EP0123969B1 - Method of making an endless tubular felt, and apparatus for carrying out this method - Google Patents

Description

The invention relates to a method for producing and / or treating an endless tubular felt or similar tubular structure, in which material, for example a nonwoven web, a coating, longitudinal threads or, is continuously produced on the tubular felt that is at least partially manufactured and rotates in the circumferential direction in this direction by means of a feed device The like is applied in a width and / or the tubular felt is treated in a width by means of a treatment device, for example flamed or needled, which is less than that of the tubular felt, the application or treatment being carried out by a relative movement between the supply or treatment device and the tube fizzle transversely to its direction of travel helically - possibly with partial overlap. The invention further relates to a device for carrying out this method with at least two spaced-apart transport rollers for the part of the tubular felt already produced and with a feed device for applying the material to and / or with a treatment device for the part of the tubular felt already produced, wherein a displacement device is provided for the relative movement between the tubular felt and the feed device or the treatment device in the axial direction of the transport rollers.

Such a method and the associated device is disclosed in DE-B-16 60 765. For this purpose, the device has two mutually adjustable transport rollers, over which the part of the tubular felt already produced runs. A nonwoven web is fed continuously in the direction of rotation of the tubular felt, in such a way that this nonwoven web partially overlaps with an edge of the already made tubular felt. After placing the nonwoven web, it is needled with the tubular felt.

Grooves are machined in the transport rollers parallel to their longitudinal axes, in which grooves run transport chains which carry needles penetrating the tubular felt. By means of these transport chains, the tubular felt is slowly moved transversely to its running direction, so that the tubular felt is gradually built up over its entire width. It has been found in practice that the transverse movement of the tubular felt does not match the movement of the transport chains. This was recognized by the fact that after a calculated number of hose revolutions the calculated hose width was not reached. The causes of this have so far not been reliably determined. The consequence of this is that the weight per unit area and thus the thickness of the respective tubular felt varied greatly, which is naturally disadvantageous for the drainage properties and also the durability of the tubular felt when used in a paper machine.

The device disclosed in DE-B-23 24 985 works in reverse kinematic fashion. In this device, the tubular felt is not moved transversely, but the feed device for the nonwoven web. However, the tubular felt is formed in the same way by screwing the nonwoven web together with partial overlap.

Here too it is important that the nonwoven webs are placed in such a way that no changes in basis weight or thickness occur. This can occur, for example, due to uncontrolled migration of the hose on the transport rollers or due to fluctuations in the transverse movement of the feed device.

Similar problems can arise if a coating or chemicals are applied helically instead of a nonwoven web. It is also important here that the distance between the 'screw threads' on the tubular felt always corresponds to a predetermined value, so that the application is uniform.

The same applies to treatment and processing measures, such as flaming, needles, brushes or the like. This can also be done in such a way that a corresponding device of small width is pushed over the width of the tubular felt rotating in the circumferential direction or, conversely, the tubular felt is moved transversely under the stationary device. Similar kinematic conditions exist when treating hose felts or corresponding hose structures in roller calenders.

Finally, threads that run at a distance from one another can also be applied for a tubular felt to form longitudinal drainage channels, in which one or more threads are guided next to one another through the gaps of a reed onto the surface of the tubular felt. By moving either the tubular felt or the feed device for the threads transversely, they receive a helical course on the tubular felt, it also being essential here that the spacing between the applied threads is as uniform as possible.

The invention has for its object to improve the above-mentioned method so that there is a uniform application of material or a uniform treatment of the tubular felt.

Another object is to find a device for performing this method.

The first-mentioned object is achieved in that the tubular felt in its circumferential direction Continuously at least one marking line contrasting this is applied in the running direction, the position - or its distance from an adjacent running marking line - in the running direction behind the application point is scanned in a non-contact manner as the actual value, the relative movement being set such that the scanned actual value is determined by a certain one Setpoint deviates as little as possible. The marking line serves here, so to speak, as an indicator of the actual relative movement between the tubular felt and the application or treatment, the cross-displacement of the marking line at a distance from the point where it is applied being scanned without contact and then this actual value being compared with a target value. The actual value can then be adjusted to the desired value by re-adjusting the drive for the transverse movement, so that the most uniform possible transverse movement is achieved. This uniform transverse movement ensures, for example when applying a nonwoven web, that the continuous construction of the tubular felt takes place optimally, the thickness being largely the same over the entire width.

