Abstract:
A warp feed controller for use in a twin beam weaving machine having a first tension detector for detecting the tension of at least one of the groups of warp yarns fed in sheet-like forms from a pair of warp beams and a first control system for controlling the rotation of one of the warp beams on the basis of the tension deviation from a target tension under detection of the tension by the tension detector. The controller also includes a pair of second tension detectors for detecting the tensions of the warp yarns fed from the warp beams in boundary portions of the sheet-like forms, and a second control system for controlling the rotation of the other of the warp beams on the basis of the tension difference output from the second tension detectors, respectively. The first control system controls the one warp beam so that the tension of the warp yarns becomes equal to a target tension, while the second control system controls the other warp beam so that the tensions of warp yarns in the boundary portions become equal to each other.
Abstract:
A centralized loom control method employing a host computer for controlling the operation of a plurality of looms. Data base including data accumulated by recording past actual weaving conditions in stored in a memory device connected to the host computer. The host computer determines standard set value for which the looms are to be set by processing the specifications of a fabric to be woven entered therein and data fetched from the memory device through predetermined calculation or interpolation. The host computer compares a standard operating speed among the standard set values with a target operating speed at which the loom is to be operated, and changes the standard set values according to the result of comparison to provide new standard set values suitable for operation at the target operating speed.
Abstract:
The present invention relates to a control system for an engagement pin employed in a drum-type weft storage unit which is mainly employed in a jet-loom for storing the weft and for measuring the same in length. A novel control system for an engagment pin employed in a drum-type weft storage unit is provided. An engagement-time is compensated on the basis of a difference in time between a target-time later than the engagement-time of the engagement pin by a normal time-lag, to make it possible that the engagement-time is always set to be optimum in spite of the existanece of variation in shuttling speed of the weft, so that it is possible to keep the variation in length of the delivered weft minimum while the weft feeler is employed in place of the disengagement sensor.
Abstract:
A warp tension control method by which the let-off motion of a loom is controlled to regulate the tension of the warp yarns. A force of the same dimension as the controlled variable, namely, the tension of the warp yarns, is applied to a mechanism supporting the tension roller of the let-off motion for displacement under the control of an electric control system to control the warp tension at a high accuracy.
Abstract:
A weft picking control method capable of realizing control of a weft picking arriving time with a quick response over a wide range. The weft picking control method in an air-jet loom includes supplying air under pressure to weft picking nozzles, and jetting air under pressure from the weft picking nozzles so as to pick a weft into a warp shed together with the jetted air. Also, a supply passage for supplying the pressurized air to the weft picking nozzles includes high and low pressure supply passages. The passages are arranged in parallel with each other, and the air under pressure is jetted from the weft picking nozzles in cooperation with the two supply passages. A deviation between a weft arrival time of the picked weft and a reference weft arrival time is detected during the weft picking operation, and time for jetting air under high pressure and a weft picking starting time are respectively changed so as to reduce the deviation to zero on the basis of the detected deviation in the next and succeeding weft picking operations.
Abstract:
A method of optimizing control of looms for the improvement of the economic efficiency of a weaving mill controls set points for the looms so that the economic efficiency of the weaving mill will not be reduced below a standard economic efficiency determined through preparatory test operation of the controlled looms. The controlled looms are operated for a predetermined preparatory test period for preparatory test operation to collect the data of parameters dominating the economic efficiency of the weaving mill and to create reference data. Data of the parameters are collected in a monitoring period during the practical operation of the looms and the data is normalized by the time of the monitoring period to create operation data. The set points for each loom are corrected on the basis of the result of comparison between the reference data and the operation data to determine new set points.
Abstract:
An apparatus for controlling a let-off motion in a loom having a let-off motion motor includes a tension detector for detecting a warp tension to produce a tension correction signal, a control unit responsive to the tension correction signal for producing a speed signal, a driving amplifier for controlling the let-off motion motor in response to the speed signal, a warp coil diameter detector for issuing a warp coil diameter correction signal inversely proportional to the diameter of a warp coil on a beam to the driving amplifier, and a normal-reverse rotation control unit responsive to the warp coil diameter correction signal for selectively applying prescribed normal- and reverse-rotation signals dependent on a rotation command to the driving amplifier. With this arrangement, the motor is rotated at a desired constant speed for feeding out or rewinding the warp yarn for a desired length irrespectively of the warp coil diameter. In an inching mode of operation, the motor is rotated in a normal or reverse direction for an interval equivalent to one pick each time a main shaft of the loom turns past a certain rotational angle, so that the warp yarn is kept under a desired tension.
Abstract:
Jet looms have feelers for detecting whether a weft yarn has been properly inserted through a warp shed at an end of the warp shed.Air jet looms have photoelectric feelers the sensitivity of which becomes lowered with time due to dust or fly waste attached to the feelers in operation. Water jet looms incorporate electrode feelers with insulation therebetween tending to be deteriorated due to water applied, and hence the sensitivity of such feelers is also reduced with time.An apparatus according to the present invention increases the gain of a variable-gain amplifier for amplifying an output signal from the feeler as the level of the output signal is lowered, so that the amplified signal is maintained at a suitable level. The amplifier gain is controlled by detecting the level of the feeler output signal with an automatic gain control circuit, and feeding a signal from the automatic gain control circuit back to the variable-gain amplifier to energize a gain varying element in the variable-gain amplifier dependent on the level of the automatic gain control signal.
Abstract:
A device for noise attenuation attenuates the noises generated from weaving machines and comprises first conversion means for receiving a sound and outputting an electrical acoustic signal corresponding to the sound, first signal processing means for receiving the acousto-electric signal and outputting a first electrical signal having the frequency and amplitude corresponding to a sound to be attenuated on the basis of the received acoustic-electric signal, second signal processing means for receiving the first electrical signal and outputting a second electrical signal having the same frequency and inverted phase relative to the first electrical signal, and second conversion means for receiving the second electrical signal and generating a sound corresponding to the received second electrical signal.
Abstract:
A control method for a weaving machine comprises the steps of obtaining the rotational frequency to be varied by the use of the fuzzy interference on the basis of the evaluation index representing the running condition level of the weaving machine, and then varying the actual rotational frequency of the weaving machine on the basis of the obtained rotational frequency. As the evaluation index, use is made of the control allowance level of the weaving machine, the quality allowance level of woven fabric, the working allowance level of the operator, the stop level of the weaving machine, the rate of a change value of the stop level to a variation value of the rotational frequency or the operating rate of the weaving machine.