Abstract: A monitoring circuit for a knitting machine with at least one yarn feeding arrangement comprises two yarn monitoring devices which are provided with switches and connected via a first rectifier circuit and an indicating lamp to a supply line. The supply line is coupled to a supply voltage source in such a way that when one of the two yarn monitoring devices is operated, the indicating lamp is only activated by one half-wave which is associated with the yarn monitoring devices and belongs to an a.c. voltage signal generated by the supply voltage source. To improve the recognizability of an indication by the indicating lamp, the a.c. voltage signal generated by the supply voltage source has a first interval during which the signal has exclusively positive half-waves and a second interval during which the signal has exclusively negative a.c. voltage half-waves.

Abstract: A weft yarn insertion nozzle device for a jet weaving machine, comprises a supply, an outlet nozzle, a conduit connecting the supply and the outlet nozzle and a valve unit. The valve unit comprises a displaceable, soft-magnetic valve body and a coil for generating a magnetic field extending through the valve body, wherein the valve body is arranged within the conduit such that the flowing of pressurized medium therethrough exerts a force on the valve body which is opposite to the force as generated by the magnetic field.

Abstract: A device for positive feeding of yarn to a knitting machine, which device has independently rotatable first and second wheels disposed axially closely adjacent and individually supported for rotation about first and second axes which extend in the same general direction but are slightly inclined relative to one another. First and second feeding tapes are drivingly engaged with the first and second wheels respectively. A shiftable yarn guiding element feeds a yarn therethrough to a selected one of the wheels, with the guiding element being shiftable between first and second positions to enable the yarn to be positively fed by the first and second wheels respectively.

Abstract: A yarn feeding device comprises a stationary storage drum from which the yarn can be withdrawn. The yarn feeding device can be operated at a positive feeding mode and at a non-positive feeding mode by means of a rotatable yarn guiding member arranged at the withdrawal end. The yarn guiding member comprises at least one yarn engagement element adapted for engaging the yarn when the rotational speed of the yarn spiralling around the withdrawal end of the storage drum tends to exceed the rotational speed of the yarn guiding member. The yarn engagement element comes out of engagement with the yarn when the rotational speed of the guiding member exceeds the rotational speed of the yarn spiralling around the withdrawal end of the storage drum.

Abstract: A yarn storing and feeding device having a stationary storage drum onto which an intermediate yarn store is wound by a winding-on device, and from which the yarn is withdrawn through a gap around the withdrawal end of the storage drum. At least one yarn stopping device is associated with the gap for controlling the withdrawal of yarn. The stopping device includes a stopping element arranged radially inwardly with respect to the gap, and movable radially outwardly to extend across the gap in response to a magnetic actuator located radially outwardly with respect to the gap.

Abstract: A device for surveying the insertion of a weft yarn in a shed of a jet loom, comprises an arrival sensor arranged at one end of said shed for detecting the arrival of weft yarn there. The arrival sensor and at least one yarn sensor are connected to a surveillance circuit measuring the period of time lapsed since releasing a stopping device and periodically correcting the measured period of time on the basis of the yarn sensor signal. The surveillance circuit only generates a signal indicating the completion of the weft yarn insertion if the following two conditions are simultaneously fulfilled: The measured period of time exceeds a predetermined period of time between 80% and 99.5% of the period of time required for a complete weft yarn insertion cycle, and the arrival sensor generates a signal representing the arrival of the weft yarn.

Abstract: The present invention relates to a method for controlling a yarn storing, feeding and measuring device, having a stationary storage drum, a yarn sensor and at least one yarn stopping device, wherein the method includes the determining of the number of pulses which are to be generated by the sensor before actuating the stopping device.The reliability and speed of the device is enhanced by actuating the stopping device with a pre-determined delay-time after receipt of the pulse, the number of which corresponds to said pre-determined number.

Abstract: The take up means (5) is inhibited in response to a predetermined operating conditions of the flat knitting machine.

Abstract: A yarn feeding device adapted for positively feeding elastic yarn comprises an electric motor, a speed sensor for the speed of the knitting machine and a control unit connected to the electric motor and to the speed sensor. An optimal dynamic behavior of the yarn feeding device is obtained by making use of a rotatable drive cylinder connected to the electric motor, of a rotatable guide shaft supporting the yarn supply spool, which shaft is slidably arranged such that the yarn supply spool is kept in permanent contact with the drive cylinder, wherein the control unit drives said rotatable drive cylinder with a variable speed depending on the actual speed of the knitting machine and on a yarn demand signal, wherein the range of yarn feeding speeds is limited by predetermined minimum and maximum values.

Abstract: A yarn accumulating and feeding apparatus (1) has a stationary accumulating drum adapted to have a yarn (27) formed into a yarn supply (26) thereon, the magnitude of which is monitored between a minimum and a maximum by means of at least one mechanical probe element (28,28',28",28'",28"") adapted to be displaced by the yarn supply between two positions (I,II) and operatively associated with a switching device located outside of the accumulating drum. The probe element is mounted in the accumulating drum for displacement between one position projecting past the surface of the accumulating drum, and another position extending flush with the accumulating drum surface (15) against the bias of a return force, while a switching device contains a sensor element (20,20',21,21',20",20'") for generating a reaction signal in response to displacement of the probe element but without contacting the probe element.

Abstract: A yarn-feeding apparatus for selective positive feeding of several yarns to a knitting machine, comprising a sensor for generating sensor signals, the sensor signals representing the respective feeding condition or non-feeding condition of the yarns, and an error detection unit connected to the sensor for turning off the knitting machine in response to predetermined sensor signal combinations representing a yarn breakage and/or a yarn over-feed and/or a yarn change fault. For shortening the response time of the error detection unit and for enhancing the reliability thereof, the error detection unit comprises a working position sensing unit for generating position data representing the working position of the knitting machine, a logic circuit for deriving a yarn changing signal from the sensor signals, and a memory unit for storing yarn changing position data.

