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 W. H. Colt, Ltd. discussing tests and modifications for a 40/50 model car fan, specifically concerning blade flexing.
| Identifier | ExFiles\Box 135\1\ scan0024 | |
| Date | 22th March 1932 | |
| X1509. W. H.{Arthur M. Hanbury - Head Complaints} COLT, LTD. BETHERSDEN, NEAR ASHFORD - KENT - TELEPHONE BETHERSDEN 6 TELEGRAMS COLT BETHERSDEN KENT BUSH HOUSE ALDWYCH LONDON. W.C.2 LONDON DIRECTOR: I. J.{Mr Johnson W.M.} O'HEA. F.C.I.S. TELEPHONE AND TELEGRAMS TEMPLE BAR 5112 EXTENSIBLE UNITS WHC/KH/K March 22nd, 1932. Messrs Rolls-Royce, Ltd. DERBY. RECEIVED 1932 MAR 23 11S Dear Sirs, For the attention of Mr. Lidsey. We thank you for your letter of the 19th inst. and hope that the modified 40/50 model car fan is by this time in your hands, and that tests may be made forthwith. As to whether the improvement is maintained throughout the whole range of fan speed your tests will speedily reveal. You will be able to ascertain at what speed the flexing of the blade envelopes will cease - if they will actually have their flexing limit under three thousand revolutions. It is reasonable to assume that if flexing occurs up to speeds like two thousand, then further flexing can be obtained by modifications either in the way of material or thickness of same. Obviously we cannot possibly submit a device which will at once meet all your requirements when we have had to carry out our tests without an actual Rolls-Royce chassis. The specimen submitted is therefore intended merely to demonstrate that more air can be furnished not only without greater h.p. consumption, but at an actual saving of such. From our own tests we have reason to believe that with the material employed for these test envelopes flexing should not cease under three thousand revolutions; also, we believe that the blades of your standard fan now supporting the envelopes have sufficient flexing. If experiments at your end should prove that they have not, further tests can be made with supporting blades for the envelopes with slightly more spring at their tip end than your present kind. [STAMP: NATIONAL SCHEME FOR DISABLED MEN] | ||