Method for cutting a container closure

Abstract

To provide a cutting device and a cutting method suitable for obtaining a so-called "tethered" type closure or capsule which remains attached to a container after opening.SOLUTION: The spindle carrying the closures is moved towards a cutting device comprising one or more horizontal blades and at least one vertical or oblique blade. During cutting, the spindle rotates and the closure rolls on the cutting device. The spindle is fed to the cutting device several times, each time carrying a different closure with a portion made of a softer material than the blade. During cutting, the blade penetrates the material of the closure and sinks into the soft part of the spindle. Providing a preliminary step of moving the blade, starting from an initial position away from the nominal working position, in such a way as to gradually increase the depth of immersion of the blade in the soft part, until reaching a final position in which the blade is immersed in the soft part with a depth greater than the depth of immersion when the blade is in the nominal working position.SELECTED DRAWING: Figure 1

Description

Background of the Invention

[0001] The present invention relates to a method for cutting closures or capsules, particularly plastic closures or capsules, which can be used to close containers such as bottles.

[0002] In particular, but not exclusively, the present invention relates to cutting apparatus and methods suitable for obtaining easy-open devices that provide so-called "tethered" type closures or capsules that remain attached to the container after opening.

[0003] The prior art includes methods for providing an easy opening device for "tethered" capsules, forming one or more horizontal cuts in the capsule and at least one vertical or diagonal cut, where "horizontal," "vertical," and "diagonal" mean that the capsule's geometric axis is vertically oriented. Generally, prior art methods involve a rotating spindle supporting the capsule and moving it along a cutting path with a fixed blade, the rotating spindle acting as an abutment element to reduce the effective cutting of the fixed blade.

[0004] Patent publication EP 4324761 A2 shows a cutting method according to the preamble of claim 1. This method does not significantly reduce the wear of the soft part of the spindle due to the fact that the vertical or oblique blade always penetrates the soft part of the spindle at the same position. Thus, on the first stroke of the spindle, the vertical or oblique blade cuts a kind of vertical or oblique groove or slot into the material of the soft part of the spindle, so that on subsequent strokes it always interacts with the previously cut groove or slot in the same (linear) area without further damaging the spindle.

[0005] The method disclosed in EP 4324761 A2 thus allows the wear of the soft part of the spindle to be positioned only in the vertical or oblique area, leaving other areas unaffected, which may therefore remain intact for a long period of time, thereby optimally performing the abutment function for the closure during the cutting operation. The abutment function performed by the spindle is particularly effective considering that the vertical or oblique blade of the cutting device only interferes with a very limited area of ​​the spindle, i.e., the vertical or oblique linear area of ​​the soft part of the spindle where the vertical or oblique blade sinks, leaving the rest of the soft part of the spindle, particularly the area located in the immediate vicinity of the worn area and where the cutting is performed, intact and intact. Therefore, such areas that are worn and continuous with the actual cutting area may function as abutment elements for cutting with the greatest possible functionality.

[0006] An improvable aspect of the prior art discussed above lies in the fact that it would be desirable to further reduce the interaction between the vertical or oblique blade and the material of the soft part of the spindle. Summary of the Invention

[0007] SUMMARY OF THE INVENTION An object of the present invention is to provide a method for cutting a closure for a container that can meet the above needs.

[0008] Another object is to provide a cutting method suitable for forming a type of closure known as a "tether."

[0009] It would be advantageous to provide a cutting method that allows the vertical or angled blade to avoid contacting the bottom of the groove or slot cut by the blade when cutting the capsule.

[0010] The advantage is that when cutting the capsule, the horizontal blade (or blades, if there are several) also does not come into contact with the bottom of the grooves or circumferential grooves cut by the blades.

[0011] The advantage is that the effectiveness and quality of capsule cutting can be ensured over a long period of time, even if one or more blades become worn.

