The invention relates to an apparatus and to a method for the insertion of a weft thread into a shed of a rapier weaving machine in accordance with the preamble of claim 1 and with the preamble of claim 6 respectively as well as to a rapier weaving machine having such an apparatus or equipped for the carrying out of such a method.
In rapier weaving machines, the weft thread is usually inserted into a shed by means of a bringer rapier fastened to a rapier rod or to a flexible tape and is taken over and conveyed onward by a taker rapier at a transfer point in the central part of the shed. The bringer rapier has the task of taking up the presented weft thread reliably, of inserting the same into the shed and supplying it precisely to the taker rapier. The taker rapier has the task of taking over the weft thread reliably, conveying the same onward in the shed and releasing it at the end of the weft insertion. Each of the rapiers includes a rapier head which is usually equipped with a thread clamp to clamp the weft thread tight during the weft insertion.
With the numbers of picks usual today, the danger increases that the rapier head deviates from the ideal insertion path and in so doing damages the shed in that it for example, deviates downwardly and in so doing pulls along warp threads from the lower shed or raises upwardly and in so doing pulls along warp threads from the upper shed. In addition, with the current numbers of picks, the reliable transfer of the weft thread from the bringer rapier to the taker rapier becomes more and more difficult. This problem is further amplified by larger cloth widths. A guide is therefore usually provided in current weaving machines which guides the rapier head or the rapier tape during the weft insertion in the shed.
It has been found in this respect that a lateral guidance of the rapier tape at the edges can result in damage to the edges. Fibers are in particular exposed with rapier tapes made of fiber-reinforced plastics due to the friction load at the edges which have a very abrasive effect and can cause warp thread breaks.
A rapier weaving machine having guide teeth for the rapiers is known from EP-A-0 468 916. The guide teeth are made as a sliding support for the rapier tape and for the rapier head and are fastened to a sley of the rapier weaving machine. The rapier head is additionally equipped with a runner which is guided laterally by the guide teeth. Thanks to the runner, the rapier head can be guided laterally without the guide teeth coming into contact with the edges of the rapier tape. In two embodiment variants, the guide teeth engage around the edge of the runner or the runner engages around the edge of the guide teeth such that the rapier head is also guided with respect to the raising.
The rapier weaving machine known from EP-A-0 468 916 has the disadvantage that comparatively little time is available for the braking and accelerating of the sley since the sley has to be in the rear rest position as soon as the rapier head dips into the shed and as long as the rapier head is in the shed on the withdrawal of said rapier head. There is otherwise the risk that the rapier head is deflected by the guide teeth fastened to the sley so that it contacts the warp threads of the shed and may damage them. The braking and accelerating of the sley within a short time results in a comparatively abrupt sley movement by which the bearings and the drive parts of the sley are loaded correspondingly strongly. Furthermore, the maximum achievable number of picks can also be limited by the abrupt sley movement.
It is the object of the invention to provide an apparatus and a method for the insertion of a weft thread into a shed of a rapier weaving machine as well as a rapier weaving machine having such an apparatus or equipped to carry out such a method in which the rapier tape or the rapier head are guided in the shed and by means of which the bearings and drive parts of the sley are loaded less strongly in comparison with the prior art described above.
This object is satisfied in accordance with the invention by the apparatus defined in claim 1 and by the method defined in claim 6 as well as by the rapier weaving machine defined in claim 13.
The apparatus in accordance with the invention for the insertion of a weft thread into a shed of a rapier weaving machine includes a rapier tape movable in the insertion direction, a rapier head at the same and at least one guide part or a guide structure which are provided at the rapier tape and/or at the rapier head as well as a plurality of guide elements which cooperate with the guide part or the guide structure to guide the rapier tape and/or the rapier head in the shed, wherein the start of the guidance of the guide part or of the guide structure by the guide elements is delayed until the rapier tip is at a distance of at least 14 cm or at a distance of at least 18 cm or of at least 24 cm in the shed. The guide elements are advantageously arranged at a sley of the rapier weaving machine.
In an advantageous embodiment variant, the start of the lateral guidance of the guide part or of the guide structure by the guide elements is delayed until the rapier tip is at a distance of at least 14 cm or at a distance of at least 18 cm or of at least 24 cm in the shed. In a further advantageous embodiment variant, the start of the guidance of the guide part or of the guide structure by the guide elements is delayed with respect to the raising until the rapier tip is at a distance of at least 14 cm or at a distance of at least 18 cm or of at least 24 m in the shed.
