Cutting device for cutting relatively rigid web materials such as paper, cardboard, plastic materials or composites

Abstract

A cutting device and corresponding method for cutting a relatively rigid material), such as for example paper, cardboard, plastic material, composite or other. The cutting device includes a first cutting disc sharpened along its peripheral edge and rotating around its a first axis of rotation. A second cutting disc, also sharpened along its peripheral edge (and rotating around a first axis of rotation (X3), is disposed in front of the first cutting disc with respect to the material and is co-planar with the first cutting disc (14).

Claims

1. A cutting device for cutting a relatively rigid material (11), comprising: a first cutting disc sharpened along its peripheral edge and rotating around a first axis of rotation (X2); and at least a second cutting disc (19) sharpened along its peripheral edge (21) and rotating around a second axis of rotation (X3), and wherein said second cutting disc (19) is disposed in front of said first cutting disc (14) with respect to said material (11) and is co-planar with said first cutting disc (14), wherein said first cutting disc (14) and said second cutting disc (19) are mobile individually or together, with respect to a support plane (12) on which said material (11) to be cut is to be rested, so that a distance between the peripheral edge (16, 21) of each of said cutting discs (14, 19) is selectively adjustable with respect to said support plane (12).

2. The cutting device as in claim 1, wherein said second cutting disc (19) is sharper than said first cutting disc (14).

3. The cutting device as in claim 1, wherein said first cutting disc (14) has a first diameter, a first thickness (S1) and a first cutting angle (α1) of its peripheral edge (16), and wherein said second cutting disc (19) has a second diameter, a second thickness (S2) and a second cutting angle (α2) of its peripheral edge.

4. The cutting device as in claim 3, wherein said first diameter is comprised between about 50 mm and about 150 mm, wherein said first thickness (S1) is comprised between 1.5 mm and 3 mm and said first cutting angle (α1) is comprised between about 60° and about 120°, wherein said second diameter is comprised between 25 mm and 100 mm, and wherein said second thickness (S2) is comprised between 0.5 mm and 1 mm and said second cutting angle (α2) is comprised between about 10° and about 30°.

5. A cutting method for cutting a relatively rigid material (11), comprising: a first cutting step, in which said material (11) is cut by a first cutting disc (14) having a sharpened peripheral edge (16) and rotating around a first axis of rotation (X2); and at least a second cutting step, in which said material (11) is cut, before said first cutting step takes place, by a second cutting disc (19) having a sharpened peripheral edge (21), rotating around a second axis of rotation (X3) and disposed in front of and co-planar with said first cutting disc (14), wherein a distance between the cutting edges (16, 21) of the first and the second cutting discs (14, 19) adjusted with respect to a support plane (12), on which said material (11) to be cut is rested, by moving said first cutting disc (14) and said second cutting disc (19) individually or together, with respect to said support plane (12).

6. The cutting device as in claim 3, wherein the second cutting disc (19) has the second diameter, the second thickness (S2) and the second cutting angle (α2) of its peripheral edge that are each smaller than the first diameter, the first thickness (S1) and the first cutting angle (α1) of the first cutting disc (14).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0026] These and other characteristics of the present invention will become apparent from the following description, which is provided with the purpose of giving a better understanding of the invention. Together with the description, a series of drawings are also provided, which form an integral part of the description and show forms of embodiment of the present invention, which must not be interpreted as restrictive of the field of protection thereof, but only an example of how the present invention can be achieved. The drawings comprise the following figures:

[0027] FIG. 1 is a lateral view of a cutting device according to the present invention in an inactive position;

[0028] FIG. 2 is a lateral view of the cutting device in FIG. 1 in a first working position;

[0029] FIG. 3 is a lateral view of the cutting device in FIG. 1 in a second working position;

[0030] FIG. 4 is a lateral view of the cutting device in FIG. 1 in a third working position;

[0031] FIG. 5 is a part and plan view of the cutting device in FIG. 1;

[0032] FIG. 6 is a part and transverse view of the cutting device in FIG. 1;

[0033] FIG. 7 shows a first enlarged detail of the cutting device in FIG. 1;

[0034] FIG. 8 shows a second enlarged detail of the cutting device in FIG. 1.

