DE29724480U1 - Fabric cutting system and material feed system - Google Patents

Description

Fabric cutting and fabric feeding system

The invention relates to a fabric cutting system and a fabric feeding system.
5

A material feed system is known, for example, from EP-A-0 089. It is designed as a trough with a driven surface, so that the bale of material lying in the trough is set in rotation by frictional forces and thus unwinds. The unwound material web is placed on a conveyor belt assigned to the material unwinding device and is transferred by this to another conveyor belt assigned to a separate cutting device (and is thus fed to the cutting device as a whole, which is where the name of the system comes from).

However, conventional systems of this type are not optimal because they make it difficult to apply the fabric in a straight line without wrinkles and because the accuracy with which the fabric can be cut is limited.

The invention aims to provide a fabric cutting system which overcomes the above-mentioned disadvantages of the prior art. The invention also aims to provide an improved fabric feeding system.

This object is achieved according to one aspect by a fabric cutting system according to claim 1. According to another aspect, the object is achieved by a fabric cutting system according to claim 2.

Due to the use of the continuous conveyor belt, the control system of the fabric cutting system has highly precise information about the position of the fabric in the working area of the cutting device. This measure also makes it easier to feed the fabric out in a straight line and without creases. As a result, the cutting pattern can be positioned more precisely on the fabric, so that cutting can be carried out with greater accuracy. .... . .

The following statements relate in part to advantageous embodiments of the invention, which are specified in the subclaims.
5

While in the prior art the cutting of the fabric at the end of a cutting pattern or at the end of the fabric roll is generally carried out by the cutting device, here the fabric unwinding device is equipped with a fabric cutting device (in the case of several fabric unwinding devices, these are advantageously each equipped with a fabric cutting device). With this measure - on the basis of the increased conveying precision due to the continuous conveyor belt - the cutting at the cutting pattern - or at the end of the roll - can already be carried out at the (respective) fabric unwinding device. This increases the working speed, as it relieves the cutting device of this task and enables the fabric roll to be replaced more quickly. The cutting device allows a fabric remnant to be easily removed by cutting it at the unwinding device rather than at the cutting device. In principle, this remnant could also run off the conveyor belt. The cut fabric remnant usually has a length of 0.2 m to 1 m and can be wound up and removed by an operator or the fabric cutting system (see below). According to claim 5, the fabric unwinding device is equipped with a fabric tensioning device which holds the fabric when it is cut with the fabric cutting device.

In order to enable a particularly quick change of the material to be cut, the material unwinding device(s) is/are designed in such a way that it can automatically rewind the material onto the rest of the fabric roll (if necessary a winding tube) after it has been cut with the material cutting device.

This allows for a particularly quick changeover to a new bale of fabric.

The cutting off of the material can - as already mentioned - be done for two different reasons: one possible reason is the 0 Reach^..the. End..ed»R»es»«S^hni;ttb.i«l.d^s, :w$nji the following

Cutting pattern is to be cut from a different material (e.g. a material with a different color or pattern). The necessary cutting signal then comes from the control of the material cutting system, which has knowledge of the cutting patterns to be cut. Another reason is that the end of the material on the roll of material is reached. According to claim 7, the material unwinding device(s) is/are equipped with a material end sensor which detects when the material end is reached or approaching, preferably by detecting that the roll of material has been completely or largely unwound. According to claim 8, the material end sensor is formed by a light barrier through which the material web is passed, preferably in the area of the unwinding device. According to claim 9, the control of the material cutting system advantageously stops the unwinding process when the material end is detected and causes the material to be cut off. Due to the continuous conveyor belt, the control system knows with high accuracy when the end of the fabric arrives at the cutting device and can therefore synchronize the end of the cutting process accordingly.

For example, the fabric cutting system according to the invention makes it possible to significantly reduce the downtime of the fabric cutting system and thus significantly increase the effective working speed. As explained above, a roll of fabric must be replaced frequently because of a required change of color or pattern or because the end of the roll of fabric has been reached.

Such a change of fabric bales is possible practically without interrupting work, since after cutting a fabric with the fabric cutting device assigned to the respective fabric bale, the control system of the system causes the fabric bale in question to be rewound and the fabric to be unwound from the other fabric bale, laid out on the conveyor belt and transported to the working area of the cutting device to be carried out immediately afterwards.

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Due to the continuous conveyor belt, the arrival of the end of the fabric at the cutting device can be calculated precisely. According to claim 10, the control interrupts the cutting process at the latest when the end of the fabric is calculated to arrive at the cutting device and continues it again when a restart signal is received after the arrival of another fabric. The arrival time is advantageously calculated on the basis of the conveyor belt speed and the distance between the fabric cutting device or fabric end sensor and the cutting device. Due to the use of a continuous conveyor belt, the fabric end sensor can be arranged close to the fabric bale on the unwinding device (and not on the cutting device, although this would also be possible and would also lead to automatic detection of the fabric end).

According to claim 11, after the unwinding device has been restarted for another length of fabric, the control system can also automatically calculate the arrival time of the beginning of this length of fabric at the cutting device. The basis for this is again the continuous conveyor belt.