The marking line can be scanned at different locations. It has proven to be advantageous to scan the position of the marking line before the tubular felt has made a full revolution with the marking line. In this area, the transverse movement which has meanwhile been carried out becomes particularly clear and thus easily palpable, but with the disadvantage that this is only detected shortly before a complete revolution is completed.

As an alternative to scanning the position of the marking thread after a certain distance, the distance between the helix or spirals of a marking line can also be scanned. The marking line then forms a helical line on the already finished tubular felt, the distance between the adjacent parts of the line being a measure of the respective transverse movement.

Such a distance measurement can also be carried out if first a first marking line is plotted and a second marking line behind it in the running direction and at a transverse distance to it and then the distance between the two marking lines is scanned. This has the advantage that one does not have to wait for a full revolution of the marking line to scan the distance.

The fact that the marking line is to be applied there according to the invention does not mean that it must be continuous. It is also sufficient if the marking line is made up of dashed lines or dots. Washable paint can be used as the material for the marking line, for example. It has proven to be particularly useful to apply a marking thread as the marking line which contrasts strongly in color with the color of the tubular felt. Suitable marking threads are expediently yarns that are as smooth as possible, in particular when the marking thread, as is particularly advantageous, is applied with the part of the tubular felt that has already been produced before a nonwoven web is consolidated. In this way, the marking thread is needled with the tubular felt, so that it then no longer changes its position. Despite this needling, it can be easily removed after it has been scanned without damaging the tubular felt.

If the marking line contrasts optically with the tubular felt, optical methods are particularly suitable as scanning methods.

A device for carrying out this method is according to the invention by at least one application device for continuously applying the marking line to the tubular felt in its circumferential direction and by a contact-free scanning device for detecting the position of the marking line or its distance from an adjacent running marking line in the running direction behind the one or more Application device (s) characterized, the application device (s) and the scanning device being immovable relative to one another, specifically in the case of a transversely moving tubular felt and arranged in a stationary manner and coupled to the displacement device when the feeding device or treatment device is moved transversely, and wherein the scanning device is connected to an electronic evaluation device for determining the difference is connected between the actual value for the position or the distance of the marking line (s) supplied by the scanning device and the target value specified for this purpose and the evaluations device is connected to a control device for determining a control value for adjusting the drive of the displacement device in the direction of minimizing the difference. The generic device is therefore provided with a control device for carrying out the method according to the invention, the actual value of the transverse movement for the control device being obtained from the position of the marking line or the distance between two adjacent marking lines. The control device acts on the displacement device in such a way that the actual transverse movement of the tubular felt corresponds as uniformly as possible to a predetermined setpoint.

In an embodiment of the invention it is provided that the application device (s) is or are arranged in the running direction in front of the consolidation device, which is particularly advantageous if a marking thread is applied as the marking line, since this is then attached to the tubular felt by the consolidation device is fixed.

If the distance between two marking lines is to be used as the actual value for regulating the transverse movement, a second application device can be arranged behind the first, viewed in the direction of travel. The measure of the distance between the marking lines applied by the two application devices then corresponds to the actual transverse movement of the tubular felt.

As an alternative to this, provision can be made for the scanning device to be arranged in the region of two adjacent parts of the marking line after more than one revolution and for the scanning device to be designed for detecting the distance between the two adjacent parts of this marking line. In this case, the distance is also scanned as the actual value, but only the application of a marking line is necessary.

According to a further feature of the invention, it is provided that the scanning device is arranged in the region of the marking line shortly before completion of a cycle and that the scanning device is designed to detect the position of the marking line. This scanning device has proven itself in practice despite the relatively large distance between the application of the marking line and the scanning, since the change in position is particularly clear in this area when the transverse movement changes.

According to the invention it is further proposed that the marking line (s) contrast or contrast visually with the tubular felt and that the scanning device operates optoelectronically. This is believed to be the simplest method for applying a marking line and scanning it. This can, for example, have a light transmission measuring device, as is known as a scanner or light barrier measuring device.

Another alternative, however, has proven to be problem-free, namely to equip the scanning device with an image recording device. This can be done, for example, using a semiconductor image recording sensor based on CCD technology. However, these sensors are still relatively expensive, which is why a video camera, in particular with a Vidikon tube, is currently considered as an image recording device.

The video camera should be arranged so that the marking line (s) runs parallel to the scanning lines of the video camera in order to obtain a video signal with a constant signal amplitude between two line-tipping pulses. In addition, it is recommended that the video camera and the marking line (s) are coordinated with one another in such a way that the marking line (s) takes up at least six scanning lines. This is to get a clear video signal regardless of any glitches.

