Inserting rapier for a rapier weaving machine

Abstract

An inserting rapier (1) for a rapier weaving machine with a thread clamp (4) for the firm clamping of a weft thread (3) is presented, with the inserting rapier also including a guiding or holding device (10) with a guiding or holding element (5) and a mass (6) which are movably arranged on the inserting rapier and with the guiding or holding element (5) being movable by means of the inertia of the mass (6) in order to guide or hold the weft thread.

Description

The invention relates to an inserting rapier for a rapier weaving machine with a thread clamp for the firm clamping of at least one weft thread and to a method for guiding and holding a weft thread in an inserting rapier in accordance with the preamble of claim 8 and to a weaving machine with an inserting rapier of this kind and for carrying out a method of this kind.

In rapier weaving machines the weft thread is inserted into a shed by means of an inserting rapier, which is mounted on a bar or a flexible band, and is taken over at a transfer point in the middle part of the shed by a receiving rapier and transported further. The inserting rapier has the task of securely gripping the presented weft thread, to insert the latter into the shed and to guide it precisely to the receiving rapier. An inserting rapier of this kind, which contains a thread guide formed in it and a thread clamp is for example disclosed in the publication EP 0 441 099 A1.

In modern rapier weaving machines the inserting rapiers are moved at high speed during the weft insertion. The inserting rapiers must be braked from this high speed in order that the weft thread can be taken over by the receiving rapier at the transfer point. As a result of the inertial mass of the weft thread it can happen that the weft thread continues its movement at the transfer point so that the thread section to be taken over by the receiving rapier departs from its intended position and the receiving rapier can not grip the weft thread. In order to reduce weft insertion errors of this kind a controlled thread brake, which brakes the forwardly moving weft thread, can be provided on the insertion side in the region of the thread delivery apparatuses. The danger of the thread section to be taken over departing from its intended position in the inserting rapier is however still present, in particular in the case of heavy weft threads, even if a thread brake brakes the weft thread, since the inertial forces which arise in the deceleration of the weft thread stretch it elastically after the thread brake.

The object of the invention is to make available an inserting rapier for a rapier weaving machine and a method for guiding and holding a weft thread in an inserting rapier which prevent running on of the weft thread at the transfer point and which enable the weft thread to be guided in such a manner that it can be reliably taken over by a receiving rapier.

This object is satisfied in accordance with the invention by the inserting rapier which is defined in claim 1 and by the method for guiding and holding a weft thread in a inserting rapier which is defined in claim 8 as well as through the weaving machine which is defined in claim 10.

The inserting rapier in accordance with the invention for a rapier weaving machine comprises a thread clamp for the firm clamping of at least one weft thread. In addition the inserting rapier comprises a guiding and/or holding device for guiding and/or holding the weft thread with a guiding and/or holding element and a mass, with the guiding and/or holding element being controllable and/or movable by means of inertial forces which act on the mass during an acceleration or deceleration of the inserting rapier. In a preferred variant the guiding and/or holding element and/or the mass are movably mounted on the inserting rapier.

In a preferred embodiment the thread clamp and the guiding and/or holding element are arranged with spacing with respect to one another so that during the transfer to a receiving rapier the weft thread can be guided and/or held at both sides of the receiving rapier. In a preferred variant the inserting rapier comprises two side walls, with the thread clamp being arranged in the vicinity of the one side wall and the guiding and/or holding element in the vicinity of the second side wall.

In a further preferred embodiment the guiding and/or holding element is resiliently designed, secured or mounted, or connected to a spring element, and the mass is arranged at the guiding and/or holding element; and in an additional preferred embodiment the guiding and/or holding element is designed as a movably journalled pawl, with it being possible for the mass to be part of the pawl, so that the latter can be moved by means of the inertia of its own mass.

In a preferred variant the guiding and/or holding element is designed and arranged such that the weft thread can be held by the former in a notch which is formed in the inserting rapier, in particular in an upper part of the inserting rapier.

Furthermore, the invention comprises a method for guiding and holding a weft thread in an inserting rapier, in which the weft thread is taken up by the inserting rapier and is clamped firmly in the latter by means of a thread clamp, with the weft thread additionally being guided and/or held in the inserting rapier by means of a guiding and/or holding device which is controlled and/or moved by means of the inertia of a mass.

In a preferred embodiment of the method the guiding and/or holding device is closed by the inertia of the mass prior to reaching the transfer point, so that the weft thread extends between the thread clamp and the guiding and/or holding device on reaching the transfer point and the weft thread, which extends between the thread clamp and the guiding and/or holding device, is taken over by a receiving rapier.

