 degrees angle of lock nut was adopted because it proved the most suitable experimentally in tightening up by its contact with the wheel cone. To get a good view, if this was gradually decreased, you would find less tendency for it to crawl up until if it was flat, it would cease to move and if it went the negative way, that is an internal angle, the wheel would undo. The 10 degrees gives as much self tightening as we could expect and more suitable from a friction loss point than a slower angle for spannering up the nut. I seem to have answered your question without offering but a suggestion, but I would be more detailed when I see you. Yours sincerely, J.A.Daniell ALL COMMUNICATIONS TO BE ADDRESSED TO THE COMPANY. (Logo: MEMBERS OF THE NATIONAL UNION OF MANUFACTURERS INCORPORATED) (Logo: THE SOCIETY OF MOTOR MANUFACTURERS & TRADERS LTD) | ||