Film wrapping module for containers as a component of a packaging machine, and method thereof

Abstract

A wrapping unit that wraps a container pack with a piece of film as it moves along a container-transport path includes a linear transporter having an electromagnetic linear drive. This linear transporter circulates movement elements in a common direction around a closed movement-path. Each of these movement elements has a gripping head arranged thereon.

Claims

1. An apparatus for concurrently wrapping container packs along a container-transport path with film, wherein each container pack comprises a plurality of containers, wherein said apparatus comprises a wrapping unit, said wrapping unit comprising an electromagnetic direct drive and movement elements, wherein said electromagnetic linear drive has a closed movement path beside said container transport path, wherein said movement elements circulate in a common direction along said closed movement path, wherein said movement elements are individually controllable along said closed movement path, wherein said movement elements comprise first and second movement elements that wrap corresponding first and second container packs such that said first and second movement elements wrap their corresponding container packs concurrently, whereby said first and second container packs are transported by said container transport path at the same time while said first and second container packs are being wrapped by said first and second movement elements, wherein, in operation, different movement elements move at different velocities, wherein each movement element comprises a gripping head arranged thereon, wherein said closed movement-path comprises an outward run having an end section, and a handover section that ascends from below a transport plane and merges into said end section, wherein said closed-movement path runs parallel to said transport plane, wherein said end section is adjoined by a first deflection region that is adjoined by a descending movement section that is guided from above said transport plane to below said transport plane and that merges into an end section of a return run running parallel to said transport plane, said end section being adjoined by a second deflection region that is adjoined by said handover section, and wherein said first and second deflection regions have the same inclination.

2. The apparatus, claim 1, wherein said gripping head comprises a guide rod, wherein said guide rod comprises a bar-shaped element that extends transversely to said closed movement-path at least along a sub-section of an outward run thereof.

3. The apparatus of claim 1, wherein each movement element comprises a gripping-head set that includes said gripping head, and wherein said gripping head is controllable independently of any other gripping head in said gripping-head set.

4. The apparatus of claim 1, wherein said outward run and a return run are separated by an adjustable distance.

5. The apparatus claim 1, wherein said closed movement path has an adjustable height above said transport plane, and wherein raising and lowering said closed movement path adjusts said adjustable height.

6. The apparatus claim 1, wherein said movement element comprises a driven gripping head, a guide rod, and a coupling element connecting said gripping head and said guide rod.

7. The apparatus of claim 1, wherein said closed movement-path comprises an outward run and a return run, and wherein plural movement elements move along said outward run concurrently.

8. A method comprising providing container packs to be wrapped, each container pack comprising containers, and wrapping two or more container packs at the same time, wherein wrapping two or more container packs at the same time comprises individually controlling velocities of movement elements of an electromagnetic direct drive as said movement elements circulate in a common direction around a closed movement path, using a gripping head on a first movement element, gripping a first piece of film that is to be wrapped around a first container pack moving along a container-transport path, and wrapping said first container pack with said first piece of film, using a gripping head on a second movement element, gripping a second piece of film that is to be wrapped around a second container pack moving along said container-transport path, and wrapping said second container pack with said second piece of film concurrently with wrapping said first container pack.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a side view of a wrapping unit,

(2) FIG. 2 is an alternative embodiment of the wrapping unit shown in FIG. 1,

(3) FIG. 3 shows the feeding of the film shortly before it makes contact with the container pack according to FIG. 2, and

(4) FIGS. 4a and 4b show the position of the film and of the container pack immediately after the container pack has travelled over the film in the embodiment according to FIG. 2.

DETAILED DESCRIPTION

(5) FIG. 1 shows a transport unit 2 that includes an inlet conveyor 2.1, a wrapping conveyor 2.2, and an outlet conveyor 2.3 that adjoins a shrink tunnel 30. A wrapping unit 4 is arranged along the transport unit 2. The wrapping unit 4 wraps container packs 1 with film segments 3 as the container packs 1 move along a transport plane defined by the transport unit 2.

(6) A supply-and-film-cutting unit 20 cuts incoming film into film segments 3, each of which has a front end 3.1 and a rear end 3.2. The supply-and-film-cutting unit 20 provides these film segments 3 to the wrapping unit 4.

(7) A gripping-and-holding element guides each film segment 3 through a first gap 9 located between the inlet conveyor 2.1 and the wrapping conveyor 2.2 so that the film segment 3 crosses into the transport plane just in front of a container pack 1 to be wrapped. In a subsequent downward or return movement, which occurs at the opposite end of the wrapping conveyor 2.2, the gripping-and-holding element passes through a second gap 10 at the end of the wrapping conveyor 2.2.

