ES2886878T3 - Improved binding machine and related method - Google Patents

Abstract

Lacing machine (4), comprising: - a fixed unit comprising a support frame, - and a mobile unit (100) comprising: - a device (16) for supplying a fabric (12) along a longitudinal direction (Y-Y), the supply device (16) comprising means (28) for locking the fabric (12), configured to keep the fabric (12) pressed in the supply device (16), - a device ( 20) for positioning a needle (10) along a transverse direction (X-X), perpendicular to said longitudinal direction (Y-Y) and coplanar with the fabric (12), - a device (24) for actuating said needle ( 10) along a vertical direction (Z-Z), perpendicular to said longitudinal (Y-Y) and transversal (X-X) directions, to perform the link, in which - the machine (4) comprises a camera (103) capable of identifying a guide thread (40) arranged on at least one fabric (12) to be sewn, said guide thread (40) being inserted inside the fabric (12), thereby entering and exiting the fabric (12 ), to form a plurality of segments (44), - the machine (4) comprises a processing and control unit (56), operatively connected to the chamber (103) and to the actuators of the fabric supply device (16). (12), of the needle (10) positioning device (20) and of the needle (10) drive device (24), - for determining in real time a target sewing position of the needle (10) depending on the guide thread (40) and control in real time the fabric supply device (16) (12), the needle positioning device (20) (10) and the needle drive device (24) needle (10) to reach said target sewing position of the needle (10), wherein the linking machine (4) is equipped with an ultraviolet light illumination system (52), to highlight said thread (40) guide, said guide thread (40) being phosphorescent, characterized in that said ultraviolet light illumination system (52) is placed in the means (28) for blocking the fabric (12).

Description

DESCRIPTION

Improved binding machine and related method

Scope

The present invention relates to an improved binding machine and related binding method.

prior art

As is known, binding is a processing technique used in the textile field that consists of joining two pieces of fabric. For example, it is used to join collars, cuffs and sleeves to the rest of the garment, in order to make the finished product. The union of the flaps is made by picking up stitch by stitch both ends of the fabrics. The joining thread is "woven" between the terminal row of the two flaps, thus obtaining the continuity of the stitch. The joint made in this way is very flat and really imperceptible.

The link operation seems to be a process with important limitations:

- it is slow and expensive; in this sense, it is estimated that it takes more than 70% of the production time of a garment;

- the current bonding machine is not flexible, in fact, when the fineness of the fabric changes, it requires a different configuration and therefore a configuration time that limits its productivity;

- the link operator needs a lot of experience and skills to be able to minimize errors and acquire a certain speed, skills that he acquires after several months of practice,

- one of the main problems encountered by those who work in this sector is excessive visual fatigue due to the way in which the connection is made; such tension, if prolonged over time, can lead to a progressive reduction in the operator's vision.

For these reasons, having a link machine capable of autonomously identifying where to make the stitches, in addition to being an advantage in terms of speed, cost and precision of execution, improves the working conditions of those who use the machine, making the less heavy task and avoiding occupational accidents.

Figure 1 shows a traditional binding machine. It is a circular machine where the operator must insert the stitches from the ends of the two fabrics into the ends. Thereafter, the machine makes the link stitches on the previously positioned stitches.

There are also examples in the art of automatic or semi-automatic type bonding machines which aim to at least partially solve the aforementioned problems of the manual type machine.

However, these machines are not free of problems that prevent or limit their correct operation.

For example, the algorithm of these known binding machines represents a major limitation as it calculates an average between the distances of the holes where the needle must sew the seam and then controls the motors/actuators to move the needle with a fixed step along the seam. along the seam line. This solution is not very functional since the distance between the stitches is very variable in a fabric. For example, one of the main causes of variation in the distance between the holes is the intensity with which the fabric is held during its advance. With this choice of control, you get the loss of the correct sewing pitch at any sewing speed, causing various errors.

