DE19854153C1 - Assembly to carry parallel bands of wefts to a warp knitter has structured movements of the yarn holders at the racking grids to give a trouble-free increased yarn density at higher yarn speeds - Google Patents

Abstract

The assembly to carry parallel bands of yarns between the hooks of transport chains has a movable yarn holder (42) at the racking grid (4), with a controlled drive (47) for its movement between a racking position and a release position. The shaft of each yarn holder (42) can swing round its longitudinal axis, operated by a swing drive (47) to rotate by a given angle between the racking and release positions. The yarn holder shaft is fitted with a crank arm (423), with a common swing slide (47) acting on all the yarn holder crank arms (423) in a swing movement according to the racking movement of the racking grid (4,4'). The holder section (422) of the yarn holder is at an angle to the holder shaft of 25-75 deg and preferably 35-50 deg . An Independent claim is included for control of the yarn movements so that, when the weft yarn guide (1) passes over the hooks (31) of the transport chains (3,3') from inwards outwards, the points of the yarn holder sections (422) of the yarn holders (42) are at an angle against the movement direction with a downwards alignment. As the weft guide (1) changes its direction with lowered presser rails (12,12') at the start of racking, the points of the angled yarn holder sections (422) are moved parallel to the upper level of the transport chains (3,3') and against the direction of travel. When racking by the racking grids (4,4') is complete, the angled holder sections (422) of the yarn holders (42) are swung downwards to an intermediate angle. The yarn holder swing angle during the weft guide direction change is 25-45 deg between the laying and racking positions to give a clean laying action and a secure holding action. The swing angle between the racking and transfer positions is ?+110-140 deg for a secure transfer to the hooks (31) of the transport chains (3,3'). In the laying position, the points of the holder sections (422) of the yarn holders (42) lie behind the points of the hooks (31) at the transport chains (3,3'), aligned in parallel with the direction of movement and against the direction of travel, and this position is maintained by the yarn holders (42) during the racking by the racking grids (4,4'). For the transfer of the wefts (2), the holder sections (422) swing down into the transfer position between the away movements of the transport chains (3,3') and the weft guide (1).

Description

The invention relates to a device for inserting each other parallel sets of threads in hooked transport chains, each one of the runs of the transport chains continuously for stitch formation telle a warp knitting machine is performed with one over both trans multi-weft guide, the Liftable and lowerable push rails are assigned, each with a Ver Sentence rake per transport chain that is above and outside the trans port chain arranged and parallel to their direction of movement is, and with thread holders on the offset rake for each weft Weft thread coulter, each thread holder holding one in the offset rake tten shaft and a holding portion inclined to this.

On warp knitting machines with parallel weft insertion (see DE-AS 20 12 114) the wefts are replaced by multiple weft guides (hereinafter referred to only as weft guide) in droves in changing Directions submitted via transport chains.

The transport chains are the working width of the warp knitting on both sides machine arranged at right angles to the stitch formation point. Your top Trums move together with those stretched between them Weft coulters continuously to the stitch formation point.  

The weft guides that are close above the hook of the conveyor chains Moving in changing directions, the weft threads lay immediately before the change of direction the weft guide into the alleys between the hook of the respective transport chain and at the same time in the alleys the so-called offset rake between the thread holders.

The pusher rail following the weft guide lowers the weft dschar on the inside of the transport chain under the throats of the Ha ken. The ge between the pusher rail and the weft guide tensioned thread sections are caused by the opposite Movements of the hooks of the transport chain and the thread holder of the Offset rakes in mutually superposed planes set directions deflected. If the offset rake reaches the group of Hooks the weft thread to be tensioned in the opposite direction the offset rake adapts with its movement of the Movement of the transport chain.

The thread holder of the offset rake and the hooks of the transport chains now move at the same speed. Change at the Movement of the weft guide to the other transport chain the friction Conditions of the weft threads on the offset rake give the holding section the thread holder released the weft threads they had caught and lead them into the alleys between the selected hooks of the Trans port chain.

