Patent ID: 6213905
Filing Date: 2001-04-10
Classification: F16H

Abstract:
A roller chain and sprocket drive, comprising:a roller chain having a plurality of pairs of interleaved lengths, said pairs of lengths being interconnected by pivot pins, each of said pivot pins containing a roller member;first and second generally circular sprockets, each sprocket having a plurality of teeth spaced about its periphery, each sprocket including roots located between pairs of adjacent teeth for receiving said rollers,each of said roots having a root radius defined as the distance between the center of a sprocket and the point along said root closest to the sprocket center in the radial direction,at least one of said roots having a first root radius, at least one of said roots have a second root radius, said second root radius being less than said first root radius,said first root radius and said second root radius being defined so that the distance between the centers of adjacent rollers will be generally equal along said rollers seated in said sprocket roots, andsaid chain extending between said first and second generally circular sprockets to define a first strand length along a first length of said chain between a first initial engagement point with said first sprocket and a first initial engagement point with said second sprocket, said chain extending between said first and second generally circular sprockets to define a second strand length along a second length of said chain between a second initial engagement point with said first sprocket and a second initial engagement point with said second sprocket, said first strand length and said second strand length each varying as said chain travels around said sprockets and different portions of the chain are presented to said engagement points of said sprockets, said first strand length variation having a maximum variation defined as the difference between a maximum length of said first strand and a minimum length of said first strand, said second strand length variation having a maximum variation defined as the difference between a maximum length of said second strand and a minimum length of said second strands,a position of said engagement points of the first and second generally circular sprockets and the roller chain selected to provide favorable dynamics to the roller chain and sprocket drive.