Abstract: A method for supplying weft yarn to the shed of a weaving machine of the type in which weft yarn is inserted into the shed from at least two feed bobbins, via respective weft accumulators and insertion devices, includes the step of altering the average yarn extraction speed at which the weft yarn of at least one of the feed bobbins is extracted during unspooling of the bobbin in order to prevent yarn breakage due to an excessively high extraction speed. The method may be carried out by a device which generates a signal representative of the available supply of yarn on a feed bobbin, and controls the yarn extraction speed as a function of the available supply signal. An alternative device for carrying out the method generates a signal representative of a yarn extraction tension and regulates the yarn extraction speed as a fuction of the yarn extraction tension signal.

Abstract: A device for retrieving the end of yarn wound on a yarn-feed spool includes a system for blowing an essentially tangentially directed current of air over a rotating yarn-feed spool so that an end of the yarn wound on the yarn-feed spool can be freed from the spool. A suction nozzle is provided to capture and draw into the nozzle the end of the yarn blown free from the spool. A movable carriage system carrying at least the air current generating means and the suction nozzle is provided so that a yarn-feed spool can be approached, exposed to the air current and the freed yarn end captured by the suction nozzle. The mobile system may also carry a device for engaging the driving the yarn-feed spool in rotation. A conveyor system for moving the retrieving system over a weaving machine is also described.

Abstract: A device for supplying weft threads in a weaving machine includes a bobbin support over which it is possible to slip a bobbin, a thread guide duct extending axially through the bobbin support and which includes an opening at the top for permitting entry of a yarn end into the thread guide duct, a blower for providing an airstram in the thread guide duct, the airstream flowing towards the top of the bobbin support, a prewinder, and a suction and blower device mounted at an entry of the prewinder. The blower and the suction and blower device are simultaneously switched on to create an airstream between the thread guide duct and the prewinder to carry the yarn end situated in the thread guide duct to the prewinder.

Abstract: A weaving machine including a device for stretching a fabric in the weaving machine includes a guide bar over which the fabric is bent to thereby bring a surface of the fabric into contact with the guide bar. An array of notches on each end of the guide bar is provided to exert an outward traction on the fabric edges to maintain the fabric in stretched condition. To enable a fabric whose width is narrower than a full weaving width to be located along the guide bar in a non-symmetrical manner while effecting a lateral traction force on the edges of the fabric; the guide bar is provided with at least one array of notches located at one end of the bar arranged so that each notch in the array is broken so as to extend circumferentially less than the full circumference of the guide bar, with the array including a plurality of notches longitudinally and circumferentially spaced along the guide bar.

Abstract: A yarn storing and delivering device for a weaving machine includes a stationary base body and a hollow shaft which is rotatably mounted in the base body and which carries a laterally projecting yarn feeder element. Yarn is guided into the hollow shaft and wound by the yarn feeder element onto a storing surface of a storing drum which is maintained stationary relative to the base body. The yarn is axially withdrawn from the storing drum over a free edge of the storing surface and through a substantially central guide opening. A threading device equipped with air jet nozzles is provided for automatically threading the yarn up to a location within the guide opening. The threading device includes a compressed air conveying system disposed between the guide opening and a location adjacent the outlet of the yarn feeder element. The compressed air conveying system includes a plurality of stationary directional jet nozzles which, when activated, provide an air flow which delivers the yarn to the guide opening.

Abstract: A device for the removal of dust from parts protecting weaving machine components from weaving dust includes a dust screen, a number of freely movable blowing tubes which direct air from their open ends into an area adjacent the dust screen, and blowing devices for feeding air through the tubes. Removed dust is disposed of by a separate device such as a suction nozzle.

Abstract: A method for collecting dust and waste in weaving machines wherein a continuous waste ribbon is generated during the weaving process includes blowing the dust and waste onto the ribbon while it is being wound on a waste spool to thereby collect and compact the dust and waste matter between ribbon windings. Apparatus for carrying out the method includes a vacuum nozzle arrangement for collecting the dust and waste and a conduit for transporting the aspirated dust and waste to the waste spool while the waste ribbon is being wound thereon. A specific blowing nozzle for carrying the dust and waste to the spool and ribbon, includes a housing arrangement for the waste spool that permits dust and waste not directly deposited on the waste ribbon to be picked up during the ribbon winding process.

Abstract: A thread brake for braking a weft thread in a weaving machine includes a rigid stop and an elastically deformable blade which has a free end supported to press resiliently against the rigid stop. Thread guides are provided to guide weft threads between the rigid stop and the elastically deformable blade. The thread brake is activated when the deformable blade elastically presses against the rigid stop. When contacted by a switching device, however, the elastically deformable blade is pushed against its resilient force and removed from the rigid stop, at least in the region of the switching device, deactivating the thread brake.

