Device for covering a box

Abstract

The invention relates to a device for covering boxes by adhesive joining with a flexible cover, comprising a joining station, a smoothing station for smoothing the cover onto the box base, and further processing stations and a transport system, wherein the smoothing station comprises a stationary tool pair consisting of a driven smoother having a variable movement profile and a counter-holder, wherein the contact surface of the counter-holder moves synchronously with the particular box to be processed in the transport direction thereof.

Description

[0001] Device for covering a box

[0002] Description

[0003] The present invention relates to a device for obtaining boxes according to the preamble of claim 1.

[0004] A box manufacturing system with a device for covering the raw boxes is shown in document US2009 / 0156380A1. The raw boxes and the adhesive-coated covering material are fed from upstream devices to a joining device via conveyors. The joining device places the raw box with its base on the glued side of the covering. In a subsequent device, the covering is rolled onto all four box walls. Any excess of the blank is folded inward. For this purpose, each wall is assigned a covering device.

[0005] To remove unwanted air pockets between the cover and the box base, WO2011 / 015988A1 proposes a device for rubbing the base surface. This consists of a plurality of endlessly rotating rollers, similar to a chain. These rollers are moved beneath the box base in such a way that the freely rotating rollers roll on the box base, thus expelling trapped air in one direction. The box is pressed against the rollers by a plate acting on all its walls.

[0006] During this rubbing process, the forces acting on the edges of the base are greater than those acting on the flexible base surface due to the rigidity of the walls. This causes the edges, in particular, to be pressed against the cover. Trapped air can hardly escape from airtight cover materials. Furthermore, the rubbing process often causes the box to shift accidentally. Undesirable markings can also occur due to the rigid rollers.

[0007] The invention is therefore based on the object of creating a device for covering boxes of the generic type, which enables the processing of a wide range of different types of boxes and covering materials while producing a high product quality.

[0008] The invention solves this problem by a device having the features of patent claim 1. Advantageous developments of the invention are characterized by the features specified in the subclaims.

[0009] For this purpose, a device for covering boxes is provided, wherein the box is designed as a dimensionally stable box and the covering is made of a flexible, sheet-shaped material. The box can be formed in a simple manner from a rectangular base area as the bottom with side walls arranged at right angles to the base area on each side of the base area. The invention is not limited to this box shape. In particular, the base can be formed by any polygon or even have a curved contour. Likewise, the walls do not necessarily have to be oriented at right angles to the base.

[0010] The device has a staging position and a joining position. In the staging position, the boxes are individually presented for further processing. In the joining position, the cover is joined to the box for the first time. A positioning device is provided for this purpose. This device picks up the individual box in the staging position. It transfers the box to the joining position. It then releases the box in the joining position.

[0011] To eliminate possible air pockets between the box and the cover and to apply sufficient joining force, a grinding device is provided. This device has a grinding blade directed at the joining surface of the box-cover assembly. A counterholder is provided to apply the grinding force. During grinding, the box-cover assembly is clamped between the grinding blade on one side and the counterholder on the other. The grinding blade and the counterholder form a tool pair.

[0012] The surface of the rub that comes into contact with the product extends transversely to the transport direction. This contact surface preferably extends at least across the width of the box. This allows the rub to be designed to be stationary, allowing the cover to be rubbed across the entire width of the box.

[0013] The counterholder prevents the box-cover assembly from accidentally slipping. To this end, it has a contact surface that acts on the box-cover assembly and is positioned opposite the rubbing device. To prevent product damage, this contact surface is designed to be movable with the box-cover assembly in its transport direction. A counterholder drive is provided for this purpose. The drive enables the contact surface of the counterholder to move synchronously and slip-free with the box. A controllable drive is provided to enable different transport speeds and thus also different production speeds.

[0014] The products are advanced by a transport device. This can comprise one or more conveyor belts and / or conveyor belts. The effective conveying surface of the belts and / or conveyor belts defines a transport plane. The direction of movement of the conveying belt(s) determines the transport direction.

[0015] The transport device can be divided into at least two transport sections. A first transport section is located upstream of the rubbing device, and a second transport section is located downstream of the rubbing device. The positioning device, which places the box onto the cover, is arranged in the region of a transport section that is upstream of the rubbing device. The rubbing device is preferably formed by a brush. The flexibility of the bristles allows for gentle rubbing of the cover onto the box and the removal of unwanted air pockets. Alternatively, the brush can have one or more substantially flat lamellae instead of bristles.