The evaluation device expediently has a detector circuit for detecting the marking line (s) and a counting circuit for counting the scanning lines from the beginning of the picture to the video signal of the marking line (s) and / or between two such video signals, the count value being the actual value for the control device. The detector circuit can be designed such that it has a shift register clocked by the line tilt pulses of the video camera and reset by the image tilt pulses of the video camera for the shifting of line tilt pulses, the video signal controlling an input port such that only the line tilt pulses are present when the video signal is present the marking line (s) enter the shift register. An AND circuit should be connected to the shift register, which only emits a signal when three successive line break pulses are present. In this way, the signal output is largely secured against interference pulses when a mark is detected.

According to a further feature of the invention, the counting circuit consists of a line break pulse counter, a line break pulse memory connected to it and a counter acted upon by a multivibrator, this counter being controlled by every second break pulse such that the line break pulse memory carries a take-over pulse for taking over the count value in the line break pulse counter and then the Line break pulse counters receive an erase pulse before the next line break pulse arrives. As a result of this circuit, the line break pulses of two fields recorded in the line break pulse counter are placed in a memory and the line break pulse counter is reset to its initial position so that it can again detect the line break pulses of two fields.

In front of the input of the line tilt pulse counter, a gate can be connected, which is controlled by the detector circuit via a counting flip-flop such that it is blocked when a signal from the detector circuit is present and opens when there is a picture tilt pulse. In this way, only the line tipping pulses arrive in the line tipping pulse counter that occur from the beginning of a field until the complete detection of the marking line.

So that the distance between two marking lines can also be detected, a data flip-flop is provided in parallel with the count flip-flop, which can be switched to the gate instead of the count flip-flop and is controlled by the count flip-flop and the detector circuit in such a way that when a first signal from the detector circuit is present, the gate opened and locked again when a second signal is present is.

The control device is expediently designed as a PI controller. Such a controller has proven to be sufficient so that the arrangement of a PID controller is not necessary.

It has proven to be particularly advantageous to control the regulating device digitally via a microprocessor, since a largely flexible regulation is then possible using appropriate software.

The setpoint input and the output of the control value are expediently carried out via optocouplers so that the microprocessor is electrically isolated from the input or output.

According to the invention it is further provided that the application device (s) has or have a bobbin provided with a marking thread. A storage feeder should be arranged between the bobbin and the hose felt so that the marking thread can be pulled off the bobbin without interference. The marking thread should be guided onto the hose felt by a guide plate with a guide groove.

Furthermore, a withdrawal device for the marking thread should be provided, which consists of a motor-driven bobbin. In this case, switches for controlling the bobbin drive are expediently provided as a function of the run-off angle of the marking thread, so that precise synchronization with the revolution of the tubular felt can be dispensed with.

• Figur 1 in schematischer Darstellung eine Seitenansicht und
• Figur 2 eine Draufsicht auf eine Vorrichtung zur Herstellung eines Schlauchfilzes;
• Figur 3 eine schematische Darstellung des Aufbaues des Schlauchfilzes bei korrekter Querbewegung;
• Figur 4 eine schematische Darstellung des Aufbaues des Schlauchfilzes bei zu hoher Querbewegung;
• Figur 5 eine schematische Darstellung des Aufbaues des Schlauchfilzes bei zu geringer Querbewegung;
• Figur 6 eine schematische Darstellung der Seitenansicht der Zuführung eines Markierungsfadens;
• Figur 7 eine schematische Darstellung der Abzugeinrichtung für den Markierungsfaden;
• Figur 8 ein Blockschaltbild einer Detektorschaltung für eine Auswerteinrichtung eines Videokamerasignals;
• Figur 9 ein Blockschaltbild der Auswerteinrichtung mit der Detektorschaltung gemäß Figur 8 und
• Figur 10 ein Blockschaltbild einer von der Auswerteinrichtung nach Figur 9 angesteuerten Regeleinrichtung.

In the drawing, the invention is illustrated in more detail using an exemplary embodiment. Show it:

• Figure 1 is a schematic representation of a side view and
• Figure 2 is a plan view of a device for producing a tubular felt;
• Figure 3 is a schematic representation of the structure of the tubular felt with correct transverse movement;
• Figure 4 is a schematic representation of the structure of the tubular felt when the transverse movement is too high;
• Figure 5 is a schematic representation of the structure of the tubular felt with too little transverse movement;
• FIG. 6 shows a schematic illustration of the side view of the feeding of a marking thread;
• FIG. 7 shows a schematic illustration of the withdrawal device for the marking thread;
• FIG. 8 shows a block diagram of a detector circuit for an evaluation device of a video camera signal;
• 9 shows a block diagram of the evaluation device with the detector circuit according to FIG. 8 and
• 10 shows a block diagram of a control device controlled by the evaluation device according to FIG.

