Abstract: An ultraviolet ray measuring apparatus is provided which comprises first and second photodiodes having substantially the same spectral sensitivity at least in an ultraviolet band, and a first optical filter arranged in front of a light-receiving face of the second photodiode, for shielding only light of at least a part of the ultraviolet band. The apparatus measures the light intensity and its accumulated value in accordance with the difference between electric signals output from the first and second photodiodes. It is preferable that a second optical filter, which has a main transmitting band in the ultraviolet band and a sub-transmitting band in the visible light range, be arranged in front of the light-receiving faces of the first and second photodiode.

Abstract: The thermal shrinkage properties of yarn are measured by applying heat treatment to the yarn while it travels through a straight yarn path formed between a feed roller and a draw roller. The peripheral speed of the feed roller is set at a desired constant peripheral speed V.sub.1. The tension T of the yarn is detected at the downstream of the feed roller, and the peripheral speed of the draw roller is controlled at a speed V.sub.2 so that the detected tension T becomes equal to a desired preset tension T.sub.0 of the yarn. The thermal shrinkage S(%) is measured through the computation of S=[(V.sub.1 -V.sub.2)/V.sub.1 ].times.100. If the controlling of the peripheral speed V.sub.2 of the draw roller is effected so that V.sub.2 /V.sub.1 =a desired constant value, the detected tension of the yarn can be used for measuring the thermal shrinkage stress of the measured yarn.

Abstract: A yarn tension meter comprising a tension detecting unit, a rotary guide, at least one force transducer and fixed guides which, without damaging a running yarn, permits measurement of tension values of the yarn with a high degree of accuracy.

Abstract: In a yarn winding apparatus, yarn is fed from a spinning frame or the like at high speed, and is wound on bobbins. Shifting of yarn from a full to an empty bobbin is carried out smoothly. A plurality of bobbins is fitted on a revolving arm, and each individual bobbin is positively driven from an independent power source.A plurality of independent drives are installed on the back of the revolving mechanism and bobbins are fitted on its front. Intermediate shafts are installed concentrically with a rotatory shaft which is a part of the revolving mechanism, and pass through the revolving mechanism. Rotary power is transmitted from each independent drive to each individual bobbin by these intermediate shafts.

Abstract: Yarn is continuously supplied to a measuring system with an applied twist of at least 100 turns per meter. A beam having a continuous spectrum from the visible region to the near-infrared region is impinged upon the yarn and measurements are taken on the beams reflected from the yarn. The refected beams are divided into two parts. The characteristics of the near-infrared region are applied to one part, and luminosity characteristics are applied to the other. The ratio of intensity of the former to that of the latter is determined. This ratio corresponds to the uniformity of physical characteristics in the direction of the length of the yarn.

Abstract: Yarn is continuously supplied at constant speed to a winding apparatus having a positively driven winding spindle. The tension of the yarn is periodically detected by a force transducer located at an edge of the area covered by the traverse motion of the yarn. The force transducer generates an electrical signal related to tension. The electrical signal is compared with a pre-set desired value and the difference is fed into a controller which acts upon a regulator for varying the speed of rotation of the winding spindle. The regulator varies the speed of rotation of the winding spindle according to the output of the controller, keeping the yarn tension at the desired value throughout the winding operation.