Alternatively, the arrival of a fabric near the work area is determined not by calculation but by direct detection of the beginning of the fabric. This can be done optically, for example. For this purpose, the conveyor belt can be made in a special color that is different from the fabric colors generally used. An optical sensor is sensitive to light reflected from the conveyor belt (which has the special color of the conveyor belt). When the fabric (which has a different color) arrives, the intensity of the detected light decreases, from which the arrival signal is obtained. Another possibility of fabric detection is based on optical distance measurement. The distance between a distance measuring device above the conveyor belt and the visible surface of the conveyor belt decreases when fabric is lying on the conveyor belt. This reduction in distance allows the presence of a fabric to be detected. The measurement is based, for example, on light being shone on the conveyor belt and

the light reflected from there is detected. The presence of the material means that the focal point is below the reflecting surface (now the material), which is reflected in a significant decrease in the detected reflected light intensity. Both measurement methods can be used alternatively or in combination.

According to claim 12, on the basis of this detection, an automatic cutting pattern zero point setting takes place in the feed direction of the fabric web for the following cutting process.

This zero point is offset from the beginning of the fabric lengthwise by a predetermined distance (e.g. 2 cm) towards the inside of the fabric. The restart signal for the cutting process is preferably also generated when the zero point is set.

Across the feed direction, a selvedge that varies in width from one fabric bale to the next must be taken into account for the zero point setting. The selvedge is the edge area that differs in color and pattern from the rest of the fabric. To be more precise, the transverse zero point must be offset by a predetermined distance from the inner edge of the selvedge to the inside of the fabric. The inner edge of the selvedge can in principle be detected automatically by optical means. However, a semi-automatic setting of the transverse zero point according to claim 13 is preferred. This is based on automatic fabric bale tracking, which compensates for uneven winding of the fabric in the transverse direction. At the start of unwinding a new fabric bale, an operator defines the position of the transverse zero point relative to the fabric edge. If the transverse zero point is to be 1 cm inside the inner edge of the selvedge, for example, the operator sets the transverse zero point to 3 cm inside the fabric edge in the case of a selvedge that is 2 cm wide, for example. The fabric bale tracking system then automatically shifts the fabric bale during unwinding so that the transverse zero point is always located at a fixed transverse position of the conveyor belt (the transverse zero point position). According to claim 14, the knowledge of the fabric web edge position required for this is formed by a fabric web edge sensor in the form of a light barrier, which

light sources illuminating the fabric edge immediately after unwinding and one or more sensors for spatial detection of the light interrupted by the fabric and/or passing by the fabric. 5

In the fabric cutting system according to the invention, the control system can precisely determine in advance, due to the continuous conveyor belt, whether a cutting pattern to be cut can still be completely cut out from the existing length of the remaining fabric. According to the embodiment according to claim 15, it is even possible for the control system to determine those templates of a cutting pattern that can still be completely cut out before the end of the fabric is reached. The control system stores those templates that can no longer be completely cut out and causes these templates to be automatically cut out of the new fabric after processing is continued. In terms of control technology, this can preferably be solved according to claim 16 in that if the end of a fabric roll is reached within a cutting pattern, this is broken down by the control system by automatically recognizing those individual templates that cannot be completely cut out of the old roll and, preferably after automatic recognition of the zero point in the feed direction, cutting them out of the next fabric roll. These measures allow a significant reduction in the amount of waste.

The individual templates often have to be provided with additional seams and topstitching. This can be the case, for example, with templates for the cover of upholstered furniture, where the upholstery folds are created by sewing the individual templates before sewing the cover together. For this purpose, it is useful for the templates to be provided with markings along which the seam or topstitching lines can then be placed. In order to avoid having to mark each individual template, these markings are preferably applied to the uncut length of fabric. For later processing of the cut-out fabric templates, markings generally have to be applied to the fabric.

For example, showji .such, markings; aji,.: where later

Quilted seams are to be applied. According to claim 17, a marking device is provided for this purpose. In the prior art, a marking head (e.g. a spray head) is used for this purpose, which is attached to the cutting device, more precisely to the generally existing movable carriage, which also carries the cutting head of the cutting device. In the prior art, the material is generally processed in such a way that first the necessary markings are applied to the material by appropriate movement of the carriage, and then the necessary fabric cuts are made, again by appropriate movements of the carriage.

In contrast, the embodiment according to claim 18 proposes that a marking device is provided which is arranged separately from the cutting device and can be controlled independently of it, and that cutting and marking take place simultaneously. The marking device is advantageously arranged between the unwinding device and the cutting device. By marking the material directly after it has been unwound from the roll of material, the material strips are fed to the cutting device ready for cutting. Since the cutting device now serves exclusively for cutting, the processing speed can be increased by up to a factor of 2 by this measure.

If the cutting device or the marking device malfunctions, a fabric cutting system of the prior art must generally be shut down completely until the malfunction is remedied. In order to avoid such production downtimes, in a further development of the above embodiment according to claim 19, the marking device is also equipped with a cutting device (e.g. a cutting head) and/or the cutting device is equipped with a marking device (e.g. a marking head). The control of the system is designed in such a way that, in the event of a failure of the normally operating cutting device or marking device, cutting with the cutting device attached to the marking device can be carried out as an emergency operation.

and a marking. mj,t .dem.an.ziehneid-device an- : ::·* ·* ·..: _: * .· » · ^: ···: :: : : : :

brought marking agent is possible, i.e. a roll exchange is carried out. In the event of a total failure of one of the two devices, an additional emergency operation is provided in which the device that has not failed takes over both functions (cutting and marking). In the first case, work continues with simultaneous cutting and marking without loss of performance. In the second case, non-simultaneous cutting and marking takes place, which allows work to continue at at least half the processing speed.

The unwinding of the material and its conveyance on the conveyor belt can be carried out continuously or "discontinuously". In the first case, the material is pulled off the bales without interruption or delay and cut and, if necessary, marked during the feed. However, a feed method in which the unwinding device(s) and the conveyor belt are each stopped to cut a cutting window and, if necessary, to mark a "marking window" is easier to control.

