Chains for Power Transmission.*
Page 19
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Summary of the Discussion on Mr. Hill's Paper.—Concluded from page 137.
Mr. CAUTLEY, of Hans Renold. Ltd., who opened the discussion following the reading of the paper by Mr. A. S. Hill, of the Coventry Chain Co. (1907), Ltd., stated that he knew of a number of chain-driven change-speed gearboxes that, for the past two years, had been in regular use on some heavy petrol lorries in France, and, he added, they were giving complete satisfaction. This speaker dwelt upon the necessity for the provision of Meant; of adjustment for all chains, and also expressed his opinion that neither his company's chains, nor those of ally other chain maker, could hope to excel, in point of efficiency, results which have recently been obtained with machine-cut doulde-lielical gearing, for which form of drive, Mr. Cantley added, an efficiency of 90 per cent, had frequently been obtained.
Mr. A LLINGHA M, of the Westinghouse Brake Co., Ltd., said that his company frequently installed chain gearing with ratios as high as 1 to 10, and one set of chains which his company had in use had a ratio of 1 to 13. On the question cf chain speeds, he quoted a case in the U.S.A. where the chain ran at the high rate of 4,200 ft. per min., but, he proceHled, he, personally, would not care to approach very closely to the chain while it was running. Although directly interested in the manufacture of chains, lie dirl not advocate their employment for pleasure cars. He left the question of chain drives for commercial vehicles to be discussed by subsequent speakers who had used them.
Mr. F. C. A. COVENTRY, of the Great Western Railway Co., on the basis of his experience with 15 chain. driven cars during the past five years, condemned the use of chains in no-uncertain terms, but his remarks were subsequently criticised with severity by other speakers, one of whom has no fewer than 300 chain-driven buses.
Mr. F. SEARLE, of the London General Omnibus Co., Ltd., stated that his company had iii service over 400 geardriven buses—with rack-and-pinion final drive, and 300 chain-driven machines. He was of opinion that the latter class of drive had proved to be more economical in working than the gear-driven type— at any rate, so far as London traffic was concerned. Regarding the chain-drive change-speed gearbox which is now being used on some of his company's buses, he said it was a case of Hobson's choice: it was the only means of attaining to the standard of silence set up by the authorities at Scotland Yard. He thought that they would not be able to meet the Commissioner's ideas of silence, unless they reverted to the use of a rope drive. Col. R E. CROMPTON, C.13., an old advocate of the chain drive, reminded the audience that Aveling, in 1862, employed chains on a traction engine, and he (the speaker) gave it as his opinion that, especially for large passenger vehicles, the transmission of the final drive by means of chains was far superior to any other form of drive ; it allowed greater flexibility in the chassis. He did not think that chain cases were so necessary as some simple form of deflector plate, which would prevent gritty matter from being thrown against the inner surfaces of the chains. He expressed the pleasure he had experienced while listening to Mr. Hill's paper, in which was recorded one of the triumphs of the mechanical engineer—the evolution of driving chains, from the crude block chains used by Aveling, in 1862, to the magnificent products of the present-day factories of Hans Renold, Coventry Chain, Westinghouse, and other makers.
Mr, C. R. GARRARD, of whom Cul. Crompton had previously spoken as the inventor of the roller Alin as used on bicycles, stated that Mr. F. J. Osmond, and not he, was, he believed, the true inventor of the roller chain.
Mr. A. C. CLIFFORD, of the Metro. politan Steam Omnibus Co., Ltd., told the audience that he was getting excellent results with his chain-driven Darracq-Serpollet buses, on some of which the chain-wheel ratios were 3i to 1, whereas Mr. Hill had stated that the ratio should never exceed 2i to I. for that class of chain.
Mr. LYONS SAMPSON and Mr. F. W. LANCHESTER also spoke.
Mr. A. S. HILL, in his reply, first expressed his satisfaction with the discussion, and then proceeded to describe how some of his tests for efficiency had been carried out: in this connection, he promised to supply certain plotted results, for inclusion in the proceedings.
Dr. H. S. HELE-SHAW, F.R.S., the President of the Institution, who occupied the chair during the reading of the paper and the subsequent discussion upon it, in moving a formal vote of thanks to Mr. Hill. said he thought the author had treated the subject most impartially; the resulting discussion had been free from personal acrimony.