Machinery for handling limp materials, especially woven articles.

Abstract

The present invention relates to a machine (1) for handling a limp material (3), the machine (1) comprising at least first and second gripping devices (10) adapted to simultaneously grip the same piece of the limp material (3), at least one of the gripping devices (10) being connected to a drive system (5) adapted to displace the gripping devices (10) relative to each other, one of the gripping devices (10) being a manipulator (10) having a displacement mechanism (20) adapted to actively displace the limp material (3) in a direction generally in a plane in which the limp material (3) is held in the manipulator (10), the machine (1) further comprising at least one sensor (30) adapted to detect the limp material (3) and / or an area of ​​interest.

Description

Technical Field

[0001] The present invention relates to a machine for handling limp materials, the machine including at least first and second gripping devices adapted to simultaneously grip the same piece of limp material.

Background Art

[0002] A problem associated with handling limp materials such as textile articles is that the limp material does not have a defined shape. As a simple example, a tablecloth can have a spread rectangular shape or can exist in the form of a much smaller, wrinkled bundle. Attempts to handle limp materials in an automated way require either shaping the limp material into a predetermined shape or at least clearly identifying specific points of the limp material such as edges.

[0003] The term "limp material" as used herein refers to textile articles, particularly products for human daily necessities such as clothing, and industrial products such as panels, covers or fiber mats. It further includes paper, sheets of foil material, and knitted fabrics. These examples are not exhaustive.

[0004] An example of a machine for handling limp materials can be found in International Publication No. 2021 / 001039. The machine includes two grippers that engage a textile article at two points spaced apart from each other. The grippers can shape the textile article into a predetermined shape for further processing.

Summary of the Invention

Problems to be Solved by the Invention

[0005] The object of the present invention is to improve the handling ability of a machine used for handling limp materials.

Means for Solving the Problems

[0006] To achieve this objective, the present invention provides a machine for handling limp material, the machine comprising at least first and second gripping devices adapted to simultaneously grip the same piece of limp material, at least one of the gripping devices being connected to a drive system adapted to displace the gripping devices relative to each other, one of the gripping devices being a manipulator having a displacement mechanism adapted to actively displace the limp material in a direction generally within the plane in which the limp material is held within the manipulator, the machine further comprising at least one sensor adapted to detect the limp material and / or a region of interest of the limp material. The present invention is based on the idea of ​​adding additional functionality to a gripper known from the prior art. In the prior art, when sufficient traction force is applied to the limp material, the gripper can slide the limp material it engages with within the gripper. The displacement mechanism provided in the manipulator according to the present invention makes it possible to control the sliding motion of the limp material within the manipulator. In particular, the displacement mechanism makes it possible to actively move the textile article relative to the manipulator. Thus, it is possible to slide the limp material to a specific position relative to the manipulator. In improved embodiments, the manipulator can be made to follow the non-linear contour of the limp material to reach a location or specific point of the limp material that is beneficial for subsequent handling.

[0007] Preferably, the manipulator includes a base and a pressing part that are displaceable from each other, with the displacement mechanism provided in the base. The displaceability of the base and the pressing part allows the limp material to be loaded into the manipulator and clamped into the manipulator with a predetermined and / or controllable force. The base and the pressing part may also be displaceable from each other by a predetermined and / or controllable distance. This eliminates the need for force measurement.

[0008] In a preferred embodiment, the displacement mechanism includes at least one displacement wheel positioned to engage with the limp material. The wheel is particularly well suited to generating a sliding motion of the limp material relative to the base, to a degree of sliding motion that is easily controllable by the amount of rotation of the wheel.

[0009] In a particularly simple embodiment, the displacement wheel is an omniwheel. The omniwheel allows the limp material to slide tangentially against the base while simultaneously allowing low-friction displacement in a direction parallel to the rotation axis of the omniwheel.

[0010] To increase friction between the wheel and the limp material, guide grooves related to the displacement wheel can be provided in the pressing portion.

[0011] In one embodiment of the present invention, a accommodating space is provided between the base and the pressing portion, the accommodating space is adapted to receive the edge of the limp material, and a sensor is positioned to detect the position of the edge within the accommodating space. Assuming that it is possible to place the limp material having an edge within the accommodating space, the position of the edge within the accommodating space is particularly suitable for controlling the sliding displacement of the limp material by the wheel.

