EP0352223B1 - Weft insertion device for a gripper loom - Google Patents

Description

The invention relates to a weft insertion device of a rapier weaving machine, with a flexible entry belt which can be wound up and unwound with one end on an oscillating driven belt wheel and at the other, free end with a rapier head for inserting weft threads into a shed of the weaving machine and which is connected to a cross section that is constant over at least most of its length and is made of a fiber-reinforced plastic.

In a device of the type mentioned known from CH-A-596 355 (MR 133), the plastic formed by an epoxy or phenolic compound is reinforced by carbon fibers. Previous entry belts of this type are each formed, for example, by a strip of a plastic plate which is reinforced by a layer of bundled fibers which cross in the longitudinal and transverse directions and extend over their entire length and width. For the production of the entry belts, these strips are punched out of the plate and then ground at the interfaces. This requires a relatively large amount of processing. With the entry tapes produced in this way During weaving operation, the plastic layer surrounding the fiber bundle, particularly in the interfaces of the transverse fiber strands located at the lateral edge areas of the entry band, can expose fiber ends at which warp threads can get caught when the entry band passes through the weaving shed, resulting in fabric defects can.

In connection with a weft insertion device of another type, a gripper bar in the form of a plastic band is known from DE-A-30 42 054, which has a toothed part formed by hole-like cutouts of the plastic band, into which a drive pinion engages. The toothing part is reinforced by fiber strands guided around the cutouts in a wave-like manner and by fiber strands running along the lateral boundaries of the plastic band. In the known gripper bar, only the relatively narrow lateral edge areas are available for the arrangement of the fiber strands effective for stiffening, so that there is a risk that parts of the fiber strands will be exposed when these edge areas are worn.

The invention has for its object to provide a weft insertion device of the type mentioned improved in particular in this regard, by which escape of the fiber bundle disruptive parts of the fiber bundle from the entry belt is reliably prevented.

This object is achieved in accordance with the characterizing part of claim 1. The embodiment according to the invention enables production which is considerably simplified compared to previous embodiments and also a substantial increase in the operating time of the entry belt, as a result of which the downtimes of the weaving machine required for the replacement of the entry belt are correspondingly reduced.

Embodiments of the invention are specified in the dependent claims.

• Fig. 1 Teile einer Schusseintragsvorrichtung einer Bandgreiferwebmaschine in einer perspektivischen Teilansicht;
• Fig. 2 ein Eintragsband der Vorrichtung nach Fig. 1 in einer grösseren perspektivischen Darstellung;
• Fig. 2a eine Einzelheit aus der Fig. 2 in einer grösseren Darstellung;
• Fig. 3 einen Teil eines entsprechenden Eintragsbandes in einer Draufsicht gemäss Pfeil III in Fig. 2 und einem Teilschnitt;
• Fig. 4 den Schnitt IV-IV aus der Fig. 3;
• Fig. 5 einen entsprechenden Teil eines Eintragsbandes in einer abgewandelten Ausführungsform;
• Fig. 6 den Schnitt VI-VI aus der Fig. 5;
• Fig. 7 einen Teil eines Eintragsbandes in einer weiteren abgewandelten Ausführungsform;
• Fig. 8 den Schnitt VIII-VIII aus Fig. 7;
• Fig. 9, 9a je einen Teil eines Eintragsbandes in einer weiteren abgewandelten Ausführungsform;
• Fig. 10 den Schnitt X-X aus Fig. 9;
• Fig. 11, 12, 13 Anordnungen von Eintragsbändern je in einer weiteren Ausführungsform und je in einem Querschnitt entsprechend der Linie XI-XI in Fig. 1;
• Fig. 14, 15, 16 die Eintragsbänder nach Fig. 11 bzw. 12 bzw. 13, je in einem Querschnitt entsprechend der Linie XIV-XIV in Fig. 1;
• Fig. 17, 18, 19, 20, 21, 22 entsprechende Querschnitte von Eintragsbändern, je in einer weiteren Ausführungsform.