In a further advantageous embodiment variant, the apparatus includes a rapier tape, a rapier head and at least one guide part or a guide structure for a bringer rapier and/or a rapier tape, a rapier head and at least one guide part or a guide structure for a taker rapier, with the guide part associated with the bringer rapier or the corresponding guide structure being set back by at least 14 cm, in particular at least 18 cm or at least 24 cm, with respect to the rapier tip of the bringer rapier, and/or with the guide part associated with the taker rapier or the corresponding guide structure being set back by at least 14 cm, in particular by at least 18 cm or at least 24 cm, with respect to the rapier tip of the taker rapier.
In a further advantageous embodiment variant, the guide elements for the guidance of the guide part or of the guide structure are offset inwardly by at least 10 cm or are offset inwardly by at least 12 cm or by at least 16 cm with respect to the shed edge.
In an advantageous embodiment, a section is provided at or in the guide part or at or in the guide structure, for example a trapezoidal section or a dovetail section, with the guide elements being made at least in part shape matched to the section of the guide part or of the guide structure to guide the rapier tape and/or the rapier head in the shed by means of the section and of the guide elements.
At least some of the guide elements are advantageously made as one-sided guide elements to guide the guide part or the guide structure respectively on one side and/or to support them on one side. Respective one-sided guide elements are advantageously arranged on both sides of the guide part or of the guide structure to guide the guide part or the guide structure at both sides and/or to support them at both sides, for example in that the one-sided guide elements are arranged alternately.
In a further advantageous embodiment, the start of the guidance of the guide part or of the guide structure by the guide elements is delayed at most for so long until the rapier tip is at a distance of 50 cm or at a distance of 40 cm or of 30 cm in the shed.
In the method in accordance with the invention for the insertion of a weft thread into a shed of a rapier weaving machine, the weft thread is taken up and inserted into the shed by a rapier head which is provided at a rapier tape. Furthermore, at least one guide part or a guide structure is provided at the rapier tape and/or rapier head which cooperate with guide elements to guide the rapier tape and/or the rapier head in the shed, wherein the guide part or the guide structure are only guided by the guide elements when the rapier tip is at a distance of at least 14 cm or at a distance of a least 18 cm or of at least 24 cm in the shed.
In an advantageous embodiment variant, the weaving machine includes a reed which is provided at a sley to beat on an inserted weft thread, wherein the guide part or the guide structure are only guided by the guide elements when the sley is located in the rear rest position. In this respect, the time at which the sley reaches the rear rest position can essentially coincide with the start of the guidance of the guide part or of the guide structure by the guide elements.
In a further advantageous embodiment variant, the weft thread is taken up and inserted into the shed by a rapier head of a bringer rapier which is provided at a rapier tape and/or is taken over and conveyed onward by a rapier head of a taker rapier which is provided at a rapier tape. In addition, in each case at least one guide part or a guide structure are provided at the rapier tape and/or rapier head of the bringer rapier or of the taker rapier respectively which cooperate with guide elements to guide the respective rapier tape and/or the respective rapier head in the shed, wherein the guide part associated with the bringer rapier or the corresponding guide structure are set back by at least 14 cm, in particular at least 18 cm or at least 24 cm, with respect to the rapier tip of the bringer rapier, and/or wherein the guide part associated with the taker rapier or the corresponding guide structure are set back by at least 14 cm, in particular at least 18 cm or at least 24 cm, with respect to the rapier tip of the taker rapier.
In a further advantageous embodiment variant, the guide elements for the guidance of the guide part or of the guide structure are offset inwardly by at least 10 cm or are offset inwardly by at least 12 cm or by at least 16 cm with respect to the shed edge.
In an advantageous embodiment of the method, a section is provided at or in the guide part or at or in the guide structure, for example a trapezoidal section or a dovetail section, with the guide elements being made at least in part shape matched to the section of the guide part or of the guide structure to guide the rapier tape and/or the rapier head in the shed by means of the section and of the guide elements.
Advantageously, at least some of the guide elements are made as one-sided guide elements which guide the guide part or the guide structure on one side respectively and/or support them on one side, wherein respective one-sided guide elements are arranged on both sides of the guide part or of the guide structure to guide and/or support the guide part or the guide structure on both sides, and wherein the one-sided guide elements are arranged alternately, for example.
In a further advantageous embodiment of the method, the guide part or the guide structure are guided by the guide elements at the latest when the rapier tip is at a distance of 50 cm, in particular at a distance of 40 cm or of 30 cm, in the shed.
