METHOD FOR CREATING AT LEAST ONE CLEARANCE IN A SHEATHING THAT CONSISTS OF SHRINK FILM AND SECURES A STACK OF ITEMS ARRANGED ON A PALLET, AND SHAPING APPARATUS FOR CARRYING OUT THE METHOD
20170081063 ยท 2017-03-23
Inventors
Cpc classification
International classification
B65B59/00
PERFORMING OPERATIONS; TRANSPORTING
Abstract
A method for creating at least one clearance in a sheathing consists of shrink film and secures a stack of items arranged on a pallet. The pallet has a top standing surface for the stack of items and a plurality of spaced bottom legs forming leg clearances. The sheathing engages under the legs in the region of the four outer edges of the pallet. At least one clearance is introduced into the sheathing region located between two legs. At least one clearance is intended to be created such that the sheathing region is first of all pulled away from the pallet in the still-hot state and is subsequently displaced upwards in the still-hot state, wherein the upwardly displaced sheathing region is then fixed in its upwardly displaced position by cooling. The invention also relates to a shaping apparatus for carrying out the method.
Claims
1. Method for creating at least one clearance in a sheathing (17) that consists of shrink film and secures a stack of items arranged on a pallet (2), wherein the pallet (2) has a top standing surface (23) as a support for the stack of items and a plurality of bottom legs (19, 20, 21) that are arranged in a manner spaced apart from one another, forming leg clearances (16), and wherein the sheathing (17) engages at least partially under the underside of the legs (19, 20, 21) arranged in the region of the four outer edges of the pallet (2), and wherein at least one clearance is introduced into the sheathing region (18) located between two legs (19 and 20, and 20 and 21) which are arranged in a row having at least two legs (19, 20, 21), wherein at least one clearance is created such that the sheathing region (18) is first of all pulled away from the pallet (2) in the still-hot state and is subsequently displaced upwards in the still-hot state, wherein the upwardly displaced sheathing region (18) is then fixed in its upwardly displaced position by cooling.
2. Method according to claim 1, wherein the upward displacement takes place as far as the region of the standing surface (23), preferably as far as slightly above the standing surface (23).
3. Method according to claim 1, wherein during the upward displacement of the sheathing region (18), the sheathing (17) is pulled around the respective lower inner edge of the two legs (19 and 20, and 20 and 21).
4. Method according to claim 1, wherein the two legs (19, 20, 21) are directly adjacent or are the outermost legs of a row.
5. Method according to claim 1, wherein the sheathing (17) is fixed to the underside of the two legs (19, 20, 21) before and/or after the sheathing region (18) is pulled away from the pallet (2) and/or before and/or after the sheathing region (18) is displaced upwards.
6. Method according to claim 1, wherein the sheathing region (18) is pulled away and/or displaced upwards from the pallet (2) such that the sheathing (17) remains fixed to the underside of the two legs (19, 20, 21).
7. Method according to claim 1, wherein a shrink hood is used as the sheathing (17).
8. Method according to claim 1, wherein at least one subregion of the sheathing (17) is fixed above the sheathing region (18) from the outside in the horizontal direction with respect to the pallet (2), at least in at least one region close to a leg clearance (16), preferably by pressure exertion, at least temporarily while the sheathing region (18) is being pulled away and/or displaced upwards.
9. Method according to claim 1, wherein at least the upwardly displaced sheathing region (18) that is in the still-hot state is displaced in the direction of the pallet (2) again before cooling.
10. Method according to claim 9, wherein the displacement at least of the upwardly displaced sheathing region (18) that is in the still-hot state back in the direction of the pallet (2) takes place to such an extent in the direction of the pallet (2) before cooling that the stretched sheathing region (18) and/or those subregions of the sheathing (17) that respectively adjoin the sheathing region (18) laterally is/are pressed at least slightly at the rear against at least one leg (19, 20, 21) and/or the standing surface (23) of the pallet (2).