Abstract: A yarn storing, feeding and measuring device, particularly for jet looms, has a stationary drum onto which an intermediate yarn store is wound by a winding-on device and from which the yarn is withdrawn, yarn sensing means detecting the withdrawal of the yarn from the drum by generating pulse signals indicating that the yarn passes a detection area of the yarn sensing means, a plurality of yarn stopping devices arranged at angular intervals around the storage drum and a control device adjustable to desired yarn lengths to be withdrawn, said control device being responsive to said pulse signals such that an actuating signal is transmitted to a selected yarn stopping device whose angular position corresponds to the position of the yarn when said desired yarn length has been withdrawn.

Abstract: The present invention relates to a loom control system operable to stop a loom in the presence of a yarn breakage. This loom comprises a feeding device having a yarn storage drum for temporarily storing the yarn and a yarn store sensor for sensing the quantity of yarn stored on the drum of the feeding device and for transmitting an electric sensor signal representing the quantity of yarn stored on the drum to the feeding device to control the operation of the feeding device and to thereby control the quantity of yarn stored on the drum. A monitor circuit is electrically connected to the yarn store sensor for receiving the sensor signal, wherein the monitor circuit derives information on yarn breakage before and/or after the feeding device from the sensor signal or its variation with respect to time to generate a stop signal for the loom.

Abstract: A device for the positive feeding of a yarn, particularly for knitting machines, having a rotatable storage drum adapted to have a yarn supply wound thereonto and withdrawn therefrom over a rim thereof, a stationary yarn guide element located below the rim and outwards of the periphery of the rim in a center plane extending through the axis of rotation of the storage drum, a yarn guiding element located in the yarn path between the rim and the yarn guide element and formed with a yarn guiding edge, and a stoppage sensing element having a portion extending parallel to a tangent of the rim transversely of the yarn path between the yarn guiding edge and the yarn guide element, and being mounted for pivotal movement under the action of a biasing force.

Abstract: A yarn-feeding apparatus for the positive feeding of several yarns to a circular mechanism of a circular knitting machine, comprising fingers which are arranged in the circular mechanism for receiving and guiding the yarn into a knitting position or taking the yarn out of a knitting position, including delivery apparatus with each including a yarn-transporting element and a yarn-guiding element which is movable back and forth between a feeding area in which the yarn is in engagement with the yarn-transporting element and a nonfeeding area, and wherein for each yarn-guiding element there is provided an electric position sensor which produces an electric signal in dependence on the position of the yarn-guiding element.

Abstract: This device has a storage drum (2) onto which an intermediate weft yarn store can be wound by a winding-on member (3) and from which the weft yarn (WY) is withdrawn spiralling around the withdrawal end of the storage drum, at least one yarn stopping device (10/14) being arranged at said withdrawal end and consisting of a stopping element (14) and of actuator means (11) moving said stopping element into and out of the path of the yarn being withdrawn, and an actuator control unit (B) transmitting an actuating signal to said stopping device when a weft yarn length corresponding to the length of the shed (WMS) of woven fabric in the machine has been withdrawn from the storage drum. The actuator control unit (B) is electrically connected to a yarn sensing detector (WD), preferably of optical type and known per se, positioned at the arrival end (AE) of the shed (WMS) for the weft yarn (WY) at a predetermined distance (d) from said arrival end.

Abstract: Method of controlling a plurality of relay nozzles (RNx) is a jet weaving machine. These nozzles are consecutively actuated for supporting the insertion of the weft yarn (WY) into the shed of the weaving machine and up to the arrival end (AE) of said shed by means of consecutively opening solenoid valve associated with nozzles. The valves are controlled on the basis of calculated information representing the momentary real position of the weft yarn (WY) during it path in the shed. The invention also relates to an apparatus for carrying out said method.

Abstract: A thread storage and delivery device, with a drum-like storage body, of which the peripheral surface provides a storage surface for a thread stock and presents inside at least one cavity of which the access is ensured from the outside by at least one opening. In known devices of this type, dust and plush penetrate through the opening into the cavity and are a danger for the operation of the device, for example for the roller bearings. The shaping of the storage body as a crucible with a closed periphery and a closing lid laid from the outside is known. This configuration is technically expensive both from the construction and assembly points of view. This principle is further unapplicable when the storage body is formed of a plurality of parts which are movable with respect to each other and meshed into each other.

Abstract: The invention relates to a yarn supply device group for attaching to a textile machine, in particular a ring knitting machine with electrically controllable switching and actuating devices in every supply device which are connected in a signal-transmitting circuit by a bunch of lines common to all supply devices to a central control mechanism. Previously, every supply device in the group had to be "marked" manually prior to the start of operation. In addition, a bunch of lines with large dimensions was necessary, since each supply device needed at least one separate line.

Abstract: Machine tool having a jet turbine driving a rotatable spindle with a tool holder, said spindle is comprised in a spindle housing, said jet turbine consisting of a disc-shaped turbine rotor being closely enclosed by a turbine housing, said turbine rotor having peripherally arranged discrete recesses, each recess having a concave front actuation wall for the jet and one sidewardly arranged outlet opening which opens in the axial direction of the rotor, said housing having at least one inlet nozzle for the jet directed into the recesses and having at least one outlet opening for the spent jet medium. Known machine tools suffer under strong speed losses when the load increases or varies. This disadvantage results from a constant interference between spent air within the recesses and the working jet. Thus, the energy of the jet cannot be used with good efficiency.