WO2004085264A1

WO2004085264A1 - Release device and method for using same

Info

Publication number: WO2004085264A1
Application number: PCT/FI2004/000163
Authority: WO
Inventors: Pertti TYKKYLÄINEN; Jussi Karaiste
Original assignee: Perlos Oyj
Priority date: 2003-03-25
Filing date: 2004-03-24
Publication date: 2004-10-07
Also published as: FI20030446A0; FI20030446A; FI115122B

Abstract

A device for releasing articles and a method for using the same. The release device comprises a mating surface in accordance with the surface of which the carrier web is arranged to travel, a gripper (4, 4a, 4b) arranged to grip an article (1, 1a, 1b) attached to a part of the carrier web (2) residing on the mating surface, and a release point. The carrier web (2) is arranged to move forward when the gripper (4, 4a, 4b) grips the article (1, 1a, 1b), and the gripper (4, 4a, 4b) is arranged to move such that it has a velocity component (H) whose direction and magnitude substantially correspond with the movement of the carrier web (2) on the mating surface (8).

Description

RELEASE DEVICE AND METHOD FOR USING SAME

BACKGROUND OF THE INVENTION

[0001] The invention relates to a device for releasing articles, to which the articles are conveyed attached to a carrier web and wherein the articles are released from the carrier web in order to be used in an assembly process, the release device comprising a mating surface in the direction of which the carrier web is arranged to travel, a gripper arranged to grip an article attached to a part of the carrier web residing on the mating surface, and a release point arranged after the mating surface in the direction of travel of the carrier web to bend the carrier web such that the article attached to the gripper is released from the carrier web.

[0002] The invention further relates to a method for using a device for releasing articles, to which release device the articles are conveyed attached to a carrier web and wherein the articles are released from the carrier web, the method comprising arranging a part of the carrier web onto a mating surface, pressing a gripper against the part of the carrier web residing on the mating surface and making the gripper grip an article attached to the carrier web, conveying the article still attached to the carrier web and the gripper gripping it to a release point, and changing the direction of travel of the carrier web at the release point such that the article gripped by the gripper is released from the carrier web.

[0003] The assembly industry has for a long time known a method of using a specific carrier web for bringing articles to an assembly line or cell. The articles are stored and transported attached to the carrier web that is typically rolled into a roll or another easily handled and transported entity. At the assembly line, the product is detached from the carrier web by means of a specific release device.

[0004] The articles are typically attached by glue to the carrier web. The article can be a adhesive label, a protective window of the display of an electronic device, such as mobile phone, PDA (Personal Digital Assistan t) or communicator, an electronic component or the like.

[0005] The release device typically operates as described in the following. The carrier web and the articles on it are conveyed to a slide om the release device. The release device has a gripper that is arranged to move perpendicular to the plane of the carrier web. A robot usually runs the grip-per. Said slide is arranged in the working area of the gripper and usually has a planar mating surface and, after this in the direction of travel of the carrier web, a tip ending the mating surface. The slide is movably fastened to the frame of the release device so that it has an inner and outer position in relation to it. The carrier web is transported along the mating surface of the slide and onward around the tip so that the direction of travel of the carrier web changes substantially at the tip. The tip forms a release point, at which the article detaches from the carrier web. When the article attached to the carrier web has travelled to a specific location of the slide with respect to the gripper, the carrier web is stopped and kept stationary so that it cannot move forward or backward. Mext, the gripper is pressed against the article such that the gripper grips the article. When the gripper has fastened to the article, the carrier web is tightened at the end that has passed the gripper and the tip. The tightening of the carrier web forces the movably fastened slide of the device to move to the inner position with respect to the frame of the device. The slide then moves away from below the gripper and the tip of the slide moves from below the article fastened to the gripper. Because the direction of the carrier web changes abruptly at the tip of the slide, the article detaches from the carrier web and remains attached to the gripper. The gripper moves the article fastened to it to the actual assembly. At the same time, the slide moves back to its outer position and pulls the carrier web back from the go side to the mating surface of the slide. Next, more carrier web is fed to the mating surface, after which the work cycle described above starts again.

[0006] The slide is pulled to the inner position by the carrier web, so a load caused by the movement resistance of the slide is directed to the carrier web. A problem with the prior-art release devices is that a tensile load is directed to the carrier web, as a result of which the carrier web may break. This may cause shutdowns in the assembly process and similar inconvenience. In addition, the release rate of the release device needs to be kept relatively low, because increasing the rate would increase the above-mentioned tensile loads. The strength of the carrier web can, of course, be improved, but this increases the costs of the carrier web. Another problem is that to ensure a reliable operation of the release process, the carrier web must always be kept suitably tight, which in the solution described above requires quite complex arrangements and structures.