In other known devices, the offset rakes have rigid hook-shaped thread holder. The holding sections of these thread holders are either downwards at right angles (DE-AS 20 12 114) and / or at an angle from about 45 ° downwards and towards the center of the machine. Point of time the transfer of the threads from the holding portions of the thread holders The hooks of the transport chains can usually not be determined exactly become. The exact synchronization of the transport chain and offset rake must therefore be guaranteed over a very long period of time.  

So that the, at this not exactly defined handover time loosen Weft threads remain controllable, the thread holders have to be very precise the hooks are aligned. You helped yourself by ver Sentence rake and transport chain over a longer movement section coupled with each other (DE 36 41 640 C1).

The handover time can also fall on such a time here, where the weft guide is already in the area of the others Transport chain moved very slowly. The temporary at the handover Thread excess occurs because of the low speed the weft guide is not used up quickly enough. The Weft threads become loose and can be removed during the following insertion do not handle and work in with the required precision.

In the event of an arbitrary machine downtime, the, or even individual wefts unintentionally slide out of the offset rake. Also this leads to incorrect working.

Another disadvantage of these known devices is that another Increasing the working speed is not possible. The further increase Depending on the working speed, the thread is already very high take-off speed of the weft threads. The increase in Number of threads per weft guide with necessarily the same The distance between the hooks on the transport chain is then increased Weft thread waste.

A reduction in the mutual spacing of the weft eyelets on Weft guide, the distances of the hooks on the chain and the decency of the thread holder on the offset rake leaves the used Principle of transferring the threads from the thread holder to the hooks of the Trans port chains not too.

The increase in the working speed of the warp knitting machine are thus set narrow limits.  

With DE 42 12 538 A1 another device of this type is wrote. Here the stationary offset rake has thread holder whose holding sections are directed upwards. The shaft of the thread holder is widened. Additional retention elements, their horizontal and the threads are directed in the direction of movement of the transport chains grasp between the shafts of the thread holder, keep the threads in shape conclusively between the shafts of the thread holder until delivery to the next group of hooks of moving transport chains. When the transfer time for the threads held is reached, the Thread loops due to an offset of the retaining elements under the wide shafts of thread holder released. The shared thread are supposed to loop into the hook of the Lay transport chains.

Such a device is also unsatisfactory. Passing the shot threads from the thread holders to the specified hooks of transport Here, too, chains only take place when the weft guide is already in place again moved very slowly over the opposite transport chain. The very long threads can be loosened during the transfer do not handle exactly in the area of the next transport chain. The uniform thread tension necessary for an exact insertion process all weft threads of a group literally break during the handover together.

The interaction of the stationary poses additional difficulties Offset calculation with the moving and in use lengthen the trans port chain.

Under these very conditions you can have a sufficient function safety only with relatively large distances between the weft threads, between the hooks of the transport chains and between the thread holders ensure the offset rake.  

So this device also provides no basis for an increase in Number of weft threads per inch of transport chains and / or for an increase hung the working speed of the knitting machine.

It is the object of the present invention to guide the shot threads in all phases - essentially independent of the speed of the change in direction of the weft guide - to specify, so that the mutual distance between the hooks on the transport chain and thus the thread waste can be reduced as the number of threads per inch increases, without the weft threads being incorrectly integrated into the knitted fabric can and without the thread break frequency due to too high thread speeds increases.

This task is surprisingly accomplished through the design of the Offset calculation solved according to claim 1. The advantage of this controllable, Movable thread holder is that the thread holder and thus the Hooks of the transport chains can be arranged with a small pitch. The thread holders designed in this way are able to use the weft threads Keep the completion of the offset reliably. The handover of the threads can be done at any time.

One chooses this point in time so that it is briefly at the handover adjusting excess thread at a high take-off speed Weft threads are used up again immediately. While inserting the weft threads in the hooks of the Trans the warp threads have a precisely defined tension. On exact insertion process is also with significantly smaller hook and weft thread spacing possible.  

With reasonable weft waste you can see the number of at the same time increase weft threads. Without increasing the maximum thread take-off speed for the weft threads is a further increase in Working speed of the knitting machine possible.

You can also change the direction of the weft thread in a lot short time, just like the acceleration forces and the selected drive allow, realize. This also creates opportunities for Increase the working speed of the machine without the maxima le withdrawal speed of the threads is increased.

The execution of the offset rake and its thread holder according to An saying 2 enables easy storage and a simple drive the thread holder of an offset rake.

With the design of the thread holder and their drives according to claim 3 you can realize the necessary swinging movement with simple means.

The angle of the holding section of the thread neck defined in claim 4 tes enable optimum holding conditions with the usual thread tensions conditions during the offset and favorable conditions for the clearance be the threads on the hooks of the transport chain.

The process claims 5 and 6 make the control of Swiveling movement of the thread holder slightly higher demands. You he possible, however, a safe insertion of the weft threads in the alleys of the Thread holder - even with significantly reduced lateral distances between the Weft threads and the hook of the transport chains.  

The method according to claim 7 ensures the simplest control of the Thread holder good results with sufficiently small distances Thread holder and weft threads. This method can also be used with a reversible magnet as drive for the swiveling thread holder realize.

The invention will be explained in more detail using an exemplary embodiment.

In the accompanying drawings:

Fig. 1 is a schematic overall view of the weft guide arrangement,

Fig. 2 shows three different views (a), (b), (c) of the hooks of the transport chain, the Versatzrechens, the Schußfa denführer and the pusher rail tion in the insertion Posi,

Fig. 3 is a representation analogous to FIG. 2 in the offset Posi tion,

Fig. 4 is the same representation as Fig. 2 in the initial phase of the transfer position and

Fig. 5 in the final phase of the transfer position.

Fig. 6 shows an example of a drive arrangement for pivoting the rake offset thread holder and

Fig. 7a, 7b and 7c show the three main positions of the Fadenhal ters in an enlarged representation in degrees.

The description of the present invention is based on a weft thread-laying device, the weft threads are perpendicular to the trans port chains 3 , 3 'and flocks parallel to each other.

The individual weft threads 2 are preferably worked in at the knitting point of a warp knitting machine.

The weft guide 1 with a plurality of thread eyelets 11 (arranged on a straight line, perpendicular to the row of needles of the knitting point) is moved parallel to the row of needles (not shown) in alternating directions, across the space between the two transport chains 3 , 3 'and beyond.

The transport chains 3 , 3 'are equipped in a manner known per se with hooks 31 , the tips of which are directed upwards and outwards. These hooks 31 are held with their shafts 311 on support elements which are connected with a chain, not shown.

The shafts 311 of the hooks 31 are aligned transversely to the direction of movement of the transport chains 3 , 3 '.

In the area of each transport chain 3 , 3 'are assigned to each weft guide 1 so-called offset rake 4 , 4 ', which are parallel to the upper runs of the transport chains 3 , 3 'back and forth in a controlled manner angeord net.

These offset rakes 4 are equipped with thread holders 42 . These thread holders 42 have the same division as the hooks 31 of the transport chains 3 , 3 'and the eyes 11 of the weft thread guide 1 . The thread holder 42 are pivotally mounted with their shafts 421 in the bar 41 of the offset 4 chens.

On the side facing the hook 31 of the transport chain 3, they each have a holding section 422 angled by the angle α ( FIG. 3b) and on the opposite side each have a crank arm 423 with a crank pin 424 . All crank pins 424 engage in suitable recesses in a swivel slide 47 . This pivoting slide 47 is given a reciprocating swinging movement, so that the thread holder 42 can assume different (angular) positions at predetermined times.

The different positions of the thread holder are shown in FIGS . 2 to 5. Each of these figures shows at (a) a schematic cross section of the working elements in the area of a transport chain, at (b) a simplified top view of this and at (c) a view from the center of the machine.

In the first phase (Fig. 2), the insertion position, the weft yarn reaches leader 1 with its Schußfadenöse 11, the conveyor chain 3 and the weft threads 2 performs one by one in the lane between two hooks 31 of the conveyor chain 3. In this phase, the tips of the holding sections 422 of the thread holders 42 , which are preferably directed somewhat downwards and backwards here, are hidden behind the tips of the hooks 31 . Piercing of the weft threads 2 is avoided in this way.

