The present invention pertains to a method for covering boxes and to an apparatus for carrying out the method.
A system for producing boxes with an apparatus for covering the raw boxes is disclosed in publication US2009/0156380A1. In this system, the raw boxes and the cover material provided with glue, i.e., the sheet blanks, are fed from respective upstream apparatuses to a joining device by means of transport devices. This joining device places the bottom of the raw box on the glued side of the sheet blank. The sheet blank is rolled down on all four box walls in a downstream apparatus. Any protrusion of the sheet blank is turned inward. A covering device is assigned to each wall for this purpose.
The four covering devices are arranged opposite of one another in pairs. They respectively have a rubbing-down roller and a turn-in slide. Joining of the sheet on the outer walls takes place by rolling the rubbing-down rollers on the outer sides of the box. For this purpose, the box is vertically transported through between the stationary first pair of covering devices in a first step. The box subsequently remains in a resting position and the turn-in slides of the first pair turn the protrusions of the sheet blank inward. Subsequently, the second pair of covering devices rolls down the sheet on the remaining walls in a vertical movement of their rubbing-down rollers before their turn-in slides turn in the remaining protrusions. A form punch is subsequently lowered into the covered box in order to rub down the turned-in cover on the inner sides of the box.
Such a covering device allows a compact construction. However, one disadvantage can be seen in the resulting poor accessibility of the components. Cleaning of the elements that come in contact with the cover sheet particularly is impeded. Only one pair can process the box at all times due to the arrangement of the covering devices relative to one another. The other pair has to wait until this processing is completed or the box is transported out of the apparatus. The capacity of the system therefore remains limited. The form punch has to be manufactured extremely true to size in order to reliably glue the turn-ins of the sheet to the inner surfaces of the raw box on the one hand and to prevent damages to the box on the other hand. This requires a separate form punch for each inside dimension of a box to be produced. Format deviations of the raw boxes, e.g., due to manufacturing tolerances or climatic influences, also lead to corresponding quality losses of the finished boxes or even rejects.
An objective of the present invention therefore can be seen in developing an apparatus that is improved in comparison with the prior art, eliminates at least one of the aforementioned disadvantages of the prior art and meets the increased requirements regarding the product quality to be achieved.
The box laminating machine comprises different processing devices and transport devices. These processing devices are arranged on the transport paths of the transport devices. A transport system successively transports the respective blank box to be covered into different processing stations of the box laminating machine for processing. In this case, the transport of the blank box to be covered takes place in a plane extending parallel to the bottom of the blank box. However, the laminating machine at least comprises a transport device and two side roll-down devices.
These side roll-down devices are arranged opposite of one another with respect to the transport path of the blank boxes, designed in a mirror-inverted manner and form a pair. Consequently, their construction and function are described below with reference to only one of the at least two identical side roll-down devices.
The side roll-down device is arranged on the transport path of the transport device. It has at least one rubbing-down element and one counter-holder assigned to this rubbing-down element. The counter-holder plunges into the raw box. The rubbing-down element subsequently rubs down the corresponding wall region of the sheet blank on the associated wall of the raw box against the counter-holder. For this purpose, the rubbing-down element sweeps over the wall of the box in a rubbing-down movement. The force flow takes place from the rubbing-down element through the respective sheet to be joined and the associated wall of the blank box. In this context, it is irrelevant whether the rubbing-down element is formed by a rail, a brush or an optionally driven roller.
The apparatus has a first guidance system of the rubbing-down element, which defines the movement path of the rubbing-down element. A second guidance system of the counter-holder defines the movement path of the counter-holder. This movement path of the counter-holder comprises at least one segment that is oriented parallel to the transport path of the raw box. The rubbing-down operation during the continuing transport of the box allows a temporal overlap of movements such that an increased throughput can be achieved.
The two side roll-down devices lying opposite of one another act upon the same blank box successively in order to respectively rub down a region of the sheet. An optimal force flow through sheet and wall can be respectively achieved in that opposing walls of the box are covered successively. Quality losses resulting from format deviations of the individual blank boxes or even damages to the boxes are likewise prevented.