BRIEF DESCRIPTION OF THE INVENTION

[0007] It is an object of the present invention to provide a novel and improved release device and a method for using same, in which less tensile load than before is directed to the carrier web and with which the release process can be sped up.

[0008] The release device of the invention is characterized in that the carrier web is arranged to move forward when the gripper grips the article, that the gripper is arranged to move such that it has a velocity component whose direction and magnitude substantially correspond to the movement of the carrier web on the mating surface, and that the gripper is arranged to move to the release point while gripping the article.

[0009] Further, the method of the invention is characterized by moving the carrier web onward, bringing the gripper into a movement having a velocity component whose direction and magnitude are substantially convergent with respect to the onward movement of the carrier web, making the gripper grip the article moving with the carrier web, and bringing the gripper, attached to the article, to the release point.

[0010] The invention provides the advantage that the carrier web is not used to pull the slide back, owing to which the breaking risk of the carrier web is substantially reduced. The loads of the carrier web remain substantially similar during the entire release process, which permits the use of less expensive and weaker materials in the carrier web, or alternatively the release rate can be increased. The release cycle time can be shortened substantially, because no time is required to move the slide. Another advantage is that the structure of the release device can be simplified with respect to the structures regulating the tightness of the carrier web.

[0011] The essential idea of one embodiment of the invention is that the release device comprises two or more grippers. This provides the advantage that the work phase of the release device becomes even more efficient. [0012] The essential idea of yet another embodiment of the invention is that there are as many grippers as there are product slots in the product palette used in the assembly. This provides the advantage that one and the same work phase of the release device inserts an article in each product in the palette.

BRIEF DESCRIPTION OF THE FIGURES

[0013] The invention will now be described in greater detail by means of the attached drawings, in which

Figures 1a and 1b are schematic side views of the operation of a release device of the prior art,

Figures 2a and 2b are schematic side views of a release device of the invention, and

Figure 3 is a schematic side view of a second release device of the invention.

For the sake of clarity, the invention is shown simplified in the figures. Similar parts are marked with the same reference numbers in the figures.

DETAILED DESCRIPTION OF THE INVENTION

[0014] Figures 1a and 1 b are schematic side views of the operation of a release device of the prior art. The release device is preferably located in proximity to an assembly line. The articles 1 required in the assembly are fastened to the carrier web 2 by glue, for example. The carrier web 2 is a substantially elongated, relatively thin web-like product. The length of the carrier web may be hundreds of metres, its width typically 20 to 100 mm and thickness typically 0.1 to 0.4 mm. The number of articles 1 fastened to the carrier web 2 varies in each case. Generally, the articles 1 are fastened to the carrier web 2 one after the other in one row, but carrier webs 2 are also known, in which the articles 1 are fastened in two parallel rows. The carrier web 2 is in most cases made of plastic, such as polyethyleneterephtalate PET, or paper.

[0015] The article 1 can for instance be a tape, adhesive label, protective window of the display of an electronic device, such as mobile phone, PDA (Personal Digital Assistant) or communicator, an electronic component or a corresponding product that can be detachably attached to the carrier web and to the handling of which, the use of the carrier web provides an advantage. [0016] In the embodiment shown in Figures 1a, 1b, the carrier web with the articles 1 attached to it is rolled into an article roll 3, which is easy and simple to transport and store. The carrier web 2 is fed from the article roll 3 in the direction of arrow M to a mating surface 8 on the top surface of the frame 7 of the release device and a slide 5 movably fastened thereto, and on around the end of the slide 5 all the way to the receiving roll 9 for used carrier web. The slide 5 can move on a guide bar 6 relative to the frame 7.

[0017] The release device has a gripper 4 operated for instance by a robot or manipulator that is not shown in the figure to simplify the presentation. The gripper 4 is pressed in the direction shown by arrow D against the article 1 fastened to the carrier web 2. The article 1 thus remains between the gripper 4 and the mating surface 8. At this stage, the carrier web 2 is locked in place so that it cannot move forward or backward. A brake 11 and a pulling device 10, the pull of which is stopped, do the locking.

[0018] Next, the carrier web is tightened at the end that has passed the gripper 4 by pulling it with the pulling device 10 and keeping the brake 11 still locked. As a result of the tightening of the carrier web 2, the carrier web 2 pulls the slide 5 closer to the frame 7 until the slide 5 touches the frame 7, Figure 1b. As the slide 5 moves, the gripper 4 and the article 1 attached thereto remain stationary relative to the frame 7, but the mating surface 8 on the slide 5 moves relative to them.