11. Shaping apparatus (7) for carrying out a method for creating at least one clearance in a sheathing (17) that consists of a shrink film and secures a stack of items arranged on a pallet (2), wherein the pallet (2) has a top standing surface (23) as a support for the stack of items and a plurality of bottom legs (19, 20, 21) that are arranged in a manner spaced apart from one another, forming leg clearances (16), and wherein the sheathing (17) engages at least partially under the underside of the legs (19, 20, 21) arranged in the region of the four outer edges of the pallet (2), and wherein at least one clearance is introduced into the sheathing region (18) located between two legs (19 and 20, and 20 and 21) which are arranged in a row having at least two legs (19, 20, 21), wherein, in order to carry out the method according to claim 1, at least two shaping fingers (12.1) are provided which are displaceable in the vertical direction for the upward displacement of the sheathing region (18) and are preferably also displaceable in the horizontal direction for pulling the sheathing region (18) away from the pallet (2), preferably beforehand.
12. Shaping apparatus (7) according to claim 11, wherein at least one shaping finger (12.1) is mounted so as to be pivotable about a pivot pin (14) oriented parallel to the horizontal travel path, such that, for shaping, this shaping finger (12.1) is pivotable upwards and outwards by means of a drive.
13. Shaping apparatus (7) according to claim 11, wherein the shaping apparatus (7) has at least two shaping fingers (12) which are displaceable in the horizontal direction to pull the sheathing region (18) away from the pallet (2).
14. Shaping apparatus (7) according to claim 13, wherein at least one shaping finger (12.1) is formed and/or arranged in such a way with respect to the shaping finger(s) (12) assigned to this shaping finger (12.1) that this shaping finger (12.1) is not in contact with the sheathing region (18) during the pulling away operation.
15. Shaping apparatus (7) according to claim 11, wherein the shaping apparatus (7) has a guide (8) and a drive for a horizontal displacement and/or the shaping apparatus (7) has a vertical guide and a drive for a vertical displacement.
16. Shaping apparatus (7) according to claim 11, wherein the end of at least one shaping finger (12, 12.1) is configured as a tab and/or as a hook (24, 24.1).
17. Shaping apparatus (7) according to claim 11, wherein, in the case of at least one shaping finger (12, 12.1), at least one, preferably each, region that comes into contact with the sheathing (17) and/or with the sheathing region (18) is coated and/or provided with a non-stick and/or heat-resistant material (27).
18. Shaping apparatus (7) according to claim 11, wherein the shaping apparatus (7) consists of two halves, wherein each half has at least one shaping finger (12.1) in each case and optionally also at least one shaping finger (12), and preferably each half is constructed in a mirror-inverted manner and wherein preferably both halves are displaceable synchronously.
19. Shaping apparatus (7) according to claim 11, wherein at least one shaping finger (12.1) is assigned a stop (15) that limits the pivoting travel of this shaping finger (12.1), said stop (15) extending parallel to the horizontal travel path and in a manner protruding in the opposite direction beyond the shaping finger(s) (12) assigned to this shaping finger (12.1).
20. Shaping apparatus (7) according to claim 11, wherein, in order to adapt the orientation of the shaping apparatus (7) with respect to the pallet (2), an angle compensation element (11), preferably configured as a vertically oriented peg, is provided.
21. Shaping apparatus (7) according to claim 11, wherein, to fix the sheathing (17) while the sheathing region (18) is being pulled away and/or displaced upwards with respect to the pallet (2), preferably in the region of that side of the sheathing (17) that is to be shaped, a fixing element (25) that is displaceable in the direction of the pallet (2) is provided.
22. Shrink machine comprising a hot-air frame which is movable vertically along a stack of items arranged on a pallet (2) and provided with a sheathing (17) that consists of a shrink film, and also at least one shaping apparatus (7) according to claim 11.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0041] Exemplary embodiments of the invention that are illustrated in the drawings are explained in the following text. In the drawings:
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DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT(S)
[0051] In all of the figures, corresponding reference signs are used for components that are identical or of the same type.
