ITPI20100112A1 - A WINDING SECTION FOR THE AUTOMATED PRODUCTION OF ENVELOPE ROLLS. - Google Patents

Description

Description

A WINDING SECTION FOR PRODUCTION

AUTOMATED ENVELOPE ROLLS

Scope of the invention

The present invention relates to the technical sector relating to machinery used for the production of plastic bags and sacks.

In particular, the invention refers to an innovative device for automation applied to the production of plastic bags wrapped on cores.

Brief notes on the known art

The machines for the production of plastic bags wrapped on a plastic or cardboard core have been known for some time. The roll thus created is composed of a continuous ribbon formed by a succession of envelopes divided one from the other by a perforation line of predetermined pitch. The continuous strip is generally wound around the aforementioned axially perforated cylindrical core so that the roll can subsequently be rotatably arranged on the axis of a distributor. In this way the user can easily unroll an envelope and detach it from the remaining roll by applying a traction that causes the tear along the perforation line. These types of bags are very common and frequently used in the food sector, for example in supermarkets in order to pack fruit or other food products.

The production line for these rolls of envelopes includes an unwinding section through which a continuous ribbon of plastic material is unwound from a mother reel. The mother reel can have a width (ie a width) which varies according to the number of rolls to be produced and generally greater than one meter in order to obtain four or more rolls at the same time.

A longitudinal cutting and sealing section is arranged in succession to the unwinding section in such a way that the strip unwound from the parent reel is divided into several tracks welded laterally and folded centrally. In this way, starting from a single tape of predetermined width, a plurality of continuous tapes of smaller width are formed.

Finally, the perforation section is provided which creates the tear line between one envelope and the next along the formed tape.

The continuous web of envelopes is now wound into a special wrapping section.

In accordance with the known art, this section provides for the intervention of an operator who manually prepares a plurality of cores on a mandrel on which the tapes will be rewound. The operator must then manually prepare the spindle in the machine and remove it as soon as the winding has been completed. He will therefore have to manually remove the rolls produced and prepare a new mandrel in order to start a new winding.

It is evident that this type of machine is of low performance, given that the manual intervention of an operator greatly slows down the production cycle. Furthermore, it is evident that the use of an operator in order to carry out this manual task implies an additional production cost.

Summary of the invention

It is therefore an object of the present invention to provide a winding section for a machine used for the production of rolls of envelopes which at least partially solves the aforementioned drawbacks.

In particular, it is an object of the present invention to provide a winding section which is absolutely automated, in such a way as to allow a considerable increase in productivity and at the same time reducing the need for human intervention.

These and other purposes are thus achieved by the present winding section for a machine used for the production of rolls of envelopes according to claim 1.

The winding section (1) includes:

- A belt feed path (200);

- A winding device (10) to wind the ribbon around the core (4) and;

- Tear-off media (60, 60 ', 61, 61', 150) configured to tear the web (100) at the completion of a rewind and facilitate the start of a subsequent rewind.

In order to achieve this automation, the winding device (10) provides a support (11) rotatable around a longitudinal axis (12) and provided with at least a first (16) and a second mandrel (17) connected to the support (11 ) in a rotatable manner around their longitudinal axis, to carry out the winding of the roll being formed, and further axially sliding between an extended position, in which they emerge from the support (11) in a substantially orthogonal manner to it to achieve the winding, and a retracted position.

The winding section (1) further comprises:

- A mobile core loader (3) and;

- A handling system (50, 51, 55, 100).

The handling system (50, 51, 55, 100) is synchronized in such a way that when it drives a rotating spindle (16, 17) in the extended position to complete a first winding of a roll being formed, it brings the second spindle back from the extended position to retracted position. In this way the formed roll, possibly present on this mandrel, falls back automatically while, at the same time, the mandrel itself is already set up to load new cores for a new winding. In this sense, the movement system now controls the rotation of the loader (3) to bring it in axis with said second spindle retracted. The subsequent extraction of this second mandrel pierces the cores arranged on the loader and prepares it for the new winding. At this point the movement system commands the removal of the loader (3) so that, near the completion of the first winding, it can activate the subsequent rotation of the entire support (11) around its axis (12) and which causes an inversion of position between the two spindles (16, 17). In this way the second mandrel, placed in rotation before or during this inversion rotation, now intercepts the feeding path of the ribbon (200) and, following the tearing of the ribbon through the aforementioned tear-off means, starts a new winding on the cores. . The handling system now also controls the feedback of the first spindle driven by the support into the loading and unloading position previously occupied by the other spindle, in such a way as to cause the formed rolls to fall.

The cycle now resumes exactly as described through the new axis rotation of the loader and the extraction of the mandrel to grasp the cores.

Further advantages can be deduced from the dependent claims.

Brief description of the drawings

Further characteristics and advantages of the present winding section 1, according to the invention, will become clearer with the following description of an embodiment thereof, given by way of non-limiting example, with reference to the attached drawings, in which:

- Figure 1 shows half of this section in an axonometric view;

- Figure 2 frames the axonometry of figure 1 with a side view;

Figure 3 shows an axonometric view of the assembly of the winding device 10 belonging to the present winding section 1;

- Figure 4 shows an axonometric view of the entire winding section 1 provided with casing or frames 2 with a longitudinal axis of the section highlighted in a broken line;

Figure 5 shows a detailed axonometric view of the core loader arranged in axis with the mandrel;

- Figure 6 shows the same axonometric view in which the core loader is however rotated off-axis with respect to the mandrel;

Figure 7 shows an axonometric view of a detail of the device for longitudinal movement of the spindles;

- Figures 8 and 9 show a lateral view of a longitudinal section (plane belonging to the longitudinal axis) of the whole machine of figure 4;

- Figures 10 to 18 show the operating phases.

Description of some preferred embodiments With reference to Figure 1, an axonometric view is shown of a part of the winding section 1 for forming a continuous roll of envelopes according to the invention. The other part, as better clarified immediately below, has been omitted here only for the purpose of descriptive clarity of the drawings as it is substantially identical.

Figure 1 therefore represents a support frame 2 for the mechanical winding elements, that is a loader 3 and a winding device 10 better visible in Figure 3.

In particular, again in figure 1, the loader 3 is shown closed at one end through a base 3â € ™ and within which the cores 4 for winding are placed, which are arranged in a stacked manner. on the other. Base 3â € ™ therefore prevents the gravity of the souls contained within it from falling. Figure 2 shows a front view inherent to the axonometry of Figure 1 in order to better highlight the core loader 3 with the closure 3â € ™.

The loader, as also highlighted in figure 1, is mounted oscillating around a rotation axis 150 supported by the frame 2. In particular, the oscillation is obtained through the extraction / retraction of an actuator 55 (see figure 2 or figure 8 and figure 9).

More in detail, the loader 3 provides a sling 60 provided with said rotation axis 150 and within which one or more tracks 30 for stacking the cores are fixed. In the preferred configuration described in Figure 1, four tracks are provided in such a way as to provide four winding tracks, as better clarified in the following of the present description.

Also Figure 1 and Figure 2 further highlight a rotary device 10 (better highlighted in the axonometric view of Figure 3) comprising two discs 11 rotatably connected by a shaft 12.

More precisely, a disc 11 is arranged with respect to the frame 2 to rotate around the central rotation axis 12. The central rotation axis, as better shown in figure 3, is a shaft 12 which is rigidly connected to a further disc 11 opposed and in turn supported by its own support frame 2. In this way, through a single motorization it is possible to operate a disc 11 capable of driving the opposing disc 11 in rotation through the shaft 12.

Figure 4 better shows an overall view with the aforementioned frames 2 to which the respective rotary devices 10 are connected.

Going more into the descriptive detail of the rotary device 10 (see again Figure 2 and Figure 3), it is evident that the two discs 11 each have a first winding element 13 and a second winding element 14 arranged so as to be symmetrical according to a central symmetrical with respect to disc rotation shaft 12. The winding element 13 and the winding element 14 respectively comprise a disc 13 'and a disc 14' fixedly mounted on the disc 11. The disc 13 'supports a mandrel 16 on which cores can be loaded 4, as well as the disc 14â € ™ mounts a mandrel 17 on which the cores 4 can be loaded for winding, as will be better detailed in the following operation. The spindles (16, 17) are mounted both rotating and sliding axially with respect to their support disc (13â € ™; 14â € ™) so that a special actuation system (50, 51) can control their extraction and retraction longitudinal while a motorization 100, more detailed in the following, controls their rotation around their connection axis.

Figure 3 in fact clearly shows the spindle 17 belonging to the disc 14 'completely retracted while, in contrast, the spindle 16 belonging to the disc 13' is extended.

Figure 1, the side view of Figure 2 and the axonometric detail of Figure 5 therefore freeze an operating condition in which the loader is oscillated in a position in which the cores are perfectly aligned with the spindle 17. In this way, as a consequence of an extraction of the mandrel, the cores stretched in the loader are inserted on the mandrel itself similarly to a ring on the finger.

For this purpose, the mandrel is of the expansion type in such a way as to block the cores impaled on it.

