DESCRIPTION

The invention has for an object a machine and method for making blanks for boxes to measure.

In order to make blanks for boxes, particularly cardboard boxes, it is known to use packaging sheets suitably cut and possibly glued so as to reach the desired size.

The cutting of packaging sheets is performed perpendicularly to the plane in which the sheet lies, thereby forming a thickness which is perpendicular to the laying plane. It follows that the joining of two packaging sheets is performed by partially overlaying them after having applied a layer of adhesive material. In other words a joining portion is formed, wherein the thickness of the blank results to be double compared to the rest of the blank.

In the particular case of cardboard boxes essentially formed by two outer layers joined together by a corrugated middle layer, the adhesive material adheres to a portion of the upper outer layer of the lower packaging sheet and to a portion of the lower outer layer of the upper packaging sheet. When the subsequent folding of the blank to form the box is performed relative to, or near the joining point, this may result in the lower or upper outer layer thereof to become detached.

In this context, the technical task at the base of the invention herein is to provide a machine and method for making blanks for boxes to measure which obviate the drawbacks of the known art mentioned above.

In particular, it is an object of the present invention to provide a machine and method for making blanks for boxes to measure which is able to obtain more resistant joining portions which are not subject to ungluing even where the following box folding occurs relative to, or near the joining portion.

A further object of the invention is to provide a machine and method for making blanks for boxes to measure being able to obtain joining portions more aesthetically pleasing.

The technical task mentioned and the aims specified are substantially achieved by a machine and method for making blanks for boxes to measure, comprising the technical characteristics described in one or more of the appended claims. The dependent claims correspond to different embodiments of the invention.

According to a first aspect, the invention relates to a machine for making blanks for boxes to measure comprising a feed path of packaging sheets, suitable for making blanks for boxes to measure. At least one portion of the feed path is configured to maintain the packaging sheets in a planar configuration defining at least a plane in which the packaging sheets lies. There are provided joining means for joining two packaging sheets along a respective joining edge. At least one cutting device is arranged along the portion of the feed path wherein the packaging sheets are arranged planar. This cutting device is configured to cut each packaging sheet along a respective joining edge according to a cutting plane arranged inclined with respect to the plane in which the packaging sheet lies and the packaging sheet itself, thus forming an inclined thickness of the latter. The cutting device is arranged upstream of the joining means, along the feed path.

According to a further aspect, the present invention relates to a method for making blanks for boxes to measure. In particular there is provided to feed packaging sheets suitable for making blanks for boxes to measure, where the packing sheets are maintained in a planar configuration thereby defining at least a plane in which said packaging sheets lie; it is further provided to join two packaging sheets along a respective joining edge. Prior to being joined, each packaging sheet is cut along a respective joining edge according to a cutting plane arranged inclined with respect to the plane in which the packaging sheet lies, so as to form an inclined thickness of the packaging sheet. In one or more of the above aspects, the present invention may comprise one or more of the following characteristics.

According to a possible embodiment, the cutting plane forms an acute angle between 10° and 45°, preferably 30° degrees, with the plane in which the packaging sheets lie.

According to a possible embodiment, the cutting device comprises a rotary blade defining the cutting plane.

According to a possible embodiment, the cutting device is fixed to a bracket angled with respect to the plane in which the packaging sheets lie. According to a possible embodiment, the cutting device is fixed to a base structure of the machine while the packaging sheets are moved by feed means along the portion of the feed path in which the packaging sheets are arranged planar. In other words, there is provided to move sheets along a feed path when cutting is being performed.

According to a possible embodiment, the joining means are configured for joining two packaging sheets on the front and aligned along the plane on which the same lie. In particular there is provided to join two packaging sheets on the front and aligned along the plane. Preferably, at least one of the packaging sheets comprises an inclined thickness.

Alternatively, the joining means are configured for joining two packaging sheets set side by side and offset by the thickness of the packaging sheets. In particular there is provided to join two packaging sheets set side by side and offset by the thickness of the packaging sheets. Preferably, at least one of the packaging sheets comprises an inclined thickness.

