Cutting unit and method for removing a band from a wall of a packaging box

Abstract

A cutting unit (5) and a method for removing a band (6) from a wall (4) of a pack (1), in particular a pack of smoking articles, fed along a path (P). The cutting unit (5) has: two rotary blades (7) mounted in a manner rotatable about respective rotation axes (8) and producing two incisions on the wall (4) of the pack (1) that separate the band (6) from the rest of the wall (4) of the pack (1); and an extraction element (9) arranged close to the two rotary blades (7) to intercept the band (6) and accompany it away from the wall (4).

Description

Cutting unit and method for removing tape from the wall of a packaging box

[0001] Citations of relevant applications

[0002] This patent application claims priority to Italian Patent Application No. 102020000021748, filed on September 15, 2020, the entire disclosure of which is incorporated herein by reference. Technical Field

[0003] This invention relates to a cutting unit and method for removing a strip from the wall of a packaging box (particularly a packaging box for suction products).

[0004] The invention finds advantageous applications in packaging machines (e.g., cellophane wrapping machines) used to manufacture cigarette packs (also known as "book-style packs"), which will be clearly described in the following disclosure without losing their generality. Background Technology

[0005] The "book-pack" cigarette pack includes (at least) two compartments that accommodate corresponding cigarette packs, each having a corresponding open upper end, and are hinged to each other to rotate between a closed configuration where the two compartments overlap and an open configuration where the two compartments are separated; in addition, a lid is provided that is hinged to a rear compartment and, when in the closed position, covers the upper part of the two compartments.

[0006] Examples of “book-style” cigarette packaging boxes are provided in patent application EP1616795A1 or patent application EP1829783A1.

[0007] The production of the "book-style packaging box" cigarette box involves using two corresponding blanks to form two receptacles. These blanks are folded around the corresponding cigarette packs to connect (overlap) the two receptacles. Then, a third blank is folded around the two connected (overlapped) receptacles to connect the two receptacles and form a common lid.

[0008] After folding the third blank, a cut needs to be made in the bottom wall of the "book-shaped" cigarette box to allow the two receiving parts to separate (i.e., to allow the two receiving parts to rotate relative to each other). Typically, a double cut (i.e., two close and parallel cuts) is performed to remove the strip from the bottom wall, thus creating a clear separation between the two receiving parts. For this purpose, a cutting unit is used, equipped with two parallel and adjacent rotating blades partially housed in a collection chamber, where a suction action is performed. Once the strip separates from the rest of the bottom wall of the "book-shaped" cigarette box, it is immediately captured and removed. However, it is not uncommon for the strip to remain stuck in the bottom wall of the "book-shaped" cigarette box even after the two rotating blades have made the cut, and therefore cannot be removed by suction; thus, downstream of the cutting unit, some "book-shaped" cigarette boxes still have strip more or less fixed in place at the bottom. This can cause various problems, such as the tape getting lost in the machine before the transparent plastic wrapping is applied or before the tape is wrapped with the box in a completely random location (with a transparent plastic wrapping), thus giving the end user the impression of a poor-quality cigarette box.

[0009] Patent application US2011049781A1 describes a system for cutting and stacking paper to form a book. Summary of the Invention

[0010] The object of the present invention is to provide a cutting unit and method for removing tape from the wall of a packaging box (particularly a packaging box for squeezable products), which allows the tape to be removed after cutting, while being easy to manufacture and inexpensive.