The axonometric view of figure 6 better highlights the next phase in which the mandrel 17 was extracted, consequently inserting the two cores 4 while, subsequently, the loader was rotated in a rear position around the axis 150.

Although Figures 5 and 6 for the sake of simplicity detail a single spindle 17 protruding from a single disc 11, it is evident from Figure 3 and the present description how the preferred configuration of the invention provides for two identical and opposite discs 11 and therefore two spindles (16 , 17) for identical disc 11 which work perfectly symmetrically.

In this case, figure 5 represents in fact only two tracks 30 impaled by the mandrel belonging to a disc 11, but it is to be understood that an opposing disc 11 is provided and from which another mandrel 17 comes out to pierce the cores arranged in the other two tracks 30 omitted from that figure.

Continuing in the constructive description of the invention, figure 7 and figure 3 highlight the control system for the extraction and retraction of the mandrels (16, 17). In particular, a sliding bar 50 is shown on which a shoe 51 is slidably mounted. The shoe provides a coupling system (for example a caliper) through which to grasp the corresponding mandrel when, following the rotation of the disk 11, this is prepares in line with it. Figure 3 in fact shows the gripping phase of a mandrel (in this case the mandrel 17) which has been retracted by the backward motion of the shoe 51.

The rotation of the two spindles 16 and 17, as well as the rotation of the central shaft 12 and therefore of the two discs 11, is controlled by a special motorization system 100 such that each element can rotate absolutely independently of the other. .

Figure 3 shows in fact two motors 110 on each side (preferably of the â € œbrushlessâ € type) and a single motor-reducer 120 which, through transmission belts and pulleys, transmit the rotation to the aforementioned elements independently.

In particular, again as shown in Figure 3, two belts 400 and 410 on each side respectively connect the central axis 12 to a mandrel (16, 17) thus controlling their rotation around their axis.

In particular, two idle pulleys are used, mounted idly on axis 12 and connected through the aforementioned belts, each one to a pulley arranged on the disc 11 and integral with a spindle in such a way that a rotation can be transmitted from the motors to the spindles regardless of the rotation of the Shaft 12. In fact, since the aforesaid pulleys are mounted idle on axis 12, this implies that the rotation of the spindles continues undisturbed regardless of the rotation of the shaft 12 itself. In this way their rotation continues undisturbed even during the rigid rotation of the disc 11 around its axis 12, allowing the winding to continue even during the exchange. The motor-reducer 120, through the shaft 130 and the belts 420 and 430, allows the rotation speed of the spindles (16, 17) to be varied according to requirements, which are absolutely independent from each other.

The first belt 440 controls the rotation of the shaft 12.

A part of the motorization is visible in the axonometric view of figure 4 and highlights the disc 11 which can be rotated with respect to the frame itself. The rotation of the disc is therefore controlled at a â € œstepâ € substantially 180 ° in such a way as to be able to change the position of the spindles 16 and 17 each time, bringing them to the insertion position in correspondence with the shoe.

As then shown in the following figures 8 and 9, the winding section 1 further comprises suitable tear-off means (60, 60â € ™, 61, 61â € ™, 150) which, once winding around one of the two mandrels is completed, allow the tearing of the tape 200 and, at the same time, the start of a new winding around the second spindle set up on hold.

These tear-off means therefore comprise a tamper (60, 60â € ™) and a counter-press (61, 61â € ™) each consisting of a roller (60; 61) rotatably mounted around an arm (60â € ™; 61â € ™). Both the arm 60 'and the arm 61' are in turn hinged in such a way that the presser and counter-presser are oscillating. Figures 8 and 9 show a succession in which the tamper (60, 60â € ™) is rotated clockwise to intercept the path of the belt 200 while, at the same time, the counter tamper also rotates clockwise to increase the tension on the tape.

The combined action of the tamper and the counter press causes tension on the belt which causes tearing.

The rollers of the tamper and counter-tamper are idle mounted on the respective arms with a certain degree of mechanical resistance to rotation precisely in order to induce said tension on the belt 200.

The rotation of the tamper and counter-tamper is made possible by means of actuators, as shown in figures 8 and 9.

A blow of air 250 is then arranged integral with the tamper in such a way that after tearing the air holds the tape against the mandrel to start a new winding (see for example figure 12).

For the creation of the blow, for example, a flexible tube connected to the tamper can be used, equipped with a nozzle on one side and connected to a source of compressed air on the opposite side.

Having structurally described all the essential elements of the invention, we now pass to a description of its functioning.

For the sake of simplicity only, operation is represented with figures representing a single disc 11.

