EP4159392B1

EP4159392B1 - Apparatus and method for cutting a tubular cardboard rod

Info

Publication number: EP4159392B1
Application number: EP22187659.2A
Authority: EP
Inventors: Gian Luca CAVALIERI; Marco SPOTTI
Original assignee: Cavalieri & Amoretti Srl
Current assignee: Cavalieri & Amoretti Srl
Priority date: 2021-09-30
Filing date: 2022-07-28
Publication date: 2024-04-03
Anticipated expiration: 2042-07-28
Also published as: EP4159392A1

Description

The present invention relates to an apparatus and a method for cutting a tubular cardboard rod.
The proposed invention has application in the production of cardboard packaging.
The use of coated-cardboard cylindrical boxes is known for the sectors of perfumery, cosmetics, pharmaceuticals, herbalists, food, jewellery, distilleries, clothing, accessories, footwear, etc.
Such boxes are made starting from a tubular cardboard rod, formed with spiralling and then cut into segments.
The cutting into segments occurs perpendicularly to the longitudinal extension axis of the rod. Such a cutting machine is known from the publication WO 2021/064145 A1 .
If cuts must be made with a different inclination, in particular with an elliptical section (so-called "oblique cut"), they must be made manually, which involves long times and even imperfections.
In this context, the technical task underpinning the present invention is that of proposing an apparatus and a method for cutting a tubular cardboard rod, which obviate the drawbacks of the prior art cited above.
In particular, the object of the present invention is to propose an apparatus and a method for cutting a tubular cardboard rod, which allow to make an oblique cut on the tubular cardboard rod.
Another object of the present invention is to provide an apparatus and a method for cutting a tubular cardboard rod, which make the oblique cut with high precision and reducing imperfections as much as possible.
A further object of the present invention is to propose an apparatus and a method for cutting a tubular cardboard rod, which make the oblique cut quickly.
The defined technical task and the specified aims are substantially achieved by a cutting apparatus of a tubular cardboard rod having a longitudinal extension axis, comprising:

an oblique cutting station;
feeding means for feeding the tubular rod to the oblique cutting station;
at least a first cutting blade of the tubular rod arranged at the oblique cutting station.

The first cutting blade is inclined with respect to a transverse section of the tubular rod. The cutting apparatus comprises means for moving the first cutting blade configured to bring the first cutting blade closer to the tubular rod and to move the first cutting blade along a closed path extending around the tubular rod so as to create an elliptical cutting section.
In accordance with an embodiment, the movement means comprises a support for the first cutting blade. The support is rotatable around a rotation axis which is inclined with respect to the longitudinal axis of the tubular rod so that the rotation of the support imposes a movement on the first cutting blade around the tubular rod along the closed path.
In accordance with an embodiment, the support comprises a rotating portion which is rotating around the rotation axis and at least a first oscillating portion comprising at least a first arm having a first end oscillatingly hinged to the rotating portion and a second end bearing the first cutting blade.
In accordance with an embodiment, the first oscillating portion of the support further comprises:

a second arm having a first end hinged to the rotating portion and to the first end of the first arm and a second free end;
a compensation spring mounted between the first arm and the second arm.

In accordance with an embodiment, the first oscillating portion of the support is mounted so as to be able to slide radially with respect to the rotation axis of the support so that the first cutting blade passes from a rest position, in which it is distanced from the tubular rod, to a cutting position, in which the first cutting blade is close to the tubular rod and in contact therewith to cut it, and vice versa.
In accordance with an embodiment, the cutting apparatus comprises a second cutting blade arranged at the oblique cutting station and inclined with respect to the transverse section of the tubular rod. The support comprises a second oscillating portion bearing the second cutting blade. The first oscillating portion and the second oscillating portion are arranged from diametrically opposite parts with respect to the rotation axis so that the tubular rod is interposed between the first cutting blade and the second cutting blade.
In accordance with an embodiment, the cutting apparatus comprises further cutting means of the tubular rod arranged upstream of the oblique cutting station and configured to cut the tubular rod orthogonally to the longitudinal extension axis thereof.
In accordance with an embodiment, the support comprises a base on which the rotating portion is mounted. The base is movable at least between a first position, in which the first cutting blade is located at the oblique cutting station, and a second position, in which the first cutting blade is distanced from the oblique cutting station.
The defined technical task and the specified objects are substantially achieved by a method for cutting a tubular cardboard rod having a longitudinal extension axis, comprising the step of feeding the tubular rod to an oblique cutting station, at least a first cutting blade being arranged at the oblique cutting station. The first cutting blade is inclined with respect to a transverse section of the tubular rod. The method comprises the step of bringing the first cutting blade in contact with the tubular rod and the step of moving the first cutting blade along a closed path extending around the tubular rod so as to create an oblique cut defining an elliptical cutting section.
Preferably, the method comprises the step of making, on the tubular rod, a cut orthogonal to the longitudinal axis thereof upstream of the oblique cut so as to obtain a segment of tubular rod.
Further characteristics and advantages of the present invention will more fully emerge from the non-limiting description of a preferred but not exclusive embodiment of an apparatus and method for cutting a tubular cardboard rod, as illustrated in the accompanying drawings, in which:

