IL176593A - Knitting machine - Google Patents

Description

176593 p'ji I 453355 ΓΛΊΝ ru s Π)13» Knitting machine Karl Mayer Textilmaschinenfabrik GmbH C. 167333 RWS Group Ltd, of Europa House, Marsham Way, Gerrards Cross, Buckinghamshire, England, hereby declares that, to the best of its knowledge and belief, the following document, prepared by one of its translators competent in the art and conversant with the English and German languages, is a true and correct translation of the accompanying document in the German language.

Signed this 19th day of June 2006 For and on behalf of RWS Group Ltd MT 403 EP Knitting machine The invention relates to a knitting machine with a thread source, with a knitting region, with a fabric take-up which receives a knitted fabric produced in the knitting region, and with a piece-length counter which is connected to a machine control and which triggers a predetermined action in the knitting machine when a predetermined length of the knitted fabric is reached.

In some instances, it is necessary to monitor the length of the knitted fabric produced. When a predetermined length is reached, the knitting machine is, for example, stopped, so that the produced length of the knitted fabric can be detached, for example so that it can be taken up and packaged in the form of a knitted-fabric roll having a specific length.

The invention is described below in terms of the production of knitted nets for the packaging of hay bales. It can, however, also be applied in a comparable way to other knitted fabrics.

In the packaging of cylindrical hay bales, as soon as the hay bales have reached the desired size, they are surrounded by a knitted net, so that they do not subsequently fall apart any further. This net is unwound from a roll, the diameter of which should not overshoot a predetermined value, for example a maximum of 30 cm. The number of hay bales which can be packaged by means of a net of this type is correspondingly limited. The worker operating the hay-bale machine must therefore recognize in due time when the net stock is coming to an end.

For this purpose, it is known to provide the knitted net with one or more marking strips at its end. These marking strips have a different colour, form or structure from the rest of the net . As soon as the - 2 -strip on the net appears, the operator knows that he must exchange the stock roll.

To produce a strip of this type, it is known from EP 0 578 353 Al to guide individual threads or groups of threads, upstream of the knitting region, via a dye applicator station in which the threads can be provided selectively with a dye. The knitted net then has portions in which individual threads have been provided with a dye application and other portions in which the dye application is absent. This embodiment, however, has two disadvantages. On the one hand, the outlay involved in dyeing the threads is relatively high. On the other hand, it cannot in all instances be ensured that the dye adheres to the threads with a reliability such that the marking strip is preserved even under difficult conditions of use.

In an alternative embodiment, one or more marking threads are knitted in over the limited length of the knitted fabric. This embodiment, admittedly, has the advantage that a dyed or otherwise permanently marked thread can be used for the marking strip or marking strips. However, the outlay in terms of the production of the knitted fabric provided with a marking strip is relatively high, because a permanent monitoring of the knitting operation by an operator is basically required .

The object on which the invention is based is to make it possible at low outlay to produce a knitted fabric having at least one marked region.

This object is achieved, in a knitting machine of the type mentioned in the introduction, in that the machine control has connected to it a second- piece-length counter which triggers a predetermined second action in the knitting machine when a predetermined second length of the knitted fabric is reached.

By virtue of this embodiment, then, it is possible, for example at the commencement of the knitting operation, to knit a marking thread or a plurality of marking threads into the knitted fabric. When the knitting operation has been started, for which purpose an operator is still often required, the machine can then continue to work automatically. The presence of an operator is not necessary. During subsequent production by the knitting machine, both the first piece-length counter and the second piece-length counter count up with an increasing length of the knitted fabric. When the second piece-length counter has reached a predetermined value, the knitting machine can then, for example, be stopped, and a signal is emitted which indicates to the operator, where required, that the length of the marked region has been reached. The operator can then, for example, remove the knitted- in marking thread or marking threads and restart the knitting machine. The knitting machine can then continue the knitting operation until, for example, the predetermined length of the knitted fabric is reached, this being indicated by the first piece-length counter. The operator therefore has, if at all necessary, to be present at the machine only at a few predetermined times, to be precise at the start and at the end of the knitting operation and at the transition from a marked region to an unmarked region. As will be explained further below, even this presence is not absolutely necessary in all cases. By a second piece-length counter being used, additional work possibilities for the knitting machine, which have hitherto required permanent monitoring, can thus be implemented in a simple way.