[0016] The stiffness of the box is not constant across its width. While the box is very stiff at its closed edges, it is comparatively flexible in the central areas of its surfaces. To compensate for this, the brush, in an advantageous design, has a curved contact zone perpendicular to the transport direction. Alternatively, instead of a curved geometry, a brush can be used whose flexibility or hardness varies accordingly perpendicular to the transport direction.

[0017] The use of a round brush as a rubbing unit with a rotational axis oriented transversely to the transport direction is advantageous. Especially in combination with a controllable drive for the round brush, this allows the relative speed between the box-cover complex and the bristles or lamellae to be varied while maintaining a constant transport speed. This allows products made from different material combinations of box, cover, and adhesive to be processed without compromising quality.

[0018] A tangential speed of the circular brush in the contact area, which is directed in the direction of the transport speed and is greater than the transport speed, at least at the point of entry of the leading edge of a leading protrusion of the cover, supports the cover's contact with the brush. This prevents the protrusion from sinking below the transport plane.

[0019] A spherical round brush with a contact surface curved perpendicular to the transport direction is particularly advantageous. Its tangential speed is greatest in the center and decreases toward the outside. This expels trapped air in a transverse direction from the center to the outside. Furthermore, the yielding of the box bottom is compensated for or even overridden.

[0020] A direction of rotation is preferred in which the tangential speed of the grinder in its contact area with the cover is oriented in the same direction as the transport speed.

[0021] An overspeed of the rubbing device is particularly advantageous, with its tangential speed being greater than the transport speed. This ensures that any excess cover material is driven into the transport plane by the rubbing device. This prevents any unintentional retraction of the excess material, which may be coated with adhesive.

[0022] A speed profile for the round brush with a speed that changes during the processing of a single product is particularly advantageous. A controllable drive is provided for this purpose. The described excess speed during the cover's entry can be reduced during the actual grinding process, during which the box passes the round brush. This reduces the friction between the brush and the cover to a necessary minimum. A tangential speed lower than the transport speed or a counter-rotation direction while a trailing overhang of the cover passes the round brush keeps this overhang stretched and prevents unwanted damage to the cover.

[0023] Advantageously, the rubbing device is assigned a feed device that determines the position of the rubbing device relative to the transport plane. Particularly with an elastic rubbing device such as a brush, the rubbing force can be adjusted to the material combination of the product. Penetrating the transport plane through the rubbing device while idling enables particularly smooth passage through the box-cover complex of the rubbing station, particularly without offsets perpendicular to the transport plane. In a simple design, the contact surface of the counterholder, which moves with the box-cover complex, rotates continuously. A preferably controllable drive of the counterholder ensures that the speed of the contact surface during rubbing is identical to the transport speed.

[0024] A counterholder with a contact surface divided transversely to the transport direction, with sections spaced apart from one another, is particularly advantageous. A two-track counterholder is particularly advantageous. Its two contact surfaces each grip an edge of the box parallel to the transport direction. In particular, the box walls running transversely to the transport direction are not subjected to additional force, and trapped air can escape more easily against the transport direction.

[0025] Preferably, such a two-track counterholder is associated with a feed device. This adjusts the position of the contact surfaces transversely to the transport direction to a value predetermined by the format of the box.

[0026] In a first embodiment, the counterholder is designed as a roller. It is arranged directly opposite the starter along the transport direction. This prevents unwanted displacement of the box when entering or exiting the gap between the starter and the counterholder.

[0027] In an alternative embodiment, the counterholder is formed by a band or belt. It is particularly advantageous in this case to bridge the gap caused by the starter between the two adjacent transport systems. The band or belt extends from an area well in front of the starter in the transport direction to at least above the starter. In a particularly suitable manner, the counterholder extends into the area in which the box is already gripped by the transport system following the starter. This enables uninterrupted and fault-free transport. Preferably, the distance between the counterholder and the starter is adjustable. This allows boxes of different heights to be produced. If a feed device with a controllable drive is assigned to the counterholder, this adjustment can be automated and varied from product to product.For this purpose, the feed drive and, if applicable, other drives of the grinding device are connected to a common machine control system via control lines.

[0028] The invention will now be explained using exemplary embodiments with reference to the figures, to which reference is made for all details not mentioned in detail in the description. The figures show:

[0029] Fig. 1 is a schematic side view of a grinding device;

[0030] Fig. 2 is a schematic view of a grinding device from the rear;

[0031] Fig. 3 shows a grinding device in perspective view;

[0032] Fig. 4 is a schematic view of a grinding device;

[0033] Fig. 5 two speed profiles of the tangential speed of a grinding brush.

[0034] The device shown in Fig. 1 for rubbing a cover panel 102 onto the outer bottom surface of a box-shaped box 101 comprises a transport device 2 and a rubbing device 1. The rubbing eliminates unwanted air pockets between the box 101 and its cover 102 and ensures a full-surface and uniform bonding of the cover 102 to the box 101.

[0035] The transport device 2 is formed from two transport belts 21, 22 arranged one behind the other in the transport direction 1000. The first transport belt 21 and the second transport belt 22 are spaced apart from one another. The rubbing device 1 is arranged in this gap. The first transport belt 21 is arranged upstream of the rubbing device 1 and forms a first transport section 201. In this first transport section 201, the box 101 with the cover 102 already adhering to its bottom surface is fed to the rubbing device 1. In the second transport section 202, the box 101 with the firmly rubbed cover 102 is removed from the rubbing device 1 and made available for further processing to downstream devices (not shown).

[0036] Both conveyor belts 21, 22 are designed as suction belts to prevent unintentional displacement of the box 101 with the joined cover 102. The conveying working sections 211 of the two conveyor belts 21, 22 define the transport plane 1100. The transport direction 1000 runs parallel to the transport plane 1100 in the longitudinal direction of the conveyor belts 21, 22.

[0037] The rubbing device 1 is arranged in a gap between the first conveyor belt 21 and the second conveyor belt 22. This rubbing device 1 essentially consists of a rubbing tool and a counterholder, which together form a tool pair 10. The rubbing tool is formed from a cylindrical round brush 11. It is arranged essentially below the transport plane 1100 and oriented transversely to the transport direction 1000. The round brush 11 extends at least across the width of the box 101 to be processed.

[0038] The round brush 11 is provided with a drive 15 shown in Fig. 3. This controllable drive 15 allows the speed or tangential speed 1121 of the brush 11 to be adjusted to the transport speed 1000 or to the product properties of the box 101 with its cover 102.

[0039] As shown in Fig. 1, the bristles 112 of the round brush 11 penetrate the transport plane 1100 in the area of ​​the upper apex of the brush 11. To adjust the force applied during rubbing, the round brush 11 is accommodated in a frame (not shown) via a feed device 16. Its feed direction 1601 runs perpendicular to the transport plane 1100.

[0040] The counterholder is in the embodiment shown in Fig. 1 as a roller

[0041] 12. The rotational axes 111 of the round brush 11 and those of the counter roller 12 together define a frontal plane 1101. This frontal plane 1101 extends perpendicular to the transport plane 1100 and transverse to the transport direction 1000. The feed direction 1601 of the round brush 11 runs parallel to the frontal plane 1101.

[0042] The distance between the counter roller 12 and the transport plane 1100 or the round brush 11 corresponds to the height of the box 101 to be processed. To process different box heights, the counter roller 12, like the round brush 11, has a feed device not shown in the figures.

[0043] Like the round brush 11, the counterholder also has a controllable drive 14. The directions of rotation of the round brush 11 and the counter roller 12 shown in Fig. 1 each support the transport effect of the transport device 2. This co-directional direction of rotation of the brush 11 supports the leading projection 1021 of the cover 102 in running onto the round brush 11. This counteracts the unintentional immersion of this leading projection 1021 into the gap between the round brush 11 and the preceding conveyor belt 21.

[0044] Fig. 4 shows a spherical round brush 11 with its drive 15. The radius 115 of the bristle body 112 changes along its axis of rotation 111. In the outer regions, the radius 115 is smaller than in the central section of the round brush 11. The bristle ends 113 therefore protrude above the transport plane 1100 by different distances, depending on the respective radius 115. This compensates for the deflection of the central base region of the box 101 during rubbing. In addition, the rubbing force and the tangential speed 1121 of the bristle ends 113 are greatest in the center of the box and decrease slightly towards the side edges. This leads to the spreading of unwanted air inclusions from the center outwards and to reliable rubbing even with large box formats or with flexible box bottoms.