figure 1 shows a cutting apparatus, according to the present invention, in a perspective view;
figure 2 shows a segment of tubular rod made by means of the cutting apparatus of figure 1;
figure 3 shows an enlargement of the cutting apparatus of figure 1 (in which the tubular rod and the movement means of the tubular rod have been removed), in a perspective view;
figure 4 shows a part (cutting blade and movement means of the cutting blade) of the cutting apparatus of figure 1, in a front perspective view;
figure 5 shows the components of figure 4, with a rear perspective view;
figure 6 shows a detail (first oscillating portion) of the cutting apparatus of figure 1.

With reference to the figures, the number 1 indicates a cutting apparatus of a tubular cardboard rod 100. In particular, the cardboard referred to herein is spiralled, i.e., the tubular rod 100 is made starting from long strips of cardboard which are wound in a specific helical turning machine around a spindle. These are then glued, to themselves or to each other, making them a solid, self-supporting cylindrical structure.
Tubular rod is intended herein as a tube, a tubular profile or a hollow circular bar. The tubular rod extends along a longitudinal axis X.
The cutting apparatus 1 comprises an oblique cutting station 2.
The cutting apparatus 1 comprises feeding means 3 for feeding the tubular rod 100 to the oblique cutting station 2.
The cutting apparatus 1 comprises at least a first cutting blade 4 of the tubular rod 100 arranged at the oblique cutting station 2.
Preferably, the first cutting blade 4 has a circular extension. Preferably, the first cutting blade 4 is arranged on a circumferential edge of a disc. Preferably, the feeding means 3 is configured to feed the tubular rod 100 to the oblique cutting station 2 along a transport direction which is substantially parallel to the longitudinal axis X of the tubular rod 100. Preferably, the feeding means 3 comprises a carriage 5 sliding along the transport direction.
The first cutting blade 4 is inclined with respect to a transverse section of the tubular rod 100. Transverse section herein means the transverse section with respect to the longitudinal axis X of the tubular rod 100. That is, the first cutting blade 4 is inclined with respect to the direction perpendicular to the longitudinal axis X of the tubular rod 100.
Preferably, the inclination of the first cutting blade 4 is adjustable.
The cutting apparatus 1 comprises movement means 6 of the first cutting blade 4. Originally, the movement means 6 is configured to bring the first cutting blade 4 closer to the tubular rod 100 and move it along a closed path extending around the tubular rod 100 so as to make an oblique cut defining an elliptical cutting section.
In particular, the movement means 6 is configured to bring the first cutting blade 4 from a rest position, in which it is distanced and does not act on the tubular rod 100, to a cutting position, in which it is close to the tubular rod 100 and in contact therewith to cut it, and vice versa.
In the known type of cutting operations, in which cuts of the tubular rod 100 are made such as to create perfectly cylindrical boxes, the cutting blade is always parallel to the transverse section of the tubular rod 100 (or in other words perpendicular to the longitudinal axis of the tubular rod 100) because it must make a cut defining a flat circular section.
In this case, the first cutting blade 4 is originally inclined so as to obtain an oblique or inclined cut of the tubular rod 100. Oblique cut herein means a cut which creates an elliptical transverse section on the tubular. That is, the surface obtained with the oblique cut is inclined with respect to a horizontal or vertical plane.
The closed path therefore has an elliptical extension around the tubular rod 100.
Preferably, the movement means 6 comprises a support 7 for the first cutting blade 4. The support 7 is rotatable around a rotation axis Y which is inclined with respect to the longitudinal axis X of the tubular rod 100. Thereby, the rotation of the support 7 imposes a movement on the first cutting blade 4 around the tubular rod 100 along the closed path.
The inclination of the support 7, in particular the inclination of the rotation axis Y around which the support 7 rotates, defines the inclination of the first cutting blade 4 with respect to the tubular rod 100.
In the embodiment described and illustrated herein, the support 7 comprises a rotating portion 8 rotating around the rotation axis Y and at least a first oscillating portion 9 with respect to the rotating portion 8. The first oscillating portion 9 receives the rotation around the rotation axis Y from the rotating portion 8.
Preferably, the first oscillating portion 9 comprises at least a first arm 10 having a first end 10a oscillatingly hinged to the rotating portion 8 and a second end 10b bearing the first cutting blade 4.
The oscillating assembly of the cutting blade 4 with respect to the rotating portion 8 allows the cutting blade 4, during the rotation around the tubular rod 100 along the closed path, to maintain contact therewith, making a precise and clean cut.
Preferably, the first oscillating portion 9 of the support 7 comprises a second arm 11 having a first end 11a hinged to the rotating portion 8 and to the first end 10a of the first arm 10 and a second free end 10b. Preferably, the first oscillating portion 9 comprises a compensation spring 12 mounted between the first arm 10 and the second arm 11. The compensation spring 12 maintains the mutual position between the two arms 10, 11 and helps the first cutting blade 4 to maintain contact with the tubular rod 100.
Preferably, the extension of the first arm 10 from the first to the second end 10a, 10b occurs towards the rotation axis Y. That is, the extension occurs towards the tubular rod 100.
Preferably, the extension of the second arm 11 from the first to the second end 11a, 11b occurs towards the rotation axis Y. That is, the extension occurs towards the tubular rod 100.
Preferably, the first arm 10 and the second arm 11 define a geometry similar to a V (or a circumflex accent) with the concavity facing the tubular rod 100.
Advantageously, a further first cutting blade 4 can be mounted on the free end 11b of the second arm 11. This choice depends on the size and the thickness of the tubular rod 100 to be cut.
In the embodiment described and illustrated herein, the cutting apparatus 1 comprises a second cutting blade 13. The second cutting blade 13 is also arranged at the oblique cutting station 2 and inclined with respect to the transverse section of the tubular rod 100. The support 7 comprises a second oscillating portion 14 bearing the second cutting blade 13. What is described for the first oscillating portion 9 also applies for the second. Preferably, the first oscillating portion 9 and the second oscillating portion 14 are arranged from diametrically opposite parts with respect to the rotation axis Y so that the tubular rod 100 is interposed between the first cutting blade 4 and the second cutting blade 13.
What has been described above for the first cutting blade 4 also applies to the second cutting blade 13.
According to the same logic and configuration described above, more cutting blades and as many oscillating portions can be included depending on the size of the tubular rod 100 and the desired cycle time.
Preferably, the first oscillating portion 9 of the support 7 is mounted so as to be able to slide radially with respect to the rotation axis Y of the support 7 so that the first cutting blade 4 passes from the rest position to the cutting position, and vice versa.
In the embodiment with two opposite oscillating portions 9, 14, the support 7 is a self-centring pneumatic gripper. The pneumatic actuation allows to achieve the radial sliding of the oscillating portion 9, 14 with respect to the rotation axis Y. In particular, the first oscillating portion 9 and the second oscillating portion 14 perform a pincer movement with respect to the rotating portion 8.
In the preferred embodiment, the cutting apparatus 1 comprises further cutting means 15 of the tubular rod 100 arranged upstream of the oblique cutting station 2. The cutting means 15 is configured to cut the tubular rod 100 orthogonally to the longitudinal extension axis X thereof. Thereby, the first cutting blade 4 makes the oblique cut on a portion of the tubular rod 100 which is located at the oblique cutting station 2, while the cutting means 15 makes a perpendicular cut on a more rearward portion of the tubular rod 100, thus creating a segment 101. The segment 101 has a tronco-cylindrical shape having an inclined cut end and a flat opposite end. Preferably, the position of the cutting means 15 with respect to the oblique cutting station 2 is adjustable so as to be able to adapt the cutting apparatus 1 to different sizes of segments 101 to be obtained.
Preferably, the cutting means 15 comprises a cutting wheel which is movable between a first position, in which it is spaced from the tubular rod 100, and a second position, in which it is in contact with the tubular rod 100 to make the perpendicular cut. Preferably, the cutting wheel 15 rotates with respect to a hinging axis between the first and the second position, and vice versa.
Preferably, the feeding means 3 of the tubular rod 100 is configured to rotate the tubular rod 100 on itself with respect to the longitudinal axis X, after making the oblique cut. Thereby, the cutting wheel 15 is brought into the second position in contact with the tubular rod 100, the tubular rod 100 rotates on itself and the perpendicular cut is made which allows a segment 101 to be obtained.
In the embodiment described and illustrated herein, the cutting apparatus 1 comprises a support bar on which the tubular rod 100 is externally mounted. That is, the support bar holds the tubular rod 100 internally. The support bar has an extension such as to have a free end downstream of the oblique cutting station 2. Thereby, the obtained segments 101 are expelled, falling by gravity from the free end of the support bar.
The support bar acts as an internal support for the tubular rod 100, so that it is not cantilevered in the oblique cutting station 2.