Still alternatively, the joining means are configured for joining two packaging sheets partly on the front and offset by a distance which is less than the thickness of the packaging sheets. In particular there is provided to join two packaging sheets partly on the front and offset by a distance which is less than the thickness of the packaging sheets. Preferably, at least one of the packaging sheets comprises an inclined thickness. Still more preferably, both packaging sheets comprise an inclined thickness. According to a possible embodiment, the cutting plane is configured for cutting transversely extension lines of a central corrugated layer of the packaging sheet.

Further characteristics and advantages of the present invention will become more apparent from the indicative, and therefore non-limiting, description of a preferred but not exclusive embodiment of a machine for making blanks for boxes to measure, as illustrated in the accompanying drawings in which:

- Figure 1 is a schematic view in perspective of a machine for making blanks for boxes to measure;

- Figure 2 is a schematic view according to the direction A of Figure 1 , partially sectioned;

- Figures 3A-3D illustrate a schematic sectional view of a joining portion of a blank according to four different embodiments.

With reference to the above figures, the numeral 1 indicates a machine for making blanks 2 for boxes to measure in its entirety;

The machine 1 is suitable for being mounted in a plant for making packages of articles to measure wherein, once the size (width and length) of the plan view of the packaging have been determined, the machine 1 provides to cut the packaging sheet 3 and to make the blank 2, which blank 2 will then be conveyed to an automatic or manual station wherein the forming of the package takes place.

In figure 1 a packaging sheet 3 is illustrated, for example a cardboard, from which the blank 2 will be obtained. The packaging sheet 3 can be defined as one of a plurality of single sheets or as a portion of a continuous module 4 folded on itself.

With reference to Figure 1 , the machine 1 comprises an automatic store 5 from which the continuous module 4 is taken. From the continuous module 4 single packaging sheets 3 are then cut, for example by means of a first cutting device 6. In alternative or in addition to the automatic store 4, the machine 1 may comprise an automatic store 7 from which the single sheets are picked up, which single sheets define a packaging sheet 3 when entering into the machine 1. In the illustrated example the packaging sheet 3 has a width "La" which was chosen based on the type of product/article that is to be packed, and a length "Lu". The overall length "Lu" of the blank 2 is continuously adapted by gluing packaging sheets 3 in sequence, having the same width "La".

The machine 1 comprises joining means for joining two packaging sheets 3 along a respective joining edge. Where the joining is aimed at adjusting the length "Lu" of the blank 2, the two packaging sheets 3 are joined along a respective joining edge 3a or 3b. Where the joining is aimed at adjusting the width "La" of the blank 2, the two packaging sheets 3 are joined along a respective joining edge 3a Or 3b'.

The first of the two situations indicated above will be better detailed here below.

In general the machine 1 comprises feed means of the packaging sheets 3, configured for conveying the packaging sheets by means of the devices predisposed for obtaining the blank 2. Such devices may for example comprise cutting means to measure of the packaging sheets 3.

In particular, the machine 1 comprises a feed path P of the packaging sheets 3. At least a portion of the feed path P is configured to maintain the packaging sheets 3 in a planar configuration, thereby defining at least one plane 8 (Figure 2).

With the numeral 9 it is indicated a cutting device illustrated in detail in Figure 2. This cutting device is arranged along a portion of the feed path P configured for keeping the packaging sheets 3 in a planar configuration. In addition, the cutting device 9 is configured for cutting each packaging sheet 3 along a respective joining edge which is represented by the joining edge 3a in the example illustrated in the figures.

In particular the cutting device 9 is configured for cutting each packaging sheet 3 according to a cutting plane 10 disposed inclined to the plane 8 and to the packaging sheet 3, thereby forming an inclined thickness 11 of the packaging sheet 3.

The cutting device 9 is arranged upstream of the joining means along the feed path.

The cutting plane 10 forms with the plane 8 an acute angle β comprised between 10° and 45°, preferably 30°.

In accordance with a possible embodiment, the cutting device 9 comprises a rotary blade 12 defining the cutting plane.

In particular, the blade 12 is fitted on a rotating shaft 13 about an axis 14.

According to a possible embodiment, the cutting device 9 is fixed to a bracket 15 which is angled with respect to the plane 8.

Preferably, the cutting device 9 is secured to a base structure 16 of the machine 1 , for example by means of aforesaid bracket 15.