[0035] To facilitate comprehension, the same reference numbers have been used, where possible, to identify identical common elements in the drawings. It is understood that elements and characteristics of one form of embodiment can conveniently be incorporated into other forms of embodiment without further clarifications.

DETAILED DESCRIPTION OF A FORM OF EMBODIMENT

[0036] We shall now refer in detail to the various forms of embodiment of the present invention, of which one or more examples are shown in the attached drawing. Each example is supplied by way of illustration of the invention and shall not be understood as a limitation thereof. For example, the characteristics shown or described insomuch as they are part of one form of embodiment can be adopted on, or in association with, other forms of embodiment to produce another form of embodiment. It is understood that the present invention shall include all such modifications and variants.

[0037] With reference to FIG. 1, a cutting device 10 according to the present invention is configured to cut a relatively rigid material 11, such as for example paper, cardboard, plastic material, a composite or other, having one or more overlapping layers, with an overall thickness comprised between some tenths of a millimeter, that is, less than 1 mm, up to a maximum of about 10 mm, for example to make boxes.

[0038] The cutting device 10 comprises a support plane 12, for example horizontal, on which the material 11 is suitable to be rested.

[0039] A feed roll 13 is disposed with its cylindrical surface tangent to the upper surface of the support plane 12 and is rotatable in the direction of rotation indicated by arrow F1 around an axis of rotation X1, commanded by a motor member of any known type, for example an electric motor, not shown in the drawings.

[0040] The feed roll 13, with the collaboration of presser rolls of a known type and not shown in the drawings, is able to make the material 11 advance along the support plane 12 in the direction of feed indicated by arrow F2.

[0041] A first cutting disc 14 is mounted rotatable with respect to a first support slider 15, around its axis of rotation X2, parallel to the axis of rotation X1 of the feed roll 13. The rotation of the first cutting disc 14 (arrow F3) occurs in the opposite direction to that of the feed roll 13 and is commanded by a drive member of any known type, not shown in the drawings, for example the same electric motor that commands the feed roll 13.

[0042] The first cutting disc 14 is the known type and has a diameter indicatively comprised between about 50 mm and about 150 mm, a thickness S1 (FIG. 7) comprised between about 1.5 mm and about 3 mm and a peripheral cutting edge 16 with a cutting angle α1 comprised between about 60° and about 120°, preferably about 90°.

[0043] The first support slider 15 is mounted on a fixed structure 17 (FIG. 1) and is mobile with respect thereto in a direction perpendicular to the support plane 12, between an inactive position, in which the peripheral edge 16 of the first cutting disc 14 is distanced up to a maximum of about 10 mm, for example about 7 mm, 8 mm, 9 mm, 10 mm, from the upper surface of the support plane 12, and a working position (FIGS. 2 and 3), in which the peripheral edge 16 is in contact with the cylindrical surface of the feed roll 13.

[0044] A first pneumatic device 18 is configured to selectively command the movement in two directions of the first support slider 15 and of the first cutting disc 14 mounted on it.

[0045] A second cutting disc 19 is disposed coplanar to the first cutting disc 14 and in front of it with respect to the side on which the material 11 is introduced, that is, on the right in FIGS. 1 to 4.

[0046] The second cutting disc 19 is mounted rotatable with respect to a second support slider 20, around its axis of rotation X3, parallel to the axes of rotation X1 and X2. The rotation of the second cutting disc 19 (arrow F4) occurs in the same direction as the first cutting disc 14 and is commanded by a drive member of any known type, not shown in the drawings, for example the same electric motor that commands the feed roll 13.

[0047] The second cutting disc 19 is smaller and sharper than the first cutting disc 14, and indicatively has a diameter comprised between about 25 mm and about 100 mm, a thickness S2 (FIG. 8) comprised between about 0.5 mm and about 1 mm and a peripheral cutting edge 21 having a cutting angle α2 comprised between about 10° and about 30°, preferably about 15°.

