Device for feeding a stack of boxes

Abstract

A feeding device (1) for feeding a stack (2) of standing flat-folded boxes to a receiving station, the feeding device comprising a conveyor track (30) having a flat support plane (3) adapted to support the stack, wherein the conveyor track (30) comprises at least two rows of teeth (5, 6, 7), wherein each row of teeth (5, 6, 7) comprises a plurality of spaced-apart teeth (17) adapted to support the stack (2) of flat-folded boxes, wherein the teeth (17) can be positioned in an upright position or a folded position, and wherein the feeding device (1) comprises a guide track (24) arranged along the support plane (3) and adapted to hold the teeth (17) in a selected position, and wherein the guide track (24) ends at an end region (15) of the conveyor track (30) such that the teeth (17) are not supported at the end region (15). The invention has the advantage that stacks of flat-folded boxes can be continuously merged at a discharge region.

Description

TECHNICAL FIELD

[0001] The invention relates to a device suitable for feeding a stack of boxes to a box unfolding machine, wherein the stack of boxes comprises erected flat boxes or box blanks. The device is suitable for feeding stacks of boxes of different lengths and for merging stacks of boxes of different lengths at a discharge area. The device will be used in the packaging industry. BACKGROUND

[0002] When packaging articles, it is often desired to package the articles individually or together in an independent package. Therefore, in highly automated packaging equipment, these articles can be passed to boxes that are used as a package for the articles. Before the articles are packaged in the boxes, these boxes are erected to form a final box from a flat box. Flat boxes usually arrive at a packaging station in a magazine comprising hundreds of flat box blanks, wherein the boxes are passed from the magazine to a transport infeed conveyor that conveys the flat boxes to the packaging machine. The flat boxes are made from a box blank that is glued together at the side portions so that the side walls of the box are connected to each other.

[0003] Depending on the type of box, the boxes can be grouped in different ways in the magazine. Some types of flat boxes can constitute one large stack of flat boxes comprising hundreds of flat boxes that are simultaneously positioned at the infeed conveyor. This type of flat box is a regular rectangular flat box, wherein both end portions of the flat box have the same thickness. These flat boxes can be stacked into a large stack without the upper or lower end portion of the stack being thicker than the other end portion. Some flat boxes are delivered in smaller stacks, for example of a type that is known as a five panel box, which has a protruding double layer display panel extending from the back panel of the box, suitable for an additional display area for a product or to provide a hanging possibility for a product. Both layers are glued together, which makes the display panel thicker than the rest of the flat box. Therefore, this type of flat box is delivered in smaller stacks comprising for example about 50 flat boxes.

[0004] The feeding conveyor is preferably provided with protruding retaining teeth that are suitable for retaining a stack of flat boxes. The stack of flat boxes can be fed from the magazine to the conveyor manually or by a picking device. The picking device picks up the stack of flat boxes from the magazine and positions the stack of flat boxes between the retaining teeth of the conveyor. The distance between the retaining teeth is determined by the size of the stack of boxes. For regular large stacks of flat boxes, the distance between the retaining teeth can be up to 500 mm or more, and for stacks of flat five panel boxes, the distance between the retaining teeth can be about 100 mm.

[0005] When a feed conveyor is to convey a stack of flat-folded cartons of different sizes, the distance between the holding teeth has to be changed. In some conveyors, the distance between the middle teeth and the outer teeth of the conveyor can be changed. This solution is mainly suitable for holding erected cartons of different widths, wherein the width does not differ much. For a larger distance, it is known to remove some of the teeth, for example every second tooth, in order to provide a larger distance between the holding teeth. It is also possible to replace the conveyor belt or chain by another conveyor belt or chain comprising teeth with the required distance. This solution is not very flexible.

[0006] US 8, 182,406 B2 discloses a machine adapted to feed partially formed cartons of different sizes. The machine comprises an overhead conveyor with foldable lugs, wherein each lug can be selectively actuated to protrude from the conveyor in order to convey a carton or to be folded in the conveyor.

