GB658963A - Thread gauging instruments - Google Patents

Abstract

658,963. Testing threads; tension arrangements. GUIMBRETIERE, L..F., and SOREZ, E. J. Nov. 18, 1947, No. 30604. Convention date, Nov. 25, 1946. [Classes 120(ii) and 120(iii)] [Also in Group XIX] Apparatus for continuously gauging a thread comprises a narrow channel filled with mercury or other non-wetting liquid, means for driving the thread obliquely through the liquid surface in the longitudinal plane of symmetry of the channel and means for detecting variations in the liquid level at the point where the thread passes through the surface. The surface tension of the mercury produces an almost vertical liquid face, Fig. 7, in the vicinity of the thread, which advances or recedes as the thickness of the thread, and hence the width of the narrow spaces between the thread and the sides -of the channel varies: This liquid face may reflect a'beam of light which is focussed onto a moving photographic film to produce a record of the varying thickness. The mercury is continuously replenished to remove impurities and, as it flows past the thread a drop in the general level within the channel occurs, so that in an alternative recording arrangement, Fig. 10, electric contacts may be arranged in a horizontal line to be engaged by the upper surface only. Those contacted by the mercury complete circuits throughcorresponding solenoids arranged to act, through a system of links, on a recording arm. In a further arrangement, the solenoids are replaced by electrically-operated counters each of which is adapted to register the number of points along the thread at which the thickness falls within corresponding limits. The length of the variations in thickness may be taken into account by periodically breaking the circuit through the counters. The figures so obtained may be used to construct a frequency curve showing the number of points along the thread having given thickness, or a representation of such a. curve may be constructed by replacing the counters by ballreleasing means respectively associated with adjacent vertical chambers. Instead of counting the pulses, they may be recorded electro-chemically on a moving recording-material. In order to maintain a constant tension on the thread, the latter is arranged, as it is drawn through the mercury, to rotate a copper disc between the poles of permanent or electromagnets.