Preferably, the support 7 comprises a base 17 on which the rotating portion 8 is mounted. Preferably, the base 17 and the rotating portion 8 are interconnected by means of a rotating manifold 18. Preferably, the rotating manifold 18 is of the slip-ring type.
Preferably, the base 17 is movable at least between a first position, in which the first cutting blade 4 is located at the oblique cutting station 2, and a second position, in which the first cutting blade 4 is distanced from the oblique cutting station 2. Thereby, after having obtained the segment 101, the base 17 is moved away from the cutting station 2 so as to clear the area in front of the free end of the support bar from the support 7 to allow the segment 101 to fall.
More in detail, once the oblique and perpendicular cuts of the tubular rod 100 have been made to obtain the segment 101, a scrap portion is also formed in front of the obtained segment 101, deriving from the oblique cut of the tubular rod 100. The latter and the segment 101 itself advance and are expelled by gravity. A new portion of the tubular rod 100 to be cut is presented in the cutting station 2. Preferably, the feeding means 3 is configured to rotate the tubular rod 100 during the feeding. Thereby, the expulsion of the scrap portion and the segment 101 is facilitated. Preferably, the cutting apparatus 1 comprises collection means 19 of the segment 101 falling from the support bar. Preferably, the collection means 19 is solidly constrained to the base 17 so that it is located below the support bar when the base 17 is in the second position, distanced from the cutting station 2
Preferably, the collection means 19 comprises an unloading hopper.
Preferably, the feeding means 3 comprises a spindle 20 for the rotation of the tubular rod 100 around the longitudinal axis X thereof.
In the embodiment described and illustrated herein, the spindle 20 is mounted on the carriage 5.
A method for cutting a tubular cardboard rod, according to the present invention, is described below. Such a method is advantageously implemented by a cutting apparatus 1 having one or more of the characteristics described previously.
The method comprises the step of feeding the tubular rod 101 to an oblique cutting station 2. At least a first cutting blade 4 is arranged at the oblique cutting station 2.
The first cutting blade 4 is inclined with respect to a transverse section of the tubular rod 100. That is, the first cutting blade 4 is inclined with respect to a direction perpendicular to the longitudinal extension axis X of the tubular rod 100.
The method comprises the step of bringing the first cutting blade 4 in contact with the tubular rod 100. Such a step occurs by bringing the first cutting blade 4 closer to the tubular rod 100 until they come into contact. After bringing the first cutting blade 4 in contact with the tubular rod 100, the method comprises the step of moving the first cutting blade 4 along a closed path extending around the tubular rod 100. Thereby, the first cutting blade 4 makes an oblique cut on the tubular rod 100, defining an elliptical cutting section.
Preferably, the step of feeding the tubular rod 100 to an oblique cutting station 2 occurs by advancing the tubular rod 100 along a direction substantially parallel to its longitudinal axis X.
Preferably, the tubular rod 100 is advanced intermittently so as to consecutively feed successive portions of tubular rod 100 to the oblique cutting station 2.
More specifically, the tubular rod 100 is advanced by a predetermined amount so that an end portion thereof is located at the oblique cutting station 2. Thereafter, the first cutting blade 4 is brought in contact with the tubular rod 100 and moved around it to make the oblique cut. When the cutting blade 4 is in contact with the tubular rod 100 and during the cutting, the tubular rod 100 is stopped.
In the embodiment described and illustrated herein, the method comprises the step of making, on the tubular rod 100, a cut orthogonal to the longitudinal axis X thereof. The orthogonal cut is made upstream of the oblique cutting station 2 (therefore upstream of the oblique cut) so as to obtain a segment 101 of tubular rod 100.
Preferably, the tubular rod 100 is rotated on itself with respect to its longitudinal axis X.
Preferably, the tubular rod 100 is fed along a transport path which terminates downstream of the oblique cutting station 2. The segments 101 consecutively obtained by cutting the tubular rod 100 fall by gravity at the end of the transport path.
The characteristics of the apparatus and method for cutting a tubular cardboard rod, according to the present invention, are clear, as are the advantages.
In particular, the inclined arrangement of the cutting blade with respect to the transverse section of the tubular rod allows an oblique cut to be made, with an ellipse profile.
Furthermore, the oscillating assembly of the cutting blade with respect to the support allows the instant adjustment of the position of the cutting blade with respect to the tubular rod. Thereby, the cutting blade constantly maintains contact with the latter and makes a precise cut free of imperfections.
Furthermore, the compensation spring between the two arms contributes to this effect.