[0012] The invention will be more clearly and better understood with reference to the accompanying drawings, which show exemplary and non-limiting embodiments thereof. [Brief explanation of the drawings]

[0013] [Figure 1] FIG. 1 is a vertical elevational cross-sectional view of an example of a cutting apparatus that can be used to carry out the cutting method according to the present invention. [Figure 2] FIG. 2 is an enlarged view of a detail of FIG. [Figure 3] FIG. 3 is a plan view of the device of FIG. [Figure 4] FIG. 4 is a plan view showing another example of a cutting device that can be used to carry out the cutting method according to the present invention. [Figure 5] FIG. 5 is an enlarged view of a detail of FIG. 2 showing the grooves or slots cut by the vertical or oblique blades for carrying out the cutting method according to the invention. Detailed Description of the Invention

[0014] With reference to the figures mentioned above, an apparatus for cutting caps or capsules, in particular made of plastic, which can be used to close containers such as bottles, is shown generally at 1. The cutting apparatus 1 is particularly suitable for obtaining devices with closures or capsules of the type known as "tethers", which are easy to open, i.e. closures or capsules which remain attached to the container after opening.

[0015] The cutting device 1 may comprise cutting means configured in particular to obtain an easy opening device for "tether" type closures 2. The cutting means may in particular consist of a cutting device 3 with one or more horizontal blades 4 and at least one vertical or oblique blade 5. In the embodiment shown in Figures 1 and 2, the cutting device 3 consists of two horizontal blades 4 and a vertical blade 5.

[0016] The cutting means may in particular comprise cutting devices with different numbers of horizontal blades, for example three or more than four horizontal blades, and different numbers of vertical or diagonal blades, for example two or more than three diagonal blades.

[0017] The cutting device 3 may be configured to selectively assume an operative position, which is a position suitable for performing the desired through cut on the closure supplied to the cutting device 3, and a non-operative or retracted position in which the cutting device 3 is retracted relative to the operative position so as not to interfere with the closure supplied to the cutting device 3 and / or the means for supplying the closure.

[0018] The displacement (eg linear displacement, in particular sliding on a linear guide) of the cutting device 3 between the operating position and the retracted non-operating position can be actuated manually and / or by a drive means.

[0019] The cutting device 1 may in particular comprise feeding means adapted to feed the closures 2 to the cutting means. The feeding means may in particular comprise at least one spindle 6 having a soft part 7 made of a material softer than the blades.

[0020] The supply means may in particular be configured so that the spindles 6 pass in front of the cutting means several times, each time carrying two different closures. The supply means may in particular comprise a supply carousel 8 carrying the above-mentioned spindles 6. The carousel 8 may in particular be rotatable (e.g. motor-driven by a brushless motor) about a carousel axis X. The carousel 8 may in particular comprise two or more spindles 6, each of which may comprise a respective flexible part 7.

[0021] The carousel 8 may, in particular, include three or more spindles 6 angularly spaced about the circumference of the carousel. In the example of Figure 3, the carousel includes twelve equally spaced spindles 6. In the example of Figure 4, the carousel includes six equally spaced spindles 6.

[0022] Each spindle 6 may in particular be rotatable about a respective spindle axis Y, and the closure 2 may be moved (e.g., at least partly in a rolling motion) on the cutting means so that the blades 4 and 5 penetrate the closure 2 and thus sink into the soft parts 7 of the spindle, which act as suitable and effective abutments against the side walls of the closure 2 during the cutting operation.

[0023] Each spindle 6 is motor-rotatable about the spindle axis Y, in particular by operation of a separate motor (which can be controlled independently, for example a separate brushless motor) relative to the operation of the motor drive that operates the rotation of the carousel 8, or by operation of the same motor drive that operates the rotation of the carousel 8.

[0024] The spindle axis Y is in particular parallel to the geometric axis Z of the closure 2. The spindle axis Y can in particular be arranged at a distance from the geometric axis Z of the closure, as in this embodiment.

[0025] The cutting device 1 may in particular be provided with control means configured to regulate the rotation of the spindle 6 (about the spindle axis Y) and the feeding of the spindle 6 (i.e. its forward movement towards the cutting means, which in these examples consists of a rotational movement of the carousel 8 carrying the spindle 6) so that the vertical blade 5 (or possibly the oblique blade) always encounters the same vertical or oblique (straight) area of ​​the soft part 7 each time the spindle 6 passes in front of the cutting means.

[0026] In particular, it may be provided that the coordination of said movements (rotational movement and forward movement of the spindles) is obtained so that the ratio between the number of revolutions per unit of time of the rotation axis of the carousel (axis X) and the rotation axis of each spindle (axis Y) is equal to 1:N, where N is equal to an integer (for example a number between 8 and 18, in particular in the ratio 1:12, 1:13, 1:14).