Furthermore, the invention comprises a rapier weaving machine with an inserting rapier in accordance with any one of the above described embodiments and/or equipped for carrying out a method in accordance with the above description.

The inserting rapier in accordance with the invention and the method in accordance with the invention for guiding and holding a weft thread in an inserting rapier have the advantage that thanks to the additional guiding and/or holding device, which can be controlled by means of inertial forces, a high reliability can be achieved in the thread transfer from the inserting rapier to the receiving rapier. This is particularly important in the case of rapid weft insertions, which can for example amount to 350 insertions/min or 500 insertions/min or more. If the weft runs ahead, this takes place outside the thread transfer region, so that the running ahead hardly causes a disturbance in the thread transfer. Thanks to the additional guiding and/or holding device the weft thread need only be minimally braked at most during the thread transfer, so that most of the weft threads can be inserted without a controlled thread brake. It is particularly advantageous that the weft thread can be fixed more firmly in the receiving rapier, since the required thread tension is ensured on both sides through the holding of the weft thread on both sides of the receiving clamp. It is furthermore advantageous that the danger of the weft thread being overstretched when being hung into the receiving rapier is slight, since the basic tension can be kept low.

The above description of embodiments serves merely as an example. Further advantageous embodiments result from the independent claims and the drawings. Moreover, in the context of the present invention individual features from the described or illustrated embodiments and variants can also be combined with one another in order to form new embodiments.

The invention will be explained in the following in more detail with reference to the exemplary embodiment and with reference to the drawings. Shown are:

FIG. 1 a perspective view of an exemplary embodiment of an inserting rapier in accordance with the present invention together with a receiving rapier,

FIG. 2A an enlarged perspective view of the same exemplary embodiment with an inserted weft thread and open guiding and/or holding device,

FIG. 2B a perspective view of the exemplary embodiment which is shown in FIG. 2A with a closed guiding and/or holding device,

FIG. 3A a perspective view of a second exemplary embodiment with an inserted weft thread and open guiding and/or holding device, and

FIG. 3B a perspective view of the exemplary embodiment which is shown in FIG. 3A with a closed guiding and/or holding device.

FIG. 1 shows an exemplary embodiment of an inserting rapier in accordance with the present invention together with a receiving rapier 2 in a perspective view. The weft insertion direction is marked with an arrow 12 in FIG. 1. In the illustrated embodiment the inserting rapier 1 comprises a thread clamp 4 for firmly clamping at least one weft thread as well as additionally a guiding and/or holding device 10 for guiding and/or holding the weft thread and having a guiding and/or holding element 5 and a mass 6. The guiding and/or holding element 5 is controllable and/or movable by means of inertia forces which act on the mass 6 during an acceleration or deceleration of the inserting rapier 1. In an advantageous embodiment the guiding and/or holding element 5 and/or the mass 6 are movably mounted on the inserting rapier. The design and method of action of the guiding and/or holding device 10 will be explained in more detail in connection with the descriptions of FIGS. 2A, 2B and 3A, 3B.

In a further advantageous embodiment the inserting rapier 1 can comprise further parts, for example, as shown in FIG. 1, two side walls 1a, 1b and where required an upper part 9. The upper part can, as shown, be provided with a notch 8 into which the weft thread can be laid in order to be able to guide the latter during the insertion. Furthermore, the guiding and/or holding element 5 can be mounted on the upper part 9, for example by means of a mounting element 7, which can e.g. be executed as a screw.

In a preferred embodiment the thread clamp 4 and the guiding and/or holding element 5 are arranged with spacing with respect to one another, so that the weft thread can be guided or held on both sides of the receiving rapier during the transfer to the receiving rapier. If the inserting rapier 1 includes two side walls 1a, 1b the thread clamp can, for example, be arranged in the vicinity of the one side wall and the guiding and/or holding element can be arranged in the vicinity of the second side wall.

FIG. 2A shows an enlarged perspective view of the same exemplary embodiment with a laid in weft thread and an open guiding and/or holding device. In this exemplary embodiment the inserting rapier 1 comprises a thread clamp 4 and in addition a guiding and/or holding device 10 which is arranged with a spacing with respect to the thread clamp. In this embodiment the guiding and/or holding device 10 contains a guiding and/or holding element 5 which is designed to be resilient, for example in an advantageous variant as a bending spring which is secured at one end to the inserting rapier, e.g. with a mounting means 7 at an upper part 9 of the inserting rapier. The other end of the guiding and/or holding element 5, i.e. of the bending spring, is free and is deflected in the position which is shown in FIG. 2A toward the thread clamp 4 to such an extent that the weft thread 3 can slide past the guiding and/or holding element 5 and for example be laid into a notch 8 in the upper part 9. Furthermore, the guiding and/or holding device 10 contains a mass 6, which can for example consist of the mass of the spring element 5 or, in the event that the latter is too light, of an additional mass which is arranged on the spring element. Particularly advantageous in this variant is that the free end of the guiding and/or holding element 5 can be moved without friction.