[0007] US 2001 / 0032775 Al discloses an adjustable system for conveying individual carton blanks, which comprises a plurality of pusher elements. Each pusher element can be set in an inactive position, in which the pusher is located below the conveying surface, or in an active position, in which the pusher protrudes from the conveying surface. A selected number of pusher elements can be erected in a periodic manner in order to adapt the system to carton blanks of different sizes. The active pusher elements leave the conveying surface before the end region of the conveying track, so that the carton blanks are released and can be transferred to a receiving station.

[0008] While these solutions work well in some cases, there is still room for improvement in order to achieve a flexible feeding device for flat-folded carton stacks of different sizes. SUMMARY

[0009] It is an object of the present invention to provide an improved device for feeding and merging carton stacks of different sizes.

[0010] The solution to the problem according to the present invention is described in the main aspects of the invention relating to a feeding device and to a method of feeding a stack by means of a feeding device. Other aspects of the invention contain further advantageous improvements of the feeding device and the method.

[0011] In a feeding device for feeding a stack of erected flat-folded boxes to a receiving station, the feeding device comprises a conveyor track having a flat support plane adapted to support the stack, wherein the conveyor track comprises at least two rows of teeth, wherein each row of teeth comprises a plurality of spaced apart teeth adapted to support the stack of flat-folded boxes, wherein the teeth can be positioned in an erected position or a folded position, and wherein the feeding device comprises a guide track arranged along the support plane and adapted to hold the teeth in a selected position, the object of the invention is achieved in that the guide track ends at an end region of the conveyor track, such that the teeth are not supported at the end region.

[0012] With this first embodiment of the feeding device according to the invention, a feeding device is provided that can convey stacks of flat-folded boxes having different lengths to the receiving station, such that the feeding device can be adapted to different types of flat-folded boxes. The stacks of flat-folded boxes are merged in a continuous manner at the outfeed region of the feeding device. Some flat-folded boxes, such as regular rectangular flat-folded boxes, will have approximately the same thickness over the entire folded box, which makes it possible to stack these flat-folded boxes into relatively long stacks comprising up to 100 boxes or more. Such stacks of flat-folded boxes can have a length of up to 500 mm or more. Other types of flat-folded boxes, such as five-panel boxes with an additional display panel, have a different thickness over the folded box, with a larger thickness at the display panel. These flat-folded boxes can only be stacked into shorter stacks, for example comprising 50 boxes or less. Since this stack will somewhat resemble a fan, longer stacks will be difficult to handle without additional support of the stack.

[0013] The feeding device comprises at least two rows of teeth spaced apart at a predetermined distance. The distance between two teeth in a row preferably corresponds to the shortest stack of flat-folded boxes to be used, and can for example be 100 mm. The teeth of each row are attached to a conveyor chain, wherein the conveyor chain of each row is driven parallel to the other conveyor chains. The conveyor chains form a conveyor track on which stacks of flat-folded boxes stand upright, supported by the teeth. The conveyor track conveys the stacks from a feed area, where the stacks are inserted between the teeth manually by an operator or by a placement device, for example an industrial robot. The stacks are conveyed to a discharge area, where the stacks are merged into a continuous stream with each other. At the discharge area, the teeth are not supported by the feeding device and can thus be supported by the stacks of flat-folded boxes, i.e. the teeth are held between the stacks and the orientation of the teeth is determined by the orientation of the stacks. In this way, the orientation of the teeth will not interfere with the merging of the stacks. At the discharge area, the stacks of flat-folded boxes leave the teeth and the conveyor track first into a slide track and then into a discharge conveyor, which transports the stacks to for example a racking station. The teeth are provided on a pusher member and are arranged to have a support surface and a push surface.

[0014] The teeth of the feeding device can be positioned in a folded position, in which the support plane of the teeth is placed below the support plane of the conveyor track, or in an upright position, in which the teeth extend above the support plane. In this way, the distance between the upright teeth in a row of teeth can be extended to correspond to the length of a stack of flat-folded boxes to be used. In one example, in which the distance between the teeth is 100 mm, a 200 mm long stack can for example be supported by positioning every second tooth in the row in the upright position, or a 500 mm long stack can be supported by positioning every fifth tooth in the row in the upright position. The feeding device comprises a switch adapted to fold the teeth to a selected position.

