Abstract: A weft picking system for an air jet loom provided with a microcomputer as a controller. The weft picking system comprises a weft traction device including a pair of rollers one of which is driven by an inverter motor. A weft yarn fed from a weft measuring and storing device can be put between the rollers to be drawn toward a weft posture regulating nozzle. The weft posture regulating nozzle is arranged to project the weft yarn into the shed of warp yarns while regulating the posture of the weft yarn, under the influence of an air jet ejected therefrom and under assistance of air ejection from a plurality of sub-nozzles. The rollers are always driven to rotate during a weaving operation of the loom. A change-over device is provided to change the weft yarn from a first state of being put between the rollers to a second state of separating from the rollers or vice versa.

Abstract: A weft picking control system for accomplishing weft picking in a high response throughout a wide region of operating conditions of an air jet loom. The loom has a weft inserting nozzle which projects a weft yarn under the influence of air ejection therefrom. The weft picking control system has a first device for detecting a weft reaching timing at which the weft yarn projected from the weft inserting nozzle reaches a counter-weft picking side. A second device is provided to control an effective air ejection time for weft picking depending upon the air ejection of the weft inserting nozzle, in accordance with the detected weft reaching timing. The effective air ejection time is defined by at least one of a pawl disengagement timing (at which a weft retaining pawl is disengaged from a drum of a weft measuring and storing unit) and an air ejection termination timing (at which air ejection from the weft inserting nozzle is terminated).

Abstract: A warp transfer control system for a loom, includes a first actuator for varying a warp let-off speed, a second actuator for varying a fabric take-up speed to change a filling density, and a control unit which has a take-up control section for controlling the second actuator, a feedback control section for controlling the let-off speed through the first actuator when no change is required in the filling density, and a feedforward control section for changing the let-off speed so as to improve an appearance quality of a fabric when the density is changed. When a change from a first filling density to a second density is required, the feedforward section first changes the let-off speed excessively from a first let-off speed corresponding to the first density beyond a second let-off speed corresponding to the second density, and holds the let-off speed at such an excessive level for a limited duration.

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-bar (set mark) prevention system for a loom which can prevent a weft-bar caused when the loom is immediately restarted, after the loom has been stopped due to weft- or warp-thread cut (i.e., breakage of a weft or warp thread). When the loom is restarted from the closed-shed state, a greater additional warp tension is applied to the warp threads; when the loom is started from the open-shed state, a smaller additional warp tension is applied to the warp threads. After one or two cycles of the loom motion, the above-mentioned additional warp tensions are not applied, because the main motor is in a stable condition. The system according to the present invention comprises an optical loom-starting angle sensor for detecting whether the loom is started from the closed-shed or open-shed, a counter for determining at least one initial cycle during which warp tension is controlled, air cylinder to push the easing lever in the direction to increase warp tension.