Patent ID: 7125356
Filing Date: 2006-10-24
Classification: F16H

Abstract:
1. A chain and sprocket drive system comprising: a chain having a plurality of pairs of links being interconnected by pins; one or more generally circular sprockets which operate at varying speeds and the chain having external tensions imparted to it originating from sources other than the sprocket, the sprockets having a plurality of teeth spaced about their periphery, the sprockets having roots located between pairs of adjacent teeth for receiving the chain pins; each of the roots having a root radius extending between the center of the sprocket and a point along the root closest to the sprocket center in a radial direction; at least one of the roots having a first root radius, and at least one of the roots having a second root radius, at least one of the roots having a third root radius, the second root radius being less than the first root radius, the third root radius being less than the second root radius; and the first, second, and third root radii arranged in a pattern which continually repeats itself around the periphery of the sprocket, the repeating pattern effective to redistribute the external tensions imparted to the chain, reducing maximum tension forces exerted on the chain during operation of the system relative to the maximum tension forces in the system where the sprocket is a straight sprocket.