[0027] The cutting device 1 may in particular comprise a mechanical drive system connecting the axis of the carousel (axis X) with the axis of each of the aforementioned spindles (axis Y). Such a mechanical drive system may be constructed in order to obtain a coordination of the aforementioned movements, in particular to obtain a transmission ratio of 1:N (N equal to an integer).

[0028] Such a mechanical drive system may in particular include a transmission consisting of at least one flexible transmission member 9 (connected to a pulley connected to the spindle 6), but other types of mechanical drives may also be provided, for example gear drives.

[0029] It may further be provided that the cutting device comprises electronic control means for synchronously controlling the coordinated movement of the carousel shaft and the shaft of each of the aforementioned spindles, for example one or more electronic cams for coordinating the drive means for actuating the carousel shafts and the drive means for actuating the spindle shafts. In particular, it may be provided that the means for actuating the motors of the spindle shafts consist of several motors, in particular a motor for each spindle shaft, or a single motor connected to several spindle shafts (for example all spindle shafts arranged on the carousel) by a mechanical drive system, for example a gearing as described above.

[0030] Each spindle 6 may in particular comprise a support 10 having an annular seat open on one side, and the soft part 7 of the spindle may in particular comprise an annular insert that can be inserted (in particular axially) into said annular seat and pass through said open side (here, axially is understood with reference to the axis of the spindle).

[0031] Each spindle 6 may in particular include a locking annular element 11 that can be removably fixed (for example by screw fixing means) on the support 10 to close the aforementioned side of the annular seat, in order to lock the annular insert in place.

[0032] The operation of the cutting apparatus 1 performs a cutting method which includes, in particular, the step of feeding a spindle 6 carrying the closure 2 to a cutting device 3, which may include one or more horizontal blades 4 and at least one vertical or (oblique) blade 5, as described above.

[0033] The spindle 6 (e.g. driven in rotation by a carousel 8 along a circular forward path) can be fed into the cutting device 3 multiple times, each time carrying a different closure 2 (e.g. using a carousel 8 consisting of an input area for the closure to be cut and an output area for the cut closure, in a known manner).

[0034] Each spindle 6 may include a soft part 7 (annular and coaxial with the spindle axis Y) made of a material softer than the blades, as previously described. The soft part 7 may be made of a variety of materials, such as PEEK, Delrin®, polyethylene, polypropylene, polyurethane, aluminum, copper, tin, bronze, etc.

[0035] The cutting method may in particular comprise the steps of rotating the spindle 6 about its spindle axis Y and moving the closure 2 on the cutting device 3 so that the blades 4 and 5 penetrate the closure and sink into the soft part 7 of the spindle (see Figures 1 and 2).

[0036] The rotational movement of the spindle 6 can be coordinated with the feeding movement of the spindle 6, in particular so that the vertical or oblique blade always strikes the same vertical or oblique (straight) area of ​​the soft part 7 of the spindle each time the spindle 6 is fed into the cutting device.

[0037] For this purpose, it is possible, for example, for the spindle to be carried by a carousel 8 rotatable about a carousel axis X and to proceed in such a way that the ratio of the number of revolutions in a time unit of the carousel X to the number of revolutions in a time unit of the spindle axis Y is equal to 1:N, where N is equal to an integer number.

[0038] By doing so, the vertical or (oblique) blade 5 penetrates the soft part 7 of the spindle 6 in the same position or area (in particular a straight area whose shape substantially corresponds to the shape of the vertical or (oblique) blade 5), and the first pass of the vertical or (oblique) blade 5 cuts something like a (straight, vertical, oblique) slot or groove into the material of the soft part of the spindle at that position or area where the blade is located each time, thereby significantly reducing abrasion of the soft part 7.

[0039] In steps following the first step, the vertical or (oblique) blade 5 always interacts with the location or zone where the previously engraved (straight, vertical or oblique) slot or groove was formed, without further damaging the soft part of the spindle in other zones. Thus, the soft part of the spindle 7 may be worn in the aforementioned vertical or oblique zone during the first stroke of the spindle, in the initial stage of operation of the device, i.e. with wear circumscribing a relatively very limited area around the entire circumference of the soft part 7, after which there is no further wear in other vertical or oblique zones.