Further features and details emerge from the following description of exemplary embodiments of the invention shown schematically in the drawing, in conjunction with the claims. The drawing shows:

• 1 shows parts of a weft insertion device of a belt rapier weaving machine in a perspective partial view;
• FIG. 2 shows an entry tape of the device according to FIG. 1 in a larger perspective view;
• FIG. 2a shows a detail from FIG. 2 in a larger representation;
• 3 shows a part of a corresponding entry belt in a top view according to arrow III in FIG. 2 and a partial section;
• 4 shows the section IV-IV from FIG. 3;
• 5 shows a corresponding part of an entry tape in a modified embodiment;
• FIG. 6 shows the section VI-VI from FIG. 5;
• 7 shows a part of an entry tape in a further modified embodiment;
• 8 shows the section VIII-VIII from FIG. 7;
• 9, 9a each a part of an entry tape in a further modified embodiment;
• 10 shows the section XX from FIG. 9;
• 11, 12, 13 arrangements of entry belts each in a further embodiment and in each case in a cross section along the line XI-XI in FIG. 1;
• 14, 15, 16, the entry belts according to FIG. 11 or 12 or 13, each in a cross section along the line XIV-XIV in Fig. 1;
• 17, 18, 19, 20, 21, 22 corresponding cross-sections of entry belts, each in a further embodiment.

1 shows parts of a machine frame 1 and a sley 2 of a belt rapier weaving machine of known construction. The machine frame 1 contains on the left side and on the right side a supporting part 3, on which a belt wheel 5 of the weft insertion device is rotatably arranged. In Fig. 1, only the left side of the machine frame 1 is shown with the support part 3 arranged in mirror image to the right carrier and the belt wheel 5 arranged in mirror image to the right belt wheel. On the sley 2, a reed 6 is fastened, through which warp threads 7 and 8 are passed. On the circumference of the left belt wheel 5, one end 10a of a flexible entry belt 10 is fastened by means of a clamping piece 9, which is connected at the other, free end 10b to a gripper head 11 which is intended for gripping an end 12a of a weft thread 12. A corresponding entry belt, also provided with a gripper head, is attached to the right belt wheel.

The two belt wheels 5 are each driven oscillatingly and in opposite directions, the gripper heads 11 each being given a corresponding movement into or out of the shed 13 formed by the warp threads 7 and 8. The rapier heads 11 are moved along the sley 2 to the middle of the shed 13 and then pulled out of it again. Arranged outside the shed 13 on the right side of the loom Weft thread supply in each case the end 12a of the weft thread 12 is transferred to the rapier head arranged on the right entry belt. From this, the weft thread 12 is inserted into the first half of the shed 13 and transferred in the middle of the shed 13 to the rapier head 11 arranged on the left entry belt 10, through which the weft thread 12 is then inserted into the second half of the shed 13. After the weft insertion has been completed, the weft thread 12 is struck against the fabric 14 by the weaving blade 6 in the tip of the shed 13.

In the case of belt rapier weaving machines of a different type, the weft insertion device can also have a single belt wheel 5 and a single entry belt 10 that can be guided from one side of the loom over the entire width of the weaving machine and back, the gripper head of which accordingly carries out a complete weft insertion.

In the illustrated embodiment, the gripper head 11 is guided by the entry belt 10, which is moved when unwinding from the band wheel 5 according to arrow 15, from the operating position shown in FIG. 1 and located outside the shed 13 against the center of the shed 13 and then by winding up the entry band 10 to the belt wheel 5, returned to the illustrated operating position according to arrow 15a. After changing the shed, the rapier head 11 is guided against the center of the shed 13 and back for a new weft insertion. In the operating position shown in Fig. 1, the entry belt 10 is wound with a wrap angle of more than 360 °, for example 460 °, on the circumference of the belt wheel 5 and from the unwinding point 16 on the belt wheel 5 in a straight longitudinal section against a guide rail 17 a guide track 18 provided on the sley 2.

