Tray sealer

Abstract

The invention relates to a tray sealer with a gripper system comprising a pivot mechanism with vertically disposed pivot axles to move gripper arms relative to each other and parallel to a transport plane.

Claims

1. Tray sealer comprising: a closing device; a collection belt; a discharge belt; and a gripper system including: a transfer carriage moveable between a first position and a second position, and disposed outside the closing device; at least two guides for said transfer carriage; a linear actuator for driving said transfer carriage along said at least two guides; at least two gripper arms, wherein said at least two gripper arms extend from the transfer carriage through the closing device; a pivot mechanism for moving said gripper arms, wherein said pivot mechanism comprises a plurality of pivot axles, each pivot axle disposed for rotation and having a substantially vertical axis of rotation, and wherein rotation of the plurality of pivot axles translate said at least two gripper arms relative to each other between an open position and a gripping position and in a plane parallel to a substantially horizontal transport plane of the trays; and a pivot drive for driving said pivot mechanism; and wherein when said at least two gripper arms are disposed in the gripping position, a first portion of said at least two gripper arms is positioned over the collection belt at said first position of the transfer carriage and a second portion of said at least two gripper arms is positioned over the discharge belt at said second position of the transfer carriage.

2. Tray sealer according to claim 1, wherein said pivot mechanism comprises at least one parallelogram linkage operably connected to each of the at least two gripper arms.

3. Tray sealer according to claim 2, wherein said pivot axles are coupled to each other by a lever mechanism such that said at least one parallelogram linkage for each gripper arm can be moved synchronously.

4. Tray sealer according to claim 2, wherein said at least one parallelogram linkage is connected to an end of each respective said at least two gripper arms.

5. Tray sealer according to claim 1, wherein said transfer carriage is drivable by said linear actuator using a toothed belt drive.

6. Tray sealer according to claim 1, wherein said pivot mechanism is drivable by said pivot drive using a first and a second shaft.

7. Tray sealer according to claim 6, wherein one or more of said plurality of pivot axles of said pivot mechanism can be driven by a rotation of one of the first shaft, the second shaft, or a lever mechanism provided on said transfer carriage.

8. Tray sealer according to claim 1, wherein said at least two guides are positioned downstream of said closing device in a direction of transport of said tray sealer.

9. Tray sealer according to claim 1, wherein said at least two guides and said transfer carriage are provided below said transport plane.

10. Tray sealer according to claim 1, wherein said linear actuator and/or said pivot drive comprise a servo motor.

11. A gripper system for a packaging machine, said gripper system comprising: a transfer carriage; at least two guides for said transfer carriage; a linear actuator for driving said transfer carriage along said at least two guides; at least two gripper arms; a pivot mechanism for moving said at least two gripper arms, wherein said pivot mechanism comprises at least a first pivot axle and a second pivot axle, each pivot axle disposed for rotation and having a substantially vertical axis of rotation, wherein said first pivot axle is operably connected to a first gripper arm and said second pivot axle is operably connected to a second gripper arm, and wherein rotation of the at least two pivot axles move said first gripper arm and said second gripper arm relative to each other and in a plane parallel to a substantially horizontal transport plane of a plurality of packages of the packaging machine, and wherein said first gripper arm remains substantially parallel to said second gripper arm during said relative movement; and a pivot drive for driving said pivot mechanism.

12. A gripper system for a packaging machine, said gripper system comprising: a transfer carriage; at least two guides for supporting and guiding the movement of said transfer carriage; a linear actuator for selectively moving said transfer carriage relative to said at least two guides in and against a direction of transport of the packaging machine; a pivot mechanism for moving a first gripper arm and a second gripper arm in a direction substantially perpendicular to the direction of transport of the packaging machine, wherein said pivot mechanism comprises a first pivot axle and a second pivot axle, the first pivot axle being disposed for rotation about a substantially vertical axis of rotation and being operably connected to said first gripper arm by a first linkage, and said second pivot axle being disposed for rotation about a substantially vertical axis of rotation and being operably connected to said second gripper arm by a second linkage, wherein rotation of said first and second pivot axles causes relative movement of said first gripper arm to said second gripper arm in a direction toward or away from each other in a plane parallel to a substantially horizontal transport plane of a plurality of packages of the packaging machine; and a pivot drive for driving said pivot mechanism to cause rotation of said first pivot axle and said second pivot axle; wherein said first linkage is at least a portion of a first parallelogram linkage and wherein said second linkage is at least a portion of a second parallelogram linkage, wherein the first parallelogram linkage and said second parallelogram linkage are disposed to maintain said first gripper arm in a substantially parallel relationship with said second gripper arm during the relative movement of said first gripper arm and said second gripper arm in said direction toward or away from each other.