[0052] As illustrated in
[0053] The shrink machine illustrated has a pallet lifting device 4 having lifting rams 5, a blower module 6 and a total of two shaping apparatuses 7. Not illustrated is the hot air frame, which is usually arranged centrally in the shrink machine. The two ends of the shrink station conveyor are connected via suitable connection points to the further conveying technology or to other machine constituents, such as a hood pull-over station, for example.
[0054] As can be gathered in particular from
[0055]
[0056] In order to compensate for angular deviations in the orientation of the pallet 2, each shaping apparatus 7 has an angle compensation element 11. The angle compensation element 11 is a vertically oriented peg on which the shaping apparatus 7 is arranged in a rotatably mounted manner. By means of a spring, the shaping apparatus 7 is kept in the position which corresponds to an optimal orientation of the pallet 2 on the chain tracks 1. In the optimal orientation, the side edges of the pallet 2 are oriented orthogonally or parallel to the conveying tracks 1.
[0057] When the shaping apparatus 7 is moved up to the pallet 2, the pallet 2 can be set down on the chain tracks 1 or raised by means of the lifting rams 5. If the pallet 2 has not been set down optimally on the chain tracks 1, the orientation of the pallet 2 is generally maintained when it is raised by way of the lifting rams 5. Any angular error would thus continue to exist.
[0058] When the shaping apparatus 7 is moved up to the pallet 2, the shaping apparatus 7 is oriented automatically with respect to the pallet 2. If the pallet 2 is not oriented optimally with respect to the chain tracks 1, when contact is made with the pallet 2, the shaping apparatus 7 is rotated by the pallet 2, counter to the force of the spring, into the position which corresponds to the orientation of the pallet 2.
[0059] In the rest state, as illustrated in
[0060] As can be gathered in particular from
[0061] Each half of the shaping apparatus 7 has two shaping fingers 12 which are displaceable in the horizontal direction in order to pull the sheathing region 18 away from the pallet 2. The third shaping finger of each half, namely the shaping finger 12.1, is mounted in a pivotable manner, as can be seen for example in
[0062] Each movable shaping finger 12.1 is assigned a stop 15 which allows automatic fitting into the corners of the leg clearances 16 of the pallet 2, regardless of the format of the pallet 2. During the pivoting movement, the stop 15 projects into the contour of the pallet 2, i.e. into the leg clearance 16. If the stop 15 comes into contact with the leg of the leg clearance 16 during the pivoting of the shaping finger 12.1, the pivoting movement is stopped.
[0063] In
[0064]
[0065] In the exemplary embodiment illustrated in
[0066] As already described above, each shaping apparatus 7 consists of two halves, wherein each half is assigned to a leg clearance 16 and has the above-described two shaping fingers 12 and the shaping finger 12.1 to create a clearance. A view of the short side of the pallet 2 (as seen in the conveying direction 3) is illustrated in the respective left-hand half of
[0067] In the method illustrated in the figures, first of all a pallet 2 is conveyed into the shrink machine and stopped. Subsequently, the pallet 2 is raised for undershrinking by means of the pallet lifting device 4, which has lifting rams 5 that are displaceable in a manner corresponding to the size of the pallet 2. After raising, the undershrinking of the lower periphery of the sheathing 17 is carried out. In the meantime, the two shaping apparatuses 7 are located outside the heating region in their rest position, as is illustrated in
[0068] After completion of undershrinking, the pallet 2 is lowered to a lower height, but not set down. If desired, the undershrink created in the raised state can additionally be secured at the outer periphery of the pallet 2 by means of pressure rams 26. By means of the pressure rams 26, which are arranged between the first and the second chain track 1 and the fourth and the fifth chain track 1, respectively, the lower periphery of the sheathing 17 and thus the undershrink is pressed against the underside of the pallet 2 in the region of the sides oriented parallel to the conveying direction 3. For the movement of the pressure rams 26, a mechanical coupling can be provided for example between the pressure rams 26 and the movement of the pallet lifting device 4. Alternatively, the pressure rams 26 can also be embodied in a power-driven manner.