During this movement of the weft yarn guide 1, the weft yarn carrier 1 the following pusher rail 12 is lowered close to the movement path of the hook 31st As a result, the thread section 23 between the weft eyelet 11 and the pusher rail 12 arrives safely behind the tips of the hook 31 and behind the tips of the holding sections 422 of the thread holder 42 . The lateral deflection 312 of the hook 31 supports the securing of the thread in the lowest position on the hook 31 .

The immediately following position, the offset position, is shown in Fig. 3. The weft guide 11 changes its direction of movement in this phase. The thread holder 42 is now pivoted by an angle β ge that its holding portion 422 is directed against the direction of movement of the conveyor chains 3 and approximately parallel to them (see also Fig. 6b and 6c). In this phase, the offset rake 4 is already moving against the direction of movement of the upper run of the transport chains 3 . The weft section 23 between the first hook 31 of the trans port chain 3 , which has gripped the weft 2 , and the associated weft eyelet 11 lies in the throat formed by the shaft 421 of the thread holder 42 and the holding section 422 and is reliably guided there.

In this way, the weft guide 1 can begin its movement in the opposite direction practically without rest. The weft section 22 between the thread holder 42 and the weft eyelet 11 moves captively over the level of the thread holder 42 until the Ver set of the offset rake 4 is finished.

If the respective thread holder 42 of the offset rake 4 has reached the hook 31 to which it is to transfer the weft thread 2 , then the offset rake 4 moves briefly at the same speed and in the same direction as the transport chains 3 (cf. FIG. 4). The weft guide 1 is moving at high speed to the other transport chain.

Now the thread holders 42 are pivoted via their crank arms 423 about their longitudinal axis by the angle γ (see FIGS . 4 and 6c) in such a way that the holding sections designated here with 422 'with their tips downward and into the angle between the transport chain moving away 3 show the weft guide 1 moving away.

Through this relatively fast swiveling movement, the thread holders 42 throw off the weft thread sections 22 hanging on them and guide them into the alleys between the selected hooks 31 of the transport chain 3 . The first handover phase is shown in FIG. 4. During the pivoting of the thread holder 42 , the thread sections 22 and 23 still have the position which are shown with solid lines. In the last phase of the pivoting, these thread sections 22 ', 23 ' at high speed initially assume the dot-dash position in FIG. 4. The thread slides from the holding section 422 ′ of the thread holder 42 onto the hook 31 .

In this phase of the weft yarn guide 1 moves, as already mentioned, at very high speed to the other conveyor chain. 3 The weft thread 2 , which loosens slightly during the transfer, becomes instantly taut again and has the necessary thread tension again before the thread - as shown in FIG. 5 - lies in the throat of the hook 31 .

Then the weft guide 1 reaches the opposite transport chain, it has a precisely defined tension and can be inserted there very precisely between the hook 31 'and the thread holder 42 '

All movements of the interacting elements can be coordinated in such a way that guiding the weft threads 2 into a wrong alley or losing the weft threads 2 is avoided with certainty.

The control of the offset rake 4 and the pivotable thread holder 42 on the offset rake 4 are shown by way of example in FIG. 6. The Ver record rake 4 is moved in a known manner parallel to the upper run of the transport chains 3 , 3 'in fixed guides. For the offset of these offset rakes 4 , a controllable motor 49 can be provided, which engages via its gear 491 in a rack 44 located on the offset rake. The motor 49 is expediently controlled to move in changing directions according to a predetermined law of motion.

As already described, the crank pins 424 of the thread holders 42 are guided along a line in corresponding bores of a swivel slide 47 . This swing slide 47 receives its swing drive via a double lever 401 , which is pivotably mounted on the base body of the offset rake 4 at 402. The second arm of the double lever 401 engages in a link 4521 of a mother housing 452 . This nut housing 452 is arranged on a spindle 46 and is secured by a guide rail 451 on the bearing 45 against rotation.

