EP3009552B1 - Method of joining two textile fabrics and quilting machine - Google Patents

Description

The invention relates to a method for joining two textile fabrics and a quilting machine, which is operated according to the method.

In the textile industry it is necessary to combine two textile fabrics, in particular fabrics. For example, jackets have a deviating from the lining outer fabric. Even with blankets or curtains, two panels are connected to meet the different requirements of the respective sides of the product. Usually there is a padding between the two textile fabrics, for example a foam. The connection of the textile fabrics is usually done by means of a thread, since in this way a comparatively flexible and robust connection is created.

By means of the thread a seam is created, which has certain puncture points. Here, the thread is guided by a needle of a quilting machine through the puncture points. The seam runs in a certain pattern, which on the one hand satisfies aesthetic requirements, and on the other hand is adapted to specific requirements, such as a certain robustness. In this case, it is necessary to position the puncture points, in particular in any corners of the pattern, comparatively accurately by means of the needle guiding the thread in order to obtain a comparatively high quality of the connected structure.

If the pattern has comparatively sharp corners, ie corners whose inner winding is smaller than 90 °, an abrupt deceleration and acceleration of the needle is required in this area in order to ensure a high machine speed. This can only be realized by means of a powerful drive technology, which is comparatively expensive. In addition, the mechanical stress of the mechanical components of the quilting machine is comparatively large, which is why with a high wear of the drive technology and further mechanics of the quilting machine must be expected. This requires a long downtime for maintenance or repair of the quilting machine.

Out DE 36 32 046 A1 For example, a method of operating a sewing machine having a sewing head with a rotary housing is known. In order to correct the stitch length error resulting from the superimposition of the movement of the rotary housing and stitch forming tools, it is provided that the rotation angle change of the rotary housing from one stitch to the next is detected from the x or y coordinates of the respective insertion points, and from this a correction signal for a drive motor, in particular for the x- or y-drive motors of the fabric holder, is formed.

In EP 0 450 369 B1 a device for moving work units along some paths is disclosed. The apparatus includes a drive that is capable of moving along an axis X and carrying a carriage along an axis Y along the drive. The apparatus further comprises support means which are connected to the carriage and carry a support platform, wherein the support means is rotatable about an axis Z. A work unit is mounted on the platform, and the support means is constituted by a frame that drops vertically and is formed by a vertical arm that extends with a plurality of parts that are bent to form a C-shaped loop the end of which forms a support for the platform, the platform being further rotatable about an axis perpendicular to the plane passing through the axes X and Y and the axis coinciding with the working axis of the working unit.

Out DE 38 19 975 A1 For example, an automatic sewing machine with a sewing head for producing a tangential course of the needle relative to the seam to be produced is known. The sewing head has a rotary housing accommodating the needle bar and a housing accommodating the gripper, which housing can be pivotally driven by an actuating shaft in an angle of rotation with the rotary housing. A device for driving the actuating shaft and a drive shaft and a device for uncoupling a drive motor from the drive shaft are provided.

In US 4,383,489 A is a sewing machine with a workpiece holder known. The workpiece holder is movable in one plane in two dimensions. Also from JP S62 277990 A is a sewing machine known.

The invention has for its object to provide a particularly suitable method for connecting two textile fabrics by means of a thread and a particularly suitable quilting machine, in which on the one hand increases a processing speed and preferably a mechanical load is reduced.

With regard to the method, this object is achieved by the features of claim 1 and with respect to the quilting machine by the features of claim 7 according to the invention. Advantageous developments and refinements are the subject of the dependent claims.

The method is used to connect two textile fabrics by means of a thread. As a textile fabric, for example, a woven fabric is used, which is woven in particular from wool, cotton or polyester threads. In particular, the two sheets are positioned one above the other, preferably in direct mechanical contact. Conveniently, the two textile fabrics are pressed against each other. For example, a third textile fabric or the like, for example a foam, is arranged between the two textile fabrics. The method provides that a first puncture point, a second puncture point and a third puncture point are determined, at which the thread is to be guided through the two textile fabrics. In this case, the thread should first be guided through the first puncture point following it through the second puncture point and in a further step through the third puncture point.

