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: 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.

Abstract: A method of controlling a motor-driven let-off motion in a loom including a system for controlling a let-off motion motor includes the steps of sampling a variation of warp tension during each revolution of a main shaft of the loom, effecting at least proportional and integral control modes on the average of sampled values, adding a proportional and integral output to a basic speed signal at a prescribed ratio, and applying a sum signal to the system for controlling the let-off motion motor.

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.

Abstract: A regulating device for actuating the regulating element of the speed-changing unit of a warp-beam let-off motion as a function of the position of a lever of the balance for measuring the tension of warp threads. A jamming member is engaged over a bar which is driven in reciprocating motion by an eccentric. The jamming member is capable of selective sliding along the bar or jamming against said bar according to the orientation given to the jamming member by a rod attached to the balance lever. The energy required for regulating the speed-changing unit is supplied by a shaft which is driven by the main motor of the loom and drives the bar in reciprocating motion.

Abstract: Let-off motion for elongated material wound on a let-off beam. Such let-off motion comprises a tension detector connected to the input of a let-off element, the output of which is connected with the control element of the driven let-off unit, with the input shaft of the drive and output shaft of the let-off drive, which responds to changes of the control magnitude value in its control element by a change of the relation of angular velocities between the input and output shafts. The input of the let-off element is a rotary disc slidably arranged between two axially arranged clutch discs of the let-off element, the clutch discs being mutually positively rotatable in opposite directions. The clutch discs of the let-off element are drive-coupled with the input shaft of the driven let-off unit, and the disc of the let-off element is provided with a central, internally threaded hole which receives and is threadedly mated with the threads on the spindle of the let-off element.

Abstract: In a circular loom in which at least one shuttle is continuously travelled in one direction along an annular guide member and a plurality of shed forming mechanisms arranged annularly and coaxially with the guide member are sequentially opened prior to arrival of the shuttle to form a successive sheds through which the shuttle is to be inserted and passed, a warp tension regulating and warp feed apparatus is mounted. In this apparatus, an annular supporting member fixed to a frame of the circular loom is disposed outside the shed forming mechanisms adjacently thereto, a plurality of dancing levers guiding corresponding warps through yarn guides mounted on the top ends thereof are pivoted on the supporting member for respective warps and resilient means for absorbing variations of tensions on the respective warps is connected to the corresponding dancing levers.

Abstract: In a textile loom, the invention comprises a device for varying the speed and the tension of unreeling the warp threads from the warp beam. The device essentially includes a set of interchangeable spur gears connected to the warp beam which cooperate with a system of variable-race sheaves so that when a sheave has its race becoming narrower, the other sheave has its race widened and vice versa. Proper linkages are also provided to ensure that there is always a constant balance between the tension of the warp threads and the speed of rotation of the warp beam. Consequently, as the diameter of warp threads on the beam is decreased and the speed of the warp threads is concurrently decreased, the device imparts a pull increase to the warp threads so that the unreeling speed of the threads from the warp beam is automatically brought back to a preselected constant value.

Abstract: A device for regulating the speed at which a weaving machine having a dancer is supplied with warp threads from a warp beam such that the speed and tension of the warp threads are substantially constant. The warp beam is provided with a variable speed drive having an alternatingly operable coupling and brake controlled by a regulator which compares the actual speed of the drive with a reference value. The actual speed is generated by an optical tachometer connected to the drive and the reference value represents an averaged number of dancer deflections and is generated by an integrator which receives the output of a potentiometer connected to the dancer.

Abstract: A loom capable of weaving a wide variety of cloths, the loom requiring at most the simple exchange of gears to permit it to weave cloths of widely varying characteristics. The loom has an input driving element for the warp beam let-off motion which is drivingly connected with the output element of an adjustable transmission mechanism of the let-off motion drive, while the input element of the adjustable transmission element of the let-off motion drive is drivingly connected with the transmission mechanism of the positive drive of the cloth take-up beam. The input element of the adjustable transmission of the let-off motion drive is drivingly connected with the output element of the transmission mechanism of the positive drive for the take-up beam, the take-up beam being also drivingly connected with such output element.

Abstract: An apparatus for regulating tension in warps of a weaving machine comprising: a tension lever swingably supported on a weaving machine and having a roller supported thereon for regulating the tension in warps delivered from a warp beam; a weight lever swingably supported on the weaving machine and having a load at one end thereof; and a link operatively connecting the tension lever and the weight lever. The tension lever has an elongated hole formed thereon, and the lever ratio of the tension lever is changed by moving the link along the elongated hole.