[0015] In one example, the feeding device comprises a slide rail in the return path, which sets all the teeth in the folded position. In this case, the switch will switch the selected teeth from the folded position to the upright position. The feeding device can also comprise an upright member arranged after the slide rail in the return path, wherein the upright member sets all the teeth in the upright position. In this case, the switch will switch the selected teeth from the upright position to the folded position.

[0016] The switch can fold the teeth in a parallel group of teeth simultaneously, or can fold each tooth individually. By folding each tooth individually, only some of the rows of teeth can be used. In one example, in which the feeding device is provided with three rows of teeth, for smaller boxes with a smaller width, only two adjacent rows of teeth can be used. In this example, all the teeth in one row are folded down.

[0017] The rollers of the teeth are supported by guide rails arranged along a support plane of the conveyor track. Here, the teeth are erected or folded. At the end regions of the conveyor track, the rollers will leave the guide rails such that the teeth will not be supported and will be able to pivot freely around the pivot point of the pushing member. This will allow the teeth to be drawn out of the stack of flat-folded boxes in the vertical direction and in a gentle manner without displacing or disturbing the stack of flat-folded boxes. The stack of flat-folded boxes will in this way be joined to each other into a longitudinal flow of flat-folded boxes leading to the discharge conveyor. The conveying speed of the feeding device is preferably adapted to the pick-up speed of the box erecting machine at the discharge area.

[0018] In the shown feeding device, all teeth are folded into a folded state in the return path of the feeding device. This will save space at the first part of the return path. Then, all teeth are erected by an erecting member arranged in the return path. Thereafter, the switch will keep the teeth erected or fold the teeth into a folded state depending on the desired distance between the erected teeth. By having all teeth erected, it is ensured that all teeth have the same orientation and the switch can be made simple since the switch does not have to both erect and fold the teeth. In the shown example, the switch will only fold the teeth that need to be folded. In another example, no erecting member is used and the switch is positioned inside the conveyor chain and the switch will only erect the teeth that should be erected.

[0019] When the teeth are folded, the pushing surface of the teeth will cover the gap between the two conveyor chains or between the conveyor chain and the side rails of the feeding device. The pusher member is also provided with a covering surface that will cover the gap in case the teeth are erected. In this way, it is not possible for a person to accidentally insert a finger into the conveyor path, for example.

[0020] In a method for feeding a stack of flat-folded boxes from an infeed area of a feeding device to a receiving station for merging stacks, wherein the feeding device is adapted to convey stacks having different lengths, and wherein the stacks are conveyed by a conveyor track comprising a plurality of teeth, the method comprises the steps of determining the length of a stack of flat-folded boxes to be conveyed by the feeding device and saving the length in a control unit; setting a selected number of teeth to an erected position depending on the determined length of the stack of flat-folded boxes; inserting the stack of flat-folded boxes between the teeth at the infeed area; holding the teeth in the selected position by guide rails arranged along a support plane of the conveyor track; releasing the teeth from the selected position at an end region of the feeding device such that the teeth are not supported by the guide rails and such that the teeth are supported by the stack of flat-folded boxes; drawing out the teeth in a vertical orientation; and merging said stack with a previous stack at a discharge area of the feeding device.