In a further step, an angle between the first and the third puncture point is determined, wherein the second puncture point forms the vertex of the angle. The angle is therefore between 0 ° and 180 °, the angle being equal to 180 °, provided that the three puncture points lie on a straight line and the second puncture point between the first and the third puncture point is arranged.

In a further working step, a contour is determined on which the three puncture points lie, wherein the second puncture point between the first and the third puncture point is arranged on the contour. To determine the contour, a spline interpolation is used, provided that the angle is less than or equal to a critical angle. For example, the critical angle is 0 ° or 180 °. In other words, the spline interpolation is always used. Here, the puncture points support points or nodes, the spline and the area between the puncture points is formed by means of at least piecewise continuous polynomials of the degree at least two. As a result, the derivation of the contour at the puncture points is continuous. In a further step, the needle is moved along the contour, whereby the thread is guided through the fabric by means of the needle at each of the puncture points.

Due to the use of spline interpolation at angles smaller than or equal to the critical angle, the derivation of the contour at the second puncture point is continuous. Thus, no abrupt change of direction and / or acceleration of the needle in the region of the second puncture point is required. Consequently, the change in the force applied to the needle or to a mechanism coupled to it, ie its respective acceleration is comparatively low, but at least reduced in comparison to an angle contour, so that the mechanical load on the needle is also reduced. As a result, the wear is reduced. In addition, only relatively small-sized drive components for the movement of the needle are required. In this way, any quilting machine carrying out the method is loaded comparatively less, so that its downtime can be reduced. In particular, the method serves the operation of a quilting machine. If the angle is greater than the critical angle, a distance is used as a contour, for example, between the first piercing point and the second piercing point. In other words, the shortest connection between the first and the second puncture point is used as a contour. Alternatively or in Combination for this purpose, a distance is used as a contour between the second and the third puncture point. If the distance is used in both cases, the needle is thus moved directly in the region of the second puncture point according to the angle.

Appropriately, 90 ° is used as a critical angle. In other words, the spline interpolation is carried out, if by means of the needle after passing the thread through the second puncture point in at least one direction a reversal of motion would have to take place to reach the third puncture point, which represents a comparatively high mechanical load.

Conveniently, a fourth and a fifth puncture point are determined. In this case, the leadership of the thread through the fourth puncture point is in time before guiding the thread through the first puncture point. After the thread has been passed through the third puncture point, the thread is passed through the fifth puncture point. In summary, the fourth and fifth puncture points are also on the contour along which the needle is moved, with the first, second and third puncture points being between the fourth and a fifth puncture points. For example, a distance is used as a contour between the fourth and the first puncture point when the angle formed between the fourth and the second puncture point, which has the first puncture point as the vertex, is greater than the critical angle. Alternatively or in combination therewith, a distance is used as the contour between the third and the fifth puncture point when the angle formed between the second and the fifth puncture point, which has the third puncture point as vertex, is greater than the critical angle.

In a further embodiment, if the angle between the first, second and third puncture point is smaller than the critical angle, the spline interpolation is used to determine the contour between the fourth and first puncture point, irrespective of the angle formed between the fourth and the second puncture point, which has the first puncture point as apex. For example, to determine the contour between the third and the fifth puncture point the spline interpolation used to determine the contour, which preferably takes place independently of the angle formed between the second and the fifth puncture point, which has the third puncture point as apex. In summary, the spline interpolation is used to determine the contour between the fourth and the fifth point, the first, second, third, fourth and fifth puncture points lying on the contour. As a result, upon movement of the needle between the fourth and fifth piercing points along the contour, the mechanical load on the needle is further reduced, even though an angle formed between the fourth and second piercing points with the first piercing point as the apex is greater than the critical angle. Thus, the transition between the region of the contour, which is comparatively gentle by means of a path and the region of the contour which is determined by means of a spline interpolation, if a distance is used to determine the contour.

For example, cubic splines are used for spline interpolation. In other words, a cubic polynomial is used as the polynomial, ie a polynomial of degree 3. In this way, the contour at the second puncture point is twice continuously differentiable, which leads to a comparatively low load on the needle in the region of the second puncture point. Also, a computational effort to create cubic splines is relatively low, which shortens the time to create the contour.