A movement of the counter-holder relative to the associated wall preferably takes place perpendicular to the wall. This ensures that the counter-holder plunges into the box in a contactless manner, but the sheet itself is two-dimensionally supported against the rubbing-down element during the rubbing-down operation. A very small movement in comparison with the dimensions of the boxes is already sufficient in this case. Such a transverse movement in both opposing rubbing-down devices is particularly advantageous. For this purpose, these rubbing-down devices are designed in a mirror-inverted manner to one another.
In a first advantageous embodiment, the counter-holder is mounted so as to be pivotable about an axis. This pivoting axis extends parallel to the respective wall to be covered. It lies above the boxes in such a way that the movement of the counter-holder in the region of the box wall extends approximately transverse to the transport direction of the boxes. In an alternative embodiment, the rubbing-down device comprises a linear guide extending transverse to the transport direction, wherein the counter-holder is guided in said linear guide.
A pivoting axis of the rubbing-down element is provided in another alternative embodiment. This pivoting axis extends parallel to the respective wall to be covered. The pivoting axis is spaced apart from the contact surface of the rubbing-down element in such a way that this contact surface experiences a significant partial movement perpendicular to the wall to be covered. In a fourth embodiment, the rubbing-down element is accommodated in a linear guide of the rubbing-down device. This linear guide is oriented perpendicular to the box wall to be covered.
This transverse movement preferably is generated by a controllable drive. This controllable drive exchanges signals with the control of the box laminating machine. In this way, the transverse movement can be optimized with respect to the materials used and the current machine speed.
The device preferably has defined end positions with respect to the movement perpendicular to the wall to be covered. In this way, the respective movement of the rubbing-down element and the counter-holder is reproducible and a constant quality can be ensured. A mechanical stop, which prevents a movement beyond the permissible range independently of potential malfunctions of the control, is particularly suitable for this purpose.
It is particularly advantageous that the rubbing-down operation takes place during a continuing transport movement. For this purpose, the counter-holder moves in the transport direction synchronous with the respective box as long as it is located within the box. The receptacle of the counter-holder has a guide extending in the transport direction and a corresponding drive. In addition, rubbing-down devices lying opposite of one another with respect to the transport path are arranged behind one another in the transport direction. In this way, the product transport is not unnecessarily interrupted. The products are treated with care due to lower and less frequent accelerations and an increased output can be achieved.
The counter-holder preferably experiences a revolving movement with a pronounced linear movement segment that extends parallel to the transport direction. In this way, the respective wall to be covered only experiences a movement relative to contacting components of the apparatus on its outer side during the rubbing-down operation.
An exemplary embodiment of the invention is described below with reference to the figures, to which we refer with respect to all details that are not mentioned in greater detail in the description. In these figures:
The sheet blanks 1 are glued individually, transferred to the band conveyor 30 and moved along a linear transport path 1000. Suitable apparatuses for applying glue on the sheet 1 are sufficiently known and therefore not illustrated in the figures or described in greater detail. A not-shown robot picks up the supplied raw box 2 and places it on the bottom region 11 of the cover sheet 1 in an accurately positioned manner in a curved downward movement 1010. The now connected unit 3 consisting of the raw box 2 and the sheet blank 1 glued to its bottom 21 is transferred to a conveyor device 9 that follows the band conveyor 30 and has the same transport direction 1000.
The conveyor belts 32 of this conveyor device 9 transport the box units 3 through the processing devices 100, 200 arranged along the transport path 1000 in order to completely cover the box units 3. The elements 101, 102, 103, 105 of a left side roll-down device 100 and a right side roll-down device 200 arranged opposite and downstream thereof, which interact with the box unit 3, are illustrated in
A first rubbing-down roller 105 of the left side roll-down device 100 is illustrated in its starting position underneath the movement path of the box units 3. The rubbing-down roller 105 is essentially cylindrical. Its rotational axis extends parallel to the transport direction 1000 of the box units 3. The rubbing-down roller 105 rolls on the sidewall 23 in a vertical partial movement 1004 from its starting position and in the process rolls down the associated outer region 13 of the sheet blank 1 on the sidewall 23.