The device shown in FIGS. 1 and 2 essentially consists of two transport rollers 1, 2 arranged at a distance from one another and axially parallel, around which a partially built-up tubular felt 3 is guided. The transport rollers have grooves 4, 5, distributed in parallel to their axes, in their transport surfaces, in which transport chains 6, 7 are guided. These carry needle pieces 8, 9 which surround the tubular felt 3.

The transport rollers 1, 2 rotate the tubular felt 3 in the direction of arrow A. At the same time, the tubular felt 3 is moved transversely by means of the transport chains 6, 7 and needle pieces 8, 9, namely in the direction of the arrows B, C.

A nonwoven web 10, which runs in from a card in the direction of arrow D, is placed on the upper edge of the tubular felt 3 in FIG. The nonwoven web 10 overlaps two thirds of its width with the already assembled tubular felt 3. It is consolidated by means of a needle machine 11 arranged behind the first transport roller 1 and connected to the tubular felt 3. From Figure 1 it can be seen that it is a double-working needle machine 11, which solidifies the tubular felt 3 both in the upper and in the lower run. Up to this point, the device essentially corresponds to that according to DE-B-1660765.

As shown only schematically in FIGS. 1 and 2, but shown in more detail in FIG. 6, a marking thread 13 is drawn off from a cross-wound bobbin 12 and placed on the tubular felt 3 at a specific point by means of devices described in more detail below. This is done in front of the needle machine 11 so that the marking thread 13 is needled with the tubular felt 3. The marking thread 13 then moves with the tubular felt 3, executing the helical line shown in FIG. 2. In the area of the transport roller 1, it is again pulled off the surface of the tubular felt 3 by a removal device 14 and rolled up. Previously, its position assumed due to the transverse movement was recorded by a video camera 15 with a Vidikon tube.

The width of the marking thread 13 and the arrangement of the video camera 15 are matched to one another such that the marking thread 13 runs parallel to the scanning lines of the video camera 15 into the recorded video image and the video camera 15 the marking thread 13 with at least 6 scanning lines, i.e. 3 scanning lines per field , detected. In addition to the video camera 15, lighting fixtures can also be attached so that the marking thread 13 stands out as strongly as possible from the surface of the tubular felt 3. For this purpose, it should also contrast as far as possible in color as far as possible with respect to the color of the tubular felt 3, which is generally achieved with a deep black thread, since the tubular felt 3 generally is very bright.

It is best to use a thread that is as smooth as possible, but that should have a fiber structure so that it can be needled and fixed into the surface of the tubular felt 3 as the marking thread 13. Instead of a marking thread 13, a marking line can of course also be applied with the help of colored pencils, also with fluorescent colors. The application of metal threads is also conceivable if the scanning device is then adapted accordingly.

FIGS. 3 to 5 show how the tubular felt 3 is built up in stages. First, there is a nonwoven web a - shown here in cross section. A further nonwoven web b is then placed on this, in such a way that two thirds of its width come to lie on the nonwoven web a and one third of the width projects on the left edge. Another third nonwoven web c is then applied to the nonwoven web b, overlapping by two thirds, and another nonwoven web d is applied to this. The subsequent nonwoven webs lay on top of the previous nonwoven web in the same way as the nonwoven web d. It can be seen that the tubular felt thus constructed consists of three layers of nonwoven web that are needled together. The transverse movement is optimal in the example according to FIG. 3, so that the weight per unit area is uniform.

Figure 4 shows in principle the same structure of a tubular felt, only that in this case the transverse movement in the direction of arrow E is too large. In this way, the overlap of the nonwoven web b 'over the nonwoven web a' is less than two thirds of its width. This continues with the nonwoven web c 'and of course also with the nonwoven web d', whereby it can be seen that there is a gap between the respective upper parts of the nonwoven webs c 'and d' where the thickness - theoretically - only doubles the thickness of a nonwoven web is three times the desired thickness. Such a change in thickness is detrimental to the properties of the tubular felt, but frequently occurred with the device according to DE-B-16 60 765.

