Chain

摘要

In a transmission chain, interleaved links are articulably connected by connecting pins, each connecting pin comprising two rocker pins arranged to roll on each other. Pin holes in each of at least two overlapping link plates in each interleaved pair of link plates are shaped so that each rocker pin moves with one of the overlapping link plates and is engageable with a bend-blocking surface in the pin hole in the other of the two overlapping link plates when the two overlapping link plates are in a straight part of the chain. The engagement of the rocker pins with the bend-blocking surfaces of the pin holes prevents the links from bending backward beyond their straight condition, i.e., in an outward direction, opposite to the inward direction in which the links bend relative to each other when engaging a sprocket.

主权项

1. A chain, comprising:
a plurality of first links each composed of one or more first link plates; a plurality of second links each composed of one or more second link plates, the first and second links being arranged in alternating relationship with the first and second link plates of each adjacent pair of links being interleaved; and a plurality of connecting pins each composed of first and second rocker pins that have mutually engaging surfaces that allow the first and second rocker pins to roll against each other, each of said connecting pins extending through a first pin hole of each link plate of a first link and through a second pin hole of each link plate of an adjacent second link to connect adjacent first and second links together while permitting relative articulating movement of the connected links about pin axes along which said pins extend; wherein the permitted articulating movement of the adjacent links of the chain is sufficient to allow the chain, as it comes into engagement with a sprocket, to bend in an inward direction from a straight condition to a bent condition in which it is bent around the sprocket, and, as it disengages from the sprocket, to revert from said bent condition to a straight condition; wherein each first pin hole has a flat first bend-blocking surface and each second pin hole has a flat second bend-blocking surface; wherein each first rocker pin has a first contact portion capable of mutual contact with one of said flat second bend-blocking surfaces, and each second rocker pin has a second contact portion capable of mutual contact with one of said flat first bend-blocking surfaces, wherein said bend-blocking surfaces and contact portions are positioned so that, when a portion of said chain is stretched to a straight condition, said flat second bend-blocking surfaces in said portion of the chain are in contact with said first contact portions in said portion of the chain, and said flat first bend-blocking surfaces in said portion of the chain are in contact with said second contact portions in said portion of the chain, whereby said portion of the chain is prevented from being bent in an outward direction opposite from said inward direction beyond said straight condition; wherein each first contact portion is in the form of a plane and capable of surface-to-surface contact with one of said flat second bend-blocking surfaces; wherein each second contact portion is in the form of a plane and capable of surface-to-surface contact with one of said flat first bend-blocking surfaces; wherein each first contact portion of each connecting pin comes into surface-to-surface contact with one of said flat second bend-blocking surfaces, and each second contact portion of the same connecting pin comes into surface-to-surface contact with one of said flat first bend-blocking surfaces, when the part of the chain in which said connecting pin is located is in said straight condition; and wherein said portion of the chain, when in a straight condition, extends along a pitch plane to which said pin axes are parallel, and the first and second bend-blocking surfaces in said portion of the chain are disposed in planes parallel to said pitch plane.