[0045] Advantageously, a rotational axis interrupted as shown in Fig. 2 is

[0046] Design of the counterholder 12, 13. The contact surface 131 of the counterholder 12, 13 is limited to two tracks. Each of these tracks engages a respective side wall of the box 101. The majority of the two end walls are not subjected to any force by the counterholder during the entire rubbing process. This prevents additional force, particularly on the central regions of the leading and trailing edges of the box 101, and any air pockets can be more easily smoothed out parallel to the transport direction 1000.

[0047] In an alternative embodiment, the counterholder is not designed as a roller 12, but as a belt 13, as shown in Fig. 3. The length of the working strand bridges the gap between the two conveyor belts 21, 22. The running of the box 101 onto and off the round brush 11 is thus smoother and more stable.

[0048] Fig. 3 also schematically shows the placement of the box 101 onto the cover 102 for adhesive joining. For this purpose, a box 101 is provided in a preparation position 3001. A gripper, which can be designed as a suction cup 30 as in the figure, picks up the box 101 in the preparation position 3001 and transfers it to the joining position 3002. The cover 102 is already waiting in this joining position 3002, onto which the gripper places the box 101 so that the cover 102 adheres to the bottom of the box 101. The joining position 3002 is located on the first belt 21, which feeds the box 101 with the adhering blank 102 to the grinding device 1.

[0049] The conveying elements 11, 12, 13, 21, 22, 30 each have at least one controllable drive 14, 15. Like the feed drives 16 of the starter and the counterholder, these are controllably connected to a central control system not shown in the figures. By means of this control system, in particular the drive 15 of the round brush 11 as the starter is subjected to a speed profile which leads to the speed profiles 1121, 112T of the bristle ends 113 shown in Fig. 5. This speed profile repeats with each machine cycle, or at least with each starter process. A standard profile mainly has a constant speed with an associated tangential speed 1121 of the bristle ends 113. The tangential speed 1121 is parallel to the transport speed 1101 of the box 101 and greater in magnitude. This results in a sweeping relative movement of the bristles 112 to the cover 102 or the box 101.

[0050] The aim is to ensure that the leading overhang 1021 of the cover 102 runs onto the round brush 11 and to prevent unwanted drawing into the gap between the preceding conveyor belt 21 and the round brush 11. To this end, the speed profile 1121 shown suggests increasing the overspeed of the round brush 11 while it detects the leading overhang 1021.

[0051] In order to tighten the trailing overhang 1022 of the reference blank 102, the speed profiles 1121 shown provide for reducing the tangential speed while the round brush 11 captures the trailing overhang 1022. In particular, it is proposed to keep the tangential speed 1121 lower than the transport speed in this section.

[0052] The alternative speed profile 112T shown differs from the standard profile 1121 in that the tangential speed in the constant sections is the same as the transport speed. The alternative speed profile 112T is therefore particularly suitable for sensitive materials or surfaces. The phase position of the second section of the speed change shown, which is different from the standard profile 1121, corresponds to a changed box length.

[0053] Reference symbol

[0054] 1 Grinding device 3 Positioning device

[0055] 2 Transport device 10 Tool pair round brush 202 second transport section

[0056] Counter roller 211 working strand

[0057] Counter belt 212 Slack side first drive, counter holder 1000 Transport direction second drive, round brush 1001 Transport speed

[0058] Feed device 1002 Placement movement first conveyor belt 1011 leading wall second conveyor belt 1012 trailing wall