[0011] According to the present invention, a cutting unit and method are provided for removing a strip from the wall of a packaging box (particularly a packaging box for a sippy product). The packaging box, particularly a packaging box for a sippy product, is fed along a path. The cutting unit includes two rotating blades mounted rotatably about corresponding axes of rotation and creating two cuts in the wall of the packaging box that separate the strip from the remainder of the wall. The cutting unit also includes an extraction element arranged close to the two rotating blades to intercept the strip and accompany it away from the wall. Attached Figure Description

[0012] The invention will now be described with reference to the accompanying drawings, which illustrate non-limiting embodiments of the invention, in which:

[0013] Figure 1 is a perspective view of a "book-shaped" cigarette box in a closed configuration;

[0014] Figure 2 is a perspective view of the "book-shaped" cigarette box in Figure 1 in its open configuration;

[0015] Figure 3 is a schematic plan view of the cutting unit used to remove the strip from the bottom wall of the "book-style" cigarette box of Figure 1;

[0016] Figure 4 is a perspective view showing the removal of a portion of the cutting unit in Figure 3 to make it clearer;

[0017] Figure 5 is a schematic side view of the cutting unit in Figure 3;

[0018] Figure 6 is an enlarged view of the details in Figure 5; and

[0019] Figures 7, 8, and 9 are three schematic plan views of a portion of the cutting unit in Figure 3 at three corresponding operational moments. Detailed Implementation

[0020] In Figures 1 and 2, reference numeral 1 generally indicates a "book-style" cigarette pack, which includes two receiving portions 2 that accommodate corresponding cigarette packs, have corresponding upper open ends, and are hinged to each other to rotate between a closed configuration (shown in Figure 1) and an open configuration (shown in Figure 2). In the closed configuration, the two receiving portions 2 are stacked on top of each other, and in the open configuration, the two receiving portions 2 are separated. In addition, a cover 3 is provided, which is hinged to the rear receiving portion 2 and covers the upper part of the two receiving portions 2 when in the closed position.

[0021] The production of the “book-style packaging box” cigarette packaging box 1 involves using two corresponding blanks to form two receiving parts 2, which are folded around corresponding cigarette sets to connect (overlap) the two receiving parts 2, and then a third blank is folded around the two connected (overlapped) receiving parts 2 to connect the two receiving parts 2 and form a common cover 3.

[0022] After folding the third blank, a cut needs to be made on the bottom wall 4 of the "book-style packaging box" cigarette box to allow the two receiving parts 2 to separate (i.e., to allow the two receiving parts 2 to rotate relative to each other).

[0023] In Figures 3 and 4, reference numeral 5 generally represents the cutting unit. In order to form a distinct separation between the two receiving portions 2, the cutting unit performs a double cut (i.e., two close and parallel cuts) to remove the strip 6 (band) from the bottom wall 4 of the cigarette pack 1, which is fed along the straight path P; that is, the cutting unit 5 removes the relatively thin central portion (band 6) from the bottom wall 4 of the cigarette pack 1 to separate the two receiving portions 2.

[0024] The cutting unit 5 includes two parallel and adjacent rotating blades 7, which are arranged horizontally and mounted in a rotatable manner around the same vertical axis of rotation 8 (i.e., the two rotating blades 7 are identical and coaxial with each other); in use, the two rotating blades 7 form two parallel cuts on the bottom wall 4 to separate the strip 6 from the rest of the bottom wall 4.

[0025] In the embodiment shown in the accompanying drawings, the two rotating blades 7 are parallel to each other and rotate about the same vertical axis of rotation 8 (i.e., they are coaxial), and in use, they form two parallel cuts on the bottom wall 4, separating the strip 6 from the rest of the bottom wall 4. According to a different but equivalent embodiment (not shown), the two rotating blades 7 are inclined relative to each other (so they are both inclined in opposite ways relative to the horizontal plane), they rotate about two different axes of rotation 8 that are not parallel to each other (and are both inclined in opposite ways relative to the vertical plane), and in use, they make two parallel cuts on the bottom wall 4, separating the strip 6 from the rest of the bottom wall 4. In other words, the two rotating blades 7 are mounted in a rotatable manner about corresponding axes of rotation 8, which may coincide or differ from each other. According to another embodiment (not shown), the rotating blades 7 may make two non-(completely) parallel cuts (i.e., slightly inclined towards each other) on the bottom wall 4 in use, separating the strip 6 from the rest of the bottom wall 4, in which case the strip 6 has a trapezoidal or triangular shape instead of a rectangular shape.

