Problems Concerning Detection Device in Speed and Tension Control of Running Yarn and Fabric

Abstract

In the previous paper, dynamic characteristics of a dancer roller as a detector of the feed control system of running materials were analysed, ignoring the presence of guide rollers. In the present study, are investigated the effects of the guide rollers on the detecting properties of the dancer roller.The followings are the conclusions: 1) The dynamic characteristics of a dancer roller system with guide rollers are expressed by a set of simultaneous differential equations, and therefore the numerical calculation of the frequency response of the system requires to use an electronic computer. 2) The dancer roller performs as a detector of feed control under a certain limit of frequency. This limiting frequency is proved to be the minimum slackening frequency of the (n+1)-th member of the running material. 3) The frequency response of a virtual dancer roller, the equivalent rotating mass of which is a sum of all rollers in the actual dancer roller system, is a fairly good approximation of that of the actual system, in a range below the minimum resonance frequency. Thus the minimum slackening frequency of the virtual system coincides with that of the (n+1)-th member of the running material in the actual system.