Abstract: A method for starting a group of looms each of which has a control circuit in electrical connection with a central control device. The method includes the steps of outputting operation command signals from the central control device respectively to the control circuits of the looms in a predetermined order, and successively operating each loom in response to the operation command signal upon completing preparation for starting the loom, thereby automatically starting the looms in the predetermined order without requiring operator action for each loom.

Abstract: A loom is provided with a weft inserting nozzle for picking a weft yarn under the influence of fluid jet and equipped with a weft picking control system which consists of a device for detecting the tension of the picked weft yarn at a timing of termination of travel of the weft yarn in weft picking. The thus detected weft yarn tension is compared with a standard tension by a comparing device forming part of a control circuit thereby to obtain the difference therebetween. The pressure of air to be supplied to the weft inserting nozzle is controlled in accordance with the difference in tension, thus maintaining the weft yarn tension at a constant value.

Abstract: A method of removing a mispicked weft yarn when a mispick occurs in a loom. The operation of the loom in a state where the mispicked weft yarn is connected to weft inserting means after the mispicked weft yarn is beaten up by a reed. The mispicked weft yarn is exposed at the cloth fell of a woven cloth. A weft yarn connected to the mispicked weft yarn is inserted from a weft picking side to a counter-weft picking side of the loom. The inserted weft yarn is drawn together with the mispicked weft yarn to the counter-weft picking side, thereby effectively peeling off the mispicked weft yarn from the cloth fell.

Abstract: A fluid jet loom has a weft inserting nozzle and is equipped with a weft picking control system including means for measuring a weft picking time period for accomplishing a weft picking. The difference between the measured weft picking time period and a standard value in each weft picking is computed, and a plurality of such differences are accumulated to obtain an accumulated value. The accumulated value is compared with an allowable limit to judge as to whether the accumulated value exceeds the allowable limit or not. Upon judgement of the accumulated value exceeding the allowable limit, the air pressure to be supplied to the weft inserting nozzle is controllably changed to regulate the weft picking time period at a suitable value, thereby achieving an optimum weft picking control.

Abstract: A loom having left and right warp beams and a common tension roller is provided with an electric or mechanical control system, which detects forces exerted on left and right supports of the tension roller by the warp threads of both warp beams, and produces a left control signal corresponding to a tension of the warp threads of the left warp beam and a right control signal corresponding to a tension of the warp threads of the right warp beam in accordance with the detected forces. The rotational speeds of the left and right warp beams are controlled individually in accordance with the left and right control signals, respectively.

Abstract: A weft sensor for a loom which can detect the presence or absence of a weft inserted into a warp shed at an acceptable moderate sensitivity on the basis of the majority decision of weft detection signals. When sensor sensitivity is too high, the weft sensor erroneously detects the fluff attached to the sensor as the presence of a weft, thus keeping the loom operated continuously. This erroneous detection reduces the quality of woven cloth. On the other hand, when sensor sensitivity is too low, the weft sensor erroneously detects a slender weft as the absence of a weft, thus keeping the loom stopped unnecessarily. This erroneous detection reduces the duty cycle of the loom. The weft sensor according to the present invention comprises a plurality of weft detectors and a majority decision circuit made up of a plurality of logical circuit elements such as AND, OR, NAND gates, etc.

Abstract: A weaving machine has a first drive means which has a speed change transmission and drives a warp beam during normal weaving operation, and a second drive means for driving the warp beam independently of the first drive means when the weaving machine is moved by inching or by hand during downtime operation. A first sensor senses the weaving cycle of the weaving machine, and a second sensor senses the warp beam rotation. A warp beam rotation control system determines the angular displacement of the warp beam per weaving cycle during normal weaving operation, and controls the warp beam rotation during downtime operation in accordance with the determined angular displacement per weaving cycle.