[0021] By the inventive method, flat-folded box stacks of different lengths can be conveyed and merged by the feeding device. This allows a flexible feeding device which can easily be adapted to flat-folded box stacks of different lengths. In this way, the production line can be used for different types of boxes, for example regular rectangular boxes and five-panel boxes. The feeding device can also be adapted to boxes having different widths. BRIEF DESCRIPTION OF DRAWINGS

[0022] The application will be described in more detail in the following with reference to embodiments shown in the attached drawings, in which:

[0023] Figure 1 a view of a feeding device according to the application configured for short box stacks is shown,

[0024] Figure 2 a view of a feeding device according to the application configured for long box stacks is shown,

[0025] Figure 3 a detail of the outfeed area of a feeding device according to the application is shown,

[0026] Figure 4 a detail of the infeed area of a feeding device according to the application is shown,

[0027] Figure 5 a detail of a switch of a feeding device according to the application is shown, and

[0028] Figure 6 a flow chart of a method for feeding stacks of flat-folded boxes according to the application is shown. DETAILED DESCRIPTION

[0029] The embodiments of the application described below which make further improvements are to be regarded only as examples and in no way limit the scope of protection offered by the patent claims. The use of directional expressions, such as front, back, upper, lower, forward, etc., refers to the orientation of the stack of boxes. In the examples shown, the support plane for the stack of boxes is referred to as horizontal, even if the support plane can be slightly angled, for example by 10 to 20 degrees.

[0030] Figure 1 and Figure 2 a view of a feeding device is shown, Figures 3 to 5 a detail of a feeding device is shown, and Figure 6A flow chart of a method for feeding a stack of flat-folded boxes to a receiving station is shown. The feeding device 1 according to the invention comprises a straight conveyor track 30 having a flat support plane 3 adapted to feed a stack 2 of flat-folded boxes upright from a feed area 32 to a discharge area 13, wherein adjacent stacks conveyed by the feeding device merge into one another to form a long continuous stack of flat-folded boxes. The stack of boxes 2 is transferred via a slide track 14 bridging the conveyor track 30 and a discharge conveyor 31 to a receiving station, e.g. a box erecting machine. The conveyor track comprises a plurality of protruding teeth 17 supporting the stack of flat-folded boxes.

[0031] The conveyor track comprises at least two rows of teeth. In the shown example, the conveyor track comprises three rows of teeth: a first row of teeth 5, a second row of teeth 6 and a third row of teeth 7. The first row of teeth 5 is attached to a first conveyor chain 8, the second row of teeth 6 is attached to a second conveyor chain 9 and the third row of teeth 7 is attached to a third conveyor chain 10. The first, second and third conveyor chains are driven in parallel by one and the same drive unit 11 such that the first, second and third conveyor chains move at the same speed and such that teeth positioned adjacent to one another move simultaneously. The teeth in each row of teeth are positioned side by side such that three teeth arranged adjacent to one another form a support plane perpendicular to the direction of movement of the conveyor track.

[0032] The stack of flat-folded boxes is inserted between the teeth at the feed area. The stack of flat-folded boxes is inserted between the teeth manually by an operator or by a placement device, e.g. an industrial robot. In the shown example, the teeth are slightly angled in a forward direction with respect to a vertical plane such that the stack will be supported against the support surfaces 18 of the teeth arranged adjacent to one another. The teeth can also be perpendicular to the support plane or can be slightly angled in a backward direction with respect to a vertical plane depending on e.g. the type of boxes used. The stack of flat-folded boxes can expand when it is inserted between the teeth such that the stack of flat-folded boxes is also supported against the pushing surfaces 19 of the following teeth.

[0033] The stack of flat-folded boxes is conveyed to the discharge area 13, wherein the stack will slide over the slide track 14 when the conveyor track turns down to a return path. The slide track is followed by a discharge conveyor 31, e.g. a short belt conveyor, which actively transports the stack to e.g. a box erecting station. At the slide track and the discharge conveyor, the stacks of flat-folded boxes merge into a continuous stream of flat-folded boxes (not shown). The speed of the conveyor track is adapted to e.g. the pick-up speed of the boxes at the box erecting station such that the density of the flat-folded boxes is approximately constant on the discharge conveyor and such that no additional buffer is needed. The drive unit 11 of the feeding device can be controlled by e.g. the pick-up speed of the box erecting machine.