[0040] It should be noted that the shape of the wear area of ​​the soft part can substantially correspond to the shape of the vertical or oblique blade, except for minimal dimensional differences due to the elasticity and clearance of the system, and the remaining part of the material of the soft part is left intact as a whole and can therefore perform the abutment function with maximum effectiveness for the proper execution of the cutting operation, so that the facilitated opening device of the "tether" closure is constructed in an extremely precise and high-quality manner. The possible difference between the dimensions of the wear area of ​​the soft part and the dimensions of the vertical or oblique blade will be the smallest possible difference, considering that, as mentioned above, the shape and dimensions of the wear area are generated by the interaction between the blade and the soft part of the spindle.

[0041] The soft part of the spindle is also worn horizontally (in the circumferential direction) by the horizontal blades 4 of the cutting device. The horizontal blades 4 impact and constantly interact with the horizontal wear part of the soft part with each stroke of the spindle (i.e. with each rotation of the spindle-holder-carousel).

[0042] It should be noted that in embodiments with a single mechanical drive system for actuating both the feeding and rotating motions of the spindle, no initial timing is required to prepare the cutting apparatus by timing the spindle carousel axis before starting the apparatus and cutting the closure. In fact, the rotating spindle 6 does not need to be in a precise angular position when it passes in front of the cutting device 3 (specifically, in front of the vertical or oblique blade 5) on the first stroke, i.e., when the cutting apparatus 1 is first started. This is because it is not important which area of ​​the soft part of the spindle is affected by and therefore wears down the vertical or oblique blade. For subsequent strokes, it is sufficient for the spindle to pass in front of the cutting apparatus in the same initial angular position as it was on the first stroke; the initial angular position is irrelevant.

[0043] In the case of versions with separate drive means (one for driving the spindle feed movement, i.e. the rotation of the carousel, and the other for driving the rotation movement around the axis of each spindle), the initial timing for, for example, powering on and restarting the cutting apparatus 1 can be carried out in a very simple manner, for example by retracting the cutting device 3 (to avoid damage to the blades) and starting the drive means for a kind of initial "empty" calibration, for a short period of time required for the sensor means (including, for example, encoder means) to recognize the angular positions of the various spindles relative to the carousel and thereby carry out appropriate adjustments to restore synchronization.

[0044] After this short initial timing step, the cutting device 3 can be advanced again to the operating position and normal operation of the cutting apparatus can commence. Retracting the cutting device 3 is not strictly necessary, but is beneficial to avoid wear and tear on the material of the soft part 7.

[0045] However, it should be noted that even if the timing is absent or incorrect, the only result will be that the blade comes into contact with a previously unengraved area of ​​the soft part of the spindle without damaging the blade in any way (and additional wear of the soft part is reduced), as would be the case, for example, with the solution disclosed in WO2021 / 063776A1, which would cause the blade to come into contact with a hard area of ​​the spindle and permanently damage the blade.

[0046] The cutting device 1 may comprise anti-rotation means (not shown) configured to prevent rotation of the soft part 7 of the spindle relative to the rest of the spindle, in particular to prevent rotation about the spindle axis Y. The anti-rotation means may in particular comprise anti-rotation means 12 as described in patent publication EP 4324761 A2 (shown here in Figures 5 to 8), which is incorporated herein by reference. By preventing rotation of the soft part 7 relative to the rest of the spindle 6, the anti-rotation means ensures that the area of ​​the soft part of the spindle that is affected, and therefore worn, by the vertical or oblique blade is always the same at each rotation of the carousel.

[0047] The cutting apparatus may be controlled by a control method suitable for reducing the risk of damaging the apparatus, in particular the blades 4, 5 of the cutting device 3. Such a control method may in particular comprise a preliminary or initial start-up step (a kind of trial run) in which "empty" operation of the spindle is provided for a predetermined period of time, i.e. without closures 2, i.e. with carousel rotation and spindle rotation, but without supply of closures 2.

[0048] Such a preliminary or trial run step involves each spindle 6 being fed several times into the cutting device 3 without carrying a closure 2 ("empty"), and during this "empty" feeding, each blade (i.e., horizontal blade 4 and / or vertical blade 5) is moved (starting from an initial retracted position away from the nominal working position and moving forward), in particular gradually increasing the depth to which the blade sinks into the soft part 7 until it reaches and then exceeds the aforementioned nominal working position.

[0049] The expression "nominal working position" is used to indicate the position taken by the blades (each horizontal blade 4 and / or vertical or oblique blade 5) when actually cutting the capsule 2, with the cutting edge of the blade sinking into the soft part 7 to the desired depth.

