Abstract: At their free ends the yarns are straightened, clamped and welded with a film. Welding is performed with two welding bars to which is allocated a brush beam to tension the yarns. The welding bars are borne and/or guided by a frame to which the brush beam is also secured. The frame is fitted on a mobile chassis which also has a holder to take a roll of welding film. For use in weaving preparation works and in weaving works, especially in preparing the warp and in starting weaving.

Abstract: The warp threads (Ka) are clamped as a thread layer, are divided off individually from this and are stretched with a simultaneous measurement of the tensile force and/or stretching. These operations take place before the weaving process in a step of the weaving preparation process in which the warp threads are in the form of a prepared warp-thread layer. The device contains means (1, 2) for clamping the warp-thread layer, means (4) for dividing off the warp threads and means (FP) for measuring the tensile force and/or stretching of the divided-off warp threads, the means (1, 2) for clamping the warp-thread layer forming an integral part of a warp preparation machine, preferably of a knotting unit or of a drawing-in unit.

Abstract: An apparatus and method for effecting a warp change in weaving machines involves clamping the warp yarns of a new warp on a tying-in frame by way of clamping members. In addition, the warp yarns of the woven-out warp, the end portion of which has previously been pulled forwards over a specific length, are lifted over the tying-in frame and laid onto a roller assigned to the clamping members. The warp yarns of the woven-out warp are then fixed on the roller and pulled back out of the weaving machine over the specific length as a result of the rotation of this roller. These operations can be carried out by a single person, so that the warp change is simplified substantially. The tying-in frame and roller are mounted on a common carrier which is mountable on a warp-beam transport unit.

Abstract: A clamping device for a planer layer of threads includes a clamping rail adapted to extend across the layer of threads and provided with a contact zone for contacting one face of the thread layer, and a plurality of clamping member units spaced along the length of the clamping rail. Each of the clamping member units includes a support element having a pivot axis and mounted for pivoting movement about the pivot axis and linear movement along the axis, and a thread contacting member carried by the end portion of the supporting member. When the support element is pivoted about the pivot axis, the thread contacting member swings from a first position at right angles to the contact zone of the clamping rail to a second position parallel to the contact zone. When the support element is moved in the linear direction, the thread contacting member moves closer to or farther from the clamping rail.

Abstract: A tying machine includes a tying device, grippers for two groups of warp threads (K.sub.a, K.sub.n) which are to be tied together and a device for separating the outermost warp thread of each group and moving it out of the plane of the warp. In the region between the separating device and a gripper, the warp threads are guided over a thread guide where the outermost warp thread is deflected and moved out of the plane of the warp. A measuring device for measuring the force exerted by a deflected warp thread on the point of deflection or on the separating device is arranged in the region of deflection, and the signal of this measuring device serves as criterion for the presence of a double thread. The measuring device may be a piezoelectric pressure convertor or an elongation measuring strip or a piezo sensor which is sensitive to deflection. Thus, the measuring device is virtually unaffected by dirt or dust.

Abstract: This invention relates to a method and an apparatus for avoiding untwisting during the formation of a binding of two fiber bundles. The rotational direction of deformation members acting on the fiber bundles is selected to be different in different groups of deformation members in order to reproduce or to increase the original twist during the binding operation.