The inserting rapier which is shown in FIG. 2B differs from that in FIG. 2A only in the position of the guiding and/or holding element 5. The free end of the guiding and/or holding element 5, which is designed as a bending spring, is deflected in FIG. 2B in the direction toward a notch 8 which is arranged laterally in the inserting rapier 1, so that the free end closes off the notch, for example in that the guiding and/or holding element 5 makes contact with one side of the notch or protrudes beyond the one side. A weft thread 3 which is laid into the notch is thus closed in, even if the thread section which extends outside the inserting rapier advances past the inserting rapier, as is indicated by a forwardly directed loop in FIG. 2B. Together with the notch 8, the guiding and/or holding element 5 thus forms a guiding eye. The guiding and/or holding element 5 can optionally also be formed as part of a thread clamp, for example. The weft thread 3 is firmly held by the thread clamp 4 on the side of the inserting rapier which lies opposite to the notch 8 or to the guiding eye respectively, so that the weft thread is held at both sides of the inserting rapier. Thanks to the mass 6 which is arranged at the guiding and/or holding element 5, the free end of the latter can be laterally deflected by the inertial forces which arise during the acceleration and deceleration of the inserting rapier; and the notch 8 or the guiding eye respectively can be opened or closed.

FIG. 3A shows a perspective view of a second exemplary embodiment with a laid in weft thread and an open guiding and/or holding device. In the illustrated embodiment the inserting rapier 1 comprises a thread clamp 4 as well as additionally a guiding and/or holding device 10 which is arranged with a spacing with respect to the thread clamp. In this exemplary embodiment the guiding and/or holding device 10 contains a movably mounted pawl 5 which is for example pivotally journalled about a mounting element 5a. Furthermore, an abutment 5b can be provided in order to be able to limit the rotational movement on opening the pawl. The illustrated pawl comprises a closing part, which is pivoted toward the thread clamp 4 in the position which is shown in FIG. 3A to such an extent that the weft thread 3 can slide past the closing part and for example be laid into a notch 8 in an upper part 9 of the inserting rapier 1. In an advantageous variant the pawl 5 has sufficient mass to overcome the journalling friction, so that the pawl is movable by the inertial forces which act on the mass during the acceleration and deceleration of the inserting rapier. Where required the pawl can also be connected to a spring element, for example in order to be able to keep the pawl 5 open during slow movements of the inserting rapier.

The inserting rapier which is shown in FIG. 3B differs from that which is shown in FIG. 3A only in the position of the pawl 5. The illustrated pawl comprises a closing part, which is pivoted in FIG. 3B in the direction toward a notch 8 which is arranged laterally in the inserting rapier 1, so that the closing part closes off the notch, for example in that it makes contact with one side of the notch or protrudes beyond the one side. A weft thread 3 which is laid in into the notch is thus closed in, even if the thread section which extends outside the inserting rapier moves on forwardly relative to the inserting rapier. Together with the notch 8 the closing part of the pawl 5 forms a guiding eye. On the side of the inserting rapier which lies opposite to the notch 8 or to the guiding eye the weft thread 3 is held firmly by the thread clamp 4, so that the weft thread is held on both sides of the inserting rapier. Thanks to the inherent mass of the pawl 5 the latter can be pivoted by the inertial forces which arise on acceleration and deceleration of the inserting rapier, and the notch 8 or the guiding eye can be opened and/or closed.

An exemplary embodiment of the method in accordance with the invention for guiding and holding a weft thread in an inserting rapier will be described in the following with reference to FIGS. 2A and 2B. In this method the weft thread 3 is taken up by the inserting rapier 1 and clamped firmly in the latter by means of a thread clamp 4. For this the weft thread which is presented can for example be taken up by the inserting rapier at the beginning of the weft insertion, with the weft thread being drawn into the thread clamp and clamped firmly therein by the forward movement of the inserting rapier. On the taking up of the weft thread by the inserting rapier the former can, if desired, also be laid into a guide in the inserting rapier which is arranged with spacing with respect to the thread clamp 4, for example, as shown in FIG. 2A, into a notch 8. In this method the weft thread 3 is additionally controlled and/or held in the inserting rapier 1 by means of a guiding and/or holding device 10 which is controlled and/or moved by means of the inertia of a mass 6.