Figure 10 shows a normal phase of winding the strip 200 through the rotation of the mandrel 17 on which the cores 4 are arranged. In this phase the mandrel 16 is loaded with other cores 4 and remains in a waiting position such as not to interfere with wrapping. At the same time, in this winding configuration, the magazine 3 is also rotated externally to the disc in a rest position, as is the presser 60, in such a way as not to interfere with the winding.

Figure 10 also shows, for greater descriptive clarity, a side view of the same disc 11. However, this side view has been rotated ninety degrees counter-clockwise with respect to its front view in such a way as to clearly highlight the two spindles.

As soon as a predetermined number of wrapped bags is approached (a special software manages this count) the spindle 16 is set in rotation around its axis while, at the same time, the rotation of the disc 11 around its axis 12 is activated in such a way to reverse the position of the spindles. This inversion phase is clearly schematized in the following figure 11 and highlights a 180 ° rotation of the disc 11 around its rotation axis 12. In this way the two mandrels exchange their position thus allowing the start of the tearing phase . During this rotation phase the two spindles therefore rotate together at suitable speeds.

The tearing phase is carried out by means of the tamper and the counter-tamper which are suitably rotated so that the tamper comes into contact with the new mandrel 16 while the counter-press tensions the belt more. In particular, again as shown in Figure 11, a clockwise rotation of the tamper is provided which brings it into contact with the new spindle 16 which rotates around its axis with a tangential speed coinciding with the speed of advancement of the belt. At the same time, the counter-presser also rotates clockwise in such a way as to pull the band 200 more. The combination of the contact of the presser against the band sliding on the new mandrel 16 and the displacement of the counter-presser generate sufficient tension for tearing.

In order to start the new winding, the tamper continues to maintain contact against the mandrel 16 for a fraction of time sufficient to force the head 90 of the belt to wind around the rotating mandrel 16, in particular around the cores 4 fixed to the aforesaid. spindle. The blow of air 250, arranged integral with the presser 60, facilitates the start of the new winding by forcing the head 90 of the belt to remain in adherence against the rotating mandrel.

The following figure 12 shows the formed roll provided with the tail 80 of the broken ribbon and the head 90 of the ribbon which begins to wind on the core 4 arranged for rotation on the mandrel 16.

Once the wrapping has begun, the tamper and counter-presser return to the rest position.

Figure 13 and figure 14 show the subsequent phases in which the new winding has started and at the same time the unloading of the newly formed rolls takes place. This unloading phase provides, thanks to the independent motors used, the stop of the rotation of the spindle 17 and the subsequent longitudinal feedback of the spindle 17 through the shoe 51 sliding on the guide 50 of figure 3. The feedback of the spindle 17, as shown in figure 14 , therefore, causes the formed rolls to fall, which are, for example, collected by a suitable unloading platform 70 of the mobile type.

At this point, while the spindle 16 is still in the rotation phase to continue winding the new rolls being formed, it is necessary to prepare new cores 4 on the spindle 17.

For this purpose, figure 15 shows an anticlockwise rotation of the loader 3 which brings the cores in axis with the spindle 17.

Subsequently, as shown in figure 17 and in figure 18, the axis 17 is made to slide longitudinally through the shoe 51 along the guide 50 in such a way as to pierce the cores arranged on the loader in axis.

The magazine is now rotated into the rest position as shown in figure 19.

The cycle is therefore complete as the winding continues and the spindle 17 is now equipped with 4 cores for winding. In this sense, as soon as the winding in progress is completed, the cycle described is repeated again starting from figure 10 so that, once a winding has been completed, an exchange and unloading of the roll formed automatically take place.

Claims (12)