[0012] The sensor can be formed from separate sensing elements positioned spaced apart from each other. The distance between the individual sensing elements can be considered as the acceptable range in which the edge of the limp material should be located. The separate sensing elements enable detection of whether or not the edge is between the sensing elements. Otherwise, the limp material can be slid inward or outward by appropriately rotating a displacement wheel until the edge returns to the desired position.

[0013] One embodiment of the present invention provides a pair of displacement wheels. By using a pair of displacement wheels, better control of the displacement of the limp material relative to the manipulator is possible.

[0014] The pressing section may include a pair of pressing wheels and pressing elements, which are independently movable relative to the displacement wheels, particularly in a direction perpendicular to the plane between the displacement wheels where the limp material is held. The force that clamps the limp material between the displacement wheels and the pressing wheels can be controlled by the displacement of the pressing wheels. Furthermore, the pressing wheels and pressing elements can be retracted to allow loading and unloading of the limp material.

[0015] In one embodiment, the base can rotate around an axis perpendicular to the rotation axis of the displacement wheel. By rotating the base, it is possible to align the direction in which the limp material is displaced relative to the base with the direction in which the contour or edge of the limp material extends.

[0016] Preferably, the sensor is configured to detect the presence of limp material within a detection area extending circumferentially around the base, thereby providing the information necessary to slide the limp material relative to the base in a desired direction.

[0017] Preferably, the sensor is formed from a plurality of separate sensing elements arranged circumferentially around the base. The sensor does not need to continuously monitor the area around the base. Rather, it is sufficient to obtain information on which sectors of the circumference contain the limp material and which do not.

[0018] The sensor can also be formed from a camera system associated with an image recognition system adapted to evaluate the information provided by the camera and extract the location of the limp material from it.

[0019] Instead of using wheels to achieve the displacement of the limp material, any other element suitable for sliding the limp material against a base can be used. Examples include belts, translationally movable pusher elements, and reciprocating yaws.

[0020] In one embodiment, the machine has two manipulators with at least one displacement wheel. The use of two manipulators makes it possible to process limp materials having a more complex outer shape and to displace the limp material relative to the manipulators so as to reach a predetermined point of the limp material.

[0021] In one embodiment, the drive system includes a linear drive to which a gripping device is attached, and the linear drive is adapted to displace the gripping device from a loading position where the gripping devices are close to each other to a position where the gripping devices are spaced apart from each other, and vice versa. The linear drive is a mechanically simple and reliable system for obtaining the desired displacement of the gripping devices relative to each other.

[0022] In an alternative embodiment, the drive system includes two robotic arms, each provided with one gripping device, and the robotic arms are adapted to displace the gripping devices from a loading position where they are close to each other to a remote position where they are spaced apart from each other, and vice versa. The robotic arms assist the gripping devices when processing limp materials having a more complex contour, particularly a contour consisting not only of several straight portions.

Brief Description of the Drawings

[0023] Next, the present invention will be described with reference to the embodiments shown in the accompanying drawings. In the drawings,

[0024] [Figure 1] FIG. shows a first embodiment of a machine having two gripping devices in a loading position. [Figure 2] FIG. shows the machine of FIG. 1 with the two gripping devices in a spaced-apart position. [Figure 3] FIG. shows a second embodiment of a machine according to the present invention with the two gripping devices in a loading position. [Figure 4] FIG. shows the machine of FIG. 3 with the gripping devices in a spaced-apart position. [Figure 5] FIG. is a schematic cross-sectional view of a manipulator according to the first embodiment. [Figure 6] It is a perspective view of the manipulator of FIG. 5. [Figure 7] It is a side view of the manipulator according to the second embodiment. [Figure 8] It is a perspective view of the manipulator of FIG. 7. [Figure 9] It is a second perspective view of the manipulator of FIG. 7 where the manipulator is in the first working position. [Figure 10] It is a view showing the manipulator of FIG. 7 in the second working position. [Figure 11] It is a schematic top view of the base of the manipulator of FIG. 7. [Figure 12] It is a view schematically showing the machine according to the third embodiment in two different positions.

