An arrangement for the raising of packing container blanks.

The present invention relates to an arrangement for the raising of flattened,tubular container blanks with the help of a movable driving element, and, more particularly, such an arrangement on which the driving element is provided with suction elements for engagement with, and attachment to, the blanks.

Within the field of the packaging industry, where certain types of liquid contents, e.g. milk, are packed into consumer packages of the non-returnable type, packing machines are used, for example, which convert prefabricated packing container blanks to bottom-closed packing containers which subsequently are filled directly with the particular contents and closed. The packing container blanks in general are supplied to the machine in the form of flattened, tubular blanks which before the conversion to individual packing containers have to be raised, that is to say converted to four-sided tubes of substantially square cross-­section. This raising usually takes place in connection with the blank being transferred from a magazine at the feeding-in end of the packing machine to a first conversion station in the packing machine proper.

It is an important object of the present invention to provide an arrangement intended for the raising of flattened, tubular container blanks by means of which it is possible to provide a more reliable as well as quicker raising of the blanks than had previously been possible with arrangements known up to now of the type which comprises movable driving elements provided with suction elements.

This object has been achieved in accordance with the invention with the help of an arrangement of the type described above which has been given the characteristic that the said driving element possesses oppositely directed suction elements so as to allow simultaneous engagement with opposite sides on a flattened container blank.

In the following the invention will be described in more detail with the help of the attached drawings, whereon <ul id="ul0001" list-style="none"><li>Fig.1 shows a perspective view of an arrangement in accordance with the invention for the transfer and raising of flattened, tubular packing container blanks from a magazine to a movable conveyor arrangement for the feeding on of raised blanks into a packing machine.</li><li>Fig. 2a-2d illustrate schematically the principle of operation of the arrangement shown in Fig.1, and</li><li>Fig.3 shows an example of a conventional packing container blank in flattened condition for raising with the help of the arrangement shown.</li></ul>

In Fig.l is thus shown an arrangement 1 in accordance with the invention for the transfer and raising of flattened, tubular packing container blanks 2 from a magazine 3 to a conveyor arrangement 4 for the feeding on of raised blanks into a packing machine, not shown, which from raised packing container blanks manufactures filled and closed packing containers. The conveyor arrangement 4 has its receiving end, located to the left in the Figure, placed substantially straight above the feeding-out end of the magazine 3 and comprises, for example, conveyor belts 6 driven round rollers 5 in the direction of feed, with drivers 7 arranged so that the space between the drivers corresponds to the shape of a raised container blank.

The magazine 3 is of elongated shape with a width corresponding to the length of the container blanks 2, and preferably is oriented so that its longitudinal direction is parallel with the direction of movement of the conveyoor arrangement 4. The magazine 3, moreover, has a base plate 8 and longitudinal side supports 9 for the correct alignment of a stack of container blanks 2 lying compactly on the base plate 8. The stack of container blanks 2 lying in the magazine 3 is pressed continuously with a certain force against a driving plate 10 serving as an output device at the feeding-out end of the magazine, in order to ensure that one packing container blank 2 is ready at all times at the outlet end of the magazine for transfer to the conveyor arrangement 4. This action of the packing container blanks upon the outlet end of the magazine is not shown in the Figures, but may consist of some conventional arrangement, e.g. a pressure plate subjected to spring or weight action at the other end of the magazine.

The driving plate 10 serving as an output device at the feeding-out end of the magazine 3 has a lateral surface substantially plane against the container blanks 2 with a slightly projecting edge 11, arranged parallel with the horizontal container blanks 2, whose height substantially corresponds to, or is slightly less than, the thickness of a flattened container blank 2. The driving plate 10 is connected at the bottom to a driving rod 12 driven by a motor (not shown), and at the top is joined to two connecting arms l4 in hinged connection with each other (at 13). Each of the connecting arms 14 is joined at the top to a substantially horizontal arm l5 whose length coincides with, or even slightly exceeds, the length of a container blank 2. The arms 15 are suspended with their ends in guide tracks l6 located right opposite each other on support plates 17 arranged at the ends of the arms.The arms 15 are provided,moreover,with suction elements 18 in the form of suction heads 18a and 18b respectively arranged along the arms which via connecting ducts l9a and l9b can be joined either to a common, or each to its own, vacuum source (not shown). It is important in this context in accordance with the invention that the connection of the suction elements to the vacuum source is such that the control of the respective suction heads 18a and 18b can be done irrespectively of each other.

The driving plate 10 is drivable with the help of the driving shaft 12 in a reciprocating vertical movement between a lower and an upper position which in the example shown correspond to the projecting feed edge 11 on the driving plate 10 mentioned earlier being in its lower position directly below the bottom edge of the container blank 2 lying outermost in the magazin 3, whilst in the upper position the feed edge is level with, or just above, the top edge of the remaining container blanks. In the lower position so defined the arms 15 are in such a position that the suction heads l8a and l8b respectively find themselves right opposite each other, whilst in the upper position , owing to the upwards movement of the arms controlled away from each other along the tracks 16 in the support plates 17,the suction heads 18a and 18b are in a substantially horizontal, upwards facing position.

