Patent ID: 6857631
Filing Date: 2005-02-22
Classification: B65H

Abstract:
1. A sheet feeding system in which sheets are fed in a process direction in a sheet feeding path by plural spaced apart sheet feeding nips formed by driven sheet feeding rollers and mating idler rollers, wherein said idler rollers are mounted for rotation on idler shafts and said idler shafts are mounted within mounting slots having two opposing side walls, and wherein said idler shafts have limited movement within said mounting slots relative to said driven sheet feeding rollers, and wherein said idler shafts are spring biased by a normal force spring biasing system towards said driven sheet feeding rollers to engage said idler rollers with said driven sheet feeding rollers to provide said sheet feeding nips with a desired normal force; wherein said normal force spring biasing system provides a nonsymmetrical spring biasing of said idler shafts towards only one of said two opposing side walls of said mounting slots in which said idler shafts are mounted, wherein said nonsymmetrical spring biasing is provided by a nonsymmetrical torsion spring with a central coil wrapped around said idler shaft and integral extending uncoiled generally linear wire legs anchored adjacent their outer ends in nonsymmetrical anchoring positions.