METHOD FOR CREATING AT LEAST ONE OPENING IN A SHEATH, MADE OF STRETCH FILM, THAT RETAINS A GOODS STACK ARRANGED ON A PALLET, AND SHAPING APPARATUS FOR CARRYING OUT THE METHOD
20180282007 ยท 2018-10-04
Inventors
Cpc classification
B65D2571/00012
PERFORMING OPERATIONS; TRANSPORTING
B65B47/04
PERFORMING OPERATIONS; TRANSPORTING
B65D2571/00006
PERFORMING OPERATIONS; TRANSPORTING
B65D71/0088
PERFORMING OPERATIONS; TRANSPORTING
B65B47/02
PERFORMING OPERATIONS; TRANSPORTING
B65D71/0096
PERFORMING OPERATIONS; TRANSPORTING
International classification
Abstract
A method for creating an opening in a sheath, made of stretch film, that retains a goods stack arranged on a pallet. The pallet comprising an upper-side deck surface as support for the goods stack and lower-side support feet. The sheath engages under the support feet arranged in the region of the four outer edges of the pallet. At least one opening is in the sheath between two support feet . At least one opening is generated such that the sheath is first heated, the heated sheath is retracted from the pallet and then, still in the heated state, displaced upward. The upwardly displaced sheath is secured in its upwardly displaced position by cooling. The invention also relates to a shaping apparatus, and additionally to at least one heating device for carrying out the method.
Claims
1. A method for creating at least one opening in a sheath (17), made of stretch film, that retains a goods stack arranged on a pallet (2), the pallet (2) comprising an upper-side deck surface (23) as support for the goods stack and several lower-side support feet (19, 20, 21) arranged at a distance from one another and forming foot openings (16), and the sheath (17) engaging at least partly under the lower side of the support feet (19, 20, 21) arranged in the region of the four outer edges of the pallet (2), and at least one opening being introduced into the sheath region (18) located between two support feet (19 or 20 or 21) that are arranged in a row having at least two support feet (19, 20, 21), wherein at least one opening is generated in such a way that the sheath region (18) is firstly heated; then the heated sheath region (18) is retracted from the pallet (2) and then, still in the heated state, displaced upward, the upwardly displaced sheath region (18) then being secured in its upwardly displaced position by cooling.
2. The method according to claim 1, wherein the heated sheath region (18) is retracted from the pallet (2) only when heating of the sheath region (18) is entirely completed.
3. The method according to claim 1, wherein the pallet (2) is lifted before the sheath region (18) is heated.
4. The method according to claim 1, wherein the upward displacement occurs as far as the deck surface (23), preferably somewhat below the deck surface (23).
5. The method according to claim 1, wherein upon the upward displacement of the sheath region (18), the sheath (17) is pulled around the respective lower inner edge of the two support feet (19 or 20 or 21).
6. The method according to claim 1, wherein the two support feet (19, 20, 21) are directly adjacent or are the outermost support feet of a row.
7. The method according to claim 1, wherein the sheath (17) is secured on the lower side of the two support feet (19, 20, 21) before and/or after the sheath region (18) is retracted from the pallet (2), and/or before and/or after the upward displacement of the sheath region (18).
8. The method according to claim 1, wherein the retraction and/or upward displacement of the sheath region (18) from the pallet (2) occurs in such a way that the sheath (17) still remains secured on the lower side of the two support feet (19, 20, 21).
9. The method according to claim 1, wherein a stretch hood or stretch tube is used as a sheath (17).
10. The method according to claim 1, wherein during retraction and/or upward displacement of the sheath region (18), at least a sub-region of the sheath (17) is at least temporarily secured with respect to the pallet (2) from outside in a horizontal direction, preferably by pressure application, at least in at least one region close to a foot opening (16) above the sheath region (18).
11. The method according to claim 1, wherein at least the upwardly displaced sheath region (18) that is still in the heated state is displaced back toward the pallet (2) before cooling.
12. The method according to claim 11, wherein the displacement back toward the pallet (2) at least of the upwardly displaced sheath region (18) that is still in the heated state occurs, before cooling, sufficiently far toward the pallet (2) that the stretched-out sheath region (18) and/or the respective sub-regions of the sheath (17) laterally contiguous to the sheath region (18) is/are at least somewhat pressed on the rear side against at least one support foot (19, 20, 21) and/or against the deck surface (23) of the pallet (2).
13. The method according to claim 1, wherein the heated sheath region (18) is cooled, preferably by means of an air stream, after completion of the upward displacement.
14. A shaping apparatus (7) for carrying out a method for creating at least one opening in a sheath (17), made of stretch film, that retains a goods stack on a pallet (2), the pallet (2) comprising an upper-side deck surface (23) as support for the goods stack and several lower-side support feet (19, 20, 21) arranged at a distance from one another and forming foot openings (16), and the sheath (17) engaging at least partly under the lower side of the support feet (19, 20, 21) arranged in the region of the four outer edges of the pallet (2), and at least one opening being introduced into the sheath region (18) located between two support feet (19 or 20 or 21) that are arranged in a row having at least two support feet (19, 20, 21),
1. in order to carry out the method according to claim 1, at least two shaping fingers (12.1) are provided which are displaceable in a vertical direction for upward displacement of the sheath region (18) and are preferably also displaceable in a horizontal direction for, preferably prior, retraction of the sheath region (18) away from the pallet (2); and in addition to the shaping apparatus (7), at least one, preferably electrically operated, heating device (4) is provided for prior heating of the sheath region (18) to be displaced.
15. The shaping apparatus (7) according to claim 14, wherein at least one heating device (4) encompasses at least two heating surfaces (4, 4) oriented at an angle, preferably a right angle, to one another, the one heating surface (4) applying heat to the sheath (17) in the region of the relevant outer surface of the pallet (2), and the other heating surface (4) applying heat to the sheath (17) in the edge region, contiguous to the outer surface, of the lower side of the pallet (2).
16. The shaping apparatus (7) according to claim 14, wherein at least one heating device (4) is displaceable, preferably by pivoting, between a heating position and a parked position.
17. The shaping apparatus (7) according to claim 14, wherein at least two heating devices (4) facing toward one another are provided, the distance between the two heating devices (4) being at least somewhat greater than the distance between the two oppositely located outer surfaces of the pallet (2) into which at least one opening is respectively to be introduced.
18. The shaping apparatus (7) according to claim 14, wherein the distance between the heating devices (4) is modifiable.
19. The shaping apparatus (7) according to claim 14, wherein each heating device (4) arranged on a holding arm (6); and the holding arms (6) are connected to one another via a connecting element (25).
20. The shaping apparatus (7) according to claim 14, wherein at least one shaping finger (12.1) is mounted pivotably around a pivot shaft (14) oriented parallel to the horizontal travel path so that for shaping, that shaping finger (12.1) is pivotable upward and outward by means of a drive system.
21. The shaping apparatus (7) according to claim 14, wherein the shaping apparatus (7) comprises at least two shaping fingers (12) that are displaceable in a horizontal direction away from the pallet (2) in order to retract the sheath region away from the pallet (2).
22. The shaping apparatus (7) according to claim 21, wherein at least one shaping finger (12.1) is embodied and/or arranged, with respect to the shaping finger(s) (12) that is/are associated with that shaping finger (12.1), in such a way that upon retraction, that shaping finger (12.1) is not in contact with the sheath region (18).
23. The shaping apparatus (7) according to claim 14, wherein the shaping apparatus (7) comprises a guide (8) and a drive system for a horizontal displacement, and/or the shaping apparatus (7) comprises a vertical guide and a drive system for a vertical displacement.
24. The shaping apparatus (7) according to claim 14, wherein the end of at least one shaping finger (12, 12.1) is embodied as a tab and/or as a hook (24, 24.1).
25. The shaping apparatus (7) according to claim 14, wherein for at least one shaping finger (12, 12.1), at least one, preferably each, region coming into contact with the sheath (17) and/or with the sheath region (18) is coated and/or equipped with an anti-adhesion material and/or heat-resistant material (27).
26. The shaping apparatus (7) according to claim 14, wherein the shaping apparatus (7) is made up of two halves, each half comprising at least one respective shaping finger (12.1) and optionally also at least one shaping finger (12), and each half preferably being constructed in mirror-image fashion, and the two halves preferably being displaceable synchronously.
27. The shaping apparatus (7) according to claim 14, wherein at least one shaping finger (12.1) has associated with it a stop (15) that delimits the pivot travel of that shaping finger (12.1) and extends, parallel to the horizontal travel path in an oppositely facing direction, projectingly beyond the shaping finger(s) (12) associated with that shaping finger (12.1).
28. The shaping apparatus (7) according to claim 14, wherein an angle compensation element (11), embodied preferably as a vertically oriented peg, is provided for adapting the orientation of the shaping apparatus (7) with respect to the pallet (2).
29. The shaping apparatus (7) according to claim 14, wherein a securing element displaceable toward the pallet (2) is provided in order to secure the sheath (17) with respect to the pallet (2), preferably in the region of that side of the sheath (17) which is to be shaped, upon retraction and/or upon upward displacement of the sheath region (18).
30. Use of a system for creating at least one opening in a sheath (17), made of film, that retains a goods stack arranged on a pallet (2), encompassing a conveyor, a pallet lifting device arranged within the contour of the conveyor and preferably comprising lifting posts (5), at least one shaping apparatus (7), and in addition to the shaping apparatus (7), for prior heating of the sheath region (18) to be displaced, at least one, preferably electrically operated, heating device, according to claim 14, the sheath (17) being made of stretch film.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0054] Exemplifying embodiments of the invention depicted in the drawings will be described below. In the drawings:
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[0068] In all the Figures, corresponding reference characters are used for identical or similar components.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT(S)
[0069]
[0070] Also provided is a pallet lifting device that is arranged inside the contour of the conveyor. The pallet lifting device comprises a total of four lifting posts 5. As is evident, for example, from
[0071] The two ends of the conveyor are connected via suitable connecting points to the additional conveying technology or to other facility constituents, for example an upstream stretching unit. In the stretching unit, a sheath 17 made of stretch film is pulled over. A usual pallet 2, as depicted e.g. in
[0072] As depicted in
[0073] In the exemplifying embodiment depicted, each heating device 4 is made up of two heating surfaces 4, 4 oriented at right angles to one another. Heating surface 4 is oriented vertically, and heats sheath 17 in the region of the relevant outer surface of pallet 2. The other heating surface 4 is oriented horizontally, and heats sheath 17 in that edge region of the lower side of pallet 2 which is contiguous to the outer surface.
[0074] Both heating devices 4 are displaceable by pivoting between a heating position as depicted e.g. in
[0075] As is evident from
[0076] Upon downward pivoting, the distance between the two heating devices 4 is at least somewhat greater than the distance between the two oppositely located outer surfaces of pallet 2 into which at least one opening is respectively to be introduced. The distance between the two heating devices 4 is understood as the distance between those points on the two heating devices 4 which are located closest to one another.
[0077] In the exemplifying embodiment depicted, the distance between heating devices 4 can be modified. Each holding arm 6 has for this purpose, in the region of its end facing toward connecting element 25, a carriage 28 that is movable in a guide 29 that is associated with connecting element 25. A dedicated drive system can be associated with each holding arm 6, or a common drive system can be associated with both holding arms 6. Holding arms 6, and thus heating devices 4 as well, are thus displaceable in the direction of arrow 30. Each heating device 4 can thus be moved with its horizontally oriented heating surface 4 beneath pallet 2, i.e. into the position depicted in
[0078] In order to facilitate the pivoting movement in the direction of arrow 26, each holding arm 6 comprises a counterweight 31 on its end located oppositely from heating device 4. A drive system (not depicted in further detail) is provided for the pivoting movement in the direction of arrow 26. The drive system is connected via a transfer mechanism (not depicted) to connecting element 25. The region of counterweights 31 is protected by a protective grid 32.
[0079] A total of two shaping apparatuses 7 are also provided. As is evident in particular from
[0080]
[0081] Each shaping apparatus 7 possesses an angle compensation element 11 in order to compensate for angular deviations in the orientation of pallet 2. Angle compensation element 11 is a vertically oriented peg on which shaping apparatus 7 is arranged in rotatably mounted fashion. By means of a spring, shaping apparatus 7 is held in the position that corresponds to an optimum orientation of pallet 2 on chain tracks 1. In the optimum orientation, the lateral edges of pallet 2 are respectively oriented orthogonally and parallel to conveying tracks 1.
[0082] If pallet 2 happens not to have been optimally placed onto chain tracks 1, the orientation of pallet 2 upon lifting with lifting posts 5 as a rule is maintained. Any angular error would thus also continue to exist. When shaping apparatus 7 is brought against pallet 2, shaping apparatus 7 automatically orients itself with respect to pallet 2. If pallet 2 is not optimally oriented with respect to chain tracks 1, then upon contact with pallet 2, shaping apparatus 7 is rotated by pallet 2, against the force of the spring, into the position that corresponds to the orientation of pallet 2.
[0083] In the exemplifying embodiment depicted, pallet 2 also rests on the center chain track 1. Pallet 2 must therefore be lifted in order for the method to be carried out, so that for subsequent execution of the method according to the present invention, sheath 17 is no longer captured in the region of the two outer ends of runner board 22 that connects support feet 20.
[0084] If pallet 2 is not resting in the center, however, i.e. in the region of the two outer ends of runner board 22 that connects support feet 20, so that sheath 17 is therefore not captured in the region of the two outer ends of runner board 22 that connects support feet 20, it is not obligatorily necessary to lift pallet 2.
[0085] Shaping apparatuses 7, described in detail below, are provided in order to introduce the openings into sheath 17. In the idle state, as depicted in
[0086] As is evident in particular from
[0087] Each half of shaping apparatus 7 comprises two shaping fingers 12 that are displaceable in a horizontal direction away from pallet 2 in order to retract sheath region 18. The third shaping finger of each half, namely shaping finger 12.1, is pivotably mounted, for example as is evident from
[0088] A stop 15, which enables automatic fitting into the corners of foot openings 16 of pallet 2 regardless of the format of pallet 2, is associated with each movable shaping finger 12.1. During the pivoting movement, stop 15 projects into the contour of pallet 2, i.e. into foot opening 16. When stop 15 comes into contact with the support foot of foot opening 16 upon pivoting of shaping finger 12.1, the pivoting movement is stopped.
[0089] The outline of sheath 17 and of sheath region 18 is indicated in
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[0091] In the exemplifying embodiment depicted in
[0092] As already described above, each shaping apparatus 7 is made up of two halves, each half being associated with one foot opening 16 and comprising the above-described two shaping fingers 12 and shaping finger 12.1 for creation of an opening. In
[0093] Firstly, a sheath 17 made of stretch film is pulled over in a preceding hood pull-over unit. The encased pallet 2 is then conveyed by means of the conveyor to the device according to the present invention. Once pallet 2 is located between heating devices 4, they can be pivoted down.
[0094] In the exemplifying embodiment depicted in the Figures, pallet 2 also rests on the center chain track 1. Execution of the method requires that pellet 2 be lifted by means of the pallet lifting device, which possesses lifting posts 5. This lifting is necessary on the one hand so that for subsequent execution of the method according to the present invention, sheath 17 is no longer captured in the region of the two outer ends of runner board 22 that connects support feet 20. On the other hand, heating devices 4 can now be moved toward one another, by a displacement of holding arms 6, in such a way that each heating device 4 is moved with its horizontally oriented heating surface 4 beneath pallet 2, i.e. into the position depicted in
[0095] Each heating device 4 now heats sheath 17 in the region of sheath region 18. Heating surface 4 heats sheath 17 in the region of the relevant outer surface of pallet 2, while second heating surface 4 applies heat to sheath 17 in the edge region, contiguous to the outer surface, of the lower side of pallet 2.