[0019] At the end of the slide 5, i.e. at the opposite end of the slide to the guide bar 6, a release point 12 is formed. At the release point 12, the direction of travel of the carrier web 2 is forced to change abruptly; in other words, the carrier web 2 bends at the release point 12. When the slide 5 moves toward the frame 7, the release point moves with the movement under the article 1 attached to the gripper 4. The bending of the carrier web 2 makes the article 1 attached to the gripper 4 to detach during the movement of the slide 5 from the carrier web 2. After this, the gripper 4 and the article 1 attached to it is lifted up and conveyed to the actual assembly. Meanwhile, the slide 5 pushes into its outer position shown in Figure 1a. The brake 11 is still kept locked and the carrier web 2 that has passed the mating surface 8 and is free of articles 1 is allowed back to the mating surface 8. The part of the carrier web 2 that is allowed back is typically gathered in a loop. The loop and the means required to make it are not shown in Figures 1a, 1b. When the slide 5 is in its outer position, the brake 11 is released and the pulling device 10 pulls more carrier web 2 to the mating surface 8. The carrier web 2 thus proceeds step by step at a rate and step length determined by the movement of the slide 5 in the direction of arrow M.

[0020] The strength of the carrier web 2 limits the release rate of the articles 1 , because the slide 5 is pulled back by means of the carrier web. When increasing speed, the risk of breaking the carrier web 2 increases substantially. In addition, bringing a new article 1 to the mating surface 8 requires several method steps that take a lot of time to perform.

[0021] Figures 2a and 2b are schematic side views of a release device of the invention and its operation. The carrier web 2 and the articles 1 fastened to it move in the direction of arrow M onward from the article roll 3 to the receiving roll 9 for used carrier web. The transport of the carrier web 2 is arranged by power transmission means comprising a pulling device 10 in contact with the carrier web and run by a power unit 13. The power unit 13 is for instance an electric motor, hydraulic motor or the like. The movement of the carrier web 2 can also be arranged by other types of power transmission means.

[0022] The release device has a frame 7 that comprises a mating surface 8 and a release point 12 arranged after the mating surface in the direction of travel of the carrier web 2. The carrier web 2 is run along the mating surface 8 to the release point 12. At the release point 12, the direction of travel of the carrier web changes abruptly, as already described in connection with the previous figures.

[0023] The gripper 4 can move with a velocity component V, which is a velocity component perpendicular to the direction of travel of the carrier web 2 moving forward on the mating surface 8, and a velocity component H, which is perpendicular to the velocity component V and moves in the direction of travel of the carrier web 2 moving forward on the mating surface 8. It should be noted that in this description, the gripper refers to a machine element that attaches detachably to one article 1 on the carrier web 2, moves it to the assembly phase, and detaches from the article in the assembly phase.

[0024] The gripper 4 grips the article 1 approaching the release point 12 and moves simultaneously at substantially or exactly the same rate, i.e. collinear rate, with the direction of travel of the carrier web 2 moving forward on the mating surface 8. When the gripper 4 and the article 1 attached to it are at the release point 12, the article 1 detaches from the carrier web 2 that changes its direction of travel substantially. The change in the directior of travel of the carrier web 2 that is necessary to detach the article 1 varies from one application to another, but it is generally 100° to 170°. After the article 1 has detached from the carrier web 2, the gripper 4 moves it to the assembly. At this stage, the movement of the carrier web 2 can be stopped so as to allow the gripper 4 enough time to take the article 1 to the assembly. However, it is not necessary to stop the carrier web 2, if the time required by the gripper 4 is not very long.

[0025] The gripper 4 is arranged to a robot, manipulator or a corresponding actuator, the control system of which contains a conveyor tracking function. With this function, the control system monitors the movement and location of the articles 1 , and based on the monitoring, it sets the velocity components V and H of the gripper 4 movement such that when the gripper 4 grips an article 1 , the velocity component H is equal or substantially equal to the forward rate of travel of the carrier web on the mating surface 8.

[0026] The release device of the invention loads the carrier web 2 very little, because a slide is not moved on the carrier web. This way, the web 2 does not break as easily as in the prior-art release device, which makes it possible to increase the release rate higher than that of the prior-art release devices, or it is possible to use weaker or less expensive web materials. Test runs showed that the release cycle time of an article detached from a carrier web with a prior-art release device was approximately 6 seconds, whereas the cycle time achieved with the release device of the invention was approximately 2 seconds: in other words, a 2/3 decrease was achieved in the cycle time. In addition to the above-mentioned advantages, it should yet be mentioned that it is relatively simple to maintain suitable carrier web tightness, because a loop enabling the movement of a slide need not be formed.

[0027] It should be noted in this context that the release device also comprises other components than those examined in connection with the previous figures, such as carrier web controllers, but they are not shown in the figures to simplify the presentation. It should also be noted that the carrier web 2 need not be rolled into an article roll 3, but it can be in any form from which it can be fed into the release device. Neither is a receiving roll 9 the only alternative for arranging the reception of a carrier web 2 empty of articles 1 : the carrier web 2 can for instance be guided freely to a transport platform.