Claims

A cutting apparatus (1) for a tubular cardboard rod (100) having a longitudinal extension axis (X), comprising:
an oblique cutting station (2),

feeding means (3) for feeding the tubular rod (100) to the oblique cutting station (2);

at least a first cutting blade (4) of the tubular rod (100) arranged at the oblique cutting station (2);

characterised in that said first cutting blade (4) is inclined with respect to a transverse section of the tubular rod (100) and in that said cutting apparatus (1) comprises means for moving (6) the first cutting blade (4) configured to bring the first cutting blade (4) closer to the tubular rod (100) and to move said first cutting blade (4) along a closed path extending around the tubular rod (100) so as to create an elliptical cutting section.
The cutting apparatus (1) according to claim 1, wherein said movement means (6) comprises a support (7) for the first cutting blade (4), said support (7) being rotatable around a rotation axis (Y) which is inclined with respect to the longitudinal axis (X) of the tubular rod (100) so that the rotation of said support (7) imposes a movement on the first cutting blade (4) around the tubular rod (100) along said closed path.
The cutting apparatus (1) according to claim 2, wherein said support (7) comprises a rotating portion (8) which is rotating around said rotation axis (Y) and at least a first oscillating portion (9) comprising at least a first arm (10) having a first end (10a) oscillatingly hinged to said rotating portion (8) and a second end (10b) bearing said first cutting blade (4).
The cutting apparatus (1) according to claim 3, wherein said at least a first oscillating portion (9) of the support (7) further comprises:
- a second arm (11) having a first end (11a) hinged to said rotating portion (8) and to the first end (10a) of the first arm (10) and a second free end (10b);

- a compensation spring (12) mounted between the first arm (10) and the second arm (11).
The cutting apparatus (1) according to claim 3 or 4, wherein said at least a first oscillating portion (9) of the support (7) is mounted so as to be able to slide radially with respect to the rotation axis (Y) of the support (7) so that the first cutting blade (4) passes from a rest position in which it is distanced from the tubular rod (100), to a cutting position in which the first cutting blade (4) is close to the tubular rod (100) and in contact therewith to cut it, and vice versa.
The cutting apparatus (1) according to any one of claims 3 to 5, comprising a second cutting blade (13) arranged at the oblique cutting station (2) and inclined with respect to the transverse section of the tubular rod (100), said support (7) further comprising a second oscillating portion (14) bearing said second cutting blade (13), said first oscillating portion (9) and said second oscillating portion (14) being arranged from diametrically opposite parts with respect to the rotation axis (Y) so that the tubular rod (100) is interposed between the first cutting blade (4) and the second cutting blade (13).
The cutting apparatus (1) according to any one of the preceding claims, comprising further cutting means (15) of the tubular rod (100) arranged upstream of the oblique cutting station (2) and configured to cut the tubular rod (100) orthogonally to the longitudinal extension axis (X) thereof.
The cutting apparatus (1) according to any one of claims 3 to 7, wherein said support (7) comprises a base (17) on which the rotating portion (8) is mounted, said base (17) being movable at least between a first position, in which the first cutting blade (4) is located at the oblique cutting station (2), and a second position, in which the first cutting blade (4) is distanced from the oblique cutting station (2).
A method for cutting a tubular cardboard rod (100) having a longitudinal extension axis (X), comprising:
feeding the tubular rod (100) to an oblique cutting station (2), at least a first cutting blade (4) being arranged at said oblique cutting station (2),

characterised in that said first cutting blade (4) is inclined with respect to a transverse section of the tubular rod (100) and in that it comprises the step of bringing the first cutting blade (4) in contact with the tubular rod (100) and the step of moving said first cutting blade (4) along a closed path extending around the tubular rod (100) so as to create an oblique cut defining an elliptical cutting section.
The method according to claim 9, comprising the step of making, on the tubular rod (100), a cut orthogonal to the longitudinal axis (X) thereof upstream of the oblique cut so as to obtain a segment (101) of tubular rod (100).