(8) The wrapping unit 4 includes a linear transporter 5 having a closed movement-path 5.1 that has an outward run 5a and a return run 5b. Between the outward run 5a and the return run 5b are first and second deflection-sections 5c, 5d. In one embodiment, the linear transporter 5 is an electromagnetic drive that actuates and moves movement elements 6 independently of each other. In operation, these movement elements 6 circulate in a common direction B along this closed movement-path 5.1.

(9) In some embodiments, these movement elements 6 are runners, and in others, the movement elements 6 are movers. In either case, each movement element 6 includes a gripping element 7. In the embodiment shown in FIG. 1, the gripping element is a bar-shaped guide rod on which the film segment rests loosely. Each guide rod has a circular, semi-circular, or polygonal cross-section and extends transversely to a transport path of the container packs 1.

(10) FIG. 1 shows a first container pack 1a on the inlet conveyor 2.1, second, third, and fourth container packs 1b, 1c, 1d located on the wrapping conveyor 2.2 and downstream of the first gap 9, and a fifth container pack 1e on the outlet conveyor 2.3. All the container packs 1a-1d are of comparable size. Each container pack 1a-1d stands on a front end 3.1 of a corresponding film segment 3.

(11) Meanwhile, the movement elements 6, and thus the gripping elements 7, move relative to their corresponding container packs so that the rear end 3.2 of a corresponding film segment 3, just before the end of the wrapping step, protrudes only as far as absolutely necessary for it still to be securely held. As a movement element 6 approaches the end of the wrapping conveyor 2.2, it executes a downward movement. FIG. 1 shows one movement element 6 caught in the middle of such a downward movement as it wraps a film segment 3 around the fourth container pack 1d. The movement element 6 travels downward past the position shown in FIG. 1 and past the fourth container pack 1d, ultimately releasing the rear end 3.2 of the film segment 3 so that the fourth container pack 1d can run over it, as the fifth container pack 1e has already done.

(12) Because the linear transporter 5 can independently control each movement element, only a few movement elements 6 need to be provided in a waiting position at the end of the return run 5b. This is because it is possible to accelerate a movement element 6 back from the end of the outward run 5a to the end of the return run 5b. In principle, a backward movement of the movement element 6 is also possible, but this is not useful during normal operation.

(13) FIG. 2 is comparable with FIG. 1 but with different movement elements 6. In FIG. 1, each movement element 6 includes a driven gripping head 6.1 coupled to a guide rod 7 via a coupling element 15. The gripping head 6.1 grips a film segment 3 from the front or from the front and side. The rear end 3.2 of a film segment 3 rests loosely over the guide rod 7.

(14) As can be seen in FIG. 3, by actively guiding the front end 3.1, it becomes possible to control the extent to which a container pack 1a overlays a front end 3.1 of the film segment 3 as the inlet conveyor 2.1 advances it. The release of the film segment 3 from the gripping head 6.1 can therefore take place simultaneously since the container pack 1a pulls the film segment 3 out of the opening or just-opened grippers of the gripping head 6.1.

(15) The free front-end 3.1 can thus always be selected to be long enough to rest securely on the outward run of the wrapping conveyor 2.2 but to avoid passing a front deflection-section and to avoid being conveyed below the transport plane.

(16) FIG. 4b shows the instant at which the film segment 3 is released from the gripping head 6.1. A malfunction is thus also avoided, as shown in FIG. 4b, even with a relatively wide first gap 9.

(17) FIG. 4a shows the configuration of FIG. 4b in a side view as seen from the transport direction. It is usually sufficient if the driven gripping head 6.1, the guide rod 7 and the coupling element 15 are provided on just one side.

(18) The coupling element 15 is mounted on the gripping head 6.1 in a suitable articulated manner and is guided in the region of the linear transporter 5. A mounting and/or motor drive on both sides may be advantageous, depending on the desired output and load situation.

(19) Because of the flexibility with which movement elements 6 can be moved, it becomes possible to process a much larger range of product sizes using the same wrapping unit.

(20) This flexibility in processing different product sizes can be even further increased by providing a height adjustment or change in height of a running path. In this case, it is useful to provide a vertical course of the movement path or of the linear conveyor in the region of the first and second gaps 9, 10.

(21) In the embodiment shown in FIG. 1, the wrapping unit 4 is part of a packaging machine that includes a shrink tunnel 30 for shrinking the film segments 3 onto the container packs 1a-1e. In some embodiments, a stacking unit for placing container packs one on top of the other is installed upstream of the wrapping unit 4.

(22) Having described the invention, and a preferred embodiment thereof, what is new, and secured by letters patent is: