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AssigneeAkzo Nobel N.V.
InventorsPeter Harke, Hans Willi Louis, Wolfgang Worbs
Estimating the term…
Process for monitoring a moving yarn sheet by means of a light beam, photodetectors and an electronic analyzer, whereby the yarn sheet is guided via thread guide rods before and after the monitoring site and the shadowing of the light beam caused by an increase in thread thickness is directed perpendicularly to the direction of travel of the yarn sheet for detection by photodetectors, and evaluated and recorded by the electronic analyzer, characterized in that the intensity of a single light beam is detected by at least two photodetectors arranged in series in the direction of travel of the yarn sheet and in that the evaluation by the electronic analyzer is such that a recording only takes place when the shadowing is detected by one or more of said photodetectors following in the direction of travel of the yarn sheet with a time delay corresponding to the running speed of the yarn sheet is disclosed. It is preferred to employ at least four photodetectors of which at least two are situated in series in the direction of travel of the yarn sheet and at least two are arranged one above the other such that at least one photodetector is positioned below the yarn sheet plane and at least one photodetector is positioned above the yarn sheet plane.
A process for monitoring a moving yarn sheet comprising guiding said yarn sheet via thread guide rods before and after a monitoring site, emitting a single light beam perpendicularly to the direction of travel of said yarn sheet and parallel to the yarn sheet plane to photodetectors, evaluating and recording the signals of said photodetectors by an electronic analyzer, detecting the intensity of said single light beam by at least two of said photodetectors arranged in series in the direction of travel of said yarn sheet, carrying out the evaluation by said electronic analyzer such that a recording only takes place when the shadow projected upon one or more photodetectors which are sequentially arranged in the direction of travel of said yarn sheet is detected as having a time delay corresponding to the running speed of said yarn sheet, widening said light beam to a maximal 30 mm before striking said yarn sheet and focusing the width of said light beam beyond said yarn sheet such that it illuminates all photodetectors assigned to it.
A process for monitoring a moving yarn sheet comprising guiding said yarn sheet by means of thread guide rods before and after a monitoring site, emitting at least one light beam perpendicularly to the direction of travel of said yarn sheet and parallel to the yarn sheet plane to photodetectors evaluating and recording the signals of said photodetectors by means of an electronic analyzer, employing one or more light beams and at least four photodetectors for monitoring, of which at least two are positioned in series in the direction of travel of the yarn sheet and at least two are positioned one above the other such that at least one photodetector is situated below and one photodetector is situated above the yarn sheet plane.
Dependencies are inferred from the claim text.