The same applies in the event that - as shown in Figure 5 - the transverse movement in the direction of arrow E is too slow. It can be seen that the degree of overlap of the nonwoven web b "over the nonwoven web a" is greater than two thirds of the width of the nonwoven web b ". This continues with the nonwoven webs c" and d ", with the application of the nonwoven web d "The situation shows that the tubular felt has - in theory - four times the thickness of a nonwoven web. This becomes even clearer in the last representation after application of a further nonwoven web e ". A tubular felt is formed with a theoretical thickness of four nonwoven webs, the gaps which arise periodically resulting in large differences in thickness and thus in basis weight. Thus, the situations according to FIGS 5 does not occur, the control device described in detail later is provided.

The application device for the marking thread 13 is shown in more detail in the side view in FIG. 6, the arrow A indicating the direction of movement of the tubular felt 3. The marking thread 13 is first wound on a package 12, the package 12 being provided with a drainage network 16. The marking thread 13 is pulled off from the bobbin 12 and passes via the guide eyes 17, 18, 19 to a storage feeder 20, as is known from embroidery. This periodically fills the yarn store on its bobbin and ensures constant thread take-up tension.

The marking thread 13 is drawn off from the storage feeder 20 by the movement of the tubular felt 3, whereby it is placed on the tubular felt 3 by means of a guide plate 21, which has guide grooves for this purpose, and is then fastened by the needle machine 11. This arrangement ensures that the marker thread 13 is always placed on the tubular felt 3 at the same location and with the same possible tension.

The trigger device 14 shown in FIG. 7 has a base plate 22, on which a trigger coil 23 is rotatably mounted, which is driven by a geared motor 24. The marking thread 13 runs into the take-off device 14 - starting from the tubular felt 3 (not shown here) - via a slotted eyelet 25, then passes through a fixed eyelet 26 and then through an eyelet 28 guided transversely on a rail 27 before it reaches the take-off spool 23. The eyelet 28 is shifted from time to time so that the marking thread 13 is wound evenly over the width of the take-off spool 23.

The geared motor 24 is set so that more and more marker thread 13 is drawn off with the take-off spool 23 than is necessary. In the process, the marking thread 13 moves into the position 13a shown in broken lines due to the tension then exerted. In this position, a switch 30 is actuated via a sensor 29, which switches off the geared motor 24, so that the marking thread 13 is no longer wound on the take-off spool 23. The marker thread 13 then soon assumes the solid position 13b, in which it actuates the sensor 31 of a switch 32. This switches the geared motor 24 on again, so that the marking thread 13 is wound up again. In this way, the removal of the marking thread 13 from the tubular felt 3 is easy.

The block diagram shown in Figure 8 relates to a detector circuit 33 for an evaluation device shown in more detail in FIG. 9, which is connected to the video camera 15 (FIG. 1). The image projected onto their Vidikon tube is - as is usually the case - broken down into 625 scanning lines, with every other line being scanned in succession. An image is broken down into two fields and transmitted.

The video camera 15 delivers a video signal whose voltage is proportional to the brightness of the straight scanned image part. In the present case - as already described above - the video camera 15 is arranged in such a way that the marking thread 13 runs parallel to the scanning lines, so that the marking thread is scanned by the Videkon tube as darkened lines, whereby a corresponding video signal is produced. In addition, pulses are also picked up by the video camera 15, which once indicate the beginning of the scanning of a field, which signal the so-called image flip pulses and the start of the scanning of a line, the so-called line flip pulses.

The detector circuit 33 has a shift register 34, at whose input line break pulses F are present. Via a parallel line 35, the line break pulses also simultaneously indicate the clock for the shift register 34. The image tilt pulses G are received via a further input on the shift register 34. They have the task of returning the shift register 34 to a defined initial state when a field has been scanned. The video signal H first arrives in an amplifier 36 and then in a threshold switch 37. This opens a gate 38 as soon as a video signal H arrives that has scanned a dark line originating from the marking thread 13. A line break pulse F reaches the shift register 34 via the then opened gate. If the next line scanned is also dark, the next line break pulse F also goes into the shift register. The same happens if the third line scanned is dark.

An AND circuit 39 connected to the shift register 34 only lets out a signal if at least three successive line break pulses F have been pushed through in the shift register 34. The then outgoing signal means "marking thread recognized". After passing through the first field, the shift register 34 is reset by the image flip pulse G and is then ready to receive line flip pulses F from the second field. The gate 38 is then opened again accordingly for the line break pulses F as soon as a video signal H from the scanning of dark lines is present. An output signal is therefore generated per field behind the AND circuit 39.