[0050] According to the invention, in a preliminary (commissioning or initial start-up) step, each blade sinks into the soft portion 7 at a greater depth relative to the depth corresponding to the nominal working position, so that a relatively deep groove or slot is formed, the depth 12 (FIG. 5) of such groove or slot being spaced apart from the cutting edge of the blade when the actual cutting of the capsule 2 takes place. In other words, the bottom 12 is spaced apart (deep) relative to the nominal working position.

[0051] Figure 5 shows the bottom 12 of the slot or groove created by the vertical or oblique blade 5 in the preliminary step. Due to the preliminary commissioning step described above, each horizontal blade 4 also creates a respective slot or circumferential groove whose bottom is farther away (deeper) relative to the nominal working position of the horizontal blade 4.

[0052] Essentially, during this preliminary or initial start-up or commissioning step, the cutting device 3 is initially controlled to assume a retracted configuration, i.e., with the blade set (one or more horizontal blades 4 and at least one vertical or oblique blade 5) located in a retracted position. The blade set is then moved forward in a particularly controlled progressive manner, in particular until it reaches and exceeds (by a preset amount) the nominal cutting position.

[0053] During this gradual advance, while the carousel continues to rotate and the spindle also continues to rotate (without carrying the closure 2), the blade of the cutting device 3 sinks bit by bit progressively into the soft part 7 of the spindle 6, so that the penetration depth of the spindle 6 into the soft material progressively increases substantially with each carousel revolution of the spindle. The gradual advancement can be continuous, discontinuous or compound (partly continuous, partly discontinuous).

[0054] Such a control method (progressive engraving cycles on the soft part 7 of the spindle 6) can be controlled by the operator, in particular through specific controls on the user interface.

[0055] Upon initiation of an incremental engraving cycle (trial run or initial start) (with the carousel not in operation), the controller may automatically retract the blade assembly (which may be in a nominal working position) a predetermined distance (e.g., strictly as a non-limiting example, approximately 0.60 mm rearward relative to the normal working position of the blade).

[0056] The control device then automatically starts the rotation of the carousel and the spindles carried by it, and initiates a first step of slightly engraving the soft parts 7 of the various spindles 6. This first engraving step may have a pre-programmed duration (for example, about 2 minutes).

[0057] A second step can then be provided in which the soft part 7 is carved slightly deeper than in the previous step, by advancing the blade by a preset amount, for example about 0.05 mm. Thus, the initial advancement of the blade can, for example, be switched from position −0.60 mm to position −0.55 mm, with the reference zero being the actual or nominal working position intended for the blade in the normal cutting state of the closure 2.

[0058] This second engraving step may in particular include an initial interruption step during which the rotation of the carousel is interrupted, thus including an intermediate step for controlled advancement of the blade, and a subsequent restart step, during which the control device automatically restarts the rotation of the carousel and the spindle carried by it, thus beginning in earnest the actual engraving step of the soft part 7, which may also have a pre-programmed duration (for example, about 2 minutes).

[0059] The aforementioned cycle of pausing, advancing (e.g., by about 0.05 mm each cycle), and restarting may be automatically repeated until the blade reaches its actual nominal working position, i.e., a position where the blade height value is equal to 0.00 mm, at which point the blade will cut through the closure 2.

[0060] The second engraving step is then continued, further increasing the engraving depth in the soft part 7 beyond the nominal working position, and the blade is further advanced by a preset amount, for example always by about 0.05 mm. The advancement of the blade (i.e. the increase in the depth to which the blade sinks into the soft material) thus allows for example to switch from position 0.00 mm to position +0.05 mm, the reference zero being set as the actual or nominal working position that the blade takes under normal cutting conditions of the closure 2.

[0061] The second engraving step continues until it reaches the desired depth, obtained by gradually advancing the blade, for example +0.25 mm (values ​​are provided as non-limiting examples).

[0062] The bottom 12 of the slot thus obtained is at a predetermined distance (this distance is intended to be measured radially relative to the spindle axis) from the actual or nominal working position of the blade in the cutting state. In particular, such distance between the bottom 12 and the blade (in particular the vertical or oblique blade 5) can be 0.05 mm or more, or 0.10 mm or more, or 0.15 mm or more, or 0.20 mm or more, or 0.25 mm or more.

