FIELD OF THE INVENTION

The present invention relates to the technical sector concerning obtaining spatially-developing articles (for example advertising display cases) obtained starting from a panel of a type constituted by a reticular structure, having a constant thickness, to which two films, parallel to one another, are solidly constrained on opposite sides.

Portions of predetermined area are fashioned from the panel, on each of which predetermined bend lines, i.e. lines about which the sides of the portion adjacent to the lines, can rotate.

This is obtained by cutting the portion of the panel such as to involve a film and the reticular structure by means of two cutting paths lying in inclined planes with respect to the films (for example at 45°).

In this way a bend line defined by the confluent line of the inclined planes is defined, situated at the uncut film, i.e. the film not involved in the cutting.

Following the cutting, the cut surfaces are brought together (possibly by means of application of glue thereon) by rotation of the relative sides with respect to the bend line: in this way an angular edge of the corresponding article is realised.

DESCRIPTION OF THE PRIOR ART

At present the cuts referred-to above are obtained using fixed blades, i.e. blades subjected to a linear translational motion.

Complaints relating to this method comprise an accentuated wearing of the cutting edge of the blades, caused both by the excessive heating thereof and by the abrasive nature of the materials constituting the panel; the drawbacks deriving from this are obvious, such as for example non-optimal cuts (with chippings) and frequent replacements of the cutting means, with the consequent costs this involves.

US 2003/140762 discloses a device that uses a blade for cutting panels, or panels constituted by layered laminates, with the blade moved translatingly combined with a succession of oscillations.

SUMMARY OF THE INVENTION

The advantage of the invention is that it obviates the drawbacks in the prior art, by means of a device for cutting the panels of the above-described type, which enables a movement of the blades such as to increase the average working life of the relative cutting edges and such as to realise the cutting of the panels without chipping.

These advantages were obtained according to the contents of the claims. BRIEF DESCRIPTION OF THE DRAWINGS

The characteristics of the invention are disclosed in the following with reference to the accompanying tables of the drawings, in which: figures 1-5 schematically illustrate, in plan view, the succession of operations by means of which starting from a portion of a panel an angular cut of a corresponding article is obtained; figures 6A, 6B are two views, perpendicular to one another, of the disclosed device.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

With reference to figures 6A, 6B, 1 denotes a device bearing a cutting blade 2. The device is constituted by a shaft 3 rotatably supported by an operating unit 4 movable according to Cartesian axes X, Y, Z by means of known techniques in the sector.

The shaft 3 exits from both sides of the unit 4; the lower portion 3A of the shaft 3 is bent at an angle a with respect to the axis β thereof.

The portion 3A supports vibrating means 5 of known type developing perpendicularly to the halfway line Φ of the portion 3A; a blade 2 is keyed on the output spindle 5a of the vibrating means 5.

X defines the translating direction of the device 1 and therefore the blade 2; the vibrating means 5 impart vibrations on the blade (i.e. oscillations) or in direction X (directions W-W, figure 6B), or in the perpendicular direction to direction X (directions J-J, figure 6A).

Definitively, the cutting blade 2, apart from the translation motion (direction X), can be subjected to oscillations either in directions W-W or directions J-J; both the oscillations can coexist with the translation of the blade 2 in direction X. With reference to figure 1 , 20 denotes a panel constituted by two parallel films 21 A, 21 B between which a reticular layer 22 is solidly interposed.

The panel is cut with the device 1 according to the disclosed method after its positioning on a suitable flat support, not illustrated.

Figures 2-5 illustrate, purely by way of example, cuttings of the panel according to cutting planes 50, 60, inclined by 45° with respect to the films 21A, 21 B.

For this purpose, by moving the operating unit 4 and if necessary, by intervening such as to rotate the shaft 3 (directions N ₂ ) relative to the axis β, the blade 2 is positioned as in figure 6A.

At this point, the unit 4 is activated and the vibrating means 5 activated, such as to impart a translation on the blade 2 in direction X (figure 6B), with which the oscillations (vibrations) are combined in directions W-W, or in directions J- J, or in both the directions.

In the illustrated example the cutting of the panel only involves the film 21 A and the reticular layer 22; the two cutting planes 50, 60 (figure 2, 3) identify, in the whole film 21 B, a bend line 70 (fig. 4).

The rotation of the sides of the panel 20A, 20B adjacent to the bend line 70 enable identifying a corner-piece of an article, which article is not illustrated in the drawings as it is not pertinent to the invention.

As specified above, figures 2-5 illustrate an example of cutting of a panel; it is understood that the cutting can involve the whole panel, i.e. both the films 21 A, 21 B together with the layer 22.

It has been observed that the oscillations imparted on the blade 2 lead to a sort of self-cleaning effect on the cutting edge 2a of the blade; this prevents the chips (abrasive) of the cut panel from remaining on the blade, with a consequent increase in the duration thereof.

The above-mentioned oscillations lead, given a same operating velocity of the cutting of the panels in the prior art, to a decrease in the temperature of the cutting edge, which is translated into an increase in the duration of the blade. The positive effects mentioned above lead to an optimisation of the quality of the cutting.