The two piece-length counters are preferably synchronized with one another. The advantage of this is that identical signals are received from both piece-length counters and, where appropriate, identical - 4 -signals can also be transmitted to both piece-length counters. This simplifies the set-up. The piece-length counters may be designed differently. They may be implemented as mechanical piece-length counters. A purely electrical design is also possible when, for example, the length of the knitted fabric can be determined from the number of stitch rows produced. In this case, the piece-length counters do not have to be even physically present. It is then sufficient if the numerical value of the knitted-stitch rows can be taken into account in the machine control .

Preferably, the first piece-length counter has a first resetting input and the second piece-length counter a second resetting input, the two resetting inputs being connected to one another such that a resetting signal to the first resetting input also causes the second resetting input to receive a resetting signal, but, in the case of a resetting signal to the second resetting input, the first resetting input receives no resetting signal. There is in this case the initial assumption that, when the predetermined length of the knitted fabric is reached, this being detected by the first piece-length counter, a resetting of both piece-length counters is required, so that a new "production run" can be started, that is to say the production of a new length of a knitted fabric with a renewed marked region. Both piece-length counters are consequently reset simultaneously. The same resetting signal may be used, if appropriate, for this purpose. The situation is different when the second piece-length counter has reached its predetermined value. When the intention then is to reset the second 'piece-length counter, the first piece-length counter should not be reset, so that the first piece-length counter can be used, as before, for monitoring the length of the knitted fabric . The use of resetting inputs partially interlocked with one another is therefore a particularly simple measure. - 5 - It is also advantageous if the second piece-length counter has an intermediate stop counter. In this case, the second piece-length counter can be used several times during a production run, for example in order to produce several marked regions separated from one another in the longitudinal direction of the knitted fabric. In this case, for example, the procedure may be such that the second piece-length counter counts up a first time to a predetermined value, in order to produce a marked region of the knitted fabric. The machine is then stopped and the marking thread is removed. The knitting machine thereafter produces a further region without marking threads . The length of this region can also be detected by the second piece-length counter. This is followed by a third region which is provided in turn with a marking thread. The length of this third region can also be controlled by the second piece-length counter. If appropriate, even further marked and unmarked regions may be provided. During each stop, the intermediate stop counter is counted up, so that, after a predetermined sequence of marked and unmarked regions, the production of the knitted fabric can be pursued continuously, without the second piece- length counter causing a renewed stop. This continuous production operation starts when the intermediate stop counter has reached its predetermined value .

Preferably, the second piece-length counter has a storage device in which a plurality of desired values are stored, the desired values being capable of being read out as a function of the intermediate stop counter. By means of such an embodiment, the length of the marked and of the unmarked regions can be selected differently. Finally, by means of the desired values which are stored in the storage device, the length between two stops of the machine can in each case be set exactly. It is possible, for example, to produce a longer marked region and a shorter unmarked region and - 6 -then, again, a marked region, the length of which lies between that of the first marked and the unmarked region. This further increases the flexibility of the knitting machine.

Preferably, the thread source has at least one marking-thread carrier which dispenses a marking thread. In this case, the marking thread can be supplied separately from the other threads and, for example, be led, together with a "normal" knitting thread, through a lay needle. When the marked region is then terminated, it is sufficient to sever the marking thread, so that it is not knitted in any further. When the marking thread is required again, the only action which is necessary is that this marking thread is led through the lay needle and connected to the thread already led through the lay needle. This action can be carried out in a relatively short time. It necessitates only a low outlay.

Preferably, a severing device acting on the marking thread is connected to the machine control. In this case, intervention by an operator is unnecessary even when the end of the marked region is reached. As soon as the second piece-length counter signals that the predetermined length of the knitted fabric which is to be marked is reached, the severing device can sever the marking thread, so that the following region of the knitted fabric is no longer provided with the marking thread. The operator then has to take action, at most at the start of a new length of the knitted fabric, in order to lay the marking thread into the lay needle again or otherwise link it to the knitted fabric.