Abstract: An airjet weaving machine with a weft thread supply includes a plurality of yarn packages, thread preparation mechanisms, and thread blocking devices on the thread preparation mechanisms. A thread break detector is mounted between the yarn packages and the thread blocking devices. Upon detection of a thread break, a control unit deactivates the thread preparation mechanism in which the thread break has occurred, and thread removal devices are subsequently activated a pre-determined time interval after detection of the thread break so that at least a weft thread section into the main nozzle is removed in order to prevent the broken off piece of weft thread from becoming entangled with other weft threads and thus being blown together with the other weft threads into the shed, or to prevent the broken off piece from blocking other main nozzles.

Abstract: In a weaving machine, one of the guiding elements used to normally guide a weft thread between a thread preparation mechanism and the shed of the weaving machine is made moveable. The moveable guiding element may, for example, be an auxiliary weft insertion nozzle and can be used in place of supplemental threading and guiding mechanisms for such as purposes as retrieving a broken weft thread for automatic rethreading or extracting a defective weft thread from the shed.

Abstract: A device for supplying weft threads in weaving machines with minimal twisting includes at least one rotatable set of thread supplies and one rotatable set of thread preparation mechanisms per set of thread supplies. The sets of thread preparation mechanisms are rotatable together with corresponding sets of thread supplies forming a rotatable assembly to prevent the weft threads from becoming tangled with one another as the sets rotate, for example to bring one of the thread preparation mechanisms adjacent a repair mechanism, or to change threads. A mechanism is further included which converts the rotational motion of the rotatable assembly into a translational motion essentially in the direction of the axis around which the assembly turns. By a suitable choice of the mechanism, lengthening of the thread after rotation can be fully compensated for by the translational motion of the thread supplies and of the corresponding thread preparation mechanisms.

Abstract: A method for removing a loose incorrectly inserted piece of weft thread from the shed in a weaving machine includes the steps of inserting a weft thread into the shed and transporting it through the shed until it extends over the entire length of the shed in order to from a pulling thread. The loose weft thread is then fastened, outside the shed, to the pulling thread. The pulling thread is drawn together with the piece of weft thread fastened to it from the end of the shed located opposite to the end at which the fastening occurred in such a way that the latter piece of weft thread is removed from the fell line in the form of a loop and thereby removed from the shed.

Abstract: A mechanism for supplying weft thread to the shed of a weaving machine includes at least three different weft supply mechanisms, at least one of which is arranged to operate with at least two different weft thread sources for the purpose of acting as a reserve thread supply for either of the first two weft thread supply mechanisms.

Abstract: A method for repairing a weft thread on a weaving machine, in particular for repairing thread breaks between a yarn supply package and an accumulator, includes the step of providing at least two yarn supply packages, a second package automatically replacing the one in use when the one in use becomes empty. Additional steps include using a thread clip to hold a thread end of the second supply package, monitoring the weft thread for breaks between the supply package in use and the accumulator, and when a thread break is detected, gripping the thread end of the second supply package and joining it to the broken weft section which is connected to the accumulator. An apparatus is provided which includes means for carrying out each of the above-described steps.

Abstract: A method for removing an incorrectly inserted piece of weft thread from the shed of a weaving machine includes the steps of inserting a pulling thread which is connected to the incorrectly inserted weft thread and drawing out both threads from the insertion end of the shed. A thread guiding element is used to guide the weft thread as it is withdrawn from the shed.

Abstract: A method and apparatus for weaving with non-cleaned or as-spun thread uses a cleaning or irregularity removing system between the yarn supply and the pick insertion device of the weaving machine. The cleaning system cooperates with the pick insertion device so that substantially continuous weaving can be maintained, and includes a thread joining device so that weft thread supply can be maintained following removal of an irregularity in the weft supply. Removal of an irregularity is carried out by removing the section of weft yarn containing the irregularity.

Abstract: An airjet weaving machine weft thread supply includes at least two thread preparation mechanisms and detectors for detecting thread breaks. When the detectors detect a thread break, a control unit deactivates the thread preparation mechanism in which the thread break has occurred and transfers the task of the deactivated thread preparation mechanism to another thread preparation mechanism. The control unit also activates an alarm signalling system and may also cause the main drive of the weaving machine to shut off in response to detection of a thread break.

Abstract: A weaving machine is of the type in which the weft thread remains attached to the edge of the cloth between successive picks, the weft thread moving along with the cloth as the weaving process progresses, and in which detection of a thread break causes deactivation of a corresponding thread preparation mechanism and transfer of its task to another thread preparation mechanism. The weaving machine includes a monitoring device which, in the case of a thread break, sets a limit as to how much further the broken section of weft thread which is attached to the cloth can move. The monitoring device supplies an output signal so that further action can be taken to prevent further movement of the broken weft thread along with the cloth.

Abstract: A method for monitoring warp thread breaks on weaving machines includes the steps of locating broken warp threads and storing the number of broken warp threads in a memory as a function of the postions of the breaks.

Abstract: A method and apparatus to remove a defectively inserted weft thread includes preventing the severing of the weft thread from the ready supply of weft thread, releasing lengths of weft thread less than twice the width of the material from the ready supply of weft thread, blowing the released weft thread by pulsating blowing into the shed containing the defectively inserted weft thread, severing the newly inserted weft thread and the defectively inserted weft thread from the ready supply, and removing the weft thread from the shed by pulsating blowing of the weft thread.