GB850180A - Method and apparatus for determining, indicating and recording the irregularity of a flow of textile or like material - Google Patents

Abstract

850,180. Deluting and recording yarn &c. irregularities. BUTTICAZ A., TESAGE, C., and DEMBOWSKI, H. March 25, 1957 [May 3, 1956], No. 9749/57. Class 120(3). [Also in Group XXXVI.] The irregularity of a flow of textile material is determined by passing it between the plates of a condenser the capacity of which is compared with that of a reference condenser, the difference signal being compared with a reference signal. General principles (Fig. 1). A ribbon or thread of textile under test passes between a central plate 12 and an outer plate 13 of a condenser while a further plate 14 constitutes, with plate 12, the reference condenser. Plates 12, 13, 14 are all surrounded by guard plates. The output of an oscillator 18 is applied through the outer terminals of the centre-tapped secondary of transformer 17 to plates 13, 14. The centre plate is coupled by condenser 20 to the input of a tuned amplifier 22. The output of the amplifier is fed to a pair of detectors 23, 24. Detector 23 supplies automatic gain control for the amplifier to vary the datum of the signal at a rate determined by the time constant of an integrating circuit in the feed-back arrangement, while detector 24 feeds a signal to a differential amplifier 28 where it is compared with a continuous reference supplied by source 29. The difference signal operates a centre zero indicator to indicate the direction of deviation of thread thickness from the mean, a rectifier integrator 31 feeding meter 32 to enable the mean error signal to be determined, and an amplitude counter 33 which lights the appropriate one of lamps 34, 35 when the signal goes above, and below a predetermined value. A compound condenser construction is described with reference to Figs. 4-8, (not shown) which enables a differential condenser of size appropriate to the thread or material under test to be selected.