In an advantageous embodiment of the method the inserting rapier 1 is decelerated prior to reaching the transfer point, with the guiding and/or holding device 10 being closed by the inertial forces which act on the mass 6, so that the weft thread 3 extends between the thread clamp 4 and the guiding and/or holding device 10 on reaching the transfer point, as is shown in FIG. 2B. The weft thread, which extends between the thread clamp and the guiding and/or holding device, is now taken over by a receiving rapier. The guiding and/or holding device 10 is expediently designed such that the weft thread can be drawn out when the guiding and/or holding device is closed. In this way it can be ensured that a thread tension is present on both sides of the receiving clamp during the transfer of the weft thread.

It is advantageous that the inertia controlled guiding and/or holding device is necessarily open during the taking up of the weft thread at the beginning of the weft insertion due to the positive acceleration which is present in this phase. Only in the event of very slow rapier movements can it be expedient to ensure the opening of the guiding and/or holding device through additional measures, for example by a spring element.

Thanks to the additional guiding and/or holding device, which is controllable by means of inertia forces, a high reliability can be achieved in the thread transfer from the inserting rapier to the receiving rapier, in particular also in the case of rapid weft insertions. If running on of the weft thread arises, this takes place outside the thread section which extends between the thread clamp and the guiding and/or holding device, so that the advance hardly represents a disturbance during the thread transfer.

In addition the risk is slight that the weft thread will be overstretched when being hung in place at the receiving rapier, since the basic tension can be kept low. A further advantage is that the weft thread need only be minimally braked at most during the thread transfer, so that most of the weft threads can be inserted without a controlled thread brake, and that the weft thread can be better fixed in the receiving clamp, since the weft thread is held on both sides of the receiving rapier during the transfer and thus a tensile force is present on both sides.

Claims

1. Inserting rapier for a rapier weaving machine with a thread clamp (4) for the firm clamping of at least one weft thread (3), characterized in that the inserting rapier (1) also includes a guiding and/or holding device (10) for guiding and/or holding the weft thread with a guiding and/or holding element (5) and a mass (6); and in that the guiding and/or holding element (5) can be controlled and/or moved by means of inertial forces which act on the mass (6) during an acceleration or deceleration of the inserting rapier.

2. Inserting rapier in accordance with claim 1, with the guiding and/or holding element (5) and/or the mass (6) being movably mounted on the inserting rapier (1).

3. Inserting rapier in accordance with claim 1, with the thread clamp (4) and the guiding and/or holding element (5) being arranged spaced apart in order to be able to guide and/or to hold the weft thread (3) on transfer to a receiving rapier on both sides of the receiving rapier (2).

4. Inserting rapier in accordance with claim 2, with the inserting rapier (1) including two side walls (1a, 1b) and with the thread clamp (4) being arranged in the vicinity of the one side wall and the guiding and/or holding element (5) being arranged in the vicinity of the other side wall.

5. Inserting rapier in accordance with claim 1, with the guiding and/or holding element (5) being resiliently designed or mounted or being connected to a spring element, and with the mass (6) being arranged at the guiding and/or holding element (5).

6. Inserting rapier in accordance with claim 1, with the guiding and/or holding element being designed as a movably journalled pawl (5) which can be moved by means of the inertia of its own mass.

7. Inserting rapier in accordance with claim 1, with the guiding and/or holding element (5) being designed and arranged in such a manner that the weft thread (3) is held by the same in a notch (8) which is formed in the inserting rapier (1), in particular in an upper part (9) of the inserting rapier.

8. Method for the guiding and holding of a weft thread in an inserting rapier, in said method the weft thread (3) being taken up by the inserting rapier (1) and being clamped in the latter by means of a thread clamp (4), characterized in that the weft thread is additionally guided and/or held in the inserting rapier by means of a guiding and/or holding device (10) which is controlled and/or moved by means of the inertia of a mass (6).

9. Method in accordance with claim 8, with the guiding and/or holding device (10) being closed by the inertia of the mass (6) prior to reaching the transfer point, with the weft thread (3) extending between the thread clamp (4) and the guiding and/or holding device (10) on reaching the transfer point, and with a receiving rapier (2) taking over the weft thread which extends between the thread clamp and the guiding and/or holding device.

10. Rapier weaving machine including an inserting rapier in accordance with claim 1.

11. Rapier weaving machine equipped for carrying out a method in accordance with claim 8.