In this case, it is preferred that the severing device has a thread-holding device. In this instance, the front end of the marking thread is retained after the latter has been severed, so that it cannot move freely in the knitting machine. The thread-holding device thus - 7 -causes faults to be avoided. By contrast, the end of the marking thread which is connected to the knitted fabric presents no problems, because this end is also knitted into the knitted fabric. There is therefore no fear that this end will cause any faults.

Preferably, the thread-holding device is designed as a thread clamp. A thread clamp can grasp the thread quickly and release it again even without much effort, so that, when a new length of the knitted fabric is started or when a further marked region of the knitted fabric is produced, the operator can tie the marking thread into the knitted fabric again without much effort .

Preferably, the second piece-length counter prevents the knitting machine from starting up at high speed after the predetermined second length of the knitted fabric is reached. This consequently provides an additional safety measure whereby, after the marking thread has been tied in, the knitting machine initially has to run up at crawling speed. At crawling speed, the operator can easily check whether the marking thread is correctly tied into the knitted fabric. When the operator ascertains that this condition is fulfilled, the machine can then continue to run at high speed. To check whether the marking thread is correctly tied in, a few stitch rows are sufficient, as a rule, so that the operator's time is not occupied to too great an extent.

It is also advantageous if the second piece-length counter triggers the second action in the knitting machine, without stopping the knitting machine. The marking region can consequently be introduced into the knitted fabric without an intermediate stop, that is to say without a production interruption. The risk that a stopping and restarting of the knitting machine give rise to local structural variations in the knitted - 8 -fabric is consequently kept low.

The invention is described below by means of a preferred exemplary embodiment, in conjunction with the drawing in which: Fig. 1 shows a diagrammatic side view of a knitting machine, and Fig. 2 shows a rear view of the knitting machine.

Fig. 1 shows a highly diagrammatic illustration of a \ knitting machine 1 with a thread source 2, with a knitting region 3 and with a fabric take-up 4. The I knitting machine 1 serves, here, for the production of hay-bale nets.

For this purpose, a stock roll 5, onto which a plastic film 6 is wound, is located in the thread source 2 This plastic film 6 is subdivided by a longitudinal -cutting device 7 into a large number of narrow strips which ultimately form the knitting threads 8.

Each knitting thread 8 is led through a lay needle 9, which is arranged in the knitting region 3, and is knitted with the aid of knitting needles 10 to form a sheet-like structure. The knitting region 3 is illustrated here in highly diagrammatic ■ form.

Conventionally, at least two rows of lay ¾ieedles 9 are provided, each row of lay needles 9 being fastened to a lay bar.

In the knitting region 3, a knitted fabric 11 is produced from the knitting threads 8, for example the hay-bale net referred to above, the said knitted fabric being drawn off by a plurality of draw-off rollers 12, 13 and wound onto a reel 14 which is arranged in . the fabric take-up 4. ( - 9 - When a specific length of the knitted fabric 11 has been wound onto the reel 14, a cross-cutting device 15 comes into action, which severs the knitted fabric 11 transversely with respect to its running direction. It is thereby possible to ensure that the diameter of the reel does not overshoot a predetermined value of, for example, 30 cm.

The knitting machine 1 is controlled by a machine control 16 which may have been set up, for example, by means of SPC programming. So that the machine control 16 "knows" when the predetermined length of the knitted fabric 11 is reached, a first piece-length counter 17 is provided, which, when the predetermined length of the knitted fabric 11 is reached, transmits a corresponding signal to the machine control 16, so that the machine control 16 actuates the cross-cutting device 15 and emits a corresponding signal, for example a video screen display, so that an operator sees immediately which measures are to be taken on the then stopped knitting machine 1, in order to put the knitting machine 1 into a production state again.

