GB1461858A - Manufacture of strand-like material - Google Patents

Abstract

1461858 Automatic control of sliver thickness GENERAL ELECTRIC CO 16 April 1974 [20 April 1973] 16601/74 Heading G3R A characteristic (e.g. thickness) of a continuously moving strand-like material (e.g. yarn, fabric, fibre, wire) is controlled by a system in which the characteristic is measured by a fluidic device 12 connected to a fluidic circuit 14 which actuates at least one pressure sensitive electrical switch whenever the characteristic deviates from at least one predetermined value in a given direction, to thereby adjust the drive for the material and hence reduce the deviation. In the embodiment the fluidic circuit 14 comprises a pair of fluidpressure dividers 44 ... 52, Fig. 2, (not shown) which define upper and lower reference values with which the output of 12 is compared in respective comparators, each associated with a switch in series with forward and reverse windings of a stepping motor 16. This is supplied from a periodic source 20 (e.g. 30 secs. on, 30 secs. off) and drives a potentiometer 24 in a thyristor circuit 26 Fig. 4, (not shown) controlling the speed of a drive motor 30, for rolls 32. Similar rolls 38 are driven at constant speed by another motor 34. Thus the speed of rolls 32 are adjusted in discrete steps at 30 seconds intervals while the characteristic lies outside the predetermined values.