[0048] The second support slider 20 is also mounted on the fixed structure 17 (FIG. 1) and is mobile with respect thereto in a direction perpendicular to the support plane 12, between an inactive position (FIGS. 1 and 2), in which the peripheral edge 21 of the second cutting disc 19 is distanced up to a maximum of about 10 mm, for example about 7 mm, 8 mm, 9 mm, 10 mm, from the upper surface of the support plane 12, and a working position (FIGS. 3 and 4), in which the peripheral edge 21 is positioned at a distance of about 1 mm from the upper surface of the support plane 12.

[0049] Advantageously, the first cutting disc 14 and the second cutting disc 19 are therefore mobile individually or together, with respect to a support plane 12 on which the material 11 to be cut is suitable to be rested, so that the distance between the peripheral cutting edge 16, 21 of each of the cutting discs 14, 19 is selectively adjustable with respect to the support plane 12. This solution gives flexibility in use, depending on the material to be cut.

[0050] A second pneumatic device 22 is configured to selectively command the movement in two directions of the second support slider 20 and the second cutting disc 19 mounted on it.

[0051] The cutting device 10 as described heretofore functions as follows.

[0052] In the inactive position (FIG. 1), the two cutting discs 14 and 19 are raised with respect to the support plane 12 and the material 11 is ready to be fed toward them using any known mean, either manually or mechanically, in the direction of arrow F2.

[0053] If the material 11 has a thickness of up to 3 mm, only the first pneumatic device 18 is driven, and only the first cutting disc 14 is lowered (first working position, shown in FIG. 2), as happens in cutting devices known in the state of the art.

[0054] On the contrary, if the material 11 has a thickness from 3 mm to a maximum of about 10 mm, first the second cutting disc 19 is lowered, driving the second pneumatic device 22, and subsequently the first cutting disc 14 is also lowered, driving the first pneumatic device 18, obtaining the second working position, shown in FIG. 3.

[0055] According to a variant, again if the material 11 has a thickness from 3 mm to a maximum of about 10 mm, together with the second cutting disc 19, the first cutting disc 14 can also be lowered, driving the second pneumatic device 22 and the first pneumatic device 18 simultaneously, obtaining in this variant too the second working position shown in FIG. 3.

[0056] In this second working position, the material 11, advancing toward the first cutting disc 14 in the direction of arrow F2, before it meets the first cutting disc 14, meets the second cutting disc 19 which, thanks to its very sharp peripheral edge 21, cuts the material 11 as if it were a scalpel. Immediately after, the first cutting disc 14 completes the cutting of the material 11, easily entering into the same incision made by the second cutting disc 19.

[0057] In this way, even if it has a thickness from 3 mm to a maximum of about 10 mm, the material 11 is cut perfectly and completely.

[0058] FIG. 4 shows a third working position of the cutting device 10, with the second cutting disc 19 still lowered, while the first cutting disc 14 has already returned to its inactive position, raised with respect to the support plane 12.

[0059] We must point out that, even if it has a slightly higher production cost than known cutting devices, which have only one cutting disc, the cutting device 10, precisely because of the second cutting disc 19, allows to obtain great cutting efficiency and can operate at a much higher cutting speed than known devices, and therefore the cost of the cutting operations is greatly reduced. Furthermore, the cutting device 10, due to what we explained above, also increases the average life of the tools.

[0060] It is clear that modifications and/or additions of parts may be made to the cutting device 10 and corresponding cutting method as described heretofore, without departing from the field and scope of the present invention.

[0061] For example, the material 11 could remain stationary in a position on the support plane 12 and the two cutting discs 14 and 19 can be moved laterally, in the opposite direction to that indicated by arrow F2, toward the material 11, so that the second cutting disc 19 makes a deep incision on it and then the first cutting disc 14 completes the cutting of the material 11.

[0062] It is also clear that, although the present invention has been described with reference to some specific examples, a person of skill in the art shall certainly be able to achieve many other equivalent forms of, having the characteristics as set forth in the claims and hence all coming within the field of protection defined thereby.