[0026] According to another embodiment not shown, the two rotating blades 7 may have a predominantly vertical orientation, rather than a predominantly horizontal orientation as shown in the figures. Furthermore, the two rotating blades 7 may not be exactly the same (paired), and therefore differ relative to each other.

[0027] Finally, the strip 6 is separated from the rest of the bottom wall 4, and the two cuts formed by the two rotating blades 7 may not be perfectly parallel to each other (i.e., they may converge or deviate slightly relative to each other).

[0028] In addition, the cutting unit 5 includes an extraction element 9 arranged close to the two rotating blades 7 to intercept the strip 6 and push the strip 6 away from the bottom wall 4 (obviously on the other side of the cigarette pack 1) to separate the strip 6 from the cigarette pack 1.

[0029] Specifically, the extraction element 9 includes a tip 10 (better shown in Figures 7, 8 and 9) that first intercepts the band 6 (i.e., the tip is positioned upstream of the cigarette pack 1 along the feed direction of path P), and its width is less than the width of the band 6, i.e. less than the distance between the two rotating blades 7; for example, the distance between the two rotating blades 7 (and thus the width of the band 6) can be about 5 tenths of a millimeter, while the width of the tip 10 can be about 3-4 tenths of a millimeter.

[0030] In other words, the extraction element 9 is positioned close to the outer edge of the rotating blade 7, such that the tip 10 of the extraction element 9 touches the edge of the rotating blade 7 to intercept the belt 6 and accompany the belt 6 away from the bottom wall 4.

[0031] The extraction element 9 has an arc shape and is mounted to rotate about a rotation axis 11 that is parallel to the rotation axis 8; in the embodiment shown in the figures, the rotation axis 11 of the extraction element 9 is coaxial (i.e., coincident) with the rotation axis 8 of the rotating blade 7, while according to other embodiments, the rotation axis 11 of the extraction element 9 is parallel to and spaced apart from the rotation axis 8 of the rotating blade 7.

[0032] The cutting unit 5 includes an actuator device 12 (schematically shown in FIG. 3) that performs both the rotation of the two rotating blades 7 about the rotation axis 8 and the rotation of the extraction element 9 about the rotation axis 11. Preferably, the actuator device 12 includes a first electric motor and a second electric motor. The first electric motor rotates the two rotating blades 7, and the second electric motor (mechanically independent of the first electric motor) rotates the extraction element 9 at a different speed than the two rotating blades 7; for example, the two rotating blades 7 rotate at a constant speed of approximately 1500 rpm, while the extraction element 9 rotates synchronously with the working cycle of the cutting unit 5, i.e., at a continuously variable speed of approximately 100-400 rpm, following the working cycle of the cutting unit 5. According to different embodiments, the actuator device 12 includes a single electric motor (by means of a suitable mechanical transmission) that generates the rotational motion of the two rotating blades 7 about the rotation axis 8 and the rotational motion of the extraction element 9 about the rotation axis 11.

[0033] In the embodiments shown in Figures 7, 8, and 9, the actuator device 12 rotates the extraction element 9 between an initial position (shown in Figure 8) and a final position (shown in Figure 9). In the initial position, the tip 10 of the extraction element 9 is arranged to contact the bottom wall 4, and in the final position, the distance between the tip 10 of the extraction element 9 and the bottom wall 4 is not zero. This movement of the extraction element 9 gradually moving away from the bottom wall 4 allows the belt 6 to move away from the bottom wall 4, allowing the belt 6 to be fully separated (extracted) from the bottom wall 4.