The part of the entry belt 10 located on the belt wheel 5 is wrapped by a pressure belt 20, by means of which the entry belt 10 is prevented from being lifted off. The pressure belt 20 is fastened at one end, together with the end 10a of the entry belt 10, by the clamping piece 9 in a first looping area 5a to the circumference of the belt wheel 5 and via two deflection rollers 21, 22 against one on the circumference of the belt wheel 5, next to the first looping area 5a provided second loop area 5b for the entry belt 20 out. In the second wrap area 5b, the pressure belt 20 is - with the entry belt 10 wound up as shown - with a wrap angle of more than 360 °, e.g. 620 °, guided over the circumference of the band wheel 5 and fastened to it by a clamping piece 23. This arrangement, which is not the subject of the present invention, is described in more detail in EP patent application 053 184 (T.716).

The entry belt 10 is designed in a length section A that can be wound onto the band wheel 5 with a basic cross section determined by a rectangular outline and in an adjoining end section B is provided with a web-like elevation 10d which, with a flange section 10c determined by the basic cross section, has an essentially T- shaped cross section. This stretched end section B also remains with the entry belt 10 completely withdrawn from the shed 13 - and accordingly fully wound band wheel 5 according to FIG. 1 - between the unwinding point 16 and the shed 13.

According to the representation according to FIG. 2, the entry belt 10 is formed from a profile part with a T-shaped cross-section that was originally constant over its entire length, with a dash-dotted line shown in FIG. 2 extending over the length section A of the entry belt 10 Section 10d 'of the elevation 10d except for the flange portion 10c removed, for example, has been cut off. This embodiment allows the use of a profile part produced by a continuous manufacturing process, for example by drawing, casting and / or pressing, in particular by pultrusion.

The entry belt 10 is made of a fiber 24, e.g. Carbon, glass or Kevlar fibers, reinforced plastic part formed, e.g. can be made from an epoxy or phenolic mass. The fibers 24 are, as indicated in Fig. 2a, to threads 25 running in the longitudinal direction of the entry belt 10 or to corresponding, e.g. Strand or bundle-like fiber groups are combined, which form a band-shaped insert 27 which penetrates the entry belt 10 over its entire length, the width and thickness of which are smaller than the width C or the thickness T of the basic cross section of the entry belt 10.

According to the illustration according to FIGS. 3 and 4, the threads 25 or fiber groups running in the longitudinal direction can be surrounded by a fleece 26 formed from the fibers 24. The insert 27 thus formed passes through the entry belt 10 over its entire length within an inner cross-sectional area 28, which is surrounded on all sides by an outer cross-sectional area 29 of the entry belt 10 formed by a layer of the plastic of the entry belt 10 and free of the fibers 24 of the insert 27. The elevation 10d extending over the end section B of the entry belt 10 is formed by a corresponding web-like extension of this outer cross-sectional area 29. The bundle can be exposed by the outer cross-sectional area 29 free of fiber groups, the thickness D or E of which can be selected according to the abrasion of the input belt 10 that occurs during operation Fibers are avoided, so that the period of use of the entry belt 10 is increased accordingly and the downtimes of the weaving machine can accordingly be reduced accordingly. The elevation 10d can be of any width, for example 1/3 to 1/10 of the width of the entry belt 10.

The infeed belt 10 shown in FIGS. 5 and 6 contains, as an insert 27, a strip of a fabric 31 formed from the threads 25 or fiber groups. In this embodiment, the elevation 10d is provided with a stiffening girder 32 which extends over its longitudinal extent and which cross-sectionally extends from all sides Plastic of the entry belt is surrounded and as shown by an example can be formed from a correspondingly harder plastic tube.

The entry belt 10 according to FIGS. 7 and 8 has, as an insert 27, a belt 33 woven from the threads 25 or thread groups and is provided in its end section B with two elevations 10d running along the lateral edges, which have the same or different heights as shown can be executed.