[0034] As shown in Figure 4 The teeth 17 are arranged on a push member 16. The push member is attached to the conveyor chain at a pivot point 22, for example using a screw, so that the push member can be replaced. The push member comprises teeth 17 arranged on one side of the pivot point 22 and a frame 20 arranged on the other side of the pivot point. The frame comprises a cover surface 21. On the frame a roller 23 is mounted. The roller is adapted to hold the teeth in a selected position and the roller is adapted to travel in a guide track 24. The roller can comprise a plain bearing or a roller bearing.

[0035] The teeth 17 can be positioned in two positions, an upright position or a folded position. In the upright position the teeth protrude from the support plane of the conveyor track. In the folded position the teeth are arranged below the support plane of the conveyor track, wherein the push surface 19 is close to the support plane. In this position the push surface will cover the area between two conveyor chains and between the pivot points of two adjacent push members. This will cover the gap created between the conveyor chains and will prevent that for example fingers or other objects get caught in the conveyor track. When the teeth are upright the cover surface 21 of the frame will cover this gap. At the support plane the roller will be guided into the guide track 24 arranged parallel to the support plane 3 and will firmly hold the teeth in the upright position or the folded position.

[0036] As shown in Figure 3 The guide track 24 ends at the end region 15 and the teeth are released from their predetermined position. When the teeth are in the upright position the teeth will continue to travel in a slightly angled direction and will be guided by the stack of flat-folded boxes. The teeth will at the same time move down out of the support plane in a substantially vertical orientation and the stack of flat-folded boxes will join with a previous stack of flat-folded boxes at the slide track 14. The group of flat-folded boxes will be pushed forward at the slide track by the following teeth.

[0037] At the discharge region the conveyor track 30 travels over a drive wheel 34 to a return path. Here the teeth are free floating and the rollers are not controlled by a guide track. When the teeth reach the return path all teeth are set to a predetermined position, in the shown example to the folded position, in which the push surface 19 is supported against the slide rail 35. In the shown example at an intermediate position of the return path all teeth are uprighted by an uprighting member 33 to an upright state so that all teeth have the same orientation.

[0038] As shown in Figure 5As shown in the middle, at the return path, for each row of foldable teeth a switch 25 is arranged, wherein the switch comprises a switch cylinder 26, a switch member 27 and an actuation tab 28. The switch member is arranged at a pivot point 29 about which the switch member can pivot when the cylinder is extended or retracted. When the cylinder is retracted, the switch will be in an active state in which the actuation tab will extend into the path of the standing teeth. When the cylinder is extended, the switch will be in a passive state in which the actuation tab is pivoted away from the path of the teeth. In case the switch is in the active state, the push surface 19 of the teeth will hit the actuation tab and will be pushed into the folded state. In case the switch is in the passive state, the teeth will continue in the standing state.

[0039] In this way, the state of each tooth can be controlled by the switch. The distance between two standing teeth can be set to the length of a stack of flat-folded boxes. In this way, the stack of flat-folded boxes can be pushed through the switch without the teeth being folded. Figure 1 In the shown example, the longitudinal distance between each tooth is for example 100 mm. By positioning every second tooth in the standing position, the feeding device will be suitable for handling a stack of flat-folded boxes having a length of 200 mm. In this way, the feeding device can be suitable for several different stacks of flat-folded boxes having different lengths. For example, the feeding device can be used for a stack of flat-folded boxes of the five-panel type, wherein the length of the stack is 100 mm, and at another moment the feeding device is used for a stack of regular flat-folded boxes, wherein the length of the stack can for example be 500 mm. Figure 2 An example of a feeding device suitable for long stacks of folded boxes is shown. In this example, only some of the teeth are positioned in the standing position by the switches.

[0040] It is also possible to use only two rows of foldable teeth for smaller flat-folded boxes which are not as wide as the conveyor track. For example, the teeth in two adjacent rows of teeth can be made standing and the third row of teeth is always in the folded state. This will allow the feeding device to be used for smaller boxes or boxes having a peculiar shape, for example with extended flaps. In the shown example, an independent switch is used for each row of teeth. The switches can also use a single switch member which acts on all rows simultaneously to fold the teeth in the parallel groups simultaneously.