Alternatively, Bezier curves are used to create the contour. For example, square or cubic Bezier curves are used to determine the contour. In this way, the creation of the contour is likewise made possible by means of a comparatively simple calculation rule, whereby abrupt speed changes due to the continuous differentiability of the Bezier curve used as a contour are avoided during a movement of the needle along the contour.

Appropriately, the thread is entangled at each puncture point with a lower thread, suitably on only one side of the means of two textile fabrics to be formed structure is arranged. In this case, the thread is guided by the needle from the remaining side through the two fabrics through and devoured there with the lower thread. Following this, the thread is again passed through the puncture point to the original side. The bobbin thread remains on the original side of the structure. In other words, the two fabrics are quilted. In summary, by means of the method, two textile fabrics are connected by means of the thread, stepping being used as the type of connection. In particular, three, four or more fabrics are joined by the method, suitably stacked on top of each other. Preferably, the thread is passed through all the textile fabrics.

The quilting machine preferably has two winding rolls on which the textile fabrics to be joined are at least partially rolled up. In particular, the quilting machine comprises a further winding roll on which the bonded fabrics are rolled up after their connection. Conveniently, the further take-up roller speed and / or torque-controlled. In this way, the same longitudinal speed of the fabric can always be realized before winding onto the take-up reel. In addition, sagging of the pliable textile fabric is prevented due to the torque control.

Conveniently, the quilting machine comprises a needle by means of which a thread can be guided. For example, the needle has a hole in the region of a tip, within which the thread is partially arranged. Conveniently, the quilting machine comprises a holder or receptacle for a roll on which the thread is partially wound. Conveniently, the quilting machine further comprises a holder or guide for a lower thread. Conveniently, the lower thread is arranged on the opposite side of the needle of the two sheets.

For example, the quilting machine comprises a number of needles, which are preferably fastened in a composite. Here, the two needles are expediently moved synchronously. In other words, the needles are particularly preferably rigidly connected to each other, so that only a single mechanism for moving all the needles must be present. For example, the needles are mounted on a head, wherein the quilting machine expediently comprises a tracking, by means of which unwanted movements of the textile fabric are compensated perpendicular to the direction of movement. In other words, the head is tracked. In particular, each needle is associated with a thread.

During operation of the quilting machine, a first puncture point, a second puncture point and a third puncture point are determined in a first step. In a further step, an angle between the first puncture point, the second puncture point and the third puncture point is determined. Following this, a contour is determined, along which the needle of the quilting machine is moved, wherein the three puncture points are located on the contour. The thread is passed through the fabric by means of the needle when the needle is at one of the puncture points. A spline interpolation is used to determine the contour if the angle between the first, the second and the third puncture point is less than or equal to a critical angle. Appropriately, the quilting machine is operated continuously clocked.

Figur 1

schematisch vereinfacht eine Steppmaschine,

Figur 2

schematisch vereinfacht ein Verfahren zum Betrieb der Steppmaschine, und

Figur 3-5

zeitlich aufeinander folgende Stadien zweier zu verbindender textiler Flächengebilde in einer Draufsicht.

An exemplary embodiment of the invention is explained in more detail below with reference to a drawing:

FIG. 1

schematically simplifies a quilting machine,

FIG. 2

schematically simplifies a method for operating the quilting machine, and

Figure 3-5

temporally successive stages of two textile fabrics to be joined in a plan view.

Corresponding parts are provided in all figures with the same reference numerals.

In FIG. 1 schematically simplified a quilting machine 2 is shown in a side view. The quilting machine 2 has a first unwinding roll 4, on which a first textile fabric 6 is wound up. The first textile fabric here is an outer fabric. The quilting machine 2 also has a second unwinding roll 8, on which a second textile fabric 10 is wound up. The second textile fabric is an under fabric. The quilting machine 2 further comprises a third unwinding roll 12, on which a lining material 14 is wound up. The outer fabric 6, the lower fabric 10 and the lining material 14 are connected to a blanket 16, which is wound onto a take-up reel 18. Here, the outer fabric 6, the lower fabric 10 and de lining material 14 of the winding rollers 4, 8, 12 are unrolled and rolled up as a blanket 16 on the take-up reel 18. The winding roller 18 is torque and speed controlled, so that on the one hand the pliable ceiling 16 does not sag and on the other hand, the ceiling 16 has a constant transverse velocity, even with increasing radius of the take-up roller 18th

