Abstract: A fabric roll letoff for unrolling and inspecting a fabric roll. The apparatus includes: a continuous belt for supporting the fabric roll. A drive system for rotates the belt to letoff the fabric web. The drive system includes a drive roller; a idle roller; and a tension roller. The continuous belt rotates the fabric roll to unroll the fabric web at a constant velocity for subsequent processing. In the preferred embodiment, a pair of unloader arms is connected to the belt drive for receiving the fabric roll and for positioning the fabric roll onto the belt drive. Also, in the preferred embodiment, a guide frame is positioned downstream from the belt drive for directing the fabric web through an inspection area.

Abstract: A loom has an illuminating unit for improving the detection of deficiencies in a length of fabric. The illuminating unit extends over the entire width of the loom and at least one illumination device. The illuminating unit is pivotably fastened between loom walls in the area of a free space defined by the fabric guidance rollers and the length of fabric itself. The illuminating unit illuminates the length of the fabric and is used as a safety cover over the roller gap between the rollers.

Abstract: A woven cloth inspecting apparatus eliminates the influences of disturbances such as illuminating light and fly. At least two photoreceptor elements are arranged in the direction of the weft yarn of woven cloth. The photoreceptor elements detect different area of the woven cloth and they apply current signals to two respective current-to-voltage converters which convert the current signals into voltage signals which are fed to a difference calculating circuit. The difference calculating circuit calculates the difference between the values of the voltage signals received from the two current-to-voltage converters and supplies the obtained difference signal to a comparator which compares the received difference signal with a reference value preset by two reference value setting circuits. Exceeding the reference value is indicative of a defect in the warp. Alternatively the photoreceptor elements are arranged in the warp direction and detect defects in the weft.

Abstract: An apparatus and method for guiding a web utilizes a curved outer convex cloth guiding surface constructed of extruded aluminum with a specially hardened, brittle, wear resistant surface (A) on arcuate sections such as extrusions provided respectively at the top and bottom of the viewing area for guiding cloth and for forming a housing for the light box wherein an inner housing surface (B) is provided opposite the cloth guiding surface (A) on each extrusion. Depending receiving members (C) are provided at each respective end of the arcuate extrusions for serving as a receptacle for guiding and positioning a plexiglass viewing member and back sheet metal wall for forming a light box. A force applying member (D) is provided for controlling sag or bow in an extrusion. Apparatus and method is illustrated including diverging grooves for spreading the web as it passes over the upper section, and circuitry is provided conserving energy by limiting the time the circuitry is energized.

Abstract: A unitary light box for inspecting cloth manufactured on a loom (10) is provided with first and second viewing areas (B) and (C), respectively, wherein cloth (F) having a vertical run is guided over an intermediate curved surface (D) for inspection providing several angles of sight to the operator from the same vantage point so as to locate defects not ordinarily visible during conventional head on observation.

Abstract: A cloth inspecting device on a loom for detecting abnormality in the cloth being produced has a light emitting and receiving assembly mounted within a sealed container with a transparent window facing the cloth. Drive means for the assembly is within the container and the assembly is mounted on a rail for movement along the length of the container across the width of the fabric. One or more filters are provided. A mirror is disposed opposite the container window with the cloth path therebetween. By placing the light emitting and receiving assembly in a sealed container the assembly as well as its driving mechanism is positively protected against interference by fly or dust during loom operation.

Abstract: An apparatus and method for inspecting and guiding a web utilizes a curved outer convex cloth guiding surface (A) on arcuate sections such as extrusions provided respectively at the top and bottom of the viewing area for guiding cloth and for forming a housing for the light box wherein an inner housing surface (B) is provided opposite the cloth guiding surface (A) on each extrusion. Depending receiving members (C) are provided at each respective end of the arcuate extrusions for serving as a receptacle for guiding and positioning a plexiglass viewing member and back sheet metal wall for forming a light box. A force applying member (D) is provided for controlling sag or bow in an extrusion. Apparatus and method is illustrated including diverging grooves for spreading the web as it passes over the upper section, and circuitry is provided conserving energy by limiting the time the circuitry is energized.

Abstract: Air is jetted into the reed groove of a modified reed in a manner equivalent to that in which air is jetted in practical weaving operation, air-speed is measured at a plurality of measuring points in the reed groove on each of a plurality of planes perpendicular to the longitudinal direction of the modified reed, a maximum air-speed among air-speeds at the measuring points in each plane is determined, and the positions of the measuring points respectively corresponding to the maximum air-speeds are provided in a visually recognizable state.

Abstract: A method of measuring the yarn density of a woven fabric or the stitch density of a knitted fabric by recording a video image of the woven or knitted fabric to be examined by means of a video camera, converting the video image by an analog-to-digital converter into digital video information, storing the digital video information in a digital image memory and converting said information by a central processing unit into the yarn density or stitch density. The digital video information is converted by a digital band filter (14) with central circle frequency (.omega..sub.o) into a yarn or stitch density, and that the digital band filter (14) is arranged in such a manner that it operates according to the formula:Y.sub.k =A.sub.m .multidot.X.sub.k-m +A.sub.m-1 .multidot.X.sub.k-m+1. . . +A.sub.o X.sub.k -B.sub.1 .multidot.Y.sub.k-1 -B.sub.2 Y.sub.k-2. . . B.sub.n Y.sub.k-nwherein:X.sub.k represents a series of points of the digital information characteristic at interspace T before the digital filtering; Y.sub.

Abstract: The length of fabric is scanned continuously directly at the weaving machine and any defective variations from the texture judged to be normal are determined and displayed. Scanning is performed by an electrical-optical scanning head traversing across the width of the cloth and in the evaluation of the signals of the scanning head those signals are preferentially treated which represent an excessive variation from a specified size or number, or which have a certain periodicity. The variations of the type mentioned are representative of warp stripes and weft bars and consequently are very serious cloth faults. These cloth faults can now by means of scanning be detected directly at the weaving machine sufficiently early for corrective action to be taken in the weaving process before large quantities of fabric are produced with these faults. Thereby the occurrence of fabric of inferior quality is at least considerably reduced.

Abstract: Herein disclosed is a method of and an apparatus for marking a woven fabric with indicia of discrete events of a predetermined nature or natures such as unit lengths of the fabric woven and the occurrences of defects in weaving such as improperly inserted picks of weft yarn, wherein picks of an index yarn or yarns are inserted into the weft-filling shed of the warp yarns concurrently with insertion of picks of the weft yarn when the occurrences of events of the predetermined nature or natures are detected during weaving of the fabric, the natures of the events being distinguished from one another by the difference between the lengths, colors, numbers or any other characteristics of the picks of the index yarn inwoven into the fabric.