Sprocket construction for a zero caternary chain

摘要

A sprocket construction for a zero caternary chain. In a zero caternary chain, a tensioning system is utilized to prevent caternary or slack in the chain and as a result of the high degree of tensioning, the bushings of the chain ride against the roots of the sprocket teeth. To prevent erosion of the sprocket teeth and bushings, the root diameter is modified to provide an enlarged operating pitch diameter for a predetermined increase in pitch length of the link. The pitch line clearance is enlarged so that it is equal to 2% to 25% of the working pitch diameter and produces a pressure angle of 20 DEG to 40 DEG .