GB552472A - Improvements in or relating to driving bands or chains - Google Patents

Abstract

552,472. Driving-chains. P. I. V. CHAIN GEARS, Ltd., and ABBOTT, G. J. Oct. 7, 1941, No. 12927. [Class 24J [Also in Group XXIV] Relates to powertransmission driving bands or chains of the kind carrying a series of transversely movable slats the ends of which form teeth to engage depressions in the flanges of expanding pulleys. Such chains are described in Specifications 228,838, [Class 80 (i)], 242,416 and 335,366, [both in Class 24], the slats being mounted in the links. An improvement on this is described in Specification 519,851 wherein the slats are mounted in carriers capable of rocking about the axis of the pivots connecting each pair of links. According to the invention the links -have extensions adapted to co-operate with surfaces on the slat carriers which are thereby so tilted as to enable the slats to engage correctly the depressions in the flanges. The chain comprises a number of links A with pivots B on which are rockably mounted end plates C of the slat carriers. The centre parts of the slats D lie to the outer, and the ends D' to the inner side of the line joining the axes of the pivots. The end plates have a' central portion C' which supports the slats, and the arms of the plates, which are U-shaped, are shaped to 'engage slots E<1> formed near the ends of a cover plate E, Figs. 4, 8, held in place by a locking plate F having a central tongue F' which is bent down, to engage a slot E<2>. The plates have shoulders C' engaged by tongues E<3> bent up from the cover plate E to prevent the latter from being pressed too heavily on the slats. The central edges of each cover plate are bent down to form cam surfaces G which cooperate with hook-like cam portions A<1> on the links, as the chain comes on to a pulley, to cause the carriers to assume a radial position. As the carriers leave the pulley they are tilted forward and then, as they approach the other pulley they are tilted backwards to assume again the radial position. Further, the end plates C of the carriers are of such contour that by their inter-engagement, a prelimary backward movement is imparted before the final pre-setting operation by the extensions A<1> and cam surfaces G.