In the following the function of the arrangement shown will be described with reference to Fig. 2a-2d which schematically illustrate the course of its function during a working cycle, but in order to make this description clear, a brief description of a packing container blank will be given first with special reference to Figure 3 which shows such a container blank in flattened condition to be raised to a shape of substantially square cross-­section with the help of the aforesaid arrangement in accordance with the present invention.

The packing container blank 2, as mentioned earlier, is conventional and may be manufactured, for example, from a flexible but form-stable laminated material, e.g. a packing laminate which comprises layers of paper and plastics. After the laminate has been cut to the desired outer contour and provided with crease lines facilitating the fold-forming, two longitudinal edges are sealed together so that the laminate is converted to a tubular packing container blank. Subsequently the packing container blank is flattened by folding it together along two longitudinal crease lines 201 and 202 whereby it acquires the flattened tubular shape shown in Fig.3 with the side wall panels A-D delimited by the crease lines lying in pairs against each other so that in the example shown the panels A and B adjoining the righthand longitudinal crease line 201 and the panels C and D on the lefthand longitudinal crease line 202 respectively are situated straight opposite each other. A bundle of such flattened container blanks 2 is then arranged in a horizontal stack which in the present example means that the righthand edge line 201 will be facing downwards whilst the lefthand edge line 202 consequently faces upwards. This arrangement in the magazine 3 as shown in Fig. 2a-2d may be assumed further to imply that the side of the packing container blanks 2 facing towards the feeding-out end of the magazine 3 is constituted of the panels A and D with the panel A at the bottom, whilst the panels B and C are turned towards the other direction with the panel B at the bottom.

When the driving rod 12 and the driving plate 10 at the feeding out end of the magazine 3 connected thereto move upwards from the lower position defined earlier (as shown schematically in Fig.2a),the projecting feed edge 11 on the driving plate 10 conse­quently will get hold of the container blank 2 lying outermost in the magazine 3 from underneath along the edge line 201 and move the same upwards out of the magazine 3,as is evident from Fig. 2b,and further up to the position shown in Fig.2c which corresponds to the upper position of the upwards movement of the driving rod 12 and the driving plate 10 and which means, therefore, that the feed edge 11 will be at, or slightly above, the top edge of the magazine 3. Thereafter the driving rod 12 turns and moves down wards with the driving plate 10 back to the lower position shown in Fig.2a, with the container blank 2 advanced left behind above the magazine 3 in a position ready for the actual raising operat­ion. For the sake of clarity it should be pointed out that this raising takes place, simultaneously with the feeding out just de­scribed, on a container blank immediately preceding this one. Hence with the help of the arrangement in accordance with the invention, on the one hand the feeding out, or rather the advance, of a flattened packing container blank to the said ready position is taking place, whilst on the other hand a container blank advanced previously is raised during one and the same working cycle.

A packing container blank advanced previously to the ready position for raising is shown in Fig.2a having the designation 2ʹ, and in this position the blank lies between the arms l5 carrying suction heads in their lower position , these arms l5 having their respective suction heads l8a and l8b located straight opposite each other and level with, and aligned to, the side panels B and A respectively located at the bottom of the container blank 2ʹ.The suction heads 18a and 18b are connected to the vacuum source, not shown, via the connections l9a and l9b respectively,a suction engagement with the said panels being achieved. During the enforced upwards movement of the driving plate 10 and the inter­linked connecting arms 14, the arms l5 controlled in guide tracks 16 of the support plates 17 will move in an upwards directed path curved away from each other, as is evident from Fig.2b. During this movement the container blank 2ʹ is subjected to a raising or transfolding operation in that the suction heads 18a and 18b (which act upon the panels B and A respectively) separate the panels from each other by folding them in either direction outwards from each other about the side edge 201 so that ultimately they are substantially in line with each other. This means at the same time that the two upper side panels C and D too are subjected to a corresponding folding out operation during which the two edge lines 201 and 202 are successively brought towards each other and pass an intermediate position wherein the previously flattened container blank 2ʹ presents a square cross-section.

When the arms l5 have reached their upper position (Fig.2c), the connection between the suction heads 18a and the vacuum source is broken, which means that the suction heads 18a release the grip on the side panel B and this in turn means that the "over-folded" container blank 2ʹ, owing to a naturally inherent propensity for refolding, tends to revert to, and assume, the original flattened condition. During this refolding movement the container blank 2ʹ thus passes again the previously over-folded intermediate position of square cross-section. By synchronizing beforehand the driving of the conveyor arrangement 4 located above the arrangement so, that a driver 7 passing by will just be in the right position for the refolding container blank 2ʹ to strike against it with its edge line 202 at the very moment when the container blank has assumed its square cross-sectional shape, it becomes possible to catch the container blank in the raised intermediate position in the space between this and the immediately following driver,as is shown in Fig.2c. After the container blank has been so caught the connection between the suction heads 18b and the vacuum source is also broken, as a result of which the grip on the side panel A of the container blank 2ʹ is released and a feeding on of the container blank thus raised to square shape along the conveyor belt 6 is made possible. When this vacuum connection has been broken, the arms 15 together with the driving plate 10 and the driving rod 12 move downwards (Fig.2d) to revert to the lower position for new working cycles, that is to say the raising or the feeding out respectively of further container blanks.