A counter-holder 101 is provided in order to support the sidewall 23 against the rubbing-down roller 105 during the roll-down operation. This counter-holder 101 is formed by a pair of punches 102, 103. A supporting plate 104 is arranged between the punches 102, 103 in order to realize a full-surface support. A supporting surface 115, which is illustrated in
A revolving movement 1005 of the counter-holder 101 is realized by means of the linear guidance systems 109, 111 illustrated in
The counter-holder 101 plunges into the raw box 1 from its starting position 1100 above the box unit 3 during a closed, revolving movement 1005 on the sidewall 23 while the box 3 is continuously transported in the predefined direction 1000 by the belts 32. The revolving movement 1005 of the counter-holder 101 essentially takes place in a plane extending parallel to its supporting surface 115. In
The revolving movement 1013 of the rubbing-down element 105 is in a simplified manner characterized by three successive linear movement segments. The actual rubbing-down movement 1014 can be dissected into a portion running parallel to the transport direction 1000 and a vertical portion 1004.
A pneumatic cylinder 121 is provided for realizing the advance movement 1011b transverse to the transport direction 1000. The drive 118 for the vertical movement 1004 is realized in the form of an electric motor with a revolving toothed belt 119. In order to place the rubbing-down roller 105 against the box 3 in a particularly precise yet careful manner, its receptacle has a roller 124, which rolls on a curve 123 that essentially extends vertically and serves as a stop.
The utilization of the construction illustrated in
The horizontal movement 1001 of the counter-holder 101 is illustrated with a broken line and divided into the holding segment 1007 and the return movement 1009. The progression of the horizontal movement 1001 is identical to the transport movement 1000 of the box units 3 during the holding segment 1007. The vertical partial movement 1002 of the counter-holder 101 is illustrated with a continuous line. The coinciding gradient jumps of the vertical partial movement 1002 and the horizontal partial movement 1001 of the counter-holder 101 characterize its starting position 1100. The holding segment 1007 is defined by the lower end position of the vertical movement 1002.
The vertical partial movement 1004 of the rubbing-down roller 105 is likewise illustrated with a continuous line. The rubbing-down operation takes place during the upward movement. This upward movement coincides with the holding segment 1007 of the counter-holder 101. The horizontal partial movement of the rubbing-down roller 105 ensures that a rolling movement on the box unit 3 only runs perpendicular to the bottom 21. A movement of the rubbing-down roller 105 relative to the box 3 in the direction extending parallel to the transport movement 1000 is prevented.
The movement 1011a of the counter-holder 101 perpendicular to the wall 23 to be covered and the alternative movement 1011b of the rubbing-down roller 105 perpendicular to the wall 23 to be covered are illustrated in the form of a common curve. It has a rest period 1003 during the actual rubbing-down operation 1004. The horizontal partial movement of the rubbing-down roller 105 in the transport direction 1000 is not illustrated. It is simply identical to the horizontal partial movement 1001 of the counter-holder.
The movement diagram in
According to the invention, the respective transverse movement 1011a, 1011b of the counter-holder 101 and the rubbing-down element 105 may also take place while the box 3 to be covered is at a standstill. In this case, it is possible to forgo the respective partial movements 1001 of the counter-holder 101 and the rubbing-down element 105 parallel to the transport direction 1000. The construction is simplified accordingly, but not illustrated in the figures.
Number | Date | Country | Kind |
---|---|---|---|
10 2020 116 844.6 | Jun 2020 | DE | national |
Filing Document | Filing Date | Country | Kind |
---|---|---|---|
PCT/EP2021/064620 | 6/1/2021 | WO |