GRIPPER CARRIAGE CONTROL

Abstract

Tray sealer, comprising a sealing station for sealing trays, an infeed belt for providing trays, an outfeed belt for transporting sealed trays away, a gripper device comprising a first gripper unit which is configured to pick up trays from the infeed belt and to position them for a sealing process within the sealing station, and comprising a second gripper unit which is configured to collect the trays sealed by way of the sealing station and to position them on the outfeed belt for being transported away, where the first gripper unit comprises a first carriage as well as a first gripper mounted thereon and the second gripper unit comprises a second carriage and a second gripper mounted thereon, a lifting mechanism for opening and closing the sealing station, as well as a control device for controlling a motion of the first carriage and the first gripper as well as for controlling a motion of the second carriage and the second gripper, where, during the opening of the lifting mechanism, the control device is configured to control a closing motion of the second gripper carried out transverse to the direction of production for collecting sealed trays from the sealing station as well as an adjusting motion of the first carriage carried out in the direction of production for supplying unsealed trays into the sealing station such that a substantially predetermined minimum distance is present between the first and the second carriage when the closing motion of the second gripper is at least substantially completed. The disclosure furthermore relates to a method for controlling a gripper device of a tray sealer.

Claims

1. A tray sealer comprising: a sealing station for sealing trays; an infeed belt for providing trays; an outfeed belt for transporting sealed trays away; and a gripper device comprising a first gripper unit which is configured to pick up trays from the infeed belt and to position them for a sealing process within the sealing station, and comprising a second gripper unit which is configured to collect trays sealed by way of the sealing station and to position them on the outfeed belt for being transported away, where the first gripper unit comprises a first carriage as well as a first gripper mounted thereon and the second gripper unit comprises a second carriage and a second gripper mounted thereon, a lifting mechanism for opening and closing the sealing station, as well as a control device for controlling a motion of the first carriage and the first gripper as well as for controlling a motion of the second carriage and the second gripper, wherein, during the opening of the lifting mechanism, the control device is configured to control a closing motion of the second gripper carried out transverse to the direction of production for collecting sealed trays from the sealing station as well as an adjusting motion of the first carriage carried out in the direction of production for supplying unsealed trays into the sealing station such that a substantially predetermined minimum distance is present between the first and the second carriage when the closing motion of the second gripper is at least substantially completed.

2. The tray sealer according to claim 1, wherein the control device is configured to control the closing motion of the second gripper and the adjusting motion of the first carriage carried out in the direction of production such that that the predetermined minimum distance is present between the first and the second carriage when the first carriage is adjusted to the maximum in the direction of production.

3. The tray sealer according to claim 1, wherein the control device is configured to control the closing motion of the second gripper and the adjusting motion of the first carriage carried out in the direction of production such that that the predetermined minimum distance is present between the first and the second carriage when the second carriage begins to move in the direction of production.

4. A tray sealer according to claim 1, wherein the control device is configured to control the opening of the lifting mechanism, the closing motion of the second gripper, and the adjusting motion of the first carriage carried out in the direction of production such that that the predetermined minimum distance is present between the first and the second carriage when the second carriage has arrived at an end position in a direction opposite to the direction of production.

5. The tray sealer according to claim 1, wherein the control device is configured to control the closing motion of the second gripper and the adjusting motion of the first carriage carried out in the direction of production such that that the first and the second carriage accelerate at least temporarily at the same magnitude with opposite signs when the second gripper is adjusted to the maximum transverse to the direction of production.

6. The tray sealer according to claim 1, wherein the control device is configured to control the adjusting motion of the first carriage carried out in the direction of production such that a distance between the first and the second carriage can be changed.

7. The tray sealer according to claim 1, wherein the control device is configured to control the opening of the lifting mechanism, the closing motion of the second gripper, and the adjusting motion of the first carriage carried out in the direction of production such that that the predetermined minimum distance is present between the first and the second carriage when the lifting mechanism is open to the maximum.

8. The tray sealer according to claim 1, wherein the control device is configured to set a starting time for the adjusting motion of the first carriage carried out in the direction of production per machine work cycle in dependence of the detected closing motion of the second gripper, in dependence of the detected opening of the lifting mechanism and/or in dependence of a process parameter of the sealing station detected at the sealing station.

9. The tray sealer according to claim 1, wherein the control device is configured to determine, on the basis of a speed profile of the second carriage and/or the second gripper predetermined as a guide logic, a speed profile dependent thereon of the first carriage and/or the second gripper formed as an inference logic.

10. The tray sealer according to claim 1, wherein the control device is configured to determine the minimum distance on the basis of a desired tray exchange time that can be adjusted at the tray sealer and to control in dependence thereof the motions of the first and the second gripper unit.

11. The tray sealer according to claim 1, wherein the control device comprises a distance control device, where the first and/or the second gripper unit comprises at least one measuring unit for detecting a distance between the first and the second carriage, where an acceleration of the first carriage in the direction of production during the closing motion of the second gripper can be controlled in dependence of the distance detected.

12. A method for controlling a gripper device of a tray sealer, where a first gripper unit by way of a first gripper formed thereon picks up trays from an infeed belt and transports them into a sealing station of the tray sealer for a sealing process, and where a second gripper unit positioned in the direction of production downstream of the first gripper unit by way of a second gripper formed thereon collects the trays sealed within the sealing station and positions them on an outfeed belt for being transported away, wherein, during the opening of the lifting mechanism, the control device is configured to control a closing motion of the second gripper carried out transverse to the direction of production for collecting sealed trays from the sealing station as well as an adjusting motion of the first carriage of the gripper unit carried out in the direction of production for supplying unsealed trays into the sealing station such that a substantially predetermined minimum distance is present between the first carriage of the first gripper unit and a second carriage of the second gripper unit when the closing motion of the second gripper is at least substantially completed.

13. A tray sealer comprising: a sealing station for sealing trays; an infeed belt for providing trays; an outfeed belt for transporting sealed trays away; a gripper device comprising a first gripper station configured to pick up trays from the infeed belt and to position them within the sealing station for sealing, and comprising a second gripper station configured to collect trays sealed by way of the sealing station and to position them on the outfeed belt for being transported away, where the first gripper station comprises a first carriage as well as a first gripper mounted thereon and the second gripper station comprises a second carriage and a second gripper mounted thereon; and a lift for opening and closing the sealing station, and a controller for controlling motion of the first carriage and the first gripper as well as for controlling motion of the second carriage and the second gripper, wherein, during the opening of the lift, the controller is configured to control a closing motion of the second gripper carried out transverse to the direction of production for collecting sealed trays from the sealing station as well as an adjusting motion of the first carriage carried out in the direction of production for supplying unsealed trays into the sealing station such that a predetermined minimum distance is present between the first and the second carriage when the closing motion of the second gripper is at least substantially completed.

14. The tray sealer according to claim 13, wherein the controller is configured to control the closing motion of the second gripper and the adjusting motion of the first carriage carried out in the direction of production such that that the predetermined minimum distance is present between the first and the second carriage when the first carriage is adjusted to the maximum in the direction of production.

15. The tray sealer according to claim 13, wherein the controller is configured to control the closing motion of the second gripper and the adjusting motion of the first carriage carried out in the direction of production such that that the predetermined minimum distance is present between the first and the second carriage when the second carriage begins to move in the direction of production.

16. A tray sealer according to claim 13, wherein the controller is configured to control the opening of the lift, the closing motion of the second gripper, and the adjusting motion of the first carriage carried out in the direction of production such that that the predetermined minimum distance is present between the first and the second carriage when the second carriage has arrived at an end position in a direction opposite to the direction of production.

17. The tray sealer according to claim 13, wherein the controller is configured to control the closing motion of the second gripper and the adjusting motion of the first carriage carried out in the direction of production such that that the first and the second carriage accelerate at least temporarily at the same magnitude with opposite signs when the second gripper is adjusted to the maximum transverse to the direction of production.

18. The tray sealer according to claim 13, wherein the controller is configured to control the adjusting motion of the first carriage carried out in the direction of production such that a distance between the first and the second carriage can be changed.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Advantageous embodiments of the disclosure shall be explained with reference to the following figures.

[0027] FIG. 1 shows a schematic representation of a tray sealer according to the disclosure;

[0028] FIG. 2A shows a snapshot of a gripper device for moving to a predetermined minimum distance;

[0029] FIG. 2B shows a further snapshot of a gripper device for moving to a predetermined minimum distance;

[0030] FIGS. 3A-3D show a schematic representation of adjusting motions of the gripper device;

[0031] FIGS. 4A-4D show a further schematic representation of adjusting motions of the gripper device; and

[0032] FIGS. 5A-5C show a further representation of adjusting motions of the gripper device.

[0033] Same components are provided with the same reference characters throughout the figures.

DETAILED DESCRIPTION

[0034] FIG. 1 shows a schematic representation of a tray sealing machine 1. Such a tray sealing machine 1 is also referred to as a tray sealer. Tray sealer 1 comprises a sealing station 2 for sealing trays 3. Furthermore, tray sealer 1 comprises an infeed belt 4 for providing trays 3 and an outfeed belt 5 for transporting sealed trays 3 away.

[0035] Tray sealer 1 shown in FIG. 1 comprises a gripper device 6 with a first gripper unit 7 and with a second gripper unit 8. First gripper unit 7 is configured to pick up unsealed trays 3 from infeed belt 4 and to position them for a sealing process within sealing station 2. Second gripper unit 8 is configured to collect trays 3 sealed by way of sealing station 2 and to position them on outfeed belt 5 for being transported away. First gripper unit 7 comprises a first carriage 9 as well as a first gripper 10 mounted thereon in an adjustable manner. Second gripper unit 8 comprises a second carriage 11 and a second gripper 12 mounted thereon in an adjustable manner.

[0036] Tray sealer 1 from FIG. 1 furthermore disposes of a lifting mechanism 13 for opening and closing sealing station 2. FIG. 1 further shows a control device 14 for controlling a motion of first carriage 9 and first gripper 10 as well as for controlling a motion of second carriage 11 and second gripper 12. Control device 14 is functionally connected to a first drive 15 of first gripper unit 7 as well as functionally connected to a second drive 16 of second gripper unit 8. Control device 14 is configured to control first and second drive 15, 16 independently of one another. The control device can be configured in particular to control respective carriages 9, 11 of first and second gripper unit 7, 8 such that they move towards or away from one another while sealing station 2 is supplied with trays 3 or sealed trays 3 are transported thereoutof, respectively.

[0037] Tray sealer 1 comprises a tool lower part 17 and a tool upper part 18 arranged thereabove for a sealing process. According to FIG. 1, tool lower part 17 is mounted to be adjustable in height by way of lifting mechanism 13. The adjustability in height of tool lower part 17 is shown by way of double arrow 19. For the sealing process, tool lower part 17 can be raised to tool upper part 18 positioned thereabove in order to seal trays 3 placed on tool lower part 17 with a top film 20 passed through sealing station 2. According to FIG. 1, a sensor unit 21 is provided at sealing station 2 and is configured to detect at least one process parameter during the sealing process at sealing station 2.

[0038] According to FIG. 1, a measuring unit 22 is provided on first carriage 9 of first gripper unit 7 and is configured to detect a distance between first and second carriage 9, 11. This distance can be transmitted to a distance control device 23 of control device 14, based on which control device 14 controls a closing motion and/or an adjusting motion of first and/or second gripper unit 7, 8.

[0039] Furthermore, FIG. 1 shows that control device 14 can be assigned a desired tray exchange time t, on the basis of which control device 14 can determine a minimum distance x between first and second carriage 9, 11. Based on the predetermined minimum distance x, first and second gripper unit 7, 8 can be moved into and out of sealing station 2 for a tray exchange.

[0040] Respective carriages 9, 11 of first and second gripper units 7, 8 can be adjusted in direction of production R along a guide 24. FIG. 1 shows that first gripper unit 7 transports trays 3 in direction of production R from infeed belt 4 into sealing station 2 and second gripper unit 8 transports sealed trays 3 out of sealing station 2 and transfers them to outfeed belt 5.

[0041] Control device 14 shown in FIG. 1 is configured to control both a closing motion S (see FIG. 3A) of second gripper 12 carried out transverse to direction of production R while lifting mechanism 13 opens, i.e., while sealing station 2 opens, for collecting sealed trays 3 from sealing station 2 as well as an adjusting motion V of first carriage 9 carried out in direction of production R for supplying unsealed trays 3 into sealing station 2 such that the predetermined minimum distance x (see FIG. 3B) is substantially present between first and seconds gripper 9, 10 when closing motion S of second gripper 12 is at least substantially completed.

[0042] According to the following embodiments, closing motion S and adjusting motion V can be controlled differently by way of control device 14.

[0043] FIG. 2A shows a variant in which control device 14 controls closing motion S of second gripper 12 and adjusting motion V of first carriage 9 carried out in direction of production R such that predetermined minimum distance x is present between first and second carriage 9, 11 when first carriage 9 has been adjusted to the maximum in direction of production R. At this point in time, second gripper 12 has already left sealing station 2 to position sealed trays 3 picked up thereon onto outfeed belt 5. According to FIG. 2A, minimum distance x between first and second carriage 9, 11 has been reached when first carriage 9 is adjusted to the maximum in direction of production R, i.e., first gripper 10 is opened for transferring trays 3 picked up thereon to tool lower part 17 of sealing station 3.