The invention furthermore includes a rapier weaving machine having an apparatus in accordance with one of the embodiment variants and embodiments described above and/or equipped to carry out a method in accordance with the above description.
In an advantageous embodiment variant, the rapier weaving machine includes a sley with a reed to beat on an inserted weft thread, wherein the start of the guidance of the guide part or of the guide structure by the guide elements is not before the time at which the sley has reached the rear rest position. In this respect, the start of the guidance of the guide part or of the guide structure by the guide elements can essentially coincide with the time at which the sley has reached the rear rest position.
The apparatus and the method in accordance with the present invention as well as the rapier weaving machine in accordance with the invention have the advantage with respect to the described prior art that, thanks to the delayed start of the guidance of the rapier tape and/or rapier head in the shed, the rapier head can already be introduced into the shed before the sley has reached the rear rest position without there being any risk that the rapier tape and/or the rapier head is deflected by moving guide elements and damages the warp threads. In this respect, the rapier tape and/or the rapier head can subsequently, when the sley is in the rear rest position, still be guided reliably in the shed, and indeed optionally laterally and/or with respect to downward and/or upward deviations.
Conversely, the guidance of the rapier tape and/or rapier head ends in accordance with the invention in the second half of the weft insertion on the withdrawal of the rapier head from the shed before the rapier head has left the shed. The time duration or the machine angular range during which the rapier tape and/or the rapier head are guided in the shed can thus be shortened both in the first and the second half of the weft insertion with respect to the apparatus and methods known from the prior art so that a correspondingly longer time portion or machine angular range is available for the sley movement for the beating on of the inserted weft thread. The longer machine angular range, which is available thanks to the apparatus in accordance with the invention and to the method in accordance with the invention, allows the sley movement to be carried out less abruptly, whereby the bearings and the drive parts of the sley are saved and/or can be made lighter.
The above description of embodiments and embodiment variants only serves as an example. Further advantageous embodiments and embodiment variants can be seen from the dependent claims and from the drawing. Furthermore, individual features from the embodiments and embodiment variants described or shown can also be combined with one another within the framework of the present invention to form new embodiments.
The invention will be explained in more detail in the following with reference to the embodiment and to the drawing. There are shown:
The rapier weaving machine in which the apparatus 1 is used can, for example, include a sley 9 and, at the same, a reed 8 for the beating on of inserted weft threads. The guide elements 6.1-6.i+1, as shown in
In a further advantageous embodiment variant, the apparatus 1 includes a rapier tape 3b, a rapier head 3a and at least one guide part or a guide structure 5 for a bringer rapier 3 and/or a rapier tape 4b, a rapier head 4a and at least one guide part or a guide structure for a taker rapier, with the guide part associated with the bringer rapier or the corresponding guide structure being set back by at least 14 cm, or at least 18 cm or at least 24 cm or at least 30 cm with respect to the rapier tip
In an advantageous embodiment, a section is provided at or in the guide part or at or in the guide structure 5, for example, as shown in
Advantageously, at least some of the guide elements or, as shown in
Advantageously, respective one-sided guide elements are arranged on both sides of the guide part or of the guide structure to guide the guide part or the guide structure at both sides and/or to support them at both sides, for example in that the one-sided guide elements are arranged alternately.
In a further advantageous embodiment, the start of the guidance of the guide part or of the guide structure 5 by the guide elements 6.1-6.i+1 is delayed at most for so long until the rapier tip
The examples, embodiments and embodiment variants shown in
An embodiment of the method in accordance with the invention for the insertion of a weft thread 2 into a shed 10 of a rapier weaving machine will be described in the following with reference to
In a further advantageous embodiment variant, the weaving machine includes a reed 8 which is provided at a sley 9 to beat on an inserted weft thread, with the guide part or the guide structure 5 only being guided by the guide elements 6.1-6.i+1 when the sley is in the rear rest position. In this respect, the time at which the sley reaches the rear rest position can essentially coincide with the start of the guidance of the guide part or of the guide structure by the guide elements.