In the case of the entry belt 10 according to FIGS. 9 and 10, the insert 27 is formed by threads 25 or fiber groups running in the longitudinal direction, which are arranged in a thread winding 35 surrounding them in a helical manner. In this embodiment, two elevations 10d with a triangular cross section are provided in the end section B of the entry belt 10, the greatest width of which, as shown, is approximately 1/3 of the width of the entry belt 10.

According to Fig. 9a, the threads 25 of a thread winding 35 'formed of several layers or of one be surrounded by a corresponding tubular casing, which can be formed, for example, by a mesh, a knitted fabric, a knitted fabric or a woven fabric, or by a fleece.

11 shows a part of the belt wheel 5 with the entry belt 10 which wraps around the entire circumference in the operating position shown, which in turn is wrapped by the pressure belt 20 and has a further wrap angle of e.g. 100 ° of a second layer 10 'of the entry belt 10 and a second layer 20' of the pressure belt 20 is wound. FIG. 11 also shows two winding layers of the pressure belt 20 wound in the second wrap area 5b of the band wheel 5.

11, the insert 27 of the entry belt 10 contains a number of threads or fiber strands 37 running in the longitudinal direction, which over their entire length lie between two layers of threads or corresponding fiber strands 38 and 32 arranged in the inner cross-sectional area 28 39 are arranged.

FIG. 14 shows the end section B of the entry belt 10 guided in the guide rail 17 with the elevation 10d projecting from the outer cross-sectional area 29.

In the exemplary embodiment according to FIGS. 12 and 15, the belt wheel 5 is wrapped by an entry belt 40, which is wound over by a layer 40 'of the entry belt 40 in the circumferential region shown. The entry belt 40 is designed on its upper side facing away from the running surface 41 with a groove-like recess 42 running over its length, the width and depth of which are at least the width or the thickness of the brace against the entry belt 40 Press belt 20 correspond. In this embodiment, the insert 27 is formed by the fiber strands 37 and 39 running over the entire width of the inner cross-sectional area 28 and by two layers of transversely arranged fiber strands 38a, which the edge portions 43 of the entry belt 40 running on both sides of the recess 42 each in the unreinforced Push through the inner cross-sectional area 28 surrounding the plastic material. Correspondingly, in the winding area of the belt wheel 5, the second layer 40 'of the entry belt 40 with its edge parts 43 can be placed directly on the edge parts 43 of the section of the entry belt 40 which directly wraps around the belt wheel 5, thereby ensuring that this second layer 40' is secured against slipping sideways becomes. 15, the elevation 10d extending over the end section B of the entry belt 40 is arranged in the recess 42, projecting from the base thereof.

According to the representation according to FIGS. 13 and 16, the depression 42 receiving the pressure belt 20 can also be formed on the running surface 41 facing the belt wheel 5 of an entry belt 44 which can be overwound by a second layer 44 ', the elevation 10d in the end section B on the depression 42 bridging cross-sectional area of the entry belt 44 is formed.

17 can be designed with two elevations 10d running over its end section B or, according to FIG. 18, with a single elevation 10d protruding from one of the lateral edge parts.

19 shows an entry band 45 which, in addition to the central recess 42 formed on its upper side, has two recesses 42 formed on the running side 41 along the lateral edges of the Entry tape 45 extending recesses 46 is provided. Correspondingly, the entry band 45 has an approximately wave-like, thin-walled profile, the inner cross-section of which is penetrated by the insert 27 formed in the example shown by the fabric band 33 and correspondingly wave-like in cross-section. In this way, a low-mass design of the entry belt 45 is achieved, which on the one hand ensures high flexibility in the length section A that can be wound onto the band wheel 5 and on the other hand high rigidity in the end section B of the entry belt 45 reinforced by the elevation 10d.

20 shows a further profiled, correspondingly low-mass entry belt 47, the profile of which is determined by the central recess 42 formed on the running surface 41 and two recesses 46 formed on the upper side and running along the lateral edges.