A marking-thread carrier 18 is additionally provided, for example a bobbin, onto which a marking thread 19 is wound. The marking thread 19, which is drawn up from the marking-thread carrier 18, is likewise introduced into the knitting region 3 and led through a lay needle 9 through which a knitting thread 8 of the plastic film 6 is already led. Expediently, this lay needle 9 is in this case in the region of a longitudinal edge of the knitted fabric 11. The marking thread 19 is then knitted into the knitted fabric 11, so that a marking region is obtained in the region of the longitudinal edge. Of course, a plurality of marking threads 19 may also be knitted into the knitted fabric 11 simultaneously. These are then expediently led through different lay needles 9. - 10 - Between the marking-thread carrier 18 and the knitting region 3, a severing device 20 is provided, by means of which the marking thread 19 can be severed. The severing device 20 has a knife 21 and two clamping jaws 22, 23. When the knitted fabric with the marked region, that is to say with the knitted- in marking thread 19, has reached the desired length, the severing device 20 is then actuated. The knife 21 in this case severs the marking thread 19, and the clamping jaws 22, 23 retain that region of the marking thread which comes from the marking-thread carrier 18. The other end of the marking thread 19 remains free and is knitted into the knitted fabric 11 during the subsequent knitting operation.

In order to detect the length of the marked region, a second piece-length counter 24 is provided, which is likewise connected to the machine control 16. As soon as the second piece-length counter 24 detects that the knitted fabric 11 has reached a predetermined length, the machine control 16 actuates the severing device 20.

As can be seen particularly from Fig. 2, a plurality of knitted- fabric webs may also be produced simultaneously in the knitting machine 1. In this case, the thread source comprises a plurality of stock rolls 5 which are arranged next to one another, each stock roll 5 being assigned at least one marking-thread carrier 18.

By means of the knitting machine which is equipped with the two piece-length counters 17, 24, then, various types of operation are possible which will be explained below .

At the commencement of the production of the knitted fabric 11, more precisely at the commencement of the production of a reel 14, both piece-length counters 17, 24 are at zero and are preset with the desired stipulated values, that is to say the first piece-length counter 17 with the desired length of the - 11 -knitted fabric 11 and the second piece-length counter 24 with the desired length of the marking region. As soon as the knitting machine 1 is started, the two piece-length counters 17, 24 commence synchronous piece-length detection in parallel with one another.

When the second piece-length counter 24 reaches the corresponding stipulated value with its actual value, then, for example, an operational communication "piece length 2 reached" is issued, which may be implemented, for example, by the setting of a corresponding system flag. On the other hand, a predetermined action is triggered in the knitting machine 1. In the simplest instance, the knitting machine 1 is stopped.

When the knitting machine 1 has stopped, an operator can then remove the marking thread 19 and restart the knitting machine 1. The knitting machine then produces the knitted fabric 11 with the desired overall length, until the first piece-length counter 17 has likewise arrived at its stipulated value. The two piece- length counters 17, 24 are then reset, preferably by means of a single resetting signal.

When a new production cycle is started, the marking thread 19 is introduced into the associated lay needle 9 again, and the knitted fabric 11 can be produced, as was described above. If, for example, a plurality of regions which are alternately marked and unmarked are to be produced in the knitted fabric 11., then, after the first stop of the knitting machine 1 during which the marking thread 19 has been cut off, the second piece-length counter 24 is set to zero by means of a resetting signal and the production operation is restarted. The resetting signal may be generated, for example, as a result of the actuation of a resetting button or the like. However, it resets only the second piece-length counter 24, not the first piece-length counter 17, too. The knitted fabric 11 continues to be - 12 -produced until the second piece-length counter 24 has reached a stipulated value again. This stipulated value may be the same as for the marked region. It may also be a different value. If appropriate, the various stipulated values are stored in a store 26 and retrieved, as required.

When the second piece-length counter 24 stops the knitting machine 1 a further time, a corresponding operational communication is issued, so that the operator knows that he must introduce the marking thread 19 through the lay needle 9 once more. The knitting machine 1 is thereafter restarted. In this case, however, a start at high speed is not possible. The knitting machine 1 must be started at crawling speed, so that the operator can check whether the marking thread 19 is being knitted into the knitted fabric 11 correctly. This cycle may be repeated. So that the second piece-length counter 24 "knows" when the marked and unmarked regions are terminated, it may have an intermediate stop counter 25. When the intermediate stop counter 25 detects that the desired number of changes between marked and unmarked regions is reached, then no further intermediate stop takes place. The intermediate stop counter 25 may also be used in order to read out the store 26 in which the respective lengths of the marked and unmarked regions are stored.