[0069] Subsequently, the shaping apparatuses 2 are moved up to the pallet 2 from both sides. This takes place on the one hand by a horizontal movement (arrow 3). Furthermore, the shaping apparatuses 7 are raised in the direction of the arrow 9. This is illustrated in
[0070] The shrinking process can in this case be continued by moving the heating frame vertically upwards. The shaping apparatuses 7 moved up to the pallet 2 are therefore not located in the direct heating zone of the hot-air frame in their position moved up to the pallet 2.
[0071] In
[0072] Subsequently, the sheathing region 18 is displaced upwards in the still-hot state. This is illustrated in
[0073] During this pivoting movement, the sheathing region 18 is also pulled along and pulled upwards. The sheathing region 18 is, in the process, displaced outwardly in the direction of the outwardly directed corner of each leg clearance 16. By way of the two pivoted-up shaping fingers 12.1 of the shaping apparatus 7 acting on a common side of the pallet 2, the sheathing region 18 is stretched in this way. In order to limit the pivoting movement, each shaping finger 24.1 is assigned a stop 15. Since the stop 15 projects into the contour of the pallet 2, i.e. into the leg clearance 16, at least with its front end, the stop 15 comes into contact with the leg of the leg clearance 16 while the shaping finger 12.1 is being pivoted, such that the pivoting movement is stopped upon contact.
[0074] The shaping fingers 12, 12.1 having the respectively associated tab 24, 24.1 are in this case located outside the contour of the pallet 2, i.e. at a distance from the outer side of the leg 19, 20, 21, such that the deformed sheathing region 18 is laid from the outside around the leg clearance 16 in question and, in the exemplary embodiment illustrated in
[0075] By way of the hooks 24.1, the not-yet cooled double-ply sheathing 17 is pressed against the standing surface 23 or the outer side of the leg 19, 20, 21 of the pallet 2, as is illustrated in
[0076] In the taut position, the sheathing region 18 then sets upon cooling. As a result, the leg clearance 16 in question is durably completely free of the sheathing region 18. As a result of the stretching, the leg clearances 16 under the pallet 2 are completely freed.
[0077] If desired, the sheathing 17 can be additionally fixed on the two sides to be shaped, which, in the exemplary embodiment illustrated, are the short end sides of the pallet 2, by a fixing element 25 that is displaceable in the direction of the pallet 2 and is configured in the form of a pin, while the sheathing region 18 is being pulled away outwards and/or while the sheathing region 18 is being displaced upwards. By means of the fixing element 25, the sheathing 17 is pressed against the pallet 2. As a result of this end-side fixing, undesired half-moon formation is avoided.
[0078] In the exemplary embodiment illustrated, the middle chain track 1 consists of two spaced-apart chains that extend in parallel. The fixing element 25 is located between the two chains of the middle chain track 1. Thus, the fixing element 25 acts approximately at the level of the standing surface 23 or a little lower, in the middle of the pallet 2. In the exemplary embodiment illustrated, the fixing element 25 is displaced by a pivoting movement from its rest position illustrated in
[0079] Alternatively, the fixing element 25 can be located laterally at a short distance from the middle chain track 1. It does not then act exactly on the middle of the pallet 2, if the pivoting plane of the fixing element 25 is parallel to the axis of the chain track 1 and the conveying direction 3. However, if the pivoting plane of the fixing element 25 is not parallel to the axis of the chain track 1 and the conveying direction 3, contact is also possible in the middle of the pallet 2 in this case. Regardless of the orientation of the pivoting plane of the fixing element 25, the fixing element 25 acts on the pallet 2 approximately at the level of the standing surface 23 or a little lower.
[0080] It is of course also possible for a respective fixing element 25 to be located on each side of the middle chain track 1, such that the sheathing 17 is pressed against the pallet 2 at two locations in this way.
[0081] After completion of the shrinking process, the forming fingers 12.1 are pivoted back downwards again. This situation is illustrated in
[0082] Of course, it is also possible for only one shaping apparatus 7 to be provided, such that in this respect a clearance can be introduced into the sheathing 17 only on one side.