The spindle 46 is in turn rotatably mounted on the bearing 45 of the offset rake 4 and is held there axially immovable. The spindle 46 slides - secured against rotation by means of a wedge 461 - on the long shaft 481 . This shaft 481 is rotatably fixed to the frame and axially immovable Lich mounted. It is driven by the swivel motor 48 according to a predetermined law of motion.

It transmits its rotary movement to the spindle 46 via a corresponding profile (e.g. a keyway), regardless of the respective position of the spindle 46 .

Each drive movement of the swivel motor 48 leads to a defined change in the position of the thread holder 42 in the offset rake 4 . This relatively complicated structure of the transmission can be avoided if one uses a correspondingly small dimensioned motor for the control of the pivoting slide 47 directly on the offset rake 4 . This version is not shown in the drawings.

It is also possible to use the pivoting slide 47 with a strand of a preferably endless toothed belt guided over two wheels. One of the wheels is driven by means of a controlled servo motor with a movement synchronized with the offset movement of the offset calculation. This movement consists of the offset and the swivel movement. This device is also not shown. Such devices are already part of the prior art.

In Figs. 7a, 7b and 7c, the individual positions of the yarn holder 42 are once again shown for defining the respective pivot angle in an enlarged view.

In Fig. 7a we see the loading position. The tip of the holding section 422 is inclined slightly downwards and backwards and can thus hide behind the tip of the hook 31 .

Fig. 7b shows the so-called. Offset position. The holding section 422 is rotated by the angle β (see FIG. 7c) almost in the horizontal direction. The weft loop can thus be kept captive.

We see the transfer position in Fig. 7c. Here, the thread holder 42 has been pivoted by a large angle γ relative to the offset position according to FIG. 7b. The weft thread hanging on the holding section 422 'is released in this phase reliably and at a precisely defined point in time.

The operation of the device just described can be changed somewhat if necessary. If you are able to match the offset movement of the offset rake 4 so precisely to the movement of the transport chain 3 , the threads 2 can also be inserted in the offset position of the thread holder ( FIG. 7b). In this case, the shaft 421 would then have to be arranged approximately at the level of the tips of the hooks 31 . The tips of these hooks 31 then completely or partially cover the tips of the holding sections 422 in the insertion phase ( FIG. 2 in connection with FIG. 7b).

It is sufficient to move the thread holder 42 only between two positions. For such a form of movement, a magnet or a hydraulic piston on the offset rake can also be used as a drive for the thread holder 42 .

The transmission of the drive movement to the moving offset rake with elaborate gear elements could then be omitted. The controlled one Energy for this movement then arrives via flexible cables or via flexible hoses on the respective offset rakes.  

Reference list

1

Weft guide

11

Weft eyelet

12th

,

12th

'' Trigger rail
(

2nd

) Weft

21

Weft (stretched between the transport chains)
22, weft thread (tensioned between weft guide and thread holder)

22

'' Weft (handed over to hook - e.g. weft guide)
23, weft thread (between thread holder and first hook)

23

'' Weft (between first and last hook)

3rd

,

3rd

'' Transport chains

31

,

31

'Hook

311

shaft

312

Cranking

4th

,

4th

'Offset rake

40

camp

401

Swivel lever

41

Barre

411

Grooves

42

,

42

'Thread holder

421

shaft

422

,

422

'' Holding section

423

Crank arm

424

Crank pin

43

cover

44

Rack

45

camp

451

rail

452

Mother housing

4521

Backdrop

46

spindle

47

Swing gate valve

48

Swing motor

481

wave

49

engine

491

gear

Claims (7)