In an alternative procedure, it is possible also for only the commencement of the production of the knitted fabric 11 to be started. In this procedure, the marking thread 19 is led through the corresponding lay needle 9 and is knitted into the knitted fabric 11.

As soon as the second piece-length counter 24 has reached its stipulated value, the knitting machine 1 is not stopped, but, instead, the severing device 20 severs the marking thread 19 and retains the end - 13 -connected to the marking-thread carrier 18. The knitting machine stops only when the first piece- length counter 17 has reached its stipulated value, that is to say the knitting machine 1 has produced the complete length of . the knitted fabric 11.

When the operational communication "piece length 1 reached" is issued, both the first piece-length counter 17 and the second piece-length counter 24 are reset, in which case a corresponding operational communication may be issued and the corresponding system flag is set.

When the marking thread 19 has been introduced through the lay needle 9 once again, the production cycle can commence from the outset.

In all the alternatives, the number of marking threads 19 introduced is freely selectable. They are provided by corresponding marking-thread carriers 18, for example creel bobbins, and their run-out is monitored via corresponding sensors (not illustrated) .

The piece-length counters 17, 24 are illustrated here as discrete structural elements. However, this is not absolutely necessary. The piece length, that is to say the length of the knitted fabric 11 produced, may be detected in various ways, for example including via the number of stitch rows which can be determined by the machine control 16. It is also possible to determine the length of the knitted fabric 11 produced via the draw-off rollers 12, 13.

The cross-cutting device 15 is illustrated here practically at the outlet of the knitting machine 1. It may be expedient to move the cross-cutting device 15 more closely to the knitting region 3.

Claims (11)

176593/2 - 14 - Patent Claims

1. Knitting machine with a thread source rSvr with a knitting region { " , with a fabric take-up which receives a knitted fabric J ) produced in the knitting region < ) , and with a piece-length counter (.1-7)" which is connected to a machine control (1,6- and which triggers a predetermined action in the knitting machine {&T when a predetermined length of the knitted fabric (¾1 is reached, characterized in that the machine control JL&€) has connected to it a second piece-length counter . C2 *1 which triggers .. a predetermined second action in the knitting machine J- ** when a predetermined second length of the knitted fabric J, ") is reached. ■

2. Knitting machine according to Claim 1, characterized in that the two piece- length counters 2- f are synchronized with one another.

3. Knitting machine according to Claim 1 o 2, characterized in that the first piece-length counter l^f) has a first resetting input and the second piece- length counter ( Ά**ϊ a second resetting input, the two resetting inputs being connected to one another such that, a resetting signal to the first resetting input also causes the second resetting input to receive a resetting signal, but, in the case of a resetting signal to the second resetting input, the first resetting input receives no resetting signal.

4. ' Knitting machine according to one of Claims 1 to 3, characterized in that the second piece-length counter (24*j has an intermediate stop counter .2-5 .

5. Knitting machine according to Claim 4, characterized in that the second piece-length counter (24 has a storage device (2.,6'T in which a plurality of 176593/2 desired values are stored, ■ the desired values being capable of being read out as a function of the intermediate stop counter ,;26) . '

6. Knitting' machine according . to one of Claims 1 to' ' 5, characterized in that the thread source S.) has at least one marking-thread carrier (IS ) which dispenses -a. marking thread (19) .

7. '7. Knitting machine. according to Claim 6, characterized in that a severing device 02·Ο*) acting . on the marking thread (Js is connected to the machine control ,,(Γ6) .

8. Knitting machine according . to Claim 7, characterized in that' the severing device _(.2*c0 has" a' thread-holding device J.,2'2", .

9. Knitting machine according to Claim 8, characterized in that the thread-holding device (.22'",' 22ή* is designed as a thread clamp.

10. Knitting machine according to one of . Claims 1 to 9,.. characterized in that the second pieces-length counter { -4'H prevents the knitting, machine ' J&f. from starting up at high speed after, the predetermined second length of the knitting fabric is reached. .

11. Knitting machine according to one of Claims 1 .to 10, characterized in that the second piece-length counter (.24") triggers ' the second action in the knitting machine CI-')', without stopping the knitting machine Li . For ths Applicants BSNHQLD COHN AND PA INSS