According to a possible embodiment, the cutting device 9 is stationary with respect to the base structure 16 of the machine 1 and the packaging sheets 3 are moved by the feed means at least along the portion of the feed path P in which the cutting device 9 acts.

The joining means, not explicitly illustrated, may include a dispenser of adhesive material 17, for example glue, suitable for being arranged relative to the respective joining edge of the packaging sheets. Figures 3A-3D illustrate four possible ways of joining packaging sheets. Particularly, reference is made to a cardboard comprising a lower outer layer 18 and an upper outer layer 19 (with reference to the plane 8). One central corrugated layer 20 is disposed between the lower outer layer 18 and the upper outer layer 19.

Figures 3A and 3B refer to the illustration of figure 1 and 2, wherein there is provided only one cutting device 9 suitable for performing the cutting of the joining edge 3a. In this case the joining edge 3b is cut perpendicularly to the plane 8, thereby forming a perpendicular thickness 1 '.

Figure 3A shows the case in which the joining means are configured for joining two packaging sheets on the front and aligned along the plane 8. Figure 3B shows the case in which the joining means are configured for joining two packaging sheets set side by side and offset by the thickness thereof. The arrangement of the two packaging sheets is preferably such that the inclined thickness 11 of the lower packaging sheet is facing towards the lower outer layer 18 of the upper packaging sheet. In other words the inclined thickness 1 of one of the two packaging sheets is facing towards the other packaging sheet.

Figure 3C shows the case in which there are provided two cutting devices 9 one of which is suitable for performing the cutting of the joining edge 3a and the other is suitable for performing the cutting of the joining edge 3b. Furthermore Figure 3C shows the a case in which the joining means are configured for joining two packaging sheets partially on the front and offset by a distance that is smaller than the thickness of the packaging sheets. The contact between the two packaging sheets is partly due to a direct contact between the portions of inclined thicknesses 11 and partly to a contact between a portion of an inclined thickness 11 of a packaging sheet, and an outer layer of the other packaging sheet.

Figure 3D shows a solution in which the joining edge 3a of a first sheet 3 is L-shaped. The joining means are configured for joining two packaging sheets set side by side and offset by the thickness of said packaging sheets. The arrangement of the two packaging sheets is preferably such that the concavity of the L-shaped joining edge 3a of the lower packaging sheet is facing towards the lower outer layer 18 of the upper packaging sheet. In this case the joining edge 3a is at least partially cut perpendicularly to the plane 8 thus forming a perpendicular thickness 11'. Each joining step as shown in Figures 3A-3D may be provided with one or two inclined thicknesses.

In use, the machine 1 provides to feed the packaging sheets suitable for making blanks 2 while maintaining the packaging sheets in planar configuration and defining the plane 8, and to join two packaging sheets along a respective joining edge. The joining can be performed to adapt the length "Lu" of the blank and/or the width "La" of the blank. Prior to being joined, each packaging sheet is cut along a respective joining edge according to the cutting plane 10, disposed inclined to the plane 8 and to the packaging sheet, thus forming an inclined thickness 11 of the packaging sheet.

While joining the two packaging sheets, a frontal joining thereof can be performed, said packaging sheets being aligned along the plane 8. At least one of the packaging sheets comprises an inclined thickness 1. In this case, the adhesive material 17 is interposed between the thicknesses of the two packaging sheets.

Alternatively it is possible to join the two packaging sheets set side by side and offset by the thickness of said packaging sheets. At least one of the packaging sheets comprises an inclined thickness 11. In this case, the adhesive material 17 is interposed between the inclined thickness 11 of a packaging sheet and the outer layer of the other packaging sheet.

As a further alternative it is possible to join the two packaging sheets partially on the front and offset by a distance which is less than the thickness of said packaging sheets. At least one of the packaging sheets comprises an inclined thickness 11 , preferably both of them. In this case, the adhesive material 17 is interposed between the inclined thickness 1 of a packaging sheet and the outer layer of the other packaging sheet. As illustrated schematically in Figure 1 , the central corrugated layer 20 is made by a corrugated sheet defining a plurality of lines of extension or rods 21 , preferably arranged along the length "Lu" of the packaging sheet. Preferably the cutting plane 10 cuts the lines of extension 21 of the central corrugated layer.