The compound of the outer fabric 6, the lower fabric 10 and the lining material 14 by means of a thread 20 which is wound on a first spindle 22. The thread 20 is guided by means of a needle 24 through the outer fabric 6, the lining material 14 and the lower fabric 10. There, the thread 20 is devoured with a lower thread 26 which is wound on a second spindle 28 which is positioned on the opposite side of the first spindle 22 of the fabrics 6, 10, 14 and the ceiling 16. After entanglement of the thread 20 with the lower thread 26, the thread 20 is again guided by means of the needle 24 to the side of the first spindle 22. In other words, the fabrics 6, 10, 14 are quilted by means of the thread 20. The needle 24 is connected to a needle head 30 which is controlled by means not shown electrical drives. In this case, the control of the electric drives is realized by means of a control unit 32, which is a in FIG. 2 illustrated method 34 executes.

After the start 36 of the method 34, a desired seam 40 is determined in a first operation 38, by means of which the outer fabric 6, the lower fabric 8 and the lining material 14 are to be connected to each other. In the FIG. 3 in a The plan view of a desired seam 40 shown in section has a repeating pattern 42 in the form of a V. A first puncture point 44, a second puncture point 46, a third puncture point 48, a fourth puncture point 50, a fifth puncture point 52, a sixth puncture point 54 and a seventh puncture point 26 are determined which lie on the desired seam 40. Here are the first, third, fourth and sixth puncture point 44, 46, 50, 54 on a first straight line 58 and the second, third, fifth and seventh puncture point 46, 48, 52, 56 on another straight line 60. The two straight lines 58, 60 intersect at the second puncture point 46.

In a second step 62, an angle α between the first piercing point 44 and the third piercing point 48 is determined, wherein the second piercing point 46 forms the apex. In other words, the intersection angle between the first straight line 58 and the second straight line 60 is determined. The angle α is compared with a critical angle β, which is 90 °. If the angle α is smaller than the critical angle β, in a third step 64 to the first, second and third puncture point 44, 46, 48, the fourth and fifth puncture point 50, 52 is used and in a fourth step 66 a puncture point 44, 46, 48, 50, 52 connecting contour 68 determined by spline interpolation, the in FIG. 4a is shown. The splines used are in each case a cubic spline, ie in each case a third degree polynomial between the respective piercing points 44, 46, 48, 50, 52, so that the contour 68 can be continuously differentiated at each of the piercing points 44, 46, 48, 50, 52.

Alternatively, Bezier curves are used to create the contour 68. As a result, the contour 68 is substantially continuously curved and does not have an acute angle. In other words, the contour 68 deviates comparatively strongly from the desired seam 40 in the region of the second puncture point 46. In a further alternative, in the fourth step 66 between the fourth puncture point 50 and the first puncture point 44 and between the third puncture point 48 and the fifth puncture point 52, a distance is used as a contour 68, whereas between the first, second and third puncture point 44, 46, 48, the contour 68 is determined by spline interpolation, as in FIG FIG. 4b shown.

If the angle α formed between the puncture points is greater than the critical angle β, a fifth operation 70 is carried out in which the individual puncture points are connected by means of a straight line. This is for example given between the fourth puncture point 50 and the sixth puncture point 54 and further puncture points along the first straight line 58 and between the fifth puncture point and the seventh puncture point 56 and further puncture points, which lie on the second straight line 60.

In a subsequent to the creation of the contour 68 sixth step 72, the needle 24 is moved by means of the needle head 30 along the contour 68. Here, the needle 54 and thus also the thread 20 is first moved through the sixth insertion point 54. As a result, the thread 20 is on the side of the second spindle 28. There, the thread 20 is entangled with the lower thread 26 and the thread 20 again passed through the sixth piercing point 54. Following this, the needle is moved to the fourth puncture point 50 along the contour 68 and the thread 20 is also guided there through the puncture point 50 and engulfed with the lower thread 26. After the entanglement, the thread 20 is passed through the fourth puncture point 50 again. Following this, the needle is further moved along the contour 68, wherein the needle 24 is first passed through the first puncture point 44, then through the third puncture point 46, then through the fifth puncture point 52 and then through the seventh puncture point 56. At each of the puncture points 44, 46, 52, 56 of the thread 20 is engulfed with the lower thread 26.
Due to the guidance along the contour 68, a comparatively small force is applied to the needle 24. However, at least the force is reduced along the desired seam 40 as compared to guiding the needle 24 and thus guiding it at the second piercing point 46 along the angle α.