FIG. 9 shows the block diagram of the entire evaluation device, with the detector circuit 33 only showing a single block. The line break pulses F go via a line 40 to a Tac 41 and from there to a line break pulse counter 42, where they are counted when the gate 41 is open. The gate 41 is controlled by a multiple shaver 43. In the drawn position of the multiple switch 43, the gate 41 is continuously open. In this way, all the line break pulses F reach the line break pulse counter 42.

If the multi-switch 43 microns is moved one position to the right, the gate 41 is controlled by a counting flip-flop 44. This counting flip-flop 44 receives, on the one hand, the picture flip pulses G via line 45. These control the counting flip-flop 44 so that the gate 4t is opened. At the beginning of each field, the line break pulses F can thus reach the line break pulse counter 42.

The gate 41 remains open until the detector circuit 33 emits a stencil pulse for switching the counting flip-flop 44. This occurs - as explained in more detail in the description of FIG. 8 - whenever a total of three dark lines have been scanned and the associated line-to-flip pulses F have been pushed through the shift register 34. When the counting flip-flop 44 is switched over, the gate 41 is closed, so that the line-tipping pulse counter 42 no longer receives line-tipping pulses F. As soon as a first field has been scanned, the counting flip-flop 44 is switched over again by the image tilt pulse G, so that the gate 41 is opened again. The line tilt pulse counter 42 now receives as many line tilt pulses F again until the detector circuit 33 again reports "marking thread recognized" and emits a corresponding signal for switching the tamper flop 44. The line break pulse counter 42 now receives the line break pulses F of both fields, which have arisen from the beginning of each hat image until the scanning of three dark lines. The sum of these two series of line tipping pulses F is then a measure of the position of the marking thread 13, ie whether it has been moved too far or too little.

A data flip-flop 46 is arranged parallel to the counting flip-flop 44. It is then connected to the gate 41 by means of the multiple switch 43 when the distance between two marker threads is to be detected. For this purpose, the data flip-flop 46 is brought into a defined position at the beginning of each field by means of the image tilt pulse G via the line 45, the counting flip-flop 44 and the line 47, in which the gate 41 is locked. The line flip pulse counter 42 therefore initially does not receive any line flip pulses F. The data flip-flop 46 is only converted by an output pulse from the detector circuit 33 and then opens the gate 41. This occurs, as described above, when three dark lines are scanned have been, so a first marker thread has been detected. When the image recorded by the video camera is further scanned, the second marker thread lying next to it is then detected by again scanning three dark lines and then generating a corresponding output signal in the detector circuit 33 for switching over the data flip-flop 46. The gate 41 is closed again by this switching. The line-tipping pulse counter 42 then only counted the line-tipping pulses F that occurred between the two marking threads captured by the video camera next to one another, for the sake of accuracy it should be added that the first three line-tipping pulses F, which occur when the second marking thread is detected, are also counted . In this case too, the line break pulses F of both fields are added together in the line break pulse counter 42.

The line break pulse counter 43 is connected to a line break pulse memory 48, to which the count value in the line break pulse counter 42 is transferred after two fields have been scanned. This is done by means of a further counter 49, which is acted upon by a high-frequency multivibrator 50. The image tilt pulses G also go into the counter 49 via a line 51, a divider 2: 1 52 being interposed. The divider 52 ensures that only every second image tilt pulse G reaches the counter 49.

When an image flip pulse G arrives, its outputs are controlled by the counting of the pulses of the astable multivibrator 50 in such a way that a takeover pulse is given to the line flip pulse memory 48 via line 53, whereby the count value from the line flip pulse counter 42 reaches it.

An erase pulse then goes via line 54 into the line break pulse counter 42, which resets it to zero. Then the counter 49 itself blocks its further counting. Because of the high frequency of the multivibrator 50, this happens so quickly that the transfer of the count value and the deletion of the line tilt pulse counter 42 is completed before the first line tilt pulse F arrives after the picture tilt pulse G.

Three outputs connect to the line break pulse memory 48, the first output leading to a digital display 55 for the counter reading in the line break pulse memory 48, the second output forming the binary output for the subsequent control device and the third output going to a digital-to-analog converter, for example one Control plotter.

From line 53 there is also a line 58 which is intended to deliver synchronization pulses to the computer shown in FIG.

FIG. 10 shows the block diagram of the control device for the PI regulator, with which the drive of the transport chains 6, 7 (FIG. 2) is to be controlled so that the actual transverse movement of the tubular felt 3 corresponds as constant as possible to a specific desired value. Because of the long time constant of the controlled system, a computer based on a microprocessor is installed in the control device. Appropriate software controls this microprocessor 59.