[0063] After the above-mentioned preliminary step, each blade, in particular the vertical or oblique blade 5, is retracted from the final position of the above-mentioned preliminary step to place each blade in a nominal working position, after which the actual working step and the actual cutting are started. Thus, the closure 2 is fed and moved on the cutting device 3, and each blade, in particular the vertical or oblique blade 5, can penetrate each closure 2 and sink into the soft part 7 to the above-mentioned desired depth.

[0064] Figure 5 shows the blade in its actual working position and in its nominal working position (capsule cutting) and clearly shows the distance between the leading cutting edge of the vertical or oblique blade 5 and the bottom 12 of the groove or slot created by the blade in the material of the soft section 7 in the aforementioned preliminary step (initial commissioning procedure) carried out before starting to cut the capsule. Such a distance, combined with the fact that the vertical or oblique blade 5 hits the soft section 7 in the same slot-creating area, allows to significantly reduce the contact between the blade and the soft section material.

[0065] Thus, the aforementioned values ​​of 0.05 mm advance steps per cycle and 2 minutes of engraving time per cycle are provided as examples, and other values ​​can be programmed (e.g., advance steps of 0.01 mm, 0.02 mm, 0.03 mm, 0.04 mm, 0.06 mm, 0.07 mm, 0.08 mm, 0.09 mm, or 0.10 mm per cycle, and engraving times of 1 minute, 1.5 minutes, 2.5 minutes, or 3 minutes per cycle, any combination of advance steps and engraving times can be programmed, and different advance steps and / or engraving times can also be programmed between one cycle (pause, advance, resume) and another).

[0066] It should be noted that the aforementioned (radial) distance between the bottom 12 of the slot created by the blade in the trial run step (when there is no capsule) and the blade in the actual working configuration (when cutting a capsule) significantly reduces the risk of contact between the cutting edge of the blade and said bottom 12 during each capsule cutting cycle.

[0067] This results in an overall reduction in blade wear, which is a major advantage that more than compensates for the fact that, despite the relatively deep cutting depth in the soft material being determined in the commissioning or first start-up step, the blade is deeply immersed in the soft material when carrying out the pre-commissioning step, taking into account that there is almost no risk of the blade coming into contact with the bottom 12 during the actual working cycle, i.e. when cutting the capsule.

[0068] Furthermore, the aforementioned contact, i.e., between the cutting edge of the blade and the bottom of the slots formed by the blade in the soft material (vertical or oblique slots formed by the vertical or oblique blade 5 and circumferential slots formed by the horizontal blade 4), is eliminated, resulting in reduced interaction between the cutting device and the soft parts 7 of the various spindles, and it has been confirmed that the capsule cutting accuracy is maintained over a long period of time, even after cutting a large number of capsules.

[0069] The method may include a step of detecting the position of the cutting device 3, in particular the position of at least one of the horizontal blades 4 and / or the position of the vertical or diagonal blades 5 and / or the position of the support block to which the horizontal blades 4 and the vertical or diagonal blades 5 are fixed.

[0070] To this end, the cutting device 1 may be provided with position sensor means configured to detect the above-mentioned positions. The position sensor means may in particular be arranged on the support blocks to which the horizontal blade 4 and the vertical or oblique blade 5 are fixed, or on fixed elements of the cutting device 1 arranged close to the support blocks, so as to detect the relative position between the support blocks and the fixed elements.

[0071] The position sensor means is configured to emit a signal indicative of the detected position. Such signal is transmitted to electronic control means of the cutting apparatus 1. The control means is configured to control said position of the cutting device 3 (i.e. the position of at least one of the horizontal blade 4 and / or the vertical or oblique blade 5 and / or the position of the support block to which the horizontal blade 4 and the vertical or oblique blade 5 are fixed) in response to the signal received from the position sensor means.

[0072] The control means are configured to control the aforementioned position of the cutting device 3 as a function of one or more operating parameters of the cutting apparatus 1, for example the total operating time in the useful life of the apparatus.

[0073] The control means is configured to vary the aforementioned position of the cutting device 3, even during a processing cycle of the cutting apparatus 1, so as to vary the penetration of the horizontal blade 4 and the vertical or oblique blade 5 based on variations in at least one working condition. The expression "varying the penetration" is used to indicate a change in the position of the cutting device 3, whereby an advancement of the blades of the cutting device 3 relative to the spindle 6 results in an increased penetration, while a retraction of the blades results in a decreased penetration.