Description

DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

(1) In the accompanying drawing, which forms a part of the specification and is to be read in conjunction therewith in which like reference numerals are used to indicate like or similar parts in the various views:

(2) FIG. 1 is a side perspective view of a tray sealer in accordance with one embodiment of the present invention;

(3) FIG. 2a is plan view of a gripper system in the open position in accordance with one embodiment of the present invention;

(4) FIG. 2b is a plan view of the gripper system of FIG. 2a in the closed position for gripping the trays from the feeding belt and a closing device;

(5) FIG. 2c is a plan view of the gripper system of FIG. 2a after a motion in the direction of transport;

(6) FIG. 2d is a plan view of the gripper system of FIG. 2a in the open position for placing trays in the closing device and onto the discharge belt;

(7) FIG. 3 is a side perspective view of a gripper system as a separate module in accordance with one embodiment of the present invention;

(8) FIG. 3a is a sectional view of the gripper system of FIG. 3 from a direction opposite to the direction of transport in a first position;

(9) FIG. 3b is a sectional view of the gripper system of FIG. 3 from a direction opposite to the direction of transport in a second position;

(10) FIG. 4a is a plan view of the gripper arms and the pivot mechanism in the open position in accordance with one embodiment of the present invention;

(11) FIG. 4b is a plan view of the gripper arms and the pivot mechanism of FIG. 4a in an intermediate position; and

(12) FIG. 4c is a plan view of the gripper arms and the pivot mechanism of FIG. 4a in the closed position.

(13) Identical components are throughout the figures designated with the same reference numerals.

DETAILED DESCRIPTION OF THE INVENTION

(14) The invention will now be described with reference to the drawing figures, in which like reference numerals refer to like parts throughout. For purposes of clarity in illustrating the characteristics of the present invention, proportional relationships of the elements have not necessarily been maintained in the drawing figures.

(15) The following detailed description of the invention references specific embodiments in which the invention can be practiced. The embodiments are intended to describe aspects of the invention in sufficient detail to enable those skilled in the art to practice the invention. Other embodiments can be utilized and changes can be made without departing from the scope of the present invention. The present invention is defined by the appended claims and the description is, therefore, not to be taken in a limiting sense and shall not limit the scope of equivalents to which such claims are entitled.

(16) FIG. 1 shows a perspective view of a tray sealer (i.e., a tray sealing packaging machine) 1 according to one embodiment of the present invention. The tray sealer 1 comprises a machine frame 2 on which a closing device 3 (e.g., a sealing station) is arranged for closing and possibly for sealing and/or evacuating and/or gas flushing supplied trays 4, as well as for cutting a top filmnot shownused for closing. As show, the packaging machine 1 further comprises a conveyor belt 5 and a collection belt 6 for supplying the trays 4 filled with the product, a discharge belt 7 for conveying the sealed trays 4a away, a film feeder roller 9 for taking up and delivering a top film, and a film trim winder 10 for winding the film sheet of the top film that remains after the sealing process. A display 11 allows the operator of the tray sealer 1 to monitor and control the operation of the tray sealer 1. A gripper system 12 can comprise a transfer carriage 13, a pivot mechanism 14 and two gripper arms 15. The motion of the gripper system 12 in and against a direction of transport R can be performed from the collection belt 6 into the closing device 3 for introducing unclosed trays 4, and is performed from the closing device 3 onto the discharge belt 7 for extracting the closed trays 4a. The transport surfaces of the belts 6, 7, 8 for the trays 4, 4a define the horizontal transport plane E.

(17) The mode of operation of the gripper system 12 shall be explained using FIGS. 2a to 2d. FIG. 2a shows a plan view of a gripper system 12 in the open position. The transfer carriage 13 can be movable in the direction of transport R using guides 16 and is driven by a linear actuator 17 (see FIG. 3). The transfer carriage 13 has a pivot mechanism 14 attached (see FIG. 3) which can comprise a parallelogram linkage 18 for each gripper 15. A pivot drive 19 (see FIG. 3) may be provided for closing and opening the gripper arms 15.

(18) After opening the sealing device 3, as shown in FIG. 2b, the gripper arms 15 perform a closing motion towards each other in a horizontal plane and grip two trays 4a which were closed with a top film, and two trays 4 which were provided on the collection belt 6.

(19) The transfer carriage 13 can move in the direction of transport R in order to convey the trays 4 from the collection belt 6 into the closing device 3, and the closed trays 4a from the closing device 3 via the discharge belt 7, as shown in FIG. 2c. The motions are illustrated by arrows.