The setpoint for the transverse movement of the tubular felt 3 is specified via a latching switch 60. This has a connection to a relay block 61. This is currently in a position in which the detent switch 60 is connected directly to a converter 62 for the drive motor of the transport chains 6, 7. This drive motor, not shown here, is therefore not currently regulated, but only receives the setpoint. The converter 62 receives this specification in particular when the microprocessor 59 is switched off or when faults have occurred.

The position of the latching switch 60 and thus the setpoint are then read into the microprocessor 59 via optocouplers 63, an input multiplexer 64 and an input port 65. After the control value has been calculated, it is sent to the converter 62 via the output port 66, the output multiplexer 67, the optocouplers 63 and the relay block 61. Before this, however, the relay block 61 must be brought into the automatic position, which is done with the aid of a control circuit 68.

The control circuit 68 is controlled on the one hand by a further detector circuit 69 which reports to the control circuit 68 whether the needle machine 11 is in operation or not. In the latter case, the control circuit 68 causes the microprocessor 59 to no longer calculate a new control value. The control circuit 68 is also controlled by an operating part 70. From this operating part 70, the relay block 61 can be switched manually, for example to interrupt the activity of the microprocessor 59. In addition, the operating part 70 serves to transfer the control factors for the P and I components to the microprocessor 59. These must be adapted to the time constant of the controlled system, which is determined by the length of the tubular felt and its speed of rotation. A selection circuit 71 is provided for successively reading in the control factors and is connected to the microprocessor 59 via an input port 72 and an output port 73. The operating part 70 is connected to the microprocessor 59 via a further input port 74, via which a start pulse can be given in the microprocessor 59, which sets the microprocessor 59 in a defined starting position. Another switch causes the control circuit 68 to switch the relay block 61 into the automatic position.

The evaluation device 75 shown in more detail in FIGS. 8 and 9 is here only by one Block shown without further specification. The binary output 56 shown in FIG. 9 leads out of this evaluation device 75 and goes to a buffer stage 76 which gives the count value of the line-to-point pulses F to the microprocessor 59 via the input port 77. Each newly determined value triggers an interrupt 78, whereby the microprocessor 59 is signaled that the count value is stable at the input port 77 for a defined period of time.

The microprocessor 59 reads in a value every second, waiting beforehand for the synchronization pulse coming from the counter 49 in FIG. Appropriate software then performs certain checks before the microprocessor 59 calculates a manipulated variable. This includes, in particular, checking whether there is actually a marking thread in the camera area. If this is not the case, the system jumps to an alarm loop with a corresponding display and then aborts the program. If the checks indicate that the microprocessor 59 is to calculate a manipulated value, the count values of the line-tipping pulses given to the microprocessor 59 are first compared with the correspondingly predetermined setpoint and the difference is formed. Then the proportional and integral values are determined and then the manipulated value is calculated. A conversion of the initially binary control value into a BCD value then takes place, which is then output. Then the jump back and waiting for your own seconds.

Claims (20)

1. Method of producing and/or treating an endless tubular felt or like structure, wherein on to the already at least partly produced circumferentially rotating tubular felt, in this direction and by means of a feed device, material such as for example a fibrous fleece web, a coating, longitudinal threads or the like, is applied continuously over a width, and/or the tubular felt is treated by means of a treatment device, for example flamed or needled, over a width, which is smaller than the width of the tubular felt, the application or treatment as the case may be being effected along a helical course possibly with partial overlapping - as a result of relative movement between feed or treatment device and tubular felt transversely to the direction of travel of the latter, characterised in that there is applied continuously on to the tubular felt (3) in the circumferential direction thereof at least one marking line (13) which contrasts with the said felt and the position of which or the spacing of which from an adjacently disposed marking line - is sensed or read without physical contact as an actual value downstream of the application zone considered in the direction of travel, the relative movement being always so adjusted that the actual value read deviates as little as possible from a specified desired value.

2. Method accordiny to claim 1, characterised in that the position of the marking line (13) is read before the tubular felt (3) with the marking line (13) has carried out one complete revolution.

3. Method according to claim 1 or 2, characterised in that a marking thread (13) is applied as the marking line.

4. Method according to claim 3, characterised in that the marking thread 13 is applied before the consolidation of the fibrous fleece web (10) with the already produced part of the tubular felt (3).

5. Method according to one of claim 1 to 4, characterised in that the marking line (13) is contrasted optically with the tubular felt (3), and is read optically.