In a further advantageous embodiment variant, the weft thread 2 is taken up and inserted into the shed 10 by a rapier head 3a of a bringer rapier 3, which is provided at a rapier tape 3b, and/or is taken over and conveyed onward by a rapier head of a taker rapier which is provided at a rapier tape. In addition, in each case at least one guide part or a guide structure 5 are provided at the rapier tape and/or rapier head of the bringer rapier or of the taker rapier respectively which cooperate with guide elements 6.1-6.i+1 to guide the respective rapier tape and/or the respective rapier head in the shed, with the guide part associated with the bringer rapier or the corresponding guide structure being set back by at least 14 cm, at least 18 cm, at least 24 cm or at least 30 cm, with respect to the rapier tip
In an advantageous embodiment of the method, a section is provided at or in the guide part or at or in the guide structure 5, for example a trapezoidal section or a dovetail section, with the guide elements 6.1-6.i+1 being formed at least in part shape matched to the section of the guide part or of the guide structure to guide the rapier tape and/or the rapier head in the shed by means of the section and of the guide elements.
Advantageously, at least some of the guide elements 6.1-6.i+1 are made as one-sided guide elements which guide the guide part or the guide structure on a respective side and/or support them on one side, with respective one-sided guide elements being arranged on both sides of the guide part or of the guide structure to guide and/or support the guide part or the guide structure on both sides, and with the one-sided guide elements being arranged alternately, for example, as shown in
In a further advantageous embodiment of the method, the guide part or the guide structure 5 are guided by the guide elements 6.1-6.i+1 at the latest when the rapier tip
A second embodiment of the method in accordance with the invention will be explained in the following with reference to
The above description of the examples, embodiments and embodiment variants of the method in accordance with the invention usually makes reference to a bringer rapier. The described examples, embodiments and embodiment variants can naturally also be used in a corresponding manner and with the same advantages for a taker rapier.
The invention furthermore includes a rapier weaving machine having an apparatus 1 in accordance with one of the embodiment variants and embodiments described above and/or equipped to carry out a method in accordance with the above description.
In an advantageous embodiment variant, the rapier weaving machine includes a sley 9 with a reed 8 to beat on an inserted weft thread, with the start of the guidance of the guide part or of the guide structure 5 by the guide elements 6.1-6.i+1 not being before the time at which the sley has reached the rear rest position. In this respect, the start of the guidance of the guide part or of the guide structure by the guide elements can essentially coincide with the time at which the sley has reached the rear rest position. For the control of the apparatus for the insertion of a weft thread and in particular of the rapier movements and for the control of the sley movement, one or more control apparatus can be provided which control the rapier movements and the sley movement such, for example, that the start of the guidance of the guide part or of the guide structure by the guide elements essentially coincides with the time at which the sley has reached the rear rest position.
In addition, three respective positions 3′, 3″, 3′″, 4′, 4″, 4′″ of the bringer rapier and of the taker rapier are drawn in the graphic illustration. Position 3′ shows the bringer rapier on the insertion of the weft thread; position 3″ shows the bringer rapier on the withdrawal after the transfer of the weft thread, and position 3′″ shows the bringer rapier outside the shed shortly before reaching the reversal point. Position 4′ shows the taker rapier on the advance in the shed; position 4″ shows the taker rapier after the takeover on the insertion of the weft thread; and position 4′″ shows the taker rapier outside the shed shortly before the reaching of the reversal point.
Two further graphic illustrations can be found in
In the graphic illustration of the sley movement of a conventional apparatus for the insertion of a weft thread which is shown in
In the graphic illustration of the sley movement for an embodiment in accordance with the present invention, the sley is in the rest position 9a when the rapier tips have traveled a specific distance x along the reed or have dipped correspondingly far into the shed. The sley remains in the rest position during the weft insertion until the rapier tips have reached the outer region of the reed on the withdrawal which corresponds to the distance x or have approached the shed edge up to the distance x. From this time onward, the sley carries out a beating on movement to beat on the inserted weft thread by means of a reed which is provided at the sley. A much larger range of the machine angle is available for the sley movement from the rest position 9a to the beating on position 9b and back again in comparison with the conventional apparatus, said range corresponding to the range during which the guide part and/or the guide structure is/are located outside the range of the guide elements in the embodiment, i.e. during which the guide part and/or the guide structure are not guided.
The longer machine angle range, which is available thanks to the apparatus in accordance with the invention and thanks to the method in accordance with the invention, allows the sley movement to be carried out less abruptly, whereby the bearings and the drive parts of the sley are spared or can be made lighter. The apparatus, the method and the rapier weaving machine of the above description combine the advantages of a guidance of the rapier tape and/or of the rapier head in the shed with the advantages of a saving sley movement.
Number | Date | Country | Kind |
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08157112.7 | May 2008 | EP | regional |