Embodiments for Carrying Out the Invention

[0025] In FIGS. 1 and 2, a machine 1 for handling a limp material 3 is schematically shown. As an example, the limp material is, hereinafter, a textile article. It should be noted that the present invention is applicable to all kinds of limp materials.

[0026] The machine 1 includes two gripping devices 10, and each gripping device is adapted to receive and hold the textile article 3 currently being handled.

[0027] The two gripping devices 10 are attached to a drive system 5 that can displace the gripping devices 10 relative to each other. As can be seen by comparing FIGS. 1 and 2, the drive system 5 can displace the gripping devices 10 from the loading position shown in FIG. 1 where the gripping devices 10 are arranged close to or in contact with each other to the position shown in FIG. 2 where the gripping devices 10 are separated from each other.

[0028] The drive system 5 can be a linear drive system that allows the two gripping devices to be displaced away from each other in the direction of arrow A, and vice versa. Of course, it is also possible to position the gripping devices stationary and displace only the other gripping device 10.

[0029] At the mounting position, the woven article 3 is attached to the gripping device 10. By displacing the gripping devices 10 so that they are separated from each other, the edges of the woven article 3, which are received within the gripping devices 10, slide through the gripping devices, causing the woven article to be stretched and tension applied.

[0030] Figures 3 and 4 show a second embodiment of the machine 1 for handling the textile article 3.

[0031] The difference between the first embodiment and the second embodiment is that in the second embodiment, a robot arm 7 is used as a drive system to move the gripping devices 10 together.

[0032] In a modified version of the second embodiment, one stationary gripping device 10 is used, and only the second gripping device 10 can be displaced relative to the stationary gripping device.

[0033] In yet another modification, one side of the gripping device 10 can be used as a simple gripper to simply secure the corner of a textile article placed thereon, while the other gripper 10 displaces away from the first gripper and follows the contour of the edge.

[0034] Figures 5 and 6 show a first embodiment of the gripping device 10. The gripping devices of Figures 5 and 6 are called manipulators because, in addition to enabling passive sliding motion in response to the relative displacement of the gripping devices, they can also allow the textile article to slide against the gripping devices.

[0035] The manipulator 10 has a base 12 and a pressing part 14. The base 12 and the pressing part 14 are displaceable relative to each other between a receiving position that is spaced apart from each other and a gripping position that is close together, as shown by arrow D, and the woven article 3 is gripped in the gap between the base 12 and the pressing part 14.

[0036] The gripping device 10 is equipped with a displacement mechanism 20 adapted to actively displace the textile article in a direction substantially within the plane in which the textile article is held within the manipulator. As can be seen in Figure 5, this plane is perpendicular to the plane of the drawing and extends horizontally.

[0037] The displacement mechanism 20 includes a displacement wheel 22 rotatably mounted on the base 12. As shown in Figure 6, a portion of the displacement wheel 22 protrudes onto the surface of the base 12 facing the pressing portion 14. At the position of the base 12 relative to the pressing portion 14 shown in Figures 5 and 6, the protruding portion of the displacement wheel 22 engages with a guide groove 24 formed in the pressing portion 14.

[0038] The displacement wheel 22 can be actively rotated in either direction by the motor element 26, which is schematically shown in Figure 5.

[0039] The gap between the base 12 and the pressing portion 14 located inside the displacement wheel 22 forms a accommodating space 28 for the edge of the textile article 3 to be received between the base 12 and the pressing portion 14 (see Figure 5, which schematically shows the textile article 3).

[0040] The gripping device 10 is associated with a sensor 30 adapted to detect the position of the edge of the textile article 3.

[0041] In the embodiment shown in Figure 5, the sensor 30 is formed from separate detection elements that are spaced apart from each other in the direction of arrow T, which indicates the tolerance band where the edge of the woven article is assumed to exist.

[0042] The detection element 32 can be formed, for example, as a pair of light barriers so that it can detect the presence of the textile article 3.

[0043] The space inside the displacement wheel 22 is called the accommodating space for the edges of the textile article 3, but the space can accommodate any portion of the textile article 3 in the first step, for example, the central portion of the textile article when the pressing portion 14 and the base portion 12 are separated to accommodate the textile article 3. After the textile article is placed on the base portion 12, the textile article is manipulated until its edges are detected by the sensor 30.