1. Device for inserting parallel thread sheets in hooked transport chains, one of each strand of the transport chains being continuously guided to the stitch formation point of a warp knitting machine,
with a multiple weft thread guide ( 1 ) which can be moved in an oscillating manner over both transport chains ( 3 , 3 ') and which is associated with press rails ( 12 , 12 ') which can be separately raised and lowered,
each with a displacement rack (4, 4 ') per transport chain (3, 3'), which is arranged above and outside the transport chain (3, 3 ') and parallel to their direction of movement displaceable,
with thread holders ( 42 ) on the offset rake ( 4 , 4 ') for each weft thread ( 2 ) of the weft thread array, each thread holder ( 42 ) having a shaft held in the offset rake ( 4 ) and a holding section inclined to it,
characterized by
that the thread holder ( 42 ) is movably mounted in the offset rake ( 4 ) and
that the thread holders ( 42 ) of an offset rake ( 4 ) a controllable drive ( 46 , 47 , 48 ) for the movement of each thread holder ( 42 ) between an offset position ( Fig. 3) and a release position is assigned ( Fig. 4). 2. Device according to claim 1, characterized in that
that the shaft ( 421 ) of each thread holder ( 42 ) in the offset rake ( 4 ) is pivotally mounted about its longitudinal axis and
that the thread holders ( 42 ) of an offset rake a controllable swivel drive ( 46 , 47 , 48 ) for a swivel angle (γ) each Fa denhalters between the offset position ( Fig. 3) and the release position ( Fig. 4) is assigned. 3. Device according to claim 1 and 2, characterized in that
that a crank arm ( 423 ) is attached to the shaft ( 421 ) of each thread holder ( 42 ),
that all the crank arms ( 423 ) of the thread holder of an offset rake ( 42 ) is assigned a common pivoting slide ( 47 ) and
that the swivel slide ( 47 ) with the help of a controllable swivel drive ( 48 , 47 , 46 , 45 ) depending on the offset movement of the offset rake ( 4 , 4 ') is swingably movable. 4. Apparatus according to claim 1 or 2, characterized in that the holding section ( 422 ) relative to the shaft ( 421 ) of the thread holder ( 42 ) by an angle (α) between 25 ° and 75 °, preferably between 35 ° and 50 ° is inclined. 5. A method for controlling the thread holder with a device according to claims 1 to 4, characterized in that
that when the weft thread guide ( 1 ) crosses the hooks ( 31 ) of the transport chain ( 3 , 3 ') from the inside to the outside, ie in the detection position ( FIG. 2), the inclined holding section ( 422 ) of the thread holder ( 42 ) with its tip directed towards the transport direction and downwards,
that the inclined holding section ( 422 ) in the phase of the movement reversal of the weft thread guide ( 1 ), with the pusher rail lowered ( 12 , 12 '), ie at the beginning of the offset ( FIG. 3), with its tip approximately parallel to the upper run of the transport chain ( 3 , 3 ') and against the transport direction by an angle (β) and
that after the completed offset of the offset rake ( 4 , 4 ') relative to the transport chain ( 3 , 3 ') - ie in the transfer position ( Fig. 4) - the inclined holding section ( 422 ) of the thread holder ( 42 ) downwards and in the angle between the moving transport chain ( 3 , 3 ') and the moving weft guide ( 1 ) is pivoted by the angle (y). 6. The method according to claim 5, characterized in
that the pivoting angle (β) of the thread holder (b) between the Einlagepo position ( Fig. 2) and the offset position ( Fig. 3) to ensure unimpeded insertion and a secure holding of the weft threads between 25 ° and 45 ° and
that the swivel angle (γ) between the offset position ( Fig. 3) and the transfer position ( Fig. 4) for securing the transfer to the hooks ( 31 ) of the transport chain ( 3 , 3 ') is between plus 110 ° and 140 °. 7. A method for controlling the thread holder with a device according to claim 1 to 4, characterized in that
that the holding section ( 422 ) of the thread holder ( 42 ) is positioned in the insertion position with its tip behind the tip of a hook ( 31 ) of the transport chain ( 3 , 3 ') and approximately parallel and against the movement of the transport chain ( 3 , 3 ') is directed
that the thread holder ( 42 ) maintains this position (approximately Fig. 3) during the offset of the offset rake ( 4 , 4 ') and
that the holding section ( 422 ) then for the purpose of transferring the weft thread ( 2 ) down into the transfer position ( Fig. 4) in the angle between the moving away the transport chain ( 3 , 3 ') and the moving away weft guide ( 1 ) .