According to the illustration in FIGS. 4, 6, 8 and 10, at least in its end section B which contains the elevation and comes into contact with the warp threads 7 and 8 of the respectively closing shed 13, the entry belt can have a protective layer 48 made of an abrasion-resistant material , for example a lubricating varnish, a corresponding plastic or a cover consisting of a thin metal sheet. The protective layer 48 can extend according to FIG. 4 only over the elevation 10d, or according to FIG. 6 over the entire top side facing away from the running surface 41 and the two side surfaces of the entry belt 10. In the embodiments according to FIGS. 8 and 10, the protective layer 48 extends over both elevations 10d and the two lateral surfaces of the entry belt 10. It goes without saying that that in FIGS. 11 to 20 also illustrated entry tapes can each be provided with at least one corresponding protective layer 48.

An embodiment with a substantially constant cross-section of the entry belt, determined by a rectangular outline, is also possible, whereby the entry belt can be designed with an elevation running over the entire length, within the rectangular outline, or without a corresponding elevation . Instead of an elevation integrated into the profile of the entry belt, an elevation which can be fastened to the end section B of the entry belt, e.g. web-like or otherwise designed reinforcement part or a corresponding holding part for the gripper head.

According to FIG. 21, entry belts 10 designed according to the invention can also be made from strips of a plastic plate 50 which is reinforced by band-shaped inserts 27 arranged at appropriate intervals from one another. The inserts 27 are separated from one another by cross-sectional areas free of fiber groups, through which the interfaces 51 for the production of the entry belts 10 can run. With this design, the effort for processing the lateral edge parts of the entry belts 10 in particular can be significantly reduced in comparison to previous designs.

The entry belts 10, 44, 45, 47 can also each be reinforced by an additional insert 30, which is formed from a plurality of individual, short fiber pieces 36 distributed at least over a section of the outer cross-sectional area 29. In the embodiment shown in FIG. 22, the fiber pieces 36 are over the entire outer cross-sectional area 29 and the cross-section of the elevation 10d distributed and embedded in the plastic of the entry belt 10. This version is particularly suitable for a weaving operation in which less sensitive warp material is processed, since any individual pieces of fiber 36 of the additional insert 30 exposed by abrasion of the plastic - in contrast to bundled fiber groups - break relatively easily or detach with the rubbed-off plastic leave and accordingly can not cause any significant disruption to the weaving operation when hanging with coarser warp yarns.

For the production of the entry belts 10, 40, 44, 45, 47, instead of the previously used thermosets, a corresponding fiber-reinforced thermoplastic can also be used. This enables a particularly simple and inexpensive production of the entry belt, which, in particular owing to the polymerization phase which is eliminated when processing thermoplastics, requires a significantly shorter processing time than in previous designs. As thermoplastics e.g. Polyether ether ketones (PEEK), polyphenylene sulfides (PPS), polyamides (PA), polycarbonates (PC), polyether imides (PEI) and thermoplastic carbon fiber semi-finished products, such as "prepregs", can be used.

Claims (13)