Furthermore, the mechanics of the known machine have great limitations in the choice of components that limit its maximum speed to a maximum of 400 stitches per minute. These limits are due, for example, to the following factors:

- the use of motors that are not very versatile in terms of the number and type of parameters that can be modified to carry out the movement. In particular, it is not possible to change the gains of the PID controllers.

Furthermore, it is not possible to assign the position, velocity and acceleration profiles adopted by the motors as desired. Regarding diagnostics, it is not possible to control which are the position references and the real positions that the motors assume during a movement: this limit is the cause of more inaccuracies in the sewing points;

- the only parameters that can be modified are the maximum acceleration and speed used to make the trajectories. The lack of versatility of these engines in path planning must be considered one of the most critical points to achieve high-performance automation;

- there is also the problem of excessive elasticity and looseness of the transmission system connected to the motor responsible for advancing the fabric. The movement of the fabric must take place in a very short time (about 20 ms), the presence of elasticity (for example due to the used belts) causes a delay in the movement of the fabric with respect to the movement of the motor, avoidable by limiting the acceleration of the motor and therefore the time of movement of the fabric. This limits the maximum speed of the entire link operation;

- the high inertia of the mobile unit, to carry out the horizontal movement of the pointer in a few milliseconds, forces the motor to always work, delivering the maximum available torque, limiting the minimum movement time to a minimum value, not reducible, and therefore limiting the maximum speed of the operation;

- Another critical element identified in the movement of the moving part is the choice of the roller screw connected to the motor. In fact, it has a rather unfavorable gear ratio since the entire travel stroke of the mobile unit is done with less than one full revolution of the motor. This entails the need to exert a high torque by the motor to perform the movement quickly. A known solution, according to the preamble of current claim 1, is described in EP 0971061 A1.

Disclosure of the invention

Therefore, the need is felt to overcome the drawbacks and limitations mentioned with reference to the prior art.

The invention allows to overcome all the technical problems and the mechanical and software limitations, both of the manual and automatic linking machine used to date.

The need to overcome the drawbacks and limitations of prior art solutions is met by a linking machine according to claim 1 and by a linking method according to claim 8.

Description of the drawings

Other characteristics and advantages of the present invention will appear more clearly from the following description of non-limiting preferred embodiments thereof, in which:

figure 1 shows a view of a manual linking machine, of the traditional type;

figure 2 shows a perspective view of a binding machine according to the present invention; figure 3 shows a perspective view of a detail of a linking machine according to the present invention;

Figures 4-5 are schematic views of the operation of a binding machine according to the present invention;

figure 6 shows a perspective view of a particular plate of the link machine;

Figure 7 shows a schematic view of the operation of a linking machine according to the present invention.

Elements or parts of elements in common with the embodiments described below are designated by the same reference numerals.

Detailed description

With reference to the above figures, the reference numeral 4 globally indicates a general schematic view of a binding machine according to the present invention.

The linking machine 4 comprises a fixed unit comprising a support frame and a mobile unit 100, supported by said fixed unit, in order to suitably move and actuate a needle 10 for the linking operation on the fabric 12.

The mobile unit 100 comprises a device 16 for supplying the fabric 12 along a longitudinal direction or axis YY, a device 20 for positioning the needle 10 along a transverse direction or axis XX, perpendicular to said longitudinal direction or YY axis and coplanar with the fabric 12, and a device 24 for actuating said needle 10 along a vertical direction or ZZ axis, perpendicular to said longitudinal YY and transversal XX directions, to perform the link .

The fabric 12 supply device 16 comprises fabric 12 locking means 28 configured to hold the fabric 12 pressed onto the fabric 12 supply device 16.

According to a possible embodiment, said means 28 for blocking the fabric 12 comprise an articulated foot 36 with two rotations capable of uniformly pressing the fabric 12, even in the presence of non-uniform thicknesses of the fabric.