[0044] Here, the displacement wheel 22 is formed as an omniwheel. Therefore, by rotating the displacement wheel 22 in a clockwise or counterclockwise direction relative to Figure 5, the textile article 3 can be displaced in the direction of arrow T, and at the same time, by increasing the distance between the two gripping devices 10, for example, the textile article 3 can be displaced in a direction perpendicular to the plane of Figure 5.

[0045] Referring to Figure 2, assuming that each gripping device 10 is provided with a displacement mechanism 20, the edges of the textile article 3 can be controlled by appropriately controlling the displacement mechanism to displace the portion of the textile article gripped within the gripping device in the direction of arrow T during the step of releasing the gripping device 10. The degree of displacement of the textile article 3 can be very easily controlled by the sensor 30 that detects the position of the edges of the textile article 3. As seen in Figure 5, the information that both pairs of detection elements 32 are blocked by the textile article 3 can be interpreted as the textile article 3 being too far inward within the containment space 28, resulting in counterclockwise movement of the displacement wheel 22 until the inner detection element 32 no longer detects the presence of the textile article. The information that neither detection element 32 detects the textile article can be interpreted as the textile article not being sufficiently within the containment space 28, resulting in clockwise rotation of the displacement wheel 22 until the outer detection element 32 detects the presence of the textile article again.

[0046] A second embodiment of the gripping device 10, formed as a manipulator, is shown in Figures 7 to 10. The same reference numerals are used for components known from the first embodiment, and the above comments are referenced.

[0047] The first embodiment uses a gripping device in the form of two jaws that cooperate with each other, while the second embodiment has a post-shaped or columnar base 12 with which the pressing portion 14 cooperates. A further difference between the first and second embodiments is that the second embodiment uses two displacement wheels 22 instead of a single displacement wheel.

[0048] The displacement wheels 22 are rotatably mounted within the base 12. They can be actively driven by a motor not shown herein. The motor is adapted to rotate both displacement wheels 22 in the same direction at the same rotational speed. As an example, both displacement wheels can be fixedly connected to the same drive shaft.

[0049] To increase friction with the textile article to be displaced, the displacement wheels 23 may include appropriate configurations on their outer circumference. As shown in Figures 7 to 10, the displacement wheels 22 here have multiple teeth.

[0050] As an alternative to teeth, the displacement wheel 22 may be provided with a rubber coating or any other surface to facilitate friction between the displacement wheel and the textile article.

[0051] The pressing section 14 includes two pressing wheels 23 arranged to cooperate with the displacement wheel 22. The pressing wheels 23 have a serrated outer circumference.

[0052] The pressing portion 14 further includes a pressing element 25 that can be displaced independently of the pressing wheel 23 toward and away from the base 12. The pressing element 25 here has a spherical surface adapted to cooperate with the guide recess 27 of the base 12 (see Figure 9).

[0053] The gripping device 10 shown in Figures 7 to 10 is configured to receive and clamp a textile article within the plane P schematically shown in Figure 7. By rotating the displacement wheel 22, the textile article 3 can be displaced within this plane P in a direction tangent to the outer circumference of the displacement wheel 22. In other words, the textile article 3 can be displaced in a direction perpendicular to the plane of the drawing, as seen in Figure 7.

[0054] To load the textile article 3 into the gripping device 10, the pressing section 14 and pressing element 25 are retracted. Once the textile article is placed on the base 12, the pressing section 14 is lowered to the position shown in Figure 9. In this position, the textile article is clamped between the displacement wheel 22 and the pressing wheel 23. Therefore, rotating the displacement wheel 22 causes displacement of the textile article relative to the base 12.

[0055] When the orientation of the textile article relative to the base 12 is changed, the pressing element 25 is lowered to clamp the textile article between the pressing part and the guide recess 27, while the pressing part 14 is moved upward (see Figure 10). In this state, the textile article can be rotated relative to the base 12 by overcoming the (reduced) frictional force between the pressing element 25 and the guide recess 27. Once the textile article is brought to the desired position, the pressing part 14 is lowered again to clamp the textile article between the displacement wheel and the pressing wheel, and the pressing element 25 can be retracted.