[0096] Once sheath region 18 has been sufficiently heated, holding arms 6 having heating devices 4 can be moved back outward and then pivoted upward. The two shaping apparatuses 7 are located outside the heating region in their idle position during heating, as depicted in
[0097] As soon as holding arms 6 have been sufficiently pivoted upward, shaping apparatuses 7 can then be moved onto pallet 2 from both sides. This is accomplished on the one hand by way of a horizontal movement (arrow 3). Shaping apparatuses 7 are also lifted in the direction of arrow 9. This is depicted in
[0098] In
[0099] Sheath region 18, still in the heated state, is then displaced upward. This is depicted in
[0100] Sheath region 18 is pulled along and pulled up in the context of this pivoting movement, sheath region 18 being displaced outward toward the outward-facing corner of each foot opening 16. Thanks to the two upwardly pivoted shaping fingers 12.1 of shaping apparatus 7 acting on one common side of pallet 2, sheath region 18 is thereby tensioned. Stop 15 is associated with each shaping finger 24.1 in order to limit the pivoting movement. Because stop 15 projects at least with its front end into the contour of pallet 2, i.e. into foot opening 16, stop 15 comes into contact with the support foot of foot opening 16 upon pivoting of shaping finger 12.1, so that the pivoting movement is stopped upon contact.
[0101] Shaping fingers 12, 12.1, having the respectively associated tabs 24, 24.1, are in this context located outside the contour of pallet 2, i.e. at a distance from the outer side of support foot 19, 20, 21, so that the reshaped sheath region 18 is laid from outside around the relevant foot opening 16 or, in the exemplifying embodiment depicted in
[0102] The double-ply sheath 17, not yet cooled, is pressed by hooks 24.1 against deck surface 23 and against the outer side of support foot 19, 20, 21, as depicted in
[0103] Sheath region 18 then solidifies in the stretched-out position upon cooling. As a consequence thereof, the relevant foot opening 16 is permanently entirely free of sheath region 18. As a result of the stretching out, foot openings 16 below pallet 2 are completely exposed. In the exemplifying embodiment depicted, there is also no longer any sheath 17 in the region of the two outer ends of runner board 22 that connects support feet 20.
[0104] If sheath 17 is additionally, upon outward retraction of sheath region 18 and/or upon upward displacement of sheath region 18, to be secured at the two sides (outer surfaces) to be shaped, which in the exemplifying embodiment depicted are the short end faces of pallet 2, then for example a securing element of pin-like configuration (not depicted), displaceable toward pallet 2, can be provided. Sheath 17 can be pressed against pallet 2 by means of the securing element. This end-face securing prevents undesired half-moon formation.
[0105] In the exemplifying embodiment depicted, the center chain track 1 is made up of two chains extending in parallel at a distance from one another. A corresponding securing element can be located between the two chains of the center chain track 1. The securing element then acts at the center of pallet 2 approximately at the height of deck surface 23 or somewhat lower. The securing element can be displaced, for example by a pivoting movement, from its idle position, in which it does not project out of the plane of the chain conveyer, into its securing position. The pivot shaft and the associated drive system of a correspondingly embodied securing element can be a constituent of the conveyor. It is also entirely possible, however, for the pivot shaft and the associated drive system of the securing element to be a constituent of shaping apparatus 7.
[0106] The securing element can also, for example, be located laterally at a short distance from the center chain track 1. It then does not act exactly on the center of pallet 2 if the pivot plane of the securing element is parallel to the axis of chain track 1 and of conveying direction 3. If the pivot plane of the securing element is not parallel to the axis of chain track 1 and of conveying direction 3, however, contact at the center of pallet 2 is possible in that case as well. Regardless of the orientation of the pivot plane of the securing element, the securing element acts on pallet 2 approximately at the height of deck surface 23 or slightly lower.
[0107] It is of course also possible for a respective securing element to be located on each side of the center chain track 1, so that sheath 17 is thereby pressed against pallet 2 at two locations.
[0108] Once the relevant foot opening 16 has been rendered permanently completely free of sheath region 18, shaping fingers 12.1 are pivoted back downward. This situation is depicted in
[0109] It is of course also possible for only one shaping apparatus 7 to be provided, so that an opening can thus be introduced into sheath 17 only on one side. In this case only one heating device is also necessary.