According to claim 19, the fabric cutting system has a marking head that can be moved in the transverse direction and optionally in the feed direction of the fabric web. This can be equipped with a spray device that applies the line-like markings to the fabric web. A dry powder can be sprayed on, which can be brushed out again after further processing of the fabric, but an adhesive substance, e.g. a dye, can also be sprayed on, which is invisible without the aid of technical means (e.g. fluorescent lamp). In another preferred embodiment, the marking device is formed by a marking head that, similar to a plotter, applies the markings using a pen that is moved along the lines to be marked. A single pen can be used, but a change magazine can also be provided from which the marking head takes the pen. The latter embodiment has the advantage that, on the one hand, the pens can be replaced when they wear out without long set-up times, and, on the other hand, several pens for different colored markings can be handled by the marking head. The pens can be, for example, chalk pens or other common marker pens ·· .··. .·*, ···; .··. &igr;; .... ....

The movement of the marking head is preferably controlled by a control unit with a microprocessor. This control can be, for example, a CNC or DNC control known from machine tool construction. In addition to the position of the markings to be applied on the individual templates, the input variable of the control is also the arrangement of the cutting image. In order to be able to read in this data, the control preferably has an interface to which either a central control unit for controlling the material feed formed from the unwinding device and conveyor belt and the cutting device is connected, or via which the data can be taken from another computer, e.g. the control of the cutting system. Readable data formats are preferably the *.DXF AAMA formats commonly used in textile processing or formats according to ISO 6983, whereby the data is generally generated using CAD systems. Adaptation to any data format is possible, e.g. the system control can read and process proprietary formats from other machine manufacturers, such as the proprietary format of the French company LECTRA SYSTEMES. The program for controlling the marking head can either be read in via the interface for the position data of the markings, or stored in a permanent memory, e.g. an EPROM or an electrically erasable and rewritable EEPROM.

According to claim 21, the cutting device has a cutting head that can be moved in the transverse direction and optionally in the feed direction of the fabric web and whose position and cutting activity can be controlled by the control system of the system. The cutting head control is preferably designed in the same way as the marking head control system shown above. The two controls can use one and the same or separate microprocessors. Furthermore, the two head controls can be part of the control system of the entire fabric cutting system, which optionally has a single common microprocessor.

The cutting head may have a cutting blade that

for example a«l«s.*ej.<e^ti:ünisch: antjeffieüeneo circular knife : : : · ··: : · ··:· : : : : : : : :

In other embodiments, the cutting blade is designed as a shock blade, which can preferably be ultrasonically excited, which ensures that the cutting movement is perpendicular to the material web even with fast feeds. The cutting head can also be designed as a punch, which punches the templates out of the material web.

In a preferred embodiment, the cutting head is a laser beam cutting head. It has a laser beam source and corresponding focusing optics that focus the laser beam essentially on the fabric. To avoid undesirable oxidation, a protective glass nozzle can also be provided that displaces the oxygen in the air at the cutting point with reactant gases such as nitrogen or noble gas. In particular, with fabrics containing synthetic fibers, a smoke extraction device can be provided that extracts any substances that may be produced during cutting in order to comply with the required occupational health and safety values (MAK values) at the workplace.

Finally, the cutting head can also be designed as a water jet cutting head, which has a water jet nozzle from which a high-pressure water jet emerges for cutting the material. In this case, the cutting device has a suitable collecting device for the cutting water on the side facing away from the cutting head. A combination of one of the above-mentioned mechanical cutting or punching tools with a laser beam cutting device or a high-pressure water jet cutting device is also advantageous.

In order to be able to cut out several similar templates in one operation, it is known in the art to lay several layers of fabric on top of each other, feed the superimposed webs to the cutting device and cut them together with a continuous cut (see, for example, the EP-A-0 589 091 mentioned at the beginning). When using conventional marking devices (see, for example, DE-U-295 03 230), however, the topmost fabric can be marked in each case during this multi-layer processing. : .... ... . .··.·. · · .·· &tgr; : : : :

According to claim 2, the fabric cutting system is designed so that two or more layers of fabric are laid out on top of each other on the conveyor belt. A corresponding number of fabric unwinding devices are used for this purpose. Due to the continuous conveyor belt, the fabric strips can be positioned very precisely on top of each other.

According to claim 2, each of the unwinding devices is assigned a marking device. The marking devices are arranged in such a way that they can apply the markings before a further layer of fabric is placed on top of each other. They can be controlled in time and place in such a way that the markings of the layers of fabric that are ultimately placed on top of each other are congruent with each other. The multi-layered fabric prefabricated in this way is then fed to the cutting device. The marking patterns are congruent on the templates that are then cut out. The marking devices are advantageously arranged between the individual unwinding devices or - with regard to the last marking device - between the last unwinding device and the cutting device and mark the layer of fabric that is unwound from the assigned unwinding device before the next layer is placed on top of it by the subsequent unwinding device, if necessary. So that the markings of the individual layers are congruent after they have been placed on top of each other, the marking devices and the take-off speed of the individual unwinding systems are controlled in a time-synchronized manner.

Preferably, all marking devices work simultaneously, with each one processing a marking window that is arranged later in the sequence of the material output. The marking windows can belong to one or to different cutting patterns. After processing one marking window, the material webs are pulled forward; the next marking window is applied. In terms of control, the individual marking windows are synchronized so that the markings are congruent with one another in the finished fabric layer package. In discontinuous operation, for example, the second marking

Device applies to the second layer of material exactly the same marking pattern that the first marking device applied to the first layer of material in a previous step. The markings on the first and second layers of material then lie exactly on top of each other. Alternatively, continuous feed is also possible. The fabric strips are pulled under the marking devices during marking.