6. Apparatus for carrying out the method according to one of claims 1 to 9, with at least two spaced-apart transporting rollers for the already produced part of the tubular felt and with a feed device for the application of material and/or with a treatment device for the part of the tubular felt already produced, a shifting device being provided for the relative movement between the tubular felt and the feed device or the treatment device in the axial direction of the transporting rollers, characterised by at least one application device (12, 16, 17, 18, 19, 20, 21) for the continuous application of the marking line (13) on to the tubular felt (3) in the circumferential direction thereof and also by a sensiny or reading device operating without physical contact for detecting the position of the marking line, (13) or the spacing of the said line from an adjacently disposed marking line downstream of the application device or devices (12,16,17,18,19, 20, 21) considered in the direction of travel, the application device or devices (12, 16, 17, 18, 19, 20,21) and the reading device being immobile relatively to one another, and in fact being arranged in stationary manner when the tubular felt (3) is moved transversely and being coupled with the shifting device when the feed device or treatment device as the case may bs is moved transversely, and the reading device being connected to an electronic evaluating device (75) for ascertaining the difference between the actual value for the position or, respectively, the spacing of the marking line/lines as delivered by the reading device and the desired value preset therefor, and the evaluating device (75) being connected with a control device for determining a correcting value for adjusting the drive of the shifting device (6, 7, 8, 9) in the sense towards minimising the difference.

7. Apparatus according to claim 6, characterised in that the reading device (15) is arranged in the region of the marking line (13) shortly before the completion of a revolution, and the reading device (15) is constructed for detecting the position of the marking line (13).

8. Apparatus according to claim 6 or 7, characterised, in that the reading device has a camera apparatus (15).

9. Apparatus according to claim 8, characterised in that the camera apparatus is a video camera (15).

10. Apparatus according to claim 9, characterised in that the video camera (15) is so arranged that the marking line/fmes (13) extends/extend parallel to the scan lines of the video camera.

11. Apparatus according to claim 10, characterised in that video camera (15) and marking line/lines (13) are so adapted to one another that the marking line/lines takes/take up at least six scan lines.

12. Apparatus according to claim 9 or 10, characterised in that the evaluating device (75) has a detector circuit for detecting the marking line/lines (13) and also a counting circuit (42) for counting the scan lines from the picture start to the video signal of the marking line/lines (13) and/or between two such video signals, the count value being the actual value for the control device.

13. Apparatus according to claim 12, characterised in that the detector circuit (33) has a shift register (34) for the passing-through of line scanning pulses (F), which register is clocked by the line scanning pulses (F) of the video camera (15) and is put back again on each occasion by the flame sweep pulses (G) of the video camera (15), the video signal (H) controlling a gate (38) in such a manner that only the line scanning pulses (F) go into the shift register (34) when the video signal (H) corresponding to the detecting of the marking thread (13) is present.

14. Apparatus according to claim 12 or 13, characterised in that the shift register (34) is followed by an AND circuit (39) which emits a signal only when three line scanning pulses (F) in succession to one another occur.

15. Apparatus according to one of claims 12 to 14, characterised in that the counting circuit consists of a line scanning pulse counter (42), a line scanning pulse store (48) connected thereto, and a counter (49) acted upon by a multivibrator, this counter (49) being so controlled by each second frame sweep pulse (G) in such a manner that the line scanning pulse store (42) receives a transfer pulse for taking-over the count value in the line scanning pulse counter (42) and then the line scanning pulse counter (42) receives a quenching pulse before the next line scanning pulse (F) arrives.

16. Apparatus according to claim 15, characterised in that in the input to the line scanning pulse counter (42) there precedes a gate (41) which is so controlled by the detector circuit (33) via a counting flipflop (44) that it blocks when a signal from the detector circuit (33) occurs and opens when a frame sweep pulse (G) occurs.

17. Apparatus according to claim 16, characterised in that in parallel with the counting flipflop (44) there is arranged a data flipflop (46) which is connectable to the gate (41) instead of the counting flipflop (44), and is so controlled by the counting flipflop (44) and the detector circuit (33) that when a first signal from the detector circuit (33) is present the gate (41) opens and when a second signal is present the gate is closed again.

18. Apparatus according to one of claims 6 to 17, characterised in that the control device is constructed as a proportional plus integral controller.

19. Apparatus according to one of claims 6 to 18, characterised in that the control device is controlled digitally through the agency of a microprocessor (59).

20. Apparatus according to claim 19, characterised in that opto-couplers (63) are provided for desired-value input and for correcting-value emission.

Images