[0041] By making all teeth standing, it is ensured that all teeth have the same orientation and the switch can become simple because the switch does not have to both make each tooth standing and / or make each tooth folded. In the shown example, the switch will only fold the teeth which need to be folded. In another example, the switch can be positioned at the inner side of the conveyor chain. In this case, no standing member will be used and all teeth will arrive at the switch in the folded state. In this case, the switch will only make the teeth standing which should be standing.

[0042] In the inventive method for feeding a stack of standing, flat-folded boxes from a feed area of a feeding device to a receiving station of a merging stack by the feeding device, the feeding device is adapted to transport and merge stacks having different lengths. The stacks are transported by a conveyor track comprising a plurality of teeth.

[0043] In step 100, the length of a stack of flat-folded boxes to be transported by the feeding device is determined and saved in a control unit for the feeding device.

[0044] In step 110, a selected number of teeth of the conveyor track are continuously set to an upright position by means of a positioning device located in a return path of the conveyor track. The selected number of teeth is set in accordance with the determined length of the stack of boxes. The length of the stack sets the distance between two upright teeth, which determines the required position for each tooth. In the case of a short stack, all teeth must be upright. In the case of a longer stack, some of the teeth must be folded so that the distance between two upright teeth corresponds to the length of the stack.

[0045] In step 120, the stack of flat-folded boxes is inserted between the teeth at the feed area. The stack can be inserted by hand or by a stack placing machine.

[0046] In step 130, the teeth are held in the selected position by guide rails arranged along the support plane of the conveyor track.

[0047] In step 140, the teeth are released from the selected position at an end region of the feeding device so that the teeth are not supported by the guide rails and so that the teeth are supported by the stack of flat-folded boxes. In this way, at the discharge area, the teeth will not push, disturb or damage the stack of flat-folded boxes. The stack of flat-folded boxes merges with the previous stack. Here, the teeth stop pushing the stack of flat-folded boxes and this stack merges with the next stack and the completed merged stack of flat-folded boxes is pushed by the teeth of this stack.

[0048] In step 150, the teeth are withdrawn in vertical orientation. The teeth of the conveyor track leave the guide rails and the teeth are retracted downwards to the return path.

[0049] In step 160, the stack will merge with the previous stack at the discharge area of the feeding device.

[0050] In an additional step, the speed of the conveyor track is adjusted to a pick-up speed at the receiving station. The pick-up speed can for example be the speed at which a case erecting machine picks up a carton from a merged carton group. In this way, the density of the flat cartons at the discharge track will more or less remain constant, which will provide sufficient forward pressure on the foremost cartons, such that reliable carton pick-up is ensured. At the same time, it is ensured that the flat cartons will maintain the upright orientation of the flat cartons, such that the flat cartons will not tip over or tilt too much.

[0051] The present invention should not be considered limited to the embodiments described above, but rather those described above are presented as example embodiments only and many additional variants and modifications will be apparent to those skilled in the art in light of the above description.