In a sixth step 74, the thread 20 is tightened, so that by means of the thread 20, a seam 76 is created, which corresponds to the desired seam 40. In other words, the seam 76 has the angle α in the region of the second puncture point 46. As a result of the tightening of the thread 20, the outer fabric 6, the lower fabric 10 and the lining material 17 are firmly connected to each other and the blanket 16 is created, which is then wound onto the take-up reel 18.

Following this, the pattern 42 for joining the fabrics 6, 10, 14 by means of the thread 20 and the seam 76 created therefrom is again created, which is to be introduced into further regions of the fabrics 6, 10, 14. The tensioning of the thread 20 can alternatively take place, for example, in the sixth working step 72, ie already when guiding the needle 24 through the puncture points 44, 46, 48, 50, 52, 54, 56. The method 34 is ended by means of an end event 78. This is either a removal of the created blanket 16 from the quilting machine 2 or the use of another pattern 42, which is for example circular or the like.

The invention is not limited to the embodiment described above. Rather, other variants of the invention can be derived therefrom by the person skilled in the art without departing from the subject matter of the invention. In particular, all the individual features described in connection with the exemplary embodiment can also be combined with one another in other ways, without departing from the subject matter of the invention.

LIST OF REFERENCE NUMBERS

2

quilting machine

4

first unwinding roll

6

first textile fabric

8th

second unwinding roll

10

second textile fabric

12

third unwinding roll

14

lining

16

blanket

18

up roll

20

thread

22

first spindle

24

needle

26

lower thread

28

second spindle

30

pinhead

32

control unit

34

method

36

begin

38

first step

40

desired seam

42

template

44

first puncture point

46

second puncture point

48

third puncture point

50

fourth puncture point

52

fifth puncture point

54

sixth puncture point

56

seventh puncture point

58

first straight

60

second straight line

62

second step

64

third step

66

fourth step

68

contour

70

fifth step

72

sixth step

74

seventh step

76

seam

78

The End

α

angle

β

critical angle

Claims (7)

1. Method (34) for connecting two textile fabrics (6, 10) by means of a thread (20), in which

   - a first insertion point (44), a second insertion point (46) and a third insertion point (48) are determined,

   - an angle (α) between the first insertion point (44), the second insertion point (46) and the third insertion point (48) is determined,

   - a contour (68) is determined which has the three insertion points (44, 46, 48)

   - a needle (24) is moved along the contour (68), and

   - the thread (20) is guided through the fabrics (6, 10) at each of the insertion points (44, 46, 48) by means of the needle (24),

   characterised in that
   a spline interpolation is used to determine the contour (68) at an angle (α) smaller than or equal to a critical angle (β).
2. Method (34) according to claim 1,
   characterised in that
   at an angle (α) greater than the critical angle (β) between the first insertion point (44) and the second insertion point (46) and/or between the second insertion point (46) and the third insertion point (48), a route is used as a contour (68).
3. Method (34) according to one of claims 1 or 2,
   characterised in that
   90° is used as the critical angle (β).
4. Method (34) according to one of claims 1 to 3,
   characterised in that
   a fourth insertion point (50) and a fifth insertion point (52) are determined, wherein the first insertion point (44) between the fourth insertion point (50) and the second insertion point (46), and the third insertion point (48) between the second insertion point (46) and the fifth insertion point (52), lies on the contour (68), and wherein at an angle (α) smaller than the critical angle (β) between the fourth insertion point (50) and the first insertion point (44) and between the third insertion point (48) and the fifth insertion point (52), the spline interpolation is used to determine the contour (68).
5. Method (34) according to one of claims 1 to 4,
   characterised in that
   interpolation takes place by means of cubic splines or Bezier curves.
6. Method (34) according to one of claims 1 to 5,
   characterised in that
   the thread (20) is entwined with a lower thread (26) at each insertion point (44, 46, 48).
7. Quilting machine (2) having a needle (24) attached to a needle head (30) and having a control unit (32) for carrying out a method (34) according to one of claims 1 to 6.

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