[0034] Furthermore, in the embodiments shown in Figures 7, 8, and 9, the actuator device 12 rotates the extraction element 9, causing the extraction element 9 to travel with a working stroke (starting from the position shown in Figure 7) and a return stroke. During the working stroke, the extraction element 9 moves along path P in the same direction as the cigarette pack 1, and the feed speed of the extraction element is lower than the feed speed of the cigarette pack 1 (so that the extraction element 9 is touched by the cigarette pack 1, and thus the extraction element 9 can engage the bottom wall 4 of the cigarette pack 1). During the return stroke, the extraction element 9 moves along path P in the opposite direction to the cigarette pack 1 (from the position shown in Figure 9 to the position shown in Figure 7). In other words, during the working stroke, the extraction element 9 is located in front of the cigarette packaging box 1 and moves along the path P at a speed lower than that of the cigarette packaging box 1 so as to be touched by the cigarette packaging box 1 and thus be able to engage the bottom wall 4 of the cigarette packaging box 1; when the extraction element 9 is touched by the cigarette packaging box 1 and the tip 10 of the extraction element 9 engages with the strip 6 (as shown in Figure 8), the extraction element 9 moves away from the bottom wall 4 of the cigarette packaging box 1, causing the strip 6 to gradually move away from the bottom wall 4 of the cigarette packaging box 1 (as shown in Figure 9).

[0035] This movement of the extraction element 9 can be achieved whether the actuator device 12 causes the extraction element 9 to rotate back and forth (thus preventing the extraction element 9 from rotating completely) or whether the actuator device 12 causes the extraction element 9 to rotate continuously in the same direction (thus causing the extraction element 9 to rotate continuously and completely). If the actuator device 12 causes the extraction element 9 to rotate back and forth, the actuator device 12 causes the rotation direction of the extraction element 9 to be periodically reversed, always keeping the extraction element 9 close to the path P; on the other hand, if the actuator device 12 causes the extraction element 9 to rotate continuously in the same direction, the extraction element 9 moves away from the path P during the return stroke, passing the other side of the rotating blade 7 relative to the path P. Generally, it is preferable that the actuator device 12 causes the rotation direction of the extraction element 9 to be periodically reversed (i.e., the extraction element 9 rotates back and forth), because this motion pattern only makes the tip 10 of the extraction element 9 very thin (because it is the only part of the extraction element 9 that must be arranged between the two receiving portions 2), while the rest of the extraction element 9 can be wider and therefore more mechanically robust; on the other hand, when the actuator device 12 causes the extraction element 9 to always rotate in the same direction (so that the extraction element 9 rotates continuously and completely), the extraction element 9 must be narrower overall due to space constraints, and therefore less mechanically robust.

[0036] During the working stroke, the extraction element 9 moves along path P at a speed (slightly) lower than that of the cigarette pack 1, so the impact between the tip 10 of the extraction element 9 and the bottom wall 4 occurs at a lower relative speed (and thus in a gentle rather than traumatic manner).

[0037] According to different embodiments not shown, the extraction element 9 may not move at all along the path P. In this case, the impact between the tip 10 of the extraction element 9 and the bottom wall 4 occurs at a higher relative velocity (the extraction element 9 is stationary relative to the path P, so the impact occurs at the velocity of the cigarette pack 1). This alternative may expose the bottom wall 4 to some risk of unwanted dents due to the impact with the tip 10 of the extraction element 9, but it is still feasible. In this embodiment, the extraction element 9 may remain movable in a direction perpendicular to the path P between an initial position (as shown in FIG. 8) and a final position (as shown in FIG. 9). In the initial position, the tip 10 of the extraction element 9 is arranged to contact the bottom wall 4, and in the final position, the distance between the tip 10 of the extraction element 9 and the bottom wall 4 is not zero. Alternatively, the extraction element 9 may remain completely stationary, that is, it may not move parallel to or perpendicular to the path P.

[0038] In the embodiment shown in the accompanying drawings, the actuator device 12 causes the extraction element 9 to rotate about the rotation axis 11; according to different embodiments not shown, the actuator device 12 causes the extraction element 9 to perform linear translational motion along a direction parallel to the path P (alternating between the working stroke and the return stroke), or linear translational motion along a direction perpendicular to the path P (moving between the initial position and the final position).