Preferably, said locking means 28 is adjustable to adjust the pressure 36 of the foot on said fabric 12. The fabric supply device 16 or fabric 12 comprises an electric motor 30.

The device 20 for positioning the needle 10 comprises an electric motor 30 connected to a recirculating roller or ball screw 101, in turn connected to a mobile unit 100 that carries out the linear translation of the needle along the direction transverse XX.

The drive device 24 of the needle 10 comprises an electric motor 30 connected to the needle 10 with a connecting rod-crank mechanism to perform the reciprocating sewing movement of the needle 10.

Preferably, the needle 10 passes through a particular plate 38 with a hole 39 for the needle 10 which limits its deformation and ensures a better seam.

Fabric 12 is provided with a guide wire 40 inserted within fabric 12 to identify a plurality of segments 44.

The guide wire 40 is made of a phosphorescent material, so that it can be easily identified by a suitable optical system or a camera 103. For this, the linking machine 4 is provided with a neon ultraviolet light illumination system 52, to highlighting said phosphorescent guide wire 40 .

According to the invention, said ultraviolet light illumination system 52 is mounted on the blocking means 28 of the fabric 12.

Preferably, said guide thread 40 is made of a water-soluble material, so that it can be dissolved in the subsequent washing of the fabric, without having to be removed manually.

The linking machine 4 comprises a camera 103 suitable for identifying the guide wire 40 . The linking machine 4 is further provided with a processing and control unit 56, operatively connected to the camera 103 and to the actuators/electric motor means of the fabric 12 supply device 16, of the needle 10 positioning device 20 and of the drive device 24 of the needle 10.

In this way, the processing and control unit 56 is able to determine in real time the destination position of the needle 10 depending on the guide thread 40 and to control in real time the devices 16 for supplying the fabric 12, the devices 20 of the needle positioning 10 and the actuating devices 24 of the needle 10 to reach said destination sewing position of the needle 10.

In particular, the fabric 12 supply device 16 and/or the needle 10 positioning device 20 and/or the needle 10 drive device 24 comprise the respective electric motors 30 with feedback in real time by said unit 56 processing and control, depending on the destination sewing position of the needle 10.

The option and/or implies that at least one of the fabric 12 supply device 16, the needle 10 positioning device 20 and the needle 10 driving device 24 comprises respective real-time feed-back electric motors 30 ; preferably at least two of said devices 16, 20, 24 comprise respective real-time feed-back electric motors 30 and, even more preferably, all of said devices 16, 20, 24 comprise respective real-time feed-back electric motors 30.

According to a possible embodiment, the processing and control unit 56 is programmed so that said electric motors 30 are controlled at a variable step in real time depending on the destination sewing position of the needle 10.

Next, the operation of the binding machine according to the present invention will be described.

As mentioned, the binding machine according to the present invention is capable of performing the binding operation in a particularly efficient manner.

In particular, the method of joining a fabric 12 comprises the steps of:

- providing a fabric 12 on which to make the link, said fabric 12 being provided with a fluorescent guide thread 40 that enters and exits the fabric 12 forming segments 44,

- acquisition of an image of the fabric 12 by means of a camera 103, to identify the position of said segments 44,

- calculating the primary centroids 104 representing the midpoint of the areas of the segments 44 of the guide wire 40; said primary centroids 104 allow to identify the destination sewing position of the calculated loop or stitches 60 by searching for the intermediate position between the primary centroids 104;

- elimination of the secondary centroids 68 that cause errors in the identification of the correct stitching point, adjacent to the segments 44;

- execution of link stitching at the calculated points of the target stitches 64 .

The step of performing the sewing provides for the calculation, in real time, of the sewing target position of the needle 10 depending on the guide thread 40, the real time actuation of the supply devices 16 of the fabric 12, the devices 20 for positioning the needle 10 and the actuating devices 24 for the needle 10 to reach said target sewing position of the needle 10.