[0056] By changing the orientation of the woven article, for example by displacing the woven article in a different direction relative to the base 12, it becomes possible to "navigate" to a desired point on the woven article.

[0057] Figure 11 shows a schematic diagram of the base 12 and the woven article 3, and the pressing portion 14 is not shown here for clarity.

[0058] The base 12 shows several of the sensor elements 32 that form a sensor as a whole. The detection elements 32 are arranged circumferentially around the base 12.

[0059] Similar to the first embodiment, the sensor 30 is formed from a plurality of separate detection elements 32, which are spaced equally apart around the base 12.

[0060] A separate detection element 32 enables the detection of the position and orientation of the woven article 3, particularly the position of the edge E of the woven article 3. Assuming that the woven article 3 is randomly placed on the base 12 at the start of the handling process, all detection elements 32 are covered. By rotating the displacement wheel 22, the woven article is displaced relative to the base 12 in the direction indicated by the arrow 50 in Figure 11.

[0061] At some point, the textile article 3 is displaced until some of the detection elements 32 are exposed. This state is shown in Figure 11, where four of the detection elements 32 are exposed. Assuming that the edge E is a straight line, the orientation of the edge E can be determined to be perpendicular to the line 52 that forms the center of the sector 54 defined by the exposed detection elements 32.

[0062] It can be seen that the more detection elements are provided around the base 12, the higher the detection accuracy.

[0063] If the orientation of the edge E is determined and it is further intended to displace the woven article 3 along the edge E, the direction of displacement of the woven article 3 must be parallel to the edge E. In the state shown in Figure 11, these two directions are not yet parallel. The actual direction of displacement is indicated by arrow 50, but the direction of the edge E (indicated by arrow 56) is not parallel to direction 50.

[0064] In the first step, after lowering the pressing element 25, the pressing part 14 is retracted to press the woven article 3 against the base 12. Next, one of the woven articles 3 is rotated relative to the base 12 in the direction of arrow 58 until the orientation of the edge E is parallel to the displacement direction 50. This can be achieved by a second gripping device that engages with the woven article 3. Alternatively, the woven article 3 is held stationary and the base 12 is rotated relative to the woven article 3 in the direction of arrow 60.

[0065] When the orientation of the edge E of the woven article 3 becomes parallel to the displacement direction 50 defined by the displacement wheel 22 of the base 12, the woven article 3 can be further displaced relative to the base 12, while the position of the edge E relative to the base 12 is continuously monitored by the sensor 30. A change in the sector of the detection element 32 not covered by the woven article 3 indicates that the woven article 3 is being displaced in a direction not parallel to its edge E. Therefore, further intervention is required.

[0066] Another way to change the orientation of the textile article 3 relative to the base 12 is to use a drive mechanism adapted to rotate the two displacement wheels 22 in opposite directions or independently of each other, so that the textile article 3 can rotate around an axis located between the two displacement wheels 22 or around an axis located outside the two displacement wheels.

[0067] To rotate the textile article 3, the displacement wheels 3 are driven in the required manner (for example, opposite each other). In this embodiment, the pressing element 25 can be omitted.

[0068] In yet another variant, the displacement wheel 12 can be formed as an omniwheel that allows for the displacement of the textile article 3 in an oblique or lateral direction relative to the forward direction of the textile article defined by the rotation of the displacement wheel.

[0069] In further embodiments, the base 12 includes a set of displacement wheels 22 of the type shown in Figures 7 to 10 (driving the textile article in a direction defined by the orientation of the rotation axis of the displacement wheels 22) and an omniwheel (or two omniwheels) that allows for lateral displacement of the textile article. Different types of displacement wheels are mounted on a base 14 that is movable between the retracted position and the working position, such that one type of displacement wheel is in the working position and the other type is in the retracted position. This makes it possible to switch between two different operating modes, one having a predetermined direction of displacement of the textile article 3 and the other having the possibility of lateral displacement of the textile article 3 in addition to the displacement caused by the rotation of the (one or more) omniwheels.

[0070] Figure 12 shows an embodiment of a machine in which two of the manipulators shown in Figures 7 to 10 are used, each mounted on a robot arm 70 having six degrees of freedom. The robot arm constitutes the drive system 5.

[0071] The starting position is indicated by a continuous line on the left side of Figure 12. Both gripping devices 10 are positioned close to each other, and the textile article is gripped between the two gripping devices 10. After the textile article is loaded into the gripping devices 10, the gripping devices 10 are moved away from each other to straighten the textile article. At the same time, the textile article is displaced relative to the base 12 until the edge of the textile article is detected. Thereafter, the textile article is displaced relative to the base 12 along the detected edge until a predetermined point of the textile article is reached.

[0072] When the gripping device 10 is attached to the robot arm 70, it enables the manipulator to perform complex movements that allow it to follow the intricate contours and edges of the textile article.

[0073] Generally speaking, the machine according to the present invention can be considered a linear positioning device for spreading and positioning limp material by using two actively controlled manipulators and sensors to first reach a linear boundary segment of a woven article and then perform linear edge tracing while stopping upon corner recognition.

[0074] This example shows two gripping devices or manipulators working together, but it is possible to use three or more gripping devices to handle more complex textile articles or to increase processing speed.

Claims

1. A machine (1) for handling limp materials (3), particularly woven articles, The machine (1) includes at least first and second gripping devices (10) adapted to simultaneously grip the same piece of limp material (3), At least one of the gripping devices (10) is connected to a drive system (5) adapted to displace the gripping devices (10) relative to each other. One of the gripping devices (10) is a manipulator (10) having a displacement mechanism (20) adapted to actively displace the limp material (3) in a direction generally within the plane in which the limp material (3) is held within the manipulator (10), The system further includes at least one sensor (30) adapted to detect the limp material (3) and / or region of interest, The manipulator (10) includes a base (12) and a pressing part (14) that are displaceable relative to each other, The displacement mechanism (20) is provided on the base (12) and includes at least one displacement wheel (22) arranged to engage with the limp material (3), A accommodating space (28) is provided between the base (12) and the pressing portion (14), and the accommodating space (28) is adapted to accommodate the edge (E) of the limp material (3). The machine (1) is configured such that the sensor (30) detects the position of the edge (E) within the housing space (28).

2. The machine according to claim 1, wherein the displacement wheel (22) is an omniwheel.

3. The machine according to claim 1, wherein a guide groove (24) related to the displacement wheel (22) is provided in the pressing portion (14).

4. The machine according to claim 1, wherein the sensor (30) is formed from separate detection elements (32) arranged spaced apart from each other.

5. The machine according to any one of claims 1 to 4, wherein a pair of displacement wheels (22) are provided.

6. The machine according to claim 5, wherein the pressing portion (14) includes a pair of pressing wheels (23) and pressing elements (25), and the pressing wheels (23) and pressing elements (25) are movable independently of each other relative to the displacement wheel (22), particularly in a direction perpendicular to the plane in which the limp material (3) is held between the displacement wheel (22) and the pressing wheels (23).

7. The machine according to claim 5, wherein a drive device for the displacement wheels is provided, which is adapted to rotate the displacement wheels independently of each other or in opposite directions.

8. The machine according to claim 5, wherein the sensor (30) is configured to detect the presence of the limp material (3) in a detection area that extends circumferentially around the base (12).

9. The machine according to claim 8, wherein the sensor (30) is formed from a plurality of separate detection elements (32) arranged circumferentially around the base (12).

10. The machine according to any one of claims 1 to 4, wherein the base (12) and / or the pressing portion (14) can rotate about an axis perpendicular to the rotation axis of the displacement wheel (23).

11. The machine according to any one of claims 1 to 4, wherein two manipulators (10) are provided.

12. The machine according to any one of claims 1 to 4, wherein the drive system (5) includes a linear drive unit to which the gripping devices (10) are attached, and the linear drive unit is adapted to displace the gripping devices (10) from a loading position in which the gripping devices (10) are close to each other to a position in which the gripping devices (10) are spaced apart from each other, and vice versa.

13. The machine according to any one of claims 1 to 4, wherein the drive system (5) includes two robot arms (7), each of the robot arms (7) is provided with a gripping device (10), and the robot arms (7) are adapted to displace the gripping devices (10) from a loading position where the gripping devices (10) are close to each other to a position where the gripping devices (10) are spaced apart from each other, and vice versa.

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