Patent Application
20180111774
This application is related to application no. 16194883.1, filed Oct. 20, 2016, in the European Patent Office, the complete disclosure of which is incorporated herein by reference and to which priority is claimed.
Unwrapping apparatuses are used in practice in order to unwrap a goods stack packaged with a film. The film is removed upon unwrapping, a winding mandrel that is supported at the upper end being guided around the goods stack that is to be unwrapped. The film is gripped by the winding mandrel and wound onto it. It is disadvantageous in this context that stretch films in particular tend to stick, so that the film adheres to the winding mandrel. After each unwinding operation, the stretch film must be laboriously unrolled manually from the winding mandrel for the next unwrapping operation. For wound-on shrink-wrap films, the winding mandrel must firstly be moved oppositely to the rotation direction upon unwrapping, so that the film can slip off the winding mandrel.
An object of the invention is to describe a method that avoids the disadvantages recited above and makes possible simple removal of the wound-on film from the winding mandrel.
This object is achieved by a method for transferring a film, preferably a wound-on stretch film, wound onto a winding mandrel, oriented in particular vertically and preferably supported exclusively in the region of its upper end, of an unwrapping apparatus, such that when the transfer position of the winding mandrel is reached, the film wound onto the winding mandrel is pulled off the winding mandrel by means of at least one transfer device and delivered to a disposal area. The transfer device can be embodied, for example, as a gripping device that grips the film by means of corresponding grippers and pulls it off the winding mandrel. The film can then be delivered to a disposal area. By means of the method according to the present invention, the film is pulled off considerably more quickly than if a film were to slip downward, solely under its own weight, off the winding mandrel. Any type of film can be pulled off by means of the method according to the present invention. The method is also suitable in particular for pulling off stretch films, which tend to stick. These can be pulled off easily and quickly from the winding mandrel.
The winding mandrel on the one hand, and at least a sub-region of the transfer device, preferably the entire transfer device, on the other hand, can be displaceable relative to one another in a horizontal direction and/or in a vertical direction. For a corresponding displacement, the winding mandrel and/or the transfer device can each be mounted, for example, on a horizontally displaceable carriage. If a vertical displacement is desired, the winding mandrel and/or the transfer device can each be connected, for example, to a cylinder acting in vertical terms.
It is useful if at least a sub-region of the transfer device, preferably the entire transfer device, is horizontally and/or vertically displaceable.
The film wound onto the winding mandrel can protrude at the bottom with respect to the lower end of the winding mandrel, forming a fringe. The film can be immobilized in the region of the fringe for the transfer operation in secure and simple fashion, for example by clamping, and then pulled off.
It is useful if a displacement of the winding mandrel and/or a displacement at least of a sub-region of the transfer device, preferably of the entire transfer device, occurs without contact between the fringe and the transfer device. This ensures that the orientation of the fringe prior to displacement and the orientation of the fringe after displacement remains unchanged, and that the fringe has not become folded over due to contact upon displacement. The fringe of course also does not come into contact, upon displacement, with any other component of the apparatus for carrying out the method.
In the transfer position, the lower end of the winding mandrel can be arranged above the transfer device, i.e. in the region above the transfer device.
At least one transfer device can encompass at least one drivable roller that interacts with the adjacent sub-region of the winding mandrel in order to pull off the film. The sub-region is preferably made up of a friction-minimizing material or has a friction-minimizing coating. The surface of the sub-region can, for example, also have been treated in friction-minimizing fashion.
At least one transfer device can encompass at least two rollers that form a gap between them and preferably are displaceable with respect to one another in order to modify the width of the gap, at least one of the two rollers being driven by a drive system.
In order to convey the film to the disposal area, an aspiration system encompassing a suction opening can be used for further transport of the film that is in the process of being pulled off.