[0074] In particular, the control means can be configured to increase said penetration of the blade (i.e. the forward displacement of the cutting device 3 towards the spindle 6) as the degree of wear of the blade increases. The degree of such wear can be checked by sensor means for monitoring the blade and / or by sensor means for monitoring the cut made by the blade on the capsule and / or by analysis made by the operator on the blade and / or capsule.

[0075] As the degree of wear increases, the penetration of the blade increases, so that the blade wear can be compensated for and high efficiency and quality of cutting capsules can be maintained without prior blade replacement.

[0076] In particular, the control means may be configured to feedback-adjust the blade position (and therefore the penetration) as a function of the detected temperature of the capsule, for example the temperature of the capsule before it is cut and / or the temperature of the capsule entering the cutting device 1. In particular, it may be provided that the control is programmed so that the depth of penetration increases as the temperature of the capsule increases.

[0077] In particular, the control means can be configured to feedback-adjust said penetration of the blade into the capsule as a function of the material from which the capsule is made. For example, the control means can be configured to feedback-adjust said penetration of the blade into the capsule as a function of the PCR % content of recycled plastic material present in the capsule's material. In particular, it can be provided that the control is programmed to increase the penetration depth as the PCR content in the capsule decreases, although in some cases the opposite behavior (i.e., increasing penetration as the PCR content increases) can be provided depending on the type of material and / or the type of cut performed and / or the type of capsule.

[0078] Information regarding the PCR% content of said recycled plastic material can be provided to the control means (e.g., by a user interface connected to the control means or in any other manner) so that the cutting penetration of the blade into the capsule can be controlled.

Claims

1. A method of cutting a closure, comprising: supplying a spindle (6) carrying the closure (2) to the cutting device (3); The spindle has a soft part (7) into which at least one blade (5) of the cutting device (3) can sink; moving the closure (2) on the cutting device (3) and rotating the spindle (6) so that at least one vertical or oblique blade (5) positioned in a nominal working position penetrates the closure (2) and bites into the soft part (7) to a desired depth; adjusting the rotation of the spindle (6) by the spindle feed so that the vertical or oblique blade (5) always strikes the same vertical or oblique area of ​​the soft part (7) each time the spindle (6) is fed into the cutting device (3); a preliminary step is provided in which the spindle (6) is fed into the cutting device (3) several times, and during the feeding in the preliminary step, the at least one vertical or oblique blade (5) is moved so as to gradually increase the depth of penetration into the soft part (7), starting from an initial position away from the nominal working position until it reaches a final position; The method includes, in the final position of the preliminary step, the at least one vertical or oblique cutting edge (5) sinking into the soft part (7) to a depth greater than the depth to which it sinks when in the nominal working position, method.

2. The preliminary step is carried out without carrying the closure (2), i.e. in an "empty" state. The method of claim 1.

3. the at least one vertical or oblique blade (5) retracts, starting from the final position of the preliminary step, to reach the nominal working position, after which the closure (2) is moved on the cutting device (3), and the at least one vertical or oblique blade (5) penetrates into the closure (2) and sinks into the soft part (7) to the desired depth; The method of claim 2.

4. The vertical or oblique region of the soft portion (7) is a linear region having a shape corresponding to the shape of the vertical or oblique blade.

4. The method according to any one of claims 1 to 3.

5. During the preliminary step, the at least one vertical or oblique cutting edge (5) creates a slot in the soft part (7) of the spindle, the slot having a bottom (12) located at a distance of 0.05 mm or more from the at least one vertical or oblique cutting edge (5) in the nominal working position.

4. The method according to any one of claims 1 to 3.

6. The spindle (6) is carried by a carousel (8) rotatable about a carousel axis (X), and the ratio of the number of revolutions per unit time of the carousel axis (X) to the spindle axis (Y) is equal to 1:N, where N is an integer.

4. The method according to any one of claims 1 to 3.

7. a carousel (8) carrying two or more spindles (6) each with a flexible part (7), said carousel (8) being driven in rotation by a drive means, said two or more spindles (6) being driven in rotation about their respective spindle axes (Y) by a single motor distinct from said drive means of said carousel, said motor being connected to said spindle axes (Y) by means of a mechanical drive system; 4. The method according to any one of claims 1 to 3.