[0039] As shown in Figures 3 and 4, the cutting unit 5 includes a suction conduit 13 (i.e., connected to a suction source) designed to suction the strip 6 pushed away from the bottom wall 4 by the extraction element 9. Specifically, the suction conduit 13 has an initial end 14 arranged at the rotating blade 7 and configured to receive at least a portion of the extraction element 9; in other words, the extraction element 9 moves within the initial end 14 of the suction conduit 13. The function of the suction conduit 13 is to transport the strip 6, which has been separated from the bottom wall 4, to a suitable collection area (not shown) by suction. For example, suction in the suction conduit 13 can be generated using an impeller or a flow accelerator. In particular, the initial end 14 of the suction conduit 13 has an input opening 15 facing the bottom wall 4 through which the extraction element 9 passes.

[0040] According to a preferred embodiment, the initial end 14 of the suction pipe 13 has a tapered shape and a minimum size at the inlet opening 15 (i.e., a size that gradually widens away from the rotating blade 7 to achieve maximum air pressure at the rotating blade 7).

[0041] According to the possible embodiment shown in Figure 4, the cutting unit 5 includes a cleaning device 16 (i.e., a scraper) arranged at a fixed position around the two rotating blades 7, at a small distance from the two rotating blades 7, and having the function of cleaning the two rotating blades 7 to prevent any foreign matter (cardboard sheet of the bottom wall 4) from sticking between or to the rotating blades 7. In other words, the cleaning device 16 removes any foreign matter (cardboard sheet of the bottom wall 4) stuck between or to the rotating blades 7.

[0042] As shown in Figures 3 and 4, the cigarette pack 1 is fed along path P by a conveyor equipped with two fixed receiving guides 17, between which the cigarette pack 1 is located; in particular, the fixed guides 17 that hold the bottom wall 4 are provided with through openings through which two rotating blades 7 are arranged (for this purpose, the through openings of the fixed guides 17 are slightly wider than the pair of rotating blades 7, so as to allow them to be inserted beyond the fixed guides 17 with minimal gaps).

[0043] The embodiments described herein can be combined with each other without departing from the scope of the invention.

[0044] The cutting unit 1 described above has many advantages.

[0045] In summary, the cutting unit 1 ensures that the strip 6 is removed after cutting, preventing the strip 6 (or a portion of the strip 6) from still contacting the bottom wall 4 of the cigarette pack 1.

[0046] Furthermore, compared to similar known cutting units, the cutting unit 1 described above is simple to manufacture and low in cost, requiring only the use of commercial parts or parts that can be easily obtained through standard machining for quick modification.

Claims

1. A cutting unit (5) for removing a strip (6) from the wall (4) of a packaging box (1), the packaging box being fed along a path (P), the cutting unit (5) comprising: Two rotating blades (7) are mounted in a manner that allows them to rotate about a corresponding first axis of rotation (8) and to create two cuts in the wall (4) of the packaging box (1) that allow the strap (6) to separate from the rest of the wall (4) of the packaging box (1); And an extraction element (9) arranged close to the two rotating blades (7) to intercept the strip (6) and accompany the strip (6) away from the wall (4), characterized in that the extraction element (9) includes a tip (10) that first intercepts the strip (6), and the width of the tip is less than the width of the strip (6), that is, the width of the tip is less than the distance between the two rotating blades (7).

2. The cutting unit (5) according to claim 1, wherein, The extraction element (9) is mounted in a manner that allows it to move along a first direction perpendicular to the path (P) and the wall (4) of the packaging box (1); and the cutting unit is provided with an actuator device (12) that causes the extraction element (9) to move along the first direction between an initial position and a final position, in which the tip (10) of the extraction element (9) is arranged to contact the wall (4) of the packaging box (1), and in which the distance between the tip (10) of the extraction element (9) and the wall (4) of the packaging box (1) is not zero.