Abstract: An apparatus for regulating tension in warps of a weaving machine comprising: a tension lever swingably supported on a weaving machine and having a roller supported thereon for regulating the tension in warps delivered from a warp beam; a weight lever swingably supported on the weaving machine and having a load at one end thereof; and a link operatively connecting the tension lever and the weight lever. The tension lever has an elongated hole formed thereon, and the lever ratio of the tension lever is changed by moving the link along the elongated hole.The apparatus further includes a support member having two pairs of guide rollers and being connected to the link, so that the relative movement between the link and the tension lever can smoothly be carried out.

Abstract: This invention relates to an improvement in a pile warp thread-unwinding device for a terry cloth weaving machine with a drive for a pile warp beam controlled by an oscillatable reversing member for the pile warp threads, the improvement comprising two rotatable reversing means mounted in a stationary manner following the pile warp beam in the drawing-off direction of the threads, an oscillatable feeler means positioned therebetween whereby the warp threads are deflected from a straight path thereof, and means on said feeler means for influencing control switches for the pile warp beam drive.

Abstract: A loom comprising a resiliently arranged tension or whip roll movably mounted transversely with respect to its lengthwise axis. The tension roll serves to generate the tension of the warp threads or ends of a preferably two-part warp beam. The bearing or support means of the tension roll are arranged to be individually movable independently of one another such that the tension roll can be moved into an inclined position.

Abstract: A lever, pivoted intermediate its ends, rotatably mounts a roller at one end engaging the material being wound off a core. In one embodiment, the lever is spring biased in a direction to bias the roller against the material, and changes in the position of the opposite end of the lever are effective to adjust a potentiometer forming the control element of an asynchronous single phase variator. In another embodiment of the invention, the spring is omitted, and a pressure-resistance detector is mounted between the opposite end of the lever and a frame. In a third embodiment of the invention, the opposite end of the lever carriers a shutter cooperable with a photoelectric control, the lever being spring biased in this embodiment. The pressure-resistance detector can be substituted in the variator for the potentiometer.

Abstract: The pulse transmitter is synchronized with the weaving cycle of the machine drive and carries at least one sensing surface of variable shape. A detector is secured to the tension beam and is responsive to changes in warp tension. The detector carries a sensing element in the form of a proximity switch which is disposed over the sensing surface of the pulse transmitter. Depending upon the position of the proximity switch relative to the sensing surface, a pulse is emitted to the warp beam drive for stepping of the warp beam as the pulse transmitter rotates past the sensing element. This pulse is variable in the time-of-occurrence as well as in duration.

Abstract: A constant tension regulator for controlling the tension of positively unwound flexible material, particularly warp threads in a weaving machine. Means are operatively mounted on the frame of the regulator for sensing changes in tension in the unwinding flexible material. These sensing means output a control movement in accordance with sensed tension in the unwinding flexible material which is translated to a mechanical integrating unit and a proportional adjusting unit, arranged in parallel, which jointly transmit a control variable adjustment to the driving means of the warp beam thereby adjusting its rotary speed in accordance with the sensed tension.

Abstract: A warp tension controller for a loom comprises a warp tension sensor for generating a first signal which is a measure of the warp tension, a source of a reference signal, and means for comparing said signals and producing an output signal representing deviation of said first signal from said reference signal. An operational amplifier has an inverting input connected to receive said output signal, and has an output connected to means for adjusting the warp tension. A feedback circuit connected between said input and said output of said amplifier comprises a resistor in parallel to an integrating capacitor.

Abstract: A drive arrangement for driving a let-off beam of a fabric weaving loom and maintaining a predetermined tension in the warp threads. The drive arrangement includes an electric motor operably connected to the let-off beam by a speed-reducing apparatus and an electrically operated clutch. A tension-sensitive device is positioned adjacent the warp threads and cooperates with same to sense the tension therein. The tension-sensitive device has a switch operably connected to said clutch wherein at a predetermined tension in the warp threads the switch closes and actuates the clutch to effect selective driving of the let-off beam in a forward direction and thereby control the tension in the warp threads.

Abstract: To provide synchronization between the drawing roller and the warp beam of a loom, direct transmission is provided between the two members by means of an intermediate shaft which is independent of the speed of the loom. Any variation in the density of the fabric is transmitted to the intermediate shaft and an automatic adjustment is afforded in the drawing roller and the warp beam.

Abstract: In a control mechanism for automatically operating a warp beam in a loom, a comparison regulator is associated with a thread guide roller over which the warp passes and the regulator, through a cam arrangement, operates micro-switches for controlling the operation of an electric motor. The electric motor drives the warp beam through the medium of a variator. Further, an automatic zero setting is associated with the warp beam and operates in cooperation with the variator.