[0052] Reference signs

[0053] 1: feeding device

[0054] 2: stack of flat cartons

[0055] 3: support plane

[0056] 4: housing

[0057] 5: first row of teeth

[0058] 6: second row of teeth

[0059] 7: third row of teeth

[0060] 8: first chain

[0061] 9: second chain

[0062] 10: third chain

[0063] 11: drive unit

[0064] 12: display tab

[0065] 13: discharge area

[0066] 14: slide track

[0067] 15: end area

[0068] 16: pushing member

[0069] 17: tooth

[0070] 18: support surface

[0071] 19: pushing surface

[0072] 20: frame

[0073] 21: covering surface

[0074] 22: pivot point

[0075] 23: roller

[0076] 24: guide rail

[0077] 25: switch

[0078] 26: switch cylinder

[0079] 27: switching member

[0080] 28: actuating tab

[0081] 29: pivot point

[0082] 30: conveyor track

[0083] 31: discharge conveyor

[0084] 32: infeed area

[0085] 33: upright member

[0086] 34: drive wheel

[0087] 35: sliding guide rail

Claims

1. A feeding device (1) for feeding a stack of upright flat-folded boxes (2) to a receiving station, the feeding device (1) comprising a conveyor track (30) having a flat support plane (3) suitable for supporting the stack, wherein, The conveyor track (30) includes at least two tooth rows (5, 6, 7), wherein each tooth row (5, 6, 7) includes a plurality of spaced teeth (17) adapted to support the stack (2) of the flattened box, wherein the teeth (17) are positionable in an upright or folded position, and wherein the feeding device (1) includes a guide rail (24) arranged along the support plane (3) and adapted to hold the teeth (17) in a selected position, wherein the guide rail (24) terminates at the end region (15) of the conveyor track (30), such that the teeth ( 17) The end region (15) is unsupported, wherein the feeding device (1) includes a sliding guide (35) in the return path, wherein the sliding guide (35) is adapted to set all the teeth (17) in the folded position, wherein the feeding device (1) also includes an upright member (33) in the return path, the upright member (33) being adapted to set all the teeth (17) in the upright position, characterized in that the feeding device (1) includes a switch (25) adapted to switch the selected tooth (17) from the upright position to the folded position.

2. The feeding device according to claim 1, characterized in that, The switcher (25) is adapted to switch the selected tooth (17) from the folded position to the upright position.

3. The feeding device according to claim 1 or 2, characterized in that, The feeding device (1) includes a pushing member (16), wherein teeth (17) are provided on the pushing member (16).

4. The feeding device according to claim 3, characterized in that, The pusher is attached to the transmitter track (30) at a pivot point (22), wherein the tooth (17) is located on one side of the pivot point (22), and wherein a frame (20) is arranged on the other side of the pivot point (22).

5. The feeding device according to claim 4, characterized in that, The frame (20) includes a cover surface (21) adapted to fill the gaps in the conveyor track (30) when the teeth (17) are erected.

6. The feeding device according to claim 1 or 2, characterized in that, The feeding device (1) includes a sliding track (14) in the discharge area (13), the sliding track (14) being adapted to support the stacked pieces that are joined together in the end area (15) of the feeding device.

7. The feeding device according to claim 6, characterized in that, The feeding device (1) further includes a discharge conveyor (31) arranged in the discharge area (13), the discharge conveyor (31) being adapted to convey the combined stacked pieces (2) of the flattened box to the receiving station.

8. The feeding device according to claim 1 or 2, characterized in that, The speed of the transmitter track (30) is adapted to the pickup speed at the receiving station.

9. A method for feeding stacks (2) of upright flat-folded boxes from the feeding area of ​​the feeding device (1) to a receiving station for merging the stacks via a feeding device (1), wherein, The feeding device (1) is adapted to convey stacked pieces of different lengths, and wherein the stacked pieces are conveyed via a conveyor track (30) comprising a plurality of teeth (17), the method comprising the following steps: - Determine the length of the stacked pieces (2) of the flattened box to be conveyed by the feeding device (1) and store the length in the control unit. - Based on the determined length of the stacked parts (2) of the flattened box, set the selected number of teeth (17) to the upright position. - Insert the stacked pieces (2) of the flattened box between the teeth (17) at the feeding area. - The tooth (17) is held in a selected position by a guide rail (24) arranged along the support plane (3) of the conveyor track (30). - The tooth (17) is released from the selected position at the end region (15) of the feeding device (1), such that the tooth (17) is not supported by the guide rail (24), and the tooth (17) is supported by the stacking member (2) of the flattened box. - Extract the tooth (17) along the vertical orientation. - At the discharge area of ​​the feeding device (1), the stacked pieces are merged with the previous stacked pieces. - In the return path of the feeding device, all teeth (17) are set to the upright position, and a selected number of teeth (17) are set to the folded position by the switch (25).

10. The method according to claim 9, wherein, In the return path of the feeding device (1), all teeth (17) are set to the folded position, and the selected number of teeth (17) are set to the upright position by the switch (25).

11. The method according to claim 9 or 10, further comprising the step of adjusting the speed of the transmitter track (30) to the pickup speed at the receiving station.

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