Unwrapping apparatuses are used in practice in order to unwrap a goods stack packaged with a film. The film is removed upon unwrapping, a winding mandrel that is supported at the top being guided around the goods stack that is to be unwrapped. The film is gripped by the winding mandrel and wound onto it. It is disadvantageous in this context that stretch films in particular tend to stick, so that the film adheres to the winding mandrel. After each unwinding operation, the stretch film must be laboriously unrolled manually from the winding mandrel for the next unwrapping operation. For wound-on shrink-wrap films, the winding mandrel must firstly be moved oppositely to the rotation direction upon unwrapping so that the film can slip off the winding mandrel.
An object of the invention is to describe an apparatus that avoids the disadvantages recited above and makes possible simple removal of the wound-on film from the winding mandrel.
This object is achieved by an apparatus for transferring a film, preferably a wound-on stretch film, wound onto a winding mandrel, oriented in particular vertically and preferably supported exclusively in the region of its upper end, of an unwrapping apparatus, in particular for carrying out the method according to one of the Claims, the apparatus encompassing at least one transfer device for pulling off the film wound onto the winding mandrel when the transfer position of the winding mandrel is reached. The transfer device can be embodied, for example, as a gripping device that grips the film by means of corresponding grippers and pulls it off the winding mandrel. The film can then be delivered to a disposal area. By means of the apparatus according to the present invention, the film is pulled off considerably more quickly than if a film were to slip downward, solely under its own weight, off the winding mandrel. Any type of film can be pulled off by means of the apparatus according to the present invention. The apparatus is also suitable in particular for pulling off stretch films, which tend to stick. These can be pulled off easily and quickly from the winding mandrel,
The winding mandrel on the one hand, and at least a sub-region of the transfer device, preferably the entire transfer device, on the other hand, can be arranged displaceably relative to one another in a horizontal direction and/or in a vertical direction. For a corresponding displacement, the winding mandrel and/or the transfer device can each be mounted, for example, on a horizontally displaceable carriage. If a vertical displacement is desired, the winding mandrel and/or the transfer device can each be connected, for example, to a cylinder acting in vertical terms.
At least a sub-region of the transfer device, preferably the entire transfer device, can be arranged horizontally and/or vertically displaceably.
At least one transfer device can encompass at least one drivable roller that interacts with the adjacent sub-region of the winding mandrel in order to pull off the film. The sub-region is preferably made up of a friction-minimizing material or has a friction-minimizing coating. The surface of the sub-region can, for example, also have been treated in friction-minimizing fashion.
At least one transfer device can encompass at least two rollers that form a gap between them and preferably are displaceable with respect to one another in order to modify the width of the gap, at least one of the two rollers being driven by a drive system.
The two rollers that form a gap between them, and are closest to the, preferably lower, end of the winding mandrel, can be oriented horizontally,
The two rollers that form a gap between them, and are closest to that end of the winding mandrel over which the film is to be pulled off, can furthermore be arranged in alignment with that end of the winding mandrel over which the film is to be pulled off. The film can thus be securely gripped by the rollers for the purpose of being pulled off.
At least a sub-region of the surface of at least one drivable roller can comprise a friction-increasing surface, for example a rubber coating. The film can thereby be effectively pulled off.
In order to convey the film to the disposal area, the apparatus can comprise an aspiration system encompassing a suction opening for further transport of the film that is in the process of being pulled off.
It is useful in this context if the suction opening is arranged in alignment with that end of the winding mandrel over which the film is to be pulled off.
A delivery device, in particular a delivery device embodied as a funnel, can furthermore be provided in order to deliver the pulled-off film to the disposal area. A configuration of this kind is useful, for example, if the disposal area is embodied as a container and if the film pulled off by the transfer device is transferred solely by its own weight, after being pulled off, into the container preferably arranged below the transfer device.
The apparatus can comprise, in the region in which the winding mandrel is located in its transfer position, a detection device that activates the transfer device upon detection of a winding mandrel having a film wound thereunto. The detection device can be embodied, for example, as a light barrier.
The invention will be explained below with reference to the drawings, in which:
In all the Figures, matching reference characters are used for identical or similar components.