[0028] Figure 3 shows a schematic side view of a second release device of the invention. The release device has two grippers 4a, 4b that are arranged to be run by one actuator, herein a robot 14. Two articles 1a, 1b are released from the carrier web 2 at the same time. By increasing the number of grippers, the number of articles released in a time unit can be increased. In the embodiment of the invention shown in Figure 3, the articles 1a, 1b are taken to an assembly process 15, in which the products to be assembled are processed in product palettes 16. One product palette 16 takes two products 17a, 17b. All articles 1a, 1b to be arranged to the products of the product palette 16 are released at the same time. This way, the processing of the product palette 16 and the entire assembly process 15 is fast.

[0029] The articles 1a, 1b that are released simultaneously can also be side by side on the carrier web 2. The grippers 4a, 4b are then naturally also arranged side by side in a similar manner.

[0030] In the embodiment shown in Figure 3, each gripper 4a, 4b has a separate frame 18a, 18b. Another alternative is that the grippers 4a, 4b are arranged to a common frame.

[0031] The drawings and the related description are intended only to illustrate the inventive idea. The invention may vary in detail within the scope of the claims. Thus, the embodiment using several grippers shown in Figure 3 can also be implemented such that the grippers 4a, 4b are arranged to grip substantially non-simultaneously, for instance consecutively, the article on the carrier web 2. Articles can be released from one carrier web 2 by means of two or more actuators and grippers arranged thereto.

Claims

1. A device for releasing articles, to which release device the articles (1, 1a, 1b) are conveyed attached to a carrier web (2) and wherein the articles (1, 1a, 1b) are released from the carrier web (2) in order to be used in an assembly process, the release device comprising: a mating surface (8) in the direction of which the carrier web (2) is arranged to travel, a gripper (4, 4a, 4b) arranged to grip an article (1, 1a, 1b) attached to a part of the carrier web (2) residing on the mating surface, and a release point (12) arranged after the mating surface in the direction of travel (M) of the carrier web to bend the carrier web (2) such that the article (1, 1a, 1b) attached to the gripper (4, 4a, 4b) is released from the carrier web (2), characterized in that the carrier web (2) is arranged to move forward when the gripper (4, 4a, 4b) grips the article (1 , 1a, 1b), the gripper (4, 4a, 4b) is arranged to move such that it has a velocity component (H) whose direction and magnitude substantially correspond to the movement of the carrier web (2) on the mating surface (8), and the gripper (4, 4a, 4b) is arranged to move to the release point (12) while gripping the article.

2. A release device as claimed in claim 1, characterized in that it comprises at least two grippers (4, 4a, 4b).

3. A release device as claimed in claim 2, characterized in that the grippers (4, 4a, 4b) are arranged to grip the article (1, 1a, 1b) on the carrier web (2) substantially simultaneously.

4. A release device as claimed in claim 1 or 2, characterized in that the article (1 , 1a, 1 b) is tape.

5. A release device as claimed in claim 1 or 2, characterized in that the article (1, 1a, 1b) is a protective window of a display of an electronic device.

6. A release device as claimed in any one of the preceding claims, characterized in that the mating surface (8) is planar.

7. A method for using a device for releasing articles, to which release device the articles (1, 1a, 1b) are conveyed attached to a carrier web (2) and wherein the articles (1, 1a, 1b) are released from the carrier web (2), the method comprising: arranging a part of the carrier web (2) onto a mating surface (8), pressing a gripper (4, 4a, 4b) against the part of the carrier web (2) residing on the mating surface (8) and making the gripper (4, 4a, 4b) grip an article (1, 1a, 1b) attached to the carrier web (2), conveying the article (1, 1a, 1b) still attached to the carrier web (2) and the gripper (4, 4a, 4b) gripping it to a release point (12), and changing the direction of travel of the carrier web (2) at the release point (12) such that the article (1, 1a, 1b) gripped by the gripper is released from the carrier web (2), characterized in that the method comprises: moving the carrier web (2) onward, conveying the gripper (4, 4a, 4b) into a movement having a velocity component (H) whose direction and magnitude are substantially convergent with respect to the onward movement of the carrier web (2), making the gripper (4, 4a, 4b) grip the article (1, 1a, 1b) moving with the carrier web (2), and bringing the gripper (4, 4a, 4b), attached to the article (1, 1a, 1b), to the release point (12).

8. A method as claimed in claim 7, characterized in that the number of grippers (4, 4a, 4b) is at least two.

9. A release device as claimed in claim 8, characterized in that the grippers (4, 4a, 4b) grip the articles (1, 1a, 1b) on the carrier web substantially simultaneously.