CLAIMS 1. A wrapping section (1) for wrapping a continuous web (200) of envelopes around one or more cores (4) and comprising: - A belt feed path (200); - A winding device (10) to wind the ribbon around the core (4) and; - Tear-off means (60, 60 ', 61, 61', 150) configured to cause the tape (100) to tear at the completion of a winding and to facilitate the start of a subsequent winding; and characterized in that the winding device (10) provides a support (11) rotatable around a longitudinal axis (12) and provided with at least a first (16) and a second mandrel (17) connected to the support (11) in rotatable around their longitudinal axis to wind the roll being formed and further axially sliding between an extended position, in which they emerge from the support (11) in a substantially orthogonal manner to it to carry out the winding, and a retracted position; the winding section (1) further comprising: - A mobile core loader (3) and; - A handling system (50, 51, 55, 100); and in which said movement system (50, 51, 55, 100) is synchronized in such a way that when it drives a rotating mandrel (16, 17) in an extended position to complete a first winding of a roll being formed, it returns the second spindle from the extended position to the retracted position in such a way as to subsequently rotate the loader (3) in axis with said second spindle and pierce the cores arranged on the loader with said second spindle following its extraction from the retracted position to the extended position, said system movement being further synchronized to subsequently control the removal of the loader (3) and, near the completion of the first winding, to control the subsequent rotation of the support (11) around its axis (12) which leads to an inversion of position between the two spindles (16, 17) so that the second spindle extracted and rotated intercepts the feed path ntation of the ribbon (200) and, following the tearing of the ribbon, start a new winding while the feedback of the first mandrel causes the fall of the formed rolls. 2. A winding section (1), according to claim 1, wherein said tearing means (60, 60â € ™, 61, 61â € ™, 150) comprise a tamper (60, 60â € ™) in combination with a counter-presser (61, 61â € ™) and designed to intercept the feed path of the belt in such a way as to induce a state of tension that causes tearing. 3. A winding section (1), according to claim 2, in which said presser provides a rotatable roller (60) around an arm (60â € ™) and in which the arm is hinged in such a way as to move between a tear-off position in which the roller is brought into contact against the mandrel (16, 17) and a rest position outside the web feeding path, called counter-presser (61, 61â € ™) providing a roller (61) arranged in such a way as to intercept the feed path of the ribbon and in which the roller is further rotatable around an arm (61â € ™) hinged in such a way that a simultaneous rotation of the roller (61) towards the feed path of the ribbon and the roller (60) on the mandrel cause a state of tension on the web. 4. A winding section (1), according to claim 3, in which said rollers (60, 61) are idle mounted with a degree of resistance to rotation such as to induce a slowdown in the speed of advance of the belt. 5. A winding section (1), according to one or more claims 2 to 4, in which puffs (250) arranged on the presser (60, 60â € ™) and directed in such a way as to be able to intercept the tape are further provided broken in such a way as to force the head (90) of the broken ribbon to wind on the mandrel (16, 17) set in rotation. A winding section (1), according to claim 1, wherein the core loader is mounted pivotally around a pivot axis (150) and rotated through an actuator (55). 7. A winding section (1), according to claim 1, in which said synchronized movement system provides a shoe (51) sliding linearly on a track (50), the track being arranged with respect to the support (11) in such a way the shoe comes into contact against one end of the mandrel to grasp it. 8. A winding section (1), according to claim 1 or 7, in which said synchronized movement system provides a motorization (100) to control the rotation of the mandrels (16, 17) and the rotation of the support (11), the rotation of the mandrels being independent of each other and in turn independent of the rotation of the support (11). 9. A winding section (1), according to one or more preceding claims, in which said winding device has a central symmetry with respect to the axis (12) and provides two opposing supports (11) rigidly joined together through a tree (12). 10. A winding section (1), according to one or more preceding claims from 1 to 9, in which said support (11) is in the form of a disc. 11. A line for the production of rolls of envelopes comprising: - An unwinding section to unwind a mother reel of tape; - A folding and sealing section for folding the tape and sealing it in such a way as to obtain a continuous succession of envelopes; - A perforation section to create a tear line between one envelope and the next; and characterized in that it comprises a section (1) for winding the web of envelopes around one or more cores (4) as per one or more preceding claims from 1 to 10. 12. A method for carrying out the automated winding of a continuous web (200) of envelopes around one or more cores (4) through a winding section (1) as per one or more preceding claims from 1 to 10 and comprising the operations of: - Continuous feeding of the web (200) of envelopes along the feeding path; - Formation of a roll by winding the tape around at least one core (4) arranged in rotation and; - Tearing of the tape (200) in correspondence with the completion of the roll being formed; - Unloading of the formed roll and start of a new winding; and characterized in that the operations of forming the roll, tearing and starting a new winding are controlled through the synchronized movement of the core loader (3) and the winding device (10), said operations comprising: - Rotation of a mandrel (16, 17) of the winding device (10) and set in extended position to complete the winding of a roll of envelopes in formation; - retraction of the second mandrel of the winding device and subsequent preparation of the core loader (3) so as to be in axis with it; - Subsequently extraction of the second mandrel in such a way as to grasp the cores arranged in the loader in axis with it; - Removal of the magazine; - Subsequent rotation of the support (11) around its rotation axis (12) near the completion of said winding of the roll being formed in such a way as to reverse the positions of the spindles (16, 17) bringing the second spindle to intercept the path ribbon supply; - Tearing of the tape in correspondence with the completion of the roll being formed and start of a new winding through the rotation of the second mandrel; - Locking of the rotation of the first spindle and retraction of the first spindle to cause the fall of the formed rolls and repetition of the cycle for the preset number of windings.