The fabric cutting system is advantageously equipped with at least one cover material feed arranged downstream of an unwinding device, which lays a cover layer on the laid out fabric web. In this way, a cover material can be placed on the top layer of fabric to form a vacuum seal. A fabric web covered in this way can be sucked onto the conveyor belt by means of a negative pressure during subsequent cutting, which reduces the risk of relative displacement of the individual fabric web layers during the cutting process. A suitable cover material can be, for example, a plastic film, a paper layer or another film-like material. The air permeability of the cover material is preferably significantly lower than that of the fabric web layers, so that sufficient fixation is achieved by suction. In other embodiments, the vacuum suction takes place without covering the top fabric web. A sufficient suction effect can also be achieved solely through the relatively low air permeability of the fabric webs to be cut.

In the simpler and more cost-effective embodiment according to claim 22, the conveyor belt is provided with a rough and/or adhesive covering that can hold the fabric strip(s) securely without vacuum suction. This is preferably a felt covering. This saves on the one hand the relatively complex suction device and on the other hand makes covering the fabric strip obsolete.

In order to be able to cut with high precision and to keep the reject rate as low as possible, various measures are required..for. faJ.teofoe.ieH. display.»·.of the S;tc3f£bahn(s) on the

Conveyor belt is provided. Thus, according to claim 23, the advance of the unwinding device(s) or of the fabric tension application device(s) that may be present is somewhat smaller than the advance of the conveyor belt. This means that the fabric is placed on the belt with a certain tension. According to claim 24, the fabric web is pressed against the conveyor belt by a pressure device, in particular in the form of a pressure roller.

In the prior art, so-called notches are often cut into the edge area of templates when cutting. These are triangular incisions which show the sewer where the seams to be sewn begin or end during the subsequent sewing of the fabric template. In order to further shorten the processing time, claim 25 proposes applying the markings for the end or beginning of the seam to the fabric in the form of (colored) markings instead of cut notches. This is preferably done by the above-mentioned marking device(s), which work simultaneously with the cutting device. Since the cutting device is generally more heavily utilized than the marking device(s), replacing the cut notches with (visually recognizable) markings results in a more even utilization and thus an overall increase in the processing speed.

The marking device(s) can also be used advantageously for other marking of the pieces of fabric. Such a marking can, for example, indicate the allocation of different pieces of fabric to a certain piece of furniture. This is particularly valuable if the pieces of fabric belonging to a piece of furniture come from different cutting patterns (for example because the piece of furniture is to be covered in a different color) or if a cutting pattern is cut partly from an old and partly from a new roll of fabric because of the end of a roll of fabric. According to the claim, this allocation information or other information is applied to a so-called seam allowance using the marking device(s). This is a piece of fabric that is later sewn onto a seam allowance. The : : · : : : . · . . · · ·· · · : : :

&bull; · &diams;· ·

14
Information can be presented in coded or uncoded form.

The material cutting system can - alternatively or additionally - have a labelling device which labels the individual templates of a cutting pattern or of different cutting patterns so that the templates can be assigned to one another during further processing. The labelling device can be arranged either in front of or behind the cutting device and can be controlled via the system control system.

The unwinding device is advantageously designed as a rodless unwinding device, wherein the fabric bale rests on bearings arranged underneath it and is set in rotation in the unwinding direction by a movement of the bearings tangential to its outer surface in order to unwind the fabric.

The fabric cutting system can also have a removal belt downstream of the conveyor belt, which removes the finished

cut and possibly marked templates or distributed, for example, to different transport baskets. The clearing belt can also be formed by an extended section of the conveyor belt.
25

Finally, the fabric cutting system advantageously has at least one monitor on which the cutting pattern and/or the markings to be applied can be read.

As mentioned at the beginning, the state of the art uses separate systems for feeding and cutting the material, which are assembled in the company. The above-mentioned designs of the material cutting system are also advantageous for such separate systems, even if they do not achieve the optimal results of the fabric cutting system according to the invention, which is designed as a unit. In the textile processing countries there is a large stock of such separate systems, which can still be used for several years. In order to allow these existing systems to benefit from the advantages of the new designs,

·

·

7» a- S 3
■ » » · »a

it is proposed to retain the cutting part and to replace the feed part with a material feed system designed according to one or more of the above embodiments. According to claim 27, a material feed system is therefore proposed with at least one material unwinding device for a bale of material, a conveyor belt for transporting the unwound material, the unwinding device laying the material web directly on the conveyor belt or on one or more material webs already laid out on it. The material feed system preferably has one or more features of claims 2-26. Insofar as a material cutting device is mentioned in these claims, the separate cutting part is meant in this context. If necessary, the separate cutting part is coupled in terms of control to the material feed system according to the invention, so that, for example, the subject matter of claim 15 (determination and processing of templates that can still be removed before the end of the material) is also highly advantageous in the feed device according to the invention with a conventional cutting part supplied. A design that enables multi-layer marking is also particularly advantageous. Existing cut parts benefit greatly from this when they are operated together with a feed device designed in this way.

The invention will now be described in more detail using embodiments and the attached schematic drawing.