(20) FIG. 2d illustrates how the gripper arms 15 are moved apart, so that the trays 4a can be conveyed away on the discharge belt 7 to a next production step, and the new trays 4 can be closed in the closing device 3. This cycle starts over again after the transfer carriage 13 has been moved back in the direction opposite to the direction of transport R.

(21) FIG. 3 shows a perspective view of the gripper system 12 as a separate module without the guides 16, but with the transfer carriage 13, the linear actuator 17 and the pivot drive 19 for the closing motion of the gripper arms 15. The linear actuator 17 is attached in a stationary manner to the machine frame 2 and may move the transfer carriage 13 along the guides 16presently not shownusing a toothed belt drive 20. Alternatively, also flat belts, chains or a spindle drive can be used. The pivot drive 19 is also mounted in a stationary manner on the machine frame 2 and rotates a first shaft 21. By using levers 22 provided at the ends of the first shaft 21, a second shaft 23 may be rotated about the first shaft 21 in order to be able to transmit a torque to the pivot mechanism 14, while the pivot mechanism 14 is guided along the two shafts 21, 23.

(22) As is shown in FIGS. 3a and 3b in a sectional view, the pivot drive 19 can provide a torque transfer, via the two shafts 21, 23 and the lever 22 by using a lever mechanism 25, onto each of the pivot axles 24 of the parallelogram linkage 18, which are in the transfer carriage 13 rotatably mounted. The parallelogram linkage 18 ensures that the gripper arms 15 aligned in parallel to the direction of transport R also move in parallel to each other during the opening and closing motion in order to be able to precisely grip the trays 4, 4a. The rotational motion of the lever 22 and the closing of the gripper arms 15 are shown by arrows in FIG. 3b.

(23) The relationship of the motions of the transfer carriage 13 and the gripper arms 15 is explained using FIGS. 4a, 4b and 4c. FIG. 4a shows a plan view of a gripper system 12 in the open position. During the closing motion of the gripper arms 15 for gripping the trays (presently not shown), the gripper arms 15 must maintain their position relative to the direction of transport R. During the pivot motion of the parallelogram linkage 18, there is a relative motion of the gripper arms 15 vis--vis the transfer carriage 13. This relative motion can be compensated by a motion by the transfer carriage 13. This means that the linear actuator 17 (see FIG. 3) during the closing motion of the gripper arms 15 is coupled to the pivot drive 19 (see FIG. 3), for example, via a common controller, in a manner that such a closing motion of the gripper arms 15 is enabled. Servo motors can be provided for the linear actuator 17 and the pivot drive 19. Furthermore, FIGS. 4a and 4c show that the space required for the pivot mechanism 14, in particular of the parallelogram linkage 18, is small while it is still possible to grip both very narrow trays 4 as well as very wide trays 4 without having to make any modifications to the gripper system 12. Flexibility is thereby increased and set-up times are reduced.

(24) It is also conceivable that the transfer carriage 13 and the guides 16 are provided below the collection belt 6. FIGS. 1 to 4c show a single lane tray sealer 1 for the simultaneous closing of two trays 4. The tray sealer 1 according to the invention can also be embodied as a multi-track tray sealer 1 and is conceivable for any number of trays 4.

(25) From the foregoing, it will be seen that this invention is one well adapted to attain all the ends and objects hereinabove set forth together with other advantages which are obvious and which are inherent to the structure. It will be understood that certain features and sub combinations are of utility and may be employed without reference to other features and sub combinations. This is contemplated by and is within the scope of the claims. Since many possible embodiments of the invention may be made without departing from the scope thereof, it is also to be understood that all matters herein set forth or shown in the accompanying drawings are to be interpreted as illustrative and not limiting.

(26) The constructions and methods described above and illustrated in the drawings are presented by way of example only and are not intended to limit the concepts and principles of the present invention. Thus, there has been shown and described several embodiments of a novel invention. As is evident from the foregoing description, certain aspects of the present invention are not limited by the particular details of the examples illustrated herein, and it is therefore contemplated that other modifications and applications, or equivalents thereof, will occur to those skilled in the art. The terms having and including and similar terms as used in the foregoing specification are used in the sense of optional or may include and not as required. Many changes, modifications, variations and other uses and applications of the present construction will, however, become apparent to those skilled in the art after considering the specification and the accompanying drawings. All such changes, modifications, variations and other uses and applications which do not depart from the spirit and scope of the invention are deemed to be covered by the invention which is limited only by the claims which follow.