A goods stack 1 is, as a rule, arranged on a pallet 2 and is secured with a film 3. Such a film 3 can be, for example, a shrink-wrap film, a stretch film, a stretch hood film, or a stretch wrap film. A goods stack 1 packaged with such a film 3 is unwrapped using an unwrapping apparatus, for subsequent removal of the individual goods of goods stack 1.
An unwrapping apparatus comprises a frame 4 having a winding mandrel 5. Winding mandrel 5 is movable in all directions in a horizontal direction by way of a configuration that is not depicted in further detail. Winding mandrel 5 can thereby be guided externally around goods stack 1 along the side edges for the purpose of unwrapping.
Winding mandrel 5 can be rotated around its own longitudinal axis by means of a drive system (not depicted), and is supported in the region of its upper end and is oriented vertically. The lower end of winding mandrel 5 is freely suspended. Winding mandrel 5 is usually split in two when viewed in its longitudinal dimension, and is made up of a stationary bar and a bar that is pivotable with respect to the stationary bar,
An unwrapping apparatus furthermore usually comprises an aspiration device (not depicted in further detail) and a cutting device (not depicted in further detail). For unwrapping purposes, the aspiration device is moved against goods stack 1, the aspiration device being aspirated into place against film 3. The aspiration device is then moved via a cylinder toward winding mandrel 5. As a result, the aspirated film 3 is pulled against the cutting device and film 3 is thereby cut through vertically. If film 3 also comprises an underlayer, that is also cut through vertically,
The free vertical edge of film 3 is then introduced into the interstice between the stationary bar and the pivotable bar. Once the pivotable bar is swung in, the corresponding edge of film 3 is clamped in between the stationary bar and the pivotable bar. Winding mandrel 5 then rotates around its longitudinal axis and is moved simultaneously around goods stack 1 so that film 3 is thereby wound on. If film 3 also comprises an underlayer, film 3 is wound on in that region as well.
The speed at which winding mandrel 5 is guided around the rectangular goods stack 1, and the rotation speed of winding mandrel 5, are coordinated with the contour of goods stack 1 so that film 3 is uniformly wound on upon unwrapping. During unwrapping of the first two side surfaces film 3 can be immobilized, for example by means of PTFE clamping pieces, centeredly on that side surface of goods stack 1 which is located oppositely from the cut side. In supplementary fashion, film 3 can also be held by means of PTFE clamping pieces at the fourth corner, i.e. the last corner of goods stack 1 that is unwrapped, until shortly before the end of the unwrapping process.
As is evident from the Figures, the unwrapping apparatus encompasses a conveyor 6 on which goods stack 1 to be unpacked is transported into frame 4. Arranged in the region of the unwrapping apparatus in conveyor 6 is a lifting system 6′ in order to allow goods stack 1 to be raised for unwrapping purposes. Arranged next to conveyor 6 is a transfer device 7 that comprises, in the exemplifying embodiment depicted, two rollers 8 that form a gap between them. Rollers 8 are displaceable with respect to one another by means of a drive system (not depicted) in order to modify the width of the gap. At least one of the two rollers 8 is drivable by means of a drive system (not depicted). In
Upon unwrapping, a holddown 9 is usually lowered onto the upper side of goods stack 1 in order to stabilize goods stack 1 during unpacking; this is helpful in particular with products that shift easily, and is visible in
In
Once winding mandrel 5 has pulled film 3 completely off, winding mandrel 5 is displaced horizontally into its transfer position, this being depicted in
Transfer device 7 is then raised vertically, this being depicted in
Rollers 8 are then moved toward one another so that the gap becomes smaller and fringe 11 becomes clamped between rollers 8. After clamping, at least one of the two rollers 8 is caused to move by means of a drive system (not depicted in further detail) so that film 3 is pulled downward off winding mandrel 5. In the exemplifying embodiment depicted, for example as is apparent from
In the embodiment according to
| Number | Date | Country | Kind |
|---|---|---|---|
| 16194883.1 | Oct 2016 | EP | regional |