In the drawing show:
30

Figure 1 is a side view of a fabric cutting machine with two unwinding devices, but without a marking device; Figure 2 is a plan view of the machine shown in Figure 1.

fabric cutting machine;

Figure 3 is a side view of a fabric cutting machine similar to Figure 1, but additionally equipped with two marking devices and a clearing belt;

Figure 4 is a plan view of the 40 shown in Figure 3

Figure 5 is a schematic representation of a fabric panel with

Cutting diagram and templates to be cut; Figure 6 a cutting diagram with templates distributed over two different fabric panels; Figure 7 a side view of a fabric cutting machine

similar to Figure 1, which is against failures of the

Cutting device and marking device

is robust; and

Figure 8 is a side view of a fabric unwinding system similar to the fabric cutting system of Figure 3, but

not equipped with a cutting device

is.

In the figures, parts with the same or similar functions have the same reference symbols.

The fabric cutting system according to Figures 1 and 2 has two unwinding devices 1, 1'. A roll-like fabric bale 7 rests on a V-shaped belt arrangement 8 of the unwinding devices 1, 1' with three rollers 9. The belts are preferably driven by the middle of the three rollers 9. The strand forces of the belt arrangement 8 are transferred by friction to the fabric bale 7, which is thereby set in rotation and unwinds.

The fabric cutting system is equipped with a conveyor belt 5, which extends from the point where the fabric is deposited by the first unwinding device 1 to the working area of a cutting device 3. The "first unwinding device" is understood to be the one that is furthest away from the cutting device 3. The fabric web is deposited directly onto the conveyor belt 5 by the unwinding devices 1, 1'. The direction of the conveyor belt feed is indicated by an arrow.

According to the illustration in Figure 1, the second unwinding device 1' is active. The first unwinding device 1 is in the waiting state. The cutting device 3 therefore cuts material which is discontinuously cut by the length of a cutting window from the fabric roll 7 of the second unwinding device.

17
device 1' is unwound.

The unwinding devices 1, 1' are each equipped with a fabric end sensor (not shown in detail). This consists, for example, of a light transmitter-light receiver unit and a reflector. It can be arranged so that the light beam runs over the two outer rollers 9 of the belt arrangement 8, so that the fabric bale 7 interrupts the light barrier. If, however, the diameter of the fabric bale 7 falls below a certain value, it releases the light barrier, which is fed to a control device (not shown) as a fabric end signal.

This signal initiates a cutting of the material already laid out on the conveyor belt 5 from the material residue on the material bale 7. For this purpose, the material is held by a material tensioning device 10 and cut off by a subsequently arranged material cutting device 11. Both are arranged on the unwinding devices 1/1' in an area in which the material already unwound does not yet reach the conveyor belt 5. After cutting, the material residue is wound back onto the material bale of the second unwinding device 1'.

While the end of the fabric laid out on the conveyor belt 5 is being cut by the cutting device 3, the first unwinding device 1 has already unwound the fabric onto the conveyor belt 5. With a double belt feed, the fabric from the first unwinding device 1 is already laid out and reaches the working area of the cutting device 3, so that a fabric roll change is achieved with only a short interruption in work. The operator can now remove the rest of the fabric roll from the second unwinding device 1' and place a new fabric roll on top.

To continue the cutting process with the new material, a zero point adjustment is necessary. In the feed direction, this zero point adjustment is carried out fully automatically by a feed direction zero point sensor 11 detecting the arrival of the front edge of the material.Working area of the feed direction : ::'* .'"": :',£.'":'"V ^: .. ^:: .) K) .1.

£. * t &idigr;

detected. The detection is based on an optical detection of the fabric color deviating from the color of the conveyor belt 5 and/or an optical distance detection. In the transverse direction, the zero point setting is semi-automatic. The unwinding devices 1, 1' can each be moved in the transverse direction by a transverse drive (not shown). This is equipped with a tracking control which, on the basis of the signals from an optical fabric edge sensor, automatically moves the fabric bale in the transverse direction during unwinding so that the unwound fabric edge comes to rest in a constant transverse position. This prevents uneven unwinding of the fabric from leading to transverse displacements of the laid out fabric on the conveyor belt. The transverse position of the unwound fabric, which is automatically maintained by the tracking control, can be individually adjusted by the user from fabric bale to fabric bale. This is necessary because the width of the so-called selvedge 13 generally varies from fabric bale to fabric bale. For this setting, a lockable transverse zero point void is used

14. The transverse zero point setting therefore consists in the operator setting the transverse zero point void to a certain distance (e.g. 1 cm) within the inner selvedge edge after inserting a new roll of fabric. This ensures that the transverse drive automatically controls the unwinding device 1, 1' so that the set transverse zero point is always deposited at the same transverse position on the conveyor belt 5.

This transverse zero point adjustment can be carried out before the actual start of work of an unwinding device and therefore does not require any interruption of work.

The cutting device 3 comprises a carriage 16 which can be moved in the feed direction and is in the form of a cross-beam 17 on which a cutting head 18 can be moved. The cutting head 18 is, for example, a laser cutting head.

The control unit (not shown) has stored the cutting images to be cut. #· On gin,eni ^!kjnijtojr .^ are, among other things, these

Cut image saved #· On gin,eni ^!kjnijtojr .^

virtual cutting images can be displayed. On the basis of the stored cutting images, the control device controls the unwinding from the respective unwinding device 1 or 1', the cutting window-wise feed of the conveyor belt 5, the automatic setting of the zero point in the feed direction, the movements of the cutting head 18 in the feed and transverse directions and its cutting activity, as well as the cutting of the material and the change from one unwinding device to another due to a change from one material to another specified by the cutting task or due to the end of a material web. More details on this are described below in connection with Figures 5 and 6.

A crease-free laying out of the material on the conveyor belt 5 is achieved on the one hand by the material tension application device 10 only allowing a slightly lower material feed than would correspond to the feed of the conveyor belt 5. As a result, the material is laid out on the conveyor belt 5 under a certain tension. On the other hand, a pressure roller 19 is provided on each unwinding device 1, 1', which presses the material against the conveyor belt 5.

The conveyor belt 5 is provided with a felt-like surface. The material adheres to this surface so well that it does not slip during the cutting process.

The fabric cutting system according to Figures 3 and 4 allows the marking and cutting of multi-layered fabric strips. The above statements on Figures 1 and 2 also apply to this fabric cutting system. In addition, a marking device 2, 2' is arranged behind each unwinding device 1, 1 ^' , which applies markings to the fabric strip just unwound for stitching or seam lines to be applied later. The markings consist, for example, of a self-evaporating substance that is only visible in the ultraviolet or infrared spectral range. The marking devices 2, 2' correspond in construction to the cutting device 3 described above, namely they each have a carriage 16 that can be moved in the feed direction with a crossbar 17 and a cutting head 18 attached to it; the latter is

· 1

20

e.g. a spray head that sprays the marking substance as the spray head moves, thereby applying line-like markings of any shape to the material.

After the first layer of the fabric has been laid out by the first unwinding device 1, marked by the first marking device and transported further by the conveyor belt 5, the second unwinding device 1' places a second fabric layer on top of it. This is marked by the second marking device 2'. The marking processes are controlled in such a way that at the end the markings of the fabric webs lying one above the other are congruent. The conveyor belt 5 transports the finished, multi-layered fabric web to the cutting device 3, where all the layers are cut together in one operation. A vacuum box 21 arranged in the working area of the cutting device 3 on the underside of the upper run of the conveyor belt sucks air through the conveyor belt and the fabric webs placed above it. This causes the fabric webs to be pressed sufficiently against the conveyor belt to prevent them from slipping during the cutting process.

In this embodiment, not only the (virtual) cutting lines but also the marking lines can be displayed on the monitor 6.

Behind the cutting device 3 there is a clearing area 22, which is formed by an extended part of the conveyor belt 5. The completely cut templates can either be sorted manually by the operating personnel via the clearing area 22 or fed to an automatic distribution and sorting system. Any incorrect cuts and offcuts can also be sorted out manually here.

Figure 5 shows a length of fabric before cutting. The selvage 14, which usually has a width of 2 cm, is located on one longitudinal edge. The (virtual) zero point 23 is located slightly inside the inner edge of the selvage (e.g. 0.2 mm) in the transverse direction, and slightly inside the inner edge of the selvage in the feed direction.

the cutting lines of the templates 24 to be cut out are shown. (Note: In fabric cutting technology, the term "template" refers to a cut-out piece of fabric.) This is only for illustration purposes, because in reality these cutting lines are only present virtually in the memory of the control unit. The marking head 20 of the cutting device 3 is moved along these virtual cutting lines so that it cuts out the templates 24 shown. Marking lines 25 are also shown. These are also initially only present virtually in the memory of the control unit, but after the markings have been applied they are visible on the fabric in the form shown. In the area of the cutting lines, triangular markings 2 6 are also shown. These are also applied by the marking devices 2, 2'.

They serve as markings for the end or beginning of the seam during subsequent processing. Finally, the marking device 2, 2' sprays information 27, e.g. a commission and template number, into the seam allowances of the templates 24 in order to facilitate the assignment of the individual templates after cutting.

If the length of a cutting image, as shown by way of example in Figure 5, exceeds the length of the working area of the cutting device 3, the virtual cutting image is divided into several virtual cutting windows that correspond to this length. The control of the system is designed in such a way that after a feed of one cutting window length, the next cutting window is cut, so that as a result the cutting image shown in Figure 5 is processed piece by piece.

Figure 6 shows a cutting image in such a division into three cutting windows. In the example shown, the end of the fabric is located in the middle of the middle cutting window. The control system of the system automatically determines which of the virtual templates in this cutting window can still be cut out in their entirety and for which this is not the case. It causes the templates 24' that can still be cut out in their entirety to be cut out from the fabric strip that is coming to an end, and the templates 24' that can no longer be cut out in their entirety to be cut out from the fabric strip that is coming to an end.

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the control automatically sets the zero point 23 of the new fabric. This measure allows waste to be reduced to a minimum and allows work to continue practically without interruption when changing fabric. 5

The fabric cutting systems shown are modular in design. This means that other embodiments than those shown can be put together easily. For example, an embodiment for single-layer fabric processing similar to Figure 1 is particularly advantageous, but which also has a marking device behind the second unwinding device 1' similar to the marking devices described in Figure 3. One such embodiment is shown in Figure 7. It can be used to mark and cut single layers, whereby very high processing speeds can be achieved due to the double unwinding device and the simultaneous marking and cutting. The fabric cutting system in the figure corresponds to Figures 1-4 in the other features not mentioned.

Unlike Figures 3 and 4, in order to increase the robustness against failures, the marking device (or - in the case of several marking devices as in Figures 3 and 4 - the last marking device) is equipped with a cutting head 18'. The cutting device is correspondingly equipped with a marking head 20'. There is a vacuum box in the marking and cutting area. In normal operation, the additional heads 18', 20' are not used. If one of the normally used heads 18, 20 fails, the additional heads 18', 20' are used. This means that the roles are reversed: the cutting device 3 now takes over the marking, the marking device 2 takes over the cutting. In this emergency operation, the marking takes place after cutting; the templates that have already been cut out are marked. Because the operation is still simultaneous, the normal working speed can be maintained. In the event of a total failure of the cutting device 3 or the marking device 0, an emergency shutdown is applied. Namely : ::.. ·* :: : .· y. _{l ::} .. _: : ·. : :

23

the device 2 or 3 that is still operational functions by activating the marking head 20' or the cutting head 18', marking and cutting now take place one after the other. The system can then continue to work despite the total failure, although the processing speed is reduced because the operation is no longer simultaneous.

Figure 8 shows a material feed system that corresponds to the material cutting system shown in Figure 3. The only difference from that is that it does not have a cutting device 3 (nor a downstream clearing area 22). Rather, the conveyor belt 5 ends directly after the last marking device 2'. It is intended to be combined with a separate cutting device 3' (only partially indicated in Figure 8), which has its own conveyor belt 5'. All statements regarding Figures 1-7 therefore also apply to this material feed system. The embodiment shown, like the one in Figure 3, allows multi-layer marked fabric seams to be created before the templates are cut out together from the fabric package.

Claims (28)

1. Fabric cutting machine with - at least two fabric unwinding devices ( 1 , 1') arranged one after the other for a fabric bale ( 7 ), - wherein the fabric unwinding devices ( 1 , 1 ') are equipped with a fabric cutting device ( 11 ), - a conveyor belt ( 5 ) for transporting the unwound material, and - a cutting device ( 3 ) which cuts a pattern from the fabric web laid out on the conveyor belt ( 5 ), wherein the conveyor belt ( 5 ) extends continuously at least from the point where the fabric is deposited by the unwinding devices ( 1 , 1 ') to the working area of the cutting device ( 3 ) and the unwinding devices ( 1 , 1 ') lay the fabric web directly on the conveyor belt ( 5 ), and
wherein after cutting off a material with the material cutting device ( 11 ) associated with the respective material bale ( 7 ), the control of the system causes the respective material bale ( 7 ) to be rewound and the unwinding of the material from the other material bale ( 7 ), its laying out on the conveyor belt ( 5 ) and its transport to the working area of the cutting device ( 3 ) to be carried out immediately thereafter, so that a material bale change is achieved with no or only minimal interruption to work. 2. Fabric cutting machine with - at least two fabric unwinding devices ( 1 , 1 ') arranged one after the other for a fabric bale ( 7 ), - a conveyor belt ( 5 ) for transporting the unwound material, and - a cutting device ( 3 ) which cuts a pattern from the fabric web laid out on the conveyor belt ( 5 ), wherein the conveyor belt ( 5 ) extends continuously at least from the point where the fabric is deposited by the unwinding device ( 1 , 1 ') to the working area of the cutting device ( 3 ) and the unwinding device ( 1 , 1 ') lays the fabric web directly on the conveyor belt ( 5 ) or on one or more fabric webs already laid out thereon,
wherein two or more layers of fabric are laid out on top of each other on the conveyor belt ( 5 ), and
each of the unwinding devices ( 1 , 1 ') is assigned at least one marking device ( 2 , 2 '), the marking devices ( 2 , 2 ') being arranged in such a way that they are able to apply the markings before a further layer of fabric is placed on top, and can be controlled in terms of time and location in such a way that the markings of the layers of fabric ultimately lying one above the other are congruent with one another. 3. Fabric cutting system according to claim 1, characterized in that at least one marking device ( 2 , 2 ') is provided. 4. Fabric cutting system according to claim 2, characterized in that the fabric unwinding devices ( 1 , 1 ') are equipped with a fabric cutting device ( 11 ). 5. Fabric cutting system according to one of claims 1, 3 or 4, characterized in that the fabric unwinding devices ( 1 , 1 ') are equipped with a fabric tensioning device ( 10 ) which holds the fabric during cutting with the fabric cutting device ( 11 ). 6. Fabric cutting system according to one of claims 1 or 3 to 5, characterized in that the fabric unwinding devices ( 1 , 1 ') are designed such that they can automatically wind the fabric back onto the fabric bale ( 7 ) after it has been cut off with the fabric cutting device ( 11 ). 7. Fabric cutting system according to one of claims 1 to 6, characterized in that the fabric unwinding devices ( 1 , 1 ') are equipped with a fabric end sensor system which detects the reaching or approaching of the end of the fabric on the fabric bale ( 7 ), preferably by detecting the complete or extensive unwinding of the fabric bale. 8. Fabric cutting system according to claim 7, characterized in that the fabric end sensor is formed by a light barrier through which the fabric web is preferably guided in the region of the unwinding device ( 1 , 1 '). 9. Fabric cutting system according to claim 7 or 8, characterized in that the detection of the reaching or approaching of the fabric end initiates the cutting of the fabric with the fabric cutting device ( 11 ). 10. Fabric cutting system according to one of claims 1 or 3 to 9, characterized in that after cutting the fabric web or - if there is no fabric cutting device - detecting the end of the fabric, the control interrupts the cutting process at the latest when the cut end of the fabric web arrives at the cutting device ( 3 ), calculated in particular from the speed of the conveyor belt ( 5 ) and the distance between the fabric cutting device ( 11 ) or fabric end sensor and the cutting device ( 3 ), and to continue it again when a restart signal from the cutting device ( 3 ) arrives after a new or different fabric web - in particular from a different unwinding device ( 1 , 1 '). 11. Fabric cutting system according to claim 10, characterized in that after restarting the unwinding device ( 1 , 1 ') for a new or different fabric web, the control automatically determines the time until the beginning of this fabric web arrives at the cutting device ( 11 ). 12. Fabric cutting system according to one of the preceding claims, wherein the arrival of the fabric web at a specific point near the working area of the cutting device ( 3 ) is automatically detected, preferably optically, and on the basis of this detection an automatic zero point setting takes place in the feed direction of the fabric web for the following cutting process. 13. Fabric cutting machine according to one of the preceding claims, - which has a sensor ( 13 ) for detecting the position of the fabric edge transverse to the feed direction, - in which the fabric bale ( 7 ) is displaceable in this transverse direction by a transverse drive, and - which is equipped with a tracking device which automatically moves the fabric roll ( 7 ) in the transverse direction during unwinding so that the unwound fabric web edge comes to lie in a transverse position preselectable by the user, so that selvedges ( 14 ) of different widths and uneven winding of the fabric in the transverse direction can be compensated. 14. Fabric cutting system according to claim 13, characterized in that the fabric edge sensor ( 13 ) is formed in the manner of a light barrier by one or more light sources illuminating the fabric edge immediately after unwinding and one or more sensors for spatial detection of the light interrupted by the fabric and/or the light passing by the fabric. 15. Fabric cutting system according to one of claims 7 to 14, characterized in that the control is able to determine from the speed of the conveyor belt and the time at which the fabric end sensor detects those templates ( 24 ') of the cutting image which can be completely cut out before the fabric end is reached and is able to store the remaining templates ( 24 ") of the cutting image, the control automatically continuing to cut out the remaining templates ( 24 ") from a new fabric web. 16. Fabric cutting system according to claim 15, characterized in that - if a fabric bale end is reached within a cutting pattern - the cutting pattern is broken down by the control system in that those individual templates ( 24 ") of the cutting pattern which cannot be completely cut from the old bale ( 7 ) are automatically recognized and, preferably after automatic recognition of the zero point in the feed direction, are cut from the next fabric bale. 17. Fabric cutting system according to one of claims 2 to 16, characterized in that at least one marking device ( 2 , 2 ') is provided which applies line-like markings ( 25 ) for seam or quilting lines to the fabric web laid out by the unwinding device ( 1 , 1 ') onto the conveyor belt ( 5 ). 18. Fabric cutting system according to one of claims 4 to 17, characterized in that the marking device ( 2 , 2 ') is arranged separately from the cutting device ( 3 ) and can be controlled independently of it, and the cutting and marking take place simultaneously. 19. Fabric cutting system according to claim 18, characterized in that the marking device ( 2 , 2 ') is also equipped with a cutting means and/or the cutting device ( 3 ) is equipped with a marking means, and the control of the system is designed such that, as an emergency operation, in the event of a failure of the cutting device ( 3 ), cutting is possible with the aid of the cutting means arranged on the marking device ( 2 , 2 ') and/or in the event of a failure of the marking device ( 2 , 2 '), marking is possible with the aid of the marking means arranged on the cutting device ( 3 ). 20. Fabric cutting system according to one of the preceding claims, characterized in that the marking device ( 2 , 2 ') has a marking head ( 20 ) which can be moved in the transverse and optionally in the feed direction of the fabric web, the position and marking activity of which can be controlled by the control of the system, which is designed in particular as a CAD-supported control, which is designed in particular as a CNC or as a DNC control. 21. Fabric cutting system according to one of the preceding claims, characterized in that the cutting device ( 3 ) has a cutting head ( 18 ) whose position and cutting activity can be controlled by the control system of the system. 22. Fabric cutting system according to one of the preceding claims, characterized in that the fabric webs are sucked onto the conveyor belt ( 5 ) by negative pressure, or that the conveyor belt ( 5 ) is designed without suction devices and is instead provided with a rough and/or adhesive coating, preferably in the form of a surface formed by a felt. 23. Fabric cutting system according to one of claims 5 to 22, characterized in that for the wrinkle-free laying out of the fabric webs, the feed of the unwinding devices ( 1 , 1 ') or optionally of the fabric tension application devices ( 10 ) is slightly smaller than the feed of the conveyor belt ( 5 ). 24. Fabric cutting system according to one of the preceding claims, characterized in that, in order to lay out the fabric web without creases, the latter is pressed against the conveyor belt ( 5 ) by a pressing device, in particular a pressing roller ( 19 ). 25. Fabric cutting machine according to one of the preceding claims, in which - instead of the known cut notches - markings ( 26 ) for the seam end or seam beginning are applied in the form of markings on the fabrics, preferably by the marking devices ( 2 , 2 '). 26. Fabric cutting system according to one of the preceding claims for cutting fabric pieces with a seam allowance extending beyond a subsequent seam, in which coded or uncoded information ( 27 ) is applied to the seam allowance. 27. Material feeding system with - at least two fabric unwinding devices ( 1 , 1 ') arranged one after the other for a fabric bale ( 7 ), - a conveyor belt ( 5 ) for transporting the unwound material, wherein the unwinding device ( 1 , 1 ') lays the fabric web directly on the conveyor belt ( 5 ) or on one or more fabric webs already laid out thereon, wherein two or more layers of fabric are laid out one on top of the other on the conveyor belt ( 5 ), and
each of the unwinding devices ( 1 , 1 ') is assigned at least one marking device ( 2 , 2 '), the marking devices ( 2 , 2 ') being arranged in such a way that they are able to apply the markings before a further layer of fabric is placed on top, and can be controlled in terms of time and location in such a way that the markings of the layers of fabric ultimately lying one above the other are congruent with one another. 28. Material feed system according to claim 27, with one or more features of claims 2 to 26.