8. The carousel (8) carries two or more spindles (6) each equipped with a flexible part (7), and a mechanical drive system connects the axis (X) of the carousel with the axis (Y) of said two or more spindles (6); 4. The method according to any one of claims 1 to 3.

9. The carousel (8) carries two or more spindles (6), each equipped with a flexible part (7), the rotation and feeding of each spindle being synchronized by electronic control means and regulated by coordinated movements of the carousel axis (X) and the axis (Y) of said two or more spindles (6); 4. The method according to any one of claims 1 to 3.

10. The carousel (8) is rotated by a drive means, each spindle axis (Y) being driven in rotation by its own drive motor, separate from the drive motors of the other spindle axes (Y) and separate from the drive means of the carousel (8); 10. The method of claim 9.

11. providing means for preventing rotation of said soft part (7) relative to the rest of the spindle (6), 4. The method according to any one of claims 1 to 3.

12. The cutting device used is said cutting device (3) adapted to obtain an easy-opening arrangement for the closure (2), and a feeding means for feeding the closure (2) to the cutting device (3), the feeding means comprising a spindle (6) having a soft portion (7) configured so that at least one blade (5) of the cutting device (3) penetrates the closure (2) with a through cut and sinks into the soft portion (7) of the spindle; 4. The method according to any one of claims 1 to 3.

13. the cutting device (3) comprises said at least one vertical or oblique blade (5), in particular for obtaining closures (2) of the "tether" type, the feeding means being arranged so that a spindle (6) passes in front of said cutting device (3) several times, carrying a different closure each time, the apparatus comprising control means arranged to coordinate the rotation of said spindle with its feeding action into the cutting device, so that said vertical or oblique blade (5) always strikes the same vertical or oblique area of ​​said soft part (7) each time the spindle (6) passes in front of the cutting device (3), the control means being arranged to control the preparatory step in which said at least one vertical or oblique blade (5) sinks into said soft part (7) to a depth greater than the depth to which it sinks when in its nominal operating position; The method of claim 12.

14. detecting a position of the cutting device (3) and controlling said position as a function of at least one operating parameter so as to vary the cutting penetration of the cutting device (3) based on variations in at least one operating condition.

4. The method according to any one of claims 1 to 3.

15. the cutting penetration is modified as a function of the degree of wear of the cutting device (3), 15. The method of claim 14.

16. the cutting penetration is modified as a function of the temperature of the closure (2), 15. The method of claim 14.

17. the cutting penetration is modified as a function of the material of the closure (2), in particular as a function of the content of recycled plastic material present in the material of the closure (2); 15. The method of claim 14.

18. The cutting device (3) comprises one or more horizontal blades (4) and a support block to which the at least one vertical or oblique blade (5) and the one or more horizontal blades (4) are fixed, and the position of the cutting device (3) that is detected and controlled comprises the relative position of the support block with respect to a fixing element.

15. The method of claim 14.

19. A method of cutting a closure, comprising: supplying a spindle (6) carrying the closure (2) to the cutting device (3); The spindle has a soft part (7) into which at least one blade (5) of the cutting device (3) can sink; moving the closure (2) on the cutting device (3) and rotating the spindle (6) so that at least one vertical or oblique blade (5) positioned in a nominal working position penetrates the closure (2) and bites into the soft part (7) to a desired depth; adjusting the rotation of the spindle (6) by the spindle feed so that the vertical or oblique blade (5) always strikes the same vertical or oblique area of ​​said soft part (7) each time the spindle (6) is fed into the cutting device (3); detecting a position of the cutting device (3) and controlling said position as a function of at least one operating parameter so as to vary the cutting penetration of the cutting device (3) based on a variation of at least one operating condition. method.

20. the cutting penetration is modified as a function of the degree of wear of the cutting device (3), 20. The method of claim 19.

21. the cutting penetration is modified as a function of the temperature of the closure (2), 21. The method of claim 19 or 20.

22. the cutting penetration is modified as a function of the material of the closure (2), in particular as a function of the content of recycled plastic material present in the material of the closure (2); 21. The method of claim 19 or 20.

23. The cutting device (3) comprises one or more horizontal blades (4) and a support block to which the at least one vertical or oblique blade (5) and the one or more horizontal blades (4) are fixed, and the position of the cutting device (3) that is detected and controlled comprises the relative position of the support block with respect to a fixing element.

21. The method of claim 19 or 20.

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