The secondary centroid exclusion step 68 comprises the step of eliminating secondary centroids 68 positioned to the left, with respect to the transverse direction XX, and at the same height, along the vertical direction ZZ, of the primary centroids 104 of the segments 44 of the guide wire 40.

Preferably, the link method also provides the step of removing segments 44 that have an area smaller than a predetermined threshold value.

After identifying the primary centroids 104 of the segments 44, they are interpolated by an interpolation line.

In addition, to determine the next stitching or linking point, two consecutive segments 44', 44" are identified by the camera 103: the longitudinal coordinate of the stitching point corresponds to the average of the longitudinal coordinates of the centroids 104 of the thread 40 of guide and the transverse coordinate of the sewing point is along that interpolation line.

As can be seen from the description, the present invention enables the drawbacks of the prior art to be overcome.

In fact, the linking machine of the present invention is an automatic machine completely innovative in the way it works with respect to a known manual linking machine.

In particular, as described, this machine, due to a special vision system, is able to identify the stitches independently, calculate in real time the linking step to be made and then position the needle at these points following the indications of a particular control algorithm. In fact, the needle can move in all directions on the fabric, going to center the stitch that the camera captures in real time.

The solution of the present invention allows modernizing the link operation, solving the limits of current technology, increasing productivity, improving the quality of processed fabrics, reducing processing costs and improving the working conditions of the workers involved in the process. link.

In fact, the lacing machine can be used by an unskilled operator who simply has to place the fabric on the needle bed and operate the lacing machine with a knob. Therefore, the ease of use means that staff training time is almost zero.

Furthermore, the binding machine of the present invention is flexible; it does not require any changes in the settings to change the fineness of the fabric, since it automatically calculates the pitch, between one stitch and the next, in real time mode.

The processing speed is much higher than that of a manual binding machine; it can easily exceed a speed of 700 stitches per minute.

The quality of work no longer depends on a person, but is guaranteed by the reliability of a computer.

The link operation is much less expensive and simpler to execute, while increasing productivity and reducing processing times.

All issues related to operator health due to manual binding are fixed.

In short, the motors are no longer controlled with a fixed step, as in known automatic solutions, but instead receive instructions in real time from which the next movement is made with feedback control. The mechanics are simplified to exceed all speed limits caused by the technical choices of known automatic solutions, to reach and exceed even 700 PPM and more. The needle can move in all directions on the fabric going to center the stitch that the camera captures in real time.

Various changes and adjustments to the binding machine and binding methods described above can be made by one skilled in the art to meet specific and incidental needs.

Claims (13)

