Patent ID: 8038560

Claim:
A power transmission chain provided over a first pulley having a sheave face with a conical surface shape and a second pulley having a sheave face with a conical surface shape, including: a plurality of links having front and back insertion parts through which pins are inserted; and a set of pins comprising a plurality of first pins and a plurality of second pins for connecting the links aligned in a chain width direction so as to be bendable in a longitudinal direction such that a front insertion part of one link and a back insertion part of another link correspond to each other, in which a first pin fixed to a front insertion part of one link and movably fitted in a back insertion part of another link and a second pin movably fitted in the front insertion part of the one link and fixed to the back insertion part of the other link move relatively in a rolling and contacting manner so as to enable bending in a longitudinal direction between the links, wherein, the pins move downward at, and before, a biting position where the pins move from a linear part to a circular part contacting the pulley, and at least two kinds of said sets of pins are provided, in which loci of rolling contact movement of the first pin and the second pin are different in each of the kinds of sets of pins, and wherein one or another of said at least two kinds of sets of pins are arranged randomly in said plurality of links, wherein a locus of a contact position of the first pin and the second pin is an involute of a circle, and a basic circle radius of an involute of the one of said two kinds of sets of pins is larger than a basic circle radius of an involute of the another of said two kinds of sets of pins, whereby resonance caused by polygonal vibrations due to repetition of up and down movement of the pins is reduced.