3. The cutting unit (5) according to claim 1, wherein, The extraction element (9) is mounted in a manner that allows it to move along a second direction parallel to the path (P) and the wall (4) of the packaging box (1); and the cutting unit is provided with an actuator device (12) that causes the extraction element (9) to move along the second direction, thereby causing the extraction element (9) to travel in a working stroke and a return stroke. During the working stroke, the extraction element (9) moves along the second direction in the same direction as the packaging box (1), and the feed speed of the extraction element is lower than the feed speed of the packaging box (1). During the return stroke, the extraction element (9) moves along the second direction in the opposite direction to the packaging box (1).

4. The cutting unit (5) according to any one of claims 1 to 3, wherein: The extraction element (9) is mounted in a manner that allows it to rotate about a second rotation axis (11) parallel to the first rotation axis (8); and the cutting unit is provided with an actuator device (12) that causes the extraction element (9) to rotate alternately in two directions or always in the same direction about the second rotation axis (11).

5. The cutting unit (5) according to claim 4, wherein, The actuator device (12) rotates the extraction element (9) between an initial position and a final position, in which the tip (10) of the extraction element (9) is arranged to contact the wall (4) of the packaging box (1), and in the final position, the distance between the tip (10) of the extraction element (9) and the wall (4) of the packaging box (1) is not zero.

6. The cutting unit (5) according to claim 4, wherein, The actuator device (12) rotates the extraction element (9), causing the extraction element (9) to travel in a working stroke and a return stroke. During the working stroke, the extraction element (9) moves along the path (P) in the same direction as the packaging box (1), and the feed speed of the extraction element is lower than the feed speed of the packaging box (1). During the return stroke, the extraction element (9) moves along the path (P) in the opposite direction to the packaging box (1).

7. The cutting unit (5) according to claim 4, wherein, The extraction element (9) has an arc shape.

8. The cutting unit (5) according to claim 4, wherein, The first rotation axis (8) is coaxial with the second rotation axis (11).

9. The cutting unit (5) according to claim 4, wherein, The actuator device (12) includes a first electric motor and a second electric motor, the first electric motor causing the two rotating blades (7) to rotate about the first rotation axis (8), and the second electric motor causing the extraction element (9) to rotate about the second rotation axis (11) independently of the rotation of the two rotating blades (7).

10. The cutting unit (5) according to any one of claims 1 to 3, wherein, The cutting unit includes a suction pipe (13) arranged to suction the band (6) pushed away from the wall (4) by the extraction element (9).

11. The cutting unit (5) according to claim 10, wherein, The suction conduit (13) has an initial end (14) which is disposed at the rotating blade (7) and configured to accommodate at least a portion of the extraction element (9).

12. The cutting unit (5) according to claim 11, wherein, The initial end (14) of the suction pipe (13) has an input opening (15) facing the wall (4) of the packaging box (1), and the extraction element (9) passes through the input opening.

13. The cutting unit (5) according to any one of claims 1 to 3, wherein, The cutting unit includes a cleaning device (16) arranged at a fixed position around the two rotating blades (7) at a small distance from the two rotating blades (7) and having the function of cleaning the two rotating blades (7) to prevent possible foreign objects from sticking between or onto the two rotating blades (7).

14. The cutting unit (5) according to any one of claims 1 to 3, wherein, The cutting unit includes a fixed receiving guide (17), the wall (4) of the packaging box (1) is held against the receiving guide, and the receiving guide is provided with a through opening through which two rotating blades (7) are arranged.

15. A cutting method for removing a strip (6) from the wall (4) of a packaging box (1), the method comprising the steps of: The packaging box is fed along path (P); By means of two rotating blades (7) mounted in a manner that can rotate around the corresponding axis of rotation (8), two cuts are formed on the wall (4) of the packaging box (1) to separate the strip (6) from the rest of the wall (1) of the packaging box; And by means of an extraction element (9) arranged close to the two rotating blades (7) to intercept the strip (6) and as the strip (6) moves away from the wall (4), characterized in that the extraction element (9) includes a tip (10) that first intercepts the strip (6), and the width of the tip is less than the width of the strip (6), that is, the width of the tip is less than the distance between the two rotating blades (7).

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