[0059] Gripper 1021 leading panel overhang

[0060] Box 1022 trailing

[0061] Benefits Surplus Benefits

[0062] Longitudinal edge 1100 T transport level

[0063] Rotation axis 1101 Frontal plane

[0064] Brush body 1121 tangential speed

[0065] Bristle end 1601 feed direction

[0066] Radius 3001 deployment position

[0067] Partial area 3002 Joining position first transport section

Claims

Patent claims Device for covering a box by adhesively joining a substantially flexible cover (102) to at least one outer surface of the box (101), at least comprising • a positioning device (3) with at least one provision position (3001), in each of which a single box (101) is provided, and with at least one joining position (3002) on each cover (102), as well as with a gripper (30) movable in such a way that the gripper (30) picks up the box (101) in the provision position (3001) and transfers it to the joining position (3002) on the cover (102) and releases it there, • a grinding device (1) arranged downstream of the positioning device (3) in the product flow, said grinding device having at least one pair of tools (10) for grinding a region of the cover (102) connected to the box (101) onto the box (101), the tools (11, 12, 13) forming the pair of tools (10) being arranged on both sides of a transport plane (1100), • a transport device (2) with at least one endlessly circulating transport belt (21, 22), wherein the conveying strand (211) of the transport belt (21, 22) defines the transport plane (1100), and with a transport direction (1000) of the box (101) placed on a cover (102) that is essentially linear and parallel to the transport plane (1100), with at least one first transport section (201) upstream of the tool pair (10) of the grinding device (1) in the transport direction (1000), in which the box (101) connected to the cover (102) is fed in the transport direction (1000) of the grinding device (1), and with a second transport section (202) downstream of the grinding device (1) in the transport direction (1000), in which the boxes (101) are outer surface rubbed cover (102) is transported further by the rubbing device (1), characterized in thatthat the at least one pair of tools (10) comprises at least one grinding tool (11) which is stationary with regard to grinding and one, A counterholder (12, 13) having at least one partial surface movable in the transport direction (1000) as a contact surface (131), wherein the at least one rubbing device (11) extends substantially transversely to the transport direction (1000) and the at least one counterholder (12, 13) has a first drive (14) such that at least the contact surface (131) of the counterholder (12, 13) acting on the box (101) moves at least temporarily substantially synchronously with the transported box (101). Device according to claim 1, characterized by at least one transverse axis (111), wherein the at least one rubbing device is formed by a round brush (11) mounted for rotation about this transverse axis (111), and the round brush (11) is drive-connected to a second drive (15) of the rubbing device (1).Device according to claim 2, characterized in that the brush body (112) of the at least one round brush (11) has different radii (115) along the at least one transverse axis (111). Device according to claim 2 or 3, characterized by a tangential speed (1121) of the outer bristle ends (113) of the at least one driven round brush (11), wherein at least the tangential speed of individual bristle ends (113) is at least partially greater than the transport speed (1001) of the boxes (101) placed on the respective cover (102).Device according to one of claims 2 to 4, characterized by a controllable drive (15) of the round brush (11) with a variable speed profile (1121, 112T) of the round brush, wherein the speed of the round brush (11) changes in a predetermined manner from the time a preceding box enters the grinding device (1) until the time a box following the preceding box enters the grinding device (1). Device according to one of the preceding claims, characterized by a feed device (16) of the at least one grinding device (11). a feed direction (1601) oriented substantially orthogonally to the transport plane (1100), wherein the starter (11) at least temporarily penetrates the transport plane (1100). Device according to one of the preceding claims, characterized in that the at least one counter-holder has an endlessly circulating transport element (12, 13) driven by the at least one drive (14) of the counter-holder. Device according to one of the preceding claims, characterized in that the contact surface (131) of the at least one counter-holder acting on the boxes is interrupted transversely to the transport direction (1000) such that it has at least two spaced-apart regions, wherein the distance between the at least two regions is variable, and at least one of the at least two regions is assigned a feed device such that the distance between the at least two regions is controllably variable.Device according to claim 7 or 8, characterized in that the at least one continuously rotating transport element (12, 13) of the counterholder is formed by a rotatable roller (12), wherein the rotatable roller (12) is drive-connected to the at least one drive (14) of the counterholder, the axis of rotation of the roller (12) is oriented substantially transversely to the transport direction (1000) and, with the axis of rotation (111) of the round brush (11), spans a frontal plane (1101) that is oriented substantially orthogonal to the transport direction (1000). Device according to claim 7 or 8, characterized in that the at least one continuously rotating transport element (12, 13) of the counterholder is formed by at least one band or at least one belt (13). Device according to claim 10, characterized in that the at least one band forming the at least one counter-holder or the at least one belt (13) forming the at least one counter-holder is in. Transport direction (1000) extends at least over the at least one rubbing device (11) and at least over a region of at least one transport section (201, 202) arranged adjacent to the at least one rubbing device (11).

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