[0044] FIG. 2B shows a variant according to which control device 14 is configured to control closing motion S of second gripper 12 and adjusting motion V of first carriage 9 carried out in direction of production R such that predetermined minimum distance x is present between first and second carriage 9, 11 when second carriage 11 begins to move in direction of production R. In this variant, minimum distance x between first and second carriage 9, 11 has been reached when sealed trays 3 are picked up by way of second gripper unit 8 and first gripper unit 7 has moved towards sealing station 2 to a maximum, but does not yet project thereinto. Unlike in FIG. 2A, minimum distance x according to FIG. 2B has therefore already been reached before first carriage 9 has reached its end position in direction of production R.0}

[0045] FIGS. 3A to 3D show a motion of the gripper device 6 for transporting trays along tray sealer 1.

[0046] FIG. 3A shows gripper device 6 in an initial situation. During the opening motion of mechanism 13, both a closing motion S of second gripper 12 carried out transverse to direction of production R to collect sealed trays 3 from sealing station 2 as well as an adjusting motion V of first carriage 9 carried out in direction of production R to supply unsealed trays 3 into sealing station 2 start in this state.

[0047] Closing motion S and adjusting motion V are controlled by way of control device 14 such that a substantially predetermined minimum distance x is present between first and second carriage 9, 11 when closing motion S of second gripper 12 is at least substantially complete. This is shown in FIG. 3B.

[0048] According to FIG. 3C, sealed trays 3 collected by way of second gripper unit 8 are transported in direction of production R to outfeed belt 5. At the same time, unsealed trays 3 picked up at first gripper unit 7 are transported into sealing station 2. At this point in time, two carriages 9, 11 can already again move away from one another again.

[0049] FIG. 3D shows that, by opening second gripper unit 12, sealed trays 3 picked up thereon are transferred to outfeed belt 5. At the same time or offset in time, first gripper unit 7 transfers unsealed trays 3 picked up at first gripper 10 to sealing station 2 for the sealing process.

[0050] FIGS. 3A to 3D show that minimum distance x is substantially present between first and second carriage 9, 11 when the sealed trays are picked up by way of second gripper 12, and first gripper 10 has moved substantially at a maximum distance toward opened sealing station 2.

[0051] FIGS. 4A to 4D show an alternative motion of gripper device 6 for transporting trays 3 along tray sealer 1.

[0052] According to FIG. 4A, an initial situation is present in which closing motion S of second gripper 12 begins. At the same time or offset in time, first carriage 9 of first gripper unit 7 begins with an adjusting motion V in direction of production R.

[0053] FIG. 4B shows that first gripper unit 7 has moved further in direction of production R towards sealing station 2. The trays sealed in sealing station 2 are picked up by way of second gripper unit 8 to be transported out of sealing station 2.

[0054] FIG. 4C now shows the point in time at which predetermined minimum distance x is present between first carriage 9 and second carriage 11. According to FIG. 4C, this is the point in time at which first carriage 9 is adjusted to a maximum in direction of production R. At this point in time, second gripper 12 has already left sealing station 2.

[0055] FIG. 4D shows the opening motion of two grippers 10, 12 for delivering the trays to sealing station 2 or transferring sealed trays 3 to outfeed belt 5. Two grippers 10, 12 can be opened at the same time in a manner coordinated with one another.

[0056] FIGS. 3B and 4C show different variants of how control device 14 can control minimum distance x between first carriage 9 and second carriage 11. According to FIG. 3B, minimum distance x is present when second carriage 11 begins to move in direction of production R. According to FIG. 4C, minimum distance x is present when first carriage 9 is adjusted to the maximum in direction of production R.

[0057] FIGS. 5A to 5C show a further variant of how the motion of gripper device 6 can be controlled by way of control device 14 for moving to a minimum distance x between first carriage 9 and second carriage 11.

[0058] FIG. 5A shows an initial situation in which second gripper unit 8 is adjusted both in a direction opposite to direction of production R as well as transverse to direction of production R. On the basis of this adjusting and closing motion at the same time, it is possible for second gripper 12 to already carry out a closing motion S transverse to direction of production R during the adjusting motion of second carriage 11 in a direction opposite to direction of production R (see FIG. 5B). Control device 14 can control the opening of lifting mechanism 13, closing motion S of second gripper 12, and the adjusting motion of second carriage 11 carried out in a direction opposite to direction of production R such that predetermined minimum distance x is present between first and second carriage 9, 11 when second carriage 11 has arrived at an end position in a direction opposite to direction of production R in accordance with FIG. 5C. At this point in time, first carriage 9 has already moved so far towards sealing station 2 that predetermined minimum distance x is present between first and second carriage 9, 11. From the initial situation in FIG. 5A, the return motion shown of first gripper unit 7, similar to the motion of second gripper unit 8, can likewise take place at the same time in a direction opposite to direction of production R and transverse to direction of production R in for collecting trays 3 provided on infeed belt 4.