Abstract: A shuttleless loom weft detaining device including a drum rotatable in synchronism with the operational cycle of the loom, the drum being formed with a frustoconical section and a cylindrical section, a first weft yarn catching member disposed between the frustoconical and cylindrical sections to catch a first portion of a weft yarn to detain the weft yarn on the drum for the period of weft picking, and a second weft yarn catching member associated with the cylindrical section of the drum to catch a second portion of the weft yarn to detain the weft yarn on the drum for the period other than the weft picking period, thereby effectively preventing shortpicks of the weft yarn into the shed of warp yarns.

Abstract: A circuit arrangement operates a heavy-duty electrical equipment including an electrical relaying device having a relay coil and a set of first and second relay contacts. The first relay contacts are connected in a circuit that supplies a large amount of current to the electrical equipment. The relay coil is connected to be energized with a small amount of current in response to the closure of a normally open switch and held energized in response to the closure of the second relay contacts. The normally open switch and the second relay contacts form a closed low impedance circuit which supplies an arc current pulse to the second relay contacts during the time when the normally open switch is held closed, whereby fragmentary objects or dust collected between the second contacts is removed as the first and second contacts chatter during a closing.

Abstract: For detecting an improperly inserted pick of weft yarn in a weaving loom, a tension signal representative of a total of tensions detected of a predetermined number of warp yarns forming an end portion of the weaving shed during beating of the weft yarn in each cycle of operation of the loom is compared with a variable reference signal which is representative of, for example, a predetermined fraction of the arithmetic means of the sums of the warp yarn tensions detected during the cycles of operation prior to the cycle in which the tension signal is produced and compared with the reference signal.

Abstract: A system for controlling the stopping sequence of a plurality of weaving machines under emergency conditions and a method for the same are disclosed. The system includes a preference control circuit which upon receipt of high and low priority emergency signals from detectors activates a brake actuator to stop the associated weaving machine under the emergency condition of high priority which calls for immediate action, while introducing a delay to the corrective action to be taken in respect of the weaving machine under the emergency condition of low priority not requiring immediate action.

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.

Abstract: At least one elongate electrode is positioned on the upper surface of an upper heddle bar of each heddle frame of a loom for constituting a switch with loops loosely coupled to the upper heddle bar, each loop being spaced from the upper surface of the upper heddle bar at the lower position of the heddle bar due to upward force along the heddle produced by the tension of a warp, the switch being closed when a loop hangs over the electrode by its self weight due to loss of tension along the warp at the lower position of the heddle bar, the lower position of each heddle bar being detected by a heddle bar position detector, a corresponding LED being illuminated by a display circuitry connected to the switch and the heddle bar position detector, the circuitry including holding circuits for maintaining the illumination of the LED from the first glowing until the holding circuit is reset.

Abstract: The presence and absence of an inserted weft yarn are sensed respectively by, in moving a sensor body having an aperture opening externally of the body and two contacts located in the aperture and engaged with each other by an elastic force from a first position in which the inserted weft yarn is passed through the aperture during insertion into a second position in which the inserted weft yarn is taken out from the aperture by disengaging the contacts, sensing the contacts being disengaged and remaining engaged.

Abstract: Operation of a weaving loom is stopped when tension in warp yarn less than a reference value at beat-up is successively sensed at a plurality of successive beat-ups.

Abstract: A signal is generated indicating a defect in a woven fabric and applied to a counting circuit stopping the loom which starts at a normal operating condition after correction when a normal length of fabric has been made in response to a reset signal.

Abstract: A circuit stops a loom or indicates a malfunction on receiving either an abnormally long signal or no signal, caused respectively by, thread detector malfunction or faulty loom operation.

Abstract: Herein disclosed is a method of and a device for controlling a weft inserting motion of an automatic weaving loom so that the loom is brought to a stop in the event a weft yarn has failed to be properly picked into a shed of warp yarns a predetermined number of times within a predetermined time interval which corresponds to a predetermined unit length of a fabric produced.