1. - Link machine (4), comprising: - a fixed unit comprising a support frame, - and a mobile unit (100) comprising: - a device (16) for supplying a fabric (12) along a longitudinal direction (YY), the supply device (16) comprising means (28) for blocking the fabric (12), configured to maintain the fabric (12) pressed into the supply device (16), - a device (20) for positioning a needle (10) along a transverse direction (X-X), perpendicular to said longitudinal direction (Y-Y) and coplanar with the fabric (12), - a device (24) for actuating said needle (10) along a vertical direction (Z-Z), perpendicular to said longitudinal (Y-Y) and transversal (X-X) directions, to perform the link, in which - the machine (4) comprises a camera (103) suitable for identifying a guide thread (40) arranged on at least one fabric (12) to be sewn, said guide thread (40) being inserted inside the fabric (12), thereby entering and exiting the fabric (12), to form a plurality of segments (44), - the machine (4) comprises a processing and control unit (56), operatively connected to the camera (103) and to the actuators of the device (16) for supplying the fabric (12), of the device (20) for positioning the needle (10) and the device (24) for activating the needle (10), - to determine in real time a target sewing position of the needle (10) depending on the guide thread (40) and to control in real time the device (16) for supplying the fabric (12), the device (20) positioning of the needle (10) and the device (24) driving the needle (10) to reach said destination sewing position of the needle (10), wherein the bonding machine (4) is equipped with an ultraviolet light illumination system (52) to highlight said guidewire (40), said guidewire (40) being phosphorescent, characterized in that said system (52 ) of ultraviolet light illumination is placed on the blocking means (28) of the fabric (12). 2. - Linking machine (4) according to claim 1, wherein the device (16) for supplying the fabric (12) and/or the device (20) for positioning the needle (10) and/or the needle (10) actuation device (24) comprises the respective electric motors (30) with feedback in real time by said processing and control unit (56), depending on the destination sewing position of the needle (10). ). 3. - Link machine (4) according to claim 2, wherein the processing and control unit (56) is programmed so that said electric motors (30) are controlled at a variable pace in real time depending on the needle destination sewing position (10). 4. - Link machine (4) according to any of the preceding claims, in which the fixed unit supports the devices (16, 20, 24) of the mobile unit (100). 5. - Linking machine (4) according to any of the preceding claims, in which the means (28) for blocking the fabric (12) are configured to keep the fabric (12) pressed against a plate (32) of support, in which said means (28) for blocking the fabric (12) comprise a foot (36) articulated with two rotations capable of uniformly pressing the fabric (12), even in the presence of non-uniform thicknesses of the fabric ( 12). 6. - Machine (4) link according to any of the preceding claims, wherein the device (20) for positioning the needle (10) comprises an electric motor (30) connected to a roller spindle or spindle ( 101) of recirculation balls, in turn connected to said mobile unit (100) that carries out the linear translation of the needle (10) along the transverse direction (XX). 7. - Machine (4) link according to any of the preceding claims, in which the needle (10) passes through a plate (38) provided with a hole (39) that limits its deformation and ensures a better seam. 8. - Method of joining a fabric (12) comprising the steps of: - providing a binding machine (4) according to any of claims 1 to 7, - providing a fabric (12) on which to make the link, said fabric (12) being provided with a fluorescent guide thread (40) that enters and exits the fabric (12) forming segments (44), - acquisition of an image of the fabric (12) by means of a camera (103), to identify the position of said segments (44), - calculation of the primary centroids (104) of the segments (44) of the guide wire (40), and of the areas of said segments (44), - identification of the destination sewing points (60) of the stitches (64) to be linked, as a midpoint between the primary centroids (104), - elimination of the secondary centroids (68) that should not be considered, adjacent to the primary centroids (104), - making the link seam at the destination sewing points (60) of the destination stitches (64). 9. - Method of linking a fabric (12) according to claim 8, wherein the step of performing the sewing provides the calculation, in real time, of the destination sewing position of the needle (10) depending of the guide thread (40), the real-time actuation of the fabric (12) supply devices (16), the needle (10) positioning devices (20) and the needle (10) actuation devices (24). the needle (10) to reach said destination sewing position of the needle (10). 10. - Method of linking a fabric (12) according to claim 8 or 9, wherein the step of exclusion of the secondary centroids (68) comprises the step of elimination of the secondary centroids (68) positioned to the left, with respect to a transverse direction (XX), and at the same height, along a vertical direction (ZZ), of the centroids (104) of the segments (44), said step providing the calculation of a line of interpolating all the primary centroids (104) and verifying the position of the secondary centroids (68) on said interpolation line. 11. - Method of linking a fabric (12) according to claim 8, 9 or 10, wherein a step of removing segments (44) having an area less than a predetermined threshold value is provided. 12. - Method of linking a fabric (12) according to claim 8, 9, 10 or 11, in which, having identified the primary centroids (104) of the segments (44), they are interpolated by means of a interpolation line. 13. - Method of linking a fabric (12) according to claim 12, wherein during linking, to determine the next stitching or linking point, two consecutive segments (44', 44'') are identified by the chamber (103), and in which a longitudinal coordinate of the stitching point corresponds to the average of the longitudinal coordinates of the primary centroids (104) of the consecutive segments (44', 44"), of the thread (40) of guide, and the transverse coordinate of the sewing point is along that interpolation line.