Canadian Electrical News and Steam Engineering Journal, Vol. 9

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Excerpt from Canadian Electrical News and Steam Engineering Journal, Vol. 9: January, 1899Rope transmission. - In a paper on power transmission by ropes and belts, read before the French Society of Civil Engineers, V. Dubreuil states that one great advantage possessed by ropes is that cyclical variations in the speed of the driving pulley are damped by the ropes, so that the speed of the driving pulley is much more uniform than that of the driver. Ropes are also useful when the two lines of shafting are not peifectly parallel. The velocity of the rope should not be less than about feet per minute, nor more than feet, while with belts a velocity of as little as 600 feet per minute may be used, but the maximum should not exceed feet per minute, above which the centri fugal force prevents the proper adhesion of the belt to the pulley. For great distances between the lines of shafting ropes should be used, though in exceptional cases they may be employed with as little as 12 feet between shaft centres, in general the distance should not be less than 20 feet. Spans of as much as 328 feet have been worked by ropes with only intermediate support. Under no circumstances should the diameter of the smallest pulley be less than 30 times the diameter of the rope, and in general the pulley ratio should not be greater than four to one. Three standard ropes of manila, hemp or cotton may be used. Hemp is much cheaper than cotton, and usually wears longer, but is less pliable. To facilitate estimates, the approximate weight ofa rope pulley may be taken as 5% pounds per groove for each inch of diameter, though single groove pulleys will weigh double this amount.About the PublisherForgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.comThis book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully, any imperfections that remain are intentionally left to preserve the state of such historical works.