1. A picking mechanism in a gripper weaving machine, comprising a flexible picking belt (10, 40, 44, 45, 47), one end (10a) of which is secured so as to be windable on and off a belt wheel (5) driven in oscillation, whereas the other free end (10b) is connected to a gripper head (11) for picking weft threads (12) into a shed (13) of the weaving machine, the picking belt being of constant cross-section over at least the greater part of its length and being made of plastics reinforced with fibres (24), characterised in that the fibres (24) are disposed in an insert (27) in the form of a belt which extends through the picking belt (10, 40, 44, 45, 47) substantially along the length thereof and which is formed substantially by a number of stranded and/or bunched groups of fibres (25, 37) extending side by side in the longitudinal direction of the picking belt (10, 40, 44, 45, 47) and each being made up of a number of individual fibres (24), the insert extending along its entire length inside an inner cross-sectional part (28) of the picking belt (10, 40, 44, 45, 47) surrounded on all sides by an outer cross-sectional part (29) which is free from fibres (24) of the insert (27), said outer cross-sectional part (29) being formed by a layer of the plastics constituting the picking belt (10, 40, 44, 45, 47), the thickness (D or E) of said layer being dimensionable in accordance with a predetermined operational abrasion of the picking belt.
2. A mechanism according to claim 1, comprising transversely extending fibres (24) contained in the picking belt (10, 40, 44, 45, 47) and crossing the longitudinally extending fibre groups (25, 37), characterised in that the transversely extending fibres (24) are disposed in at least one layer of filaments or fibre groups (25, 26, 35, 35′, 38, 38a, 39) which also extend substantially over the length of the picking belt (10, 40, 44, 47) inside the inner cross-sectional part (28).
3. A mechanism according to claim 1 or 2, characterised in that the picking belt (10, 40, 44, 47) has an additional insert (30) made up of a number of individual fibre portions (36) extending over at least a part of its outer cross-sectional part (29), each fibre portion being surrounded by the plastics constituting the picking belt (10, 40, 44, 47).
4. A mechanism according to any of claims 1 to 4, characterised in that the picking belt (10, 40, 44, 45, 47) comprises a sectional part having a substantially constant cross-section along its entire length and manufactured by a continuous process such as drawing, casting and/or pressing, more particularly pultrusion.
5. A mechanism according to any of the preceding claims, characterised in that the picking belt (40, 44, 45, 47) is formed with at least one slot-like recess (42, 46) extending along its length.
6. A mechanism according to claim 5, characterised in that the recess (42) is given a width end a depth at least equal to the width and/or thickness of a clamping belt (20) for clamping against the belt wheel (5) via the picking belt (40, 44, 45, 47).
7. A mechanism according to any of the preceding claims, characterised in that the picking belt (10, 40, 44, 45, 47) is formed with at least one raised part (10d) extending over at least part of its length and projecting from at least one portion, situated nearby in the transverse direction, of the outer cross-sectional part (29), the raised part being formed by a corresponding continuation of the outer cross-sectional part (29) extending in the longitudinal direction of the picking belt (10, 40, 44, 45, 47).
8. A mechanism according to claim 7, characterised in that the raised part (10d) is disposed in an end portion (B) of the picking belt (10, 40 44, 45, 47) which is substantially straight and, when the belt wheel (5) is fully wound, remains between the shed (13) and the winding area of the belt wheel (5), the end portion extending towards the shed (13) from a place (16) where the picking belt runs off the belt wheel, and the raised part (10d) being formed by a residual portion remaining in the respective end portion (B) of a web-like part (10d′) of the sectional part which extends over the entire length of the picking belt (10, 40, 44, 45, 47), and in the longitudinal portion (A) of the picking belt (10, 40, 44, 45, 47) adapted to be wound on to the belt wheel (5) the web-like part is removed down to a flange-like base part (10d) of the sectional part, the base part being defined substantially by a rectangular contour.
9. A mechanism according to claim 7 or 8, characterised in that the raised part (10d) has a reinforcing bearing member (32) with extends through it in the longitudinal direction and in cross-section is surrounded on all sides by the material constituting the raised part (10d).
10. A mechanism according to any of the preceding claims, characterised in that the picking belt (10, 40, 44, 45, 47), or at least an end portion (B) thereof which is adjacent the gripper head (11) and comes into contact with the warp threads (7, 8) is provided with a protective layer (48) of wear-resistant material covering at least a part of the outer cross-sectional part (29).
11. A mechanism according to any of the preceding claims, characterised in that the plastics constituting the picking belt (10, 40, 44, 45, 47) is a thermoplastic.
12. A method of making a flexible picking belt for the weft picking mechanism according to any one of the preceding claims, characterised in that a sectional part having a constant cross-section along its length is made by a continuous production process, such as pultrusion, said sectional part being formed by a flange part (10c) in the form of a belt containing an insert (27) in the form of a belt, and at least one web-like raised part (10d) projecting therefrom, and in that said raised part (10d) is removed from the flange part (10c) except for a residual part extending over an end portion (B) of the sectional part).
13. A gripper weaving machine comprising a weft picking mechanism in accordance with any one of claims 1 to 11.

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