UNIT AND METHOD FOR FEEDING BLANKS

Description

The present invention concerns a unit and a method for feeding blanks, intended to form boxes enclosing one or more articles.

The invention finds preferred but not exclusive use in an apparatus for packaging boxed articles, particularly suitable for packaging articles in accordance with a process in which it is provided for forming the box by folding a preformed blank.

The invention is applied in the apparatuses provided with a loading hopper intended to contain a plurality of blanks and subsequently feed them to a handling unit. Therefore, reference will be made below to this sector without thereby losing in generality.

In this description as well as in the claims appended thereto, certain terms and expressions are deemed to have, unless otherwise expressly indicated, the meaning expressed in the following definitions.

“Blank” means a shaped sheet of suitable material and thickness adapted to be folded to form a box. Preferably, the blank is made of cardstock. Preferably, the blank has two opposed substantially planar faces having dimensions substantially greater than the dimensions of the thickness of the blank itself. Preferably, the blank has a thickness of at least 0.2 mm, more preferably less than 4 mm. In a most preferred manner, the blank has a thickness comprised between 0.25 mm and 1.6 mm, more preferably between 0.3 mm and 1 mm, even more preferably between 0.4 and 0.8 mm.

A “folding line” of a blank is a predefined line made on the blank and intended to divide two panels of the blank and around which two panels of the blank are envisaged to rotate one relatively to the other so as to fold the blank, preferably to form a box. The folding line can be a virtual, albeit predefined, line. The folding line is preferably defined by a line of weakness obtained on the blank, such as for example a crease, or a scoring or a plurality of aligned holes.

By the term “stack” is intended to mean a plurality of substantially planar objects, in particular blanks positioned one above the other, or flanked one another. In particular, a stack of blanks is a set of blanks one placed in an adjacent manner to the other so that the faces of two adjacent blanks face each other. In the stack of blanks the faces of two adjacent blanks can be in contact with one another, or spaced apart from each other.

By the term “article” is intended to mean any product that is susceptible of being packaged into boxes. The articles can have a predefined geometric shape or they can have a variable geometry.

By “packaging” of one or more articles in a box is meant obtaining a box containing said one or more articles. Such packaging can be obtained by inserting one or more articles into an already formed box or, preferably, it can be obtained by forming a box around the one or more articles to be contained.

In general terms, a first element “abuts” a second element when the first element touches the second element and is able to at least partially oppose to a relative displacement of the first element against the second element.

In particular, the blank is “abutted” by a component of the feeding unit, such as for example a retaining element, when the component is in contact with the blank. It should be specified that the abutment of the blank does not in itself imply that the blank is abutted over its entire surface by a component of the feeding unit, but it is sufficient that there is a contact between the component and the blank on a portion of the blank.

“Box” means any container adapted to contain a plurality of articles for the purpose of packaging them, and which is susceptible of being made starting from a blank. The box can be obtained by folding a blank around a mandrel and then fixing the blank at its edges or panels. Preferably, the box has at least one closed contour section, more preferably it is closed laterally around the mandrel while the longitudinal ends are kept open.

By the term “movement direction” is intended to mean the direction along which an object, for example a blank, is displaced. The movement direction is represented by an oriented line.

With reference to a particular movement direction, a first element has an “advanced position”, or is defined as “advanced”, or is positioned “downstream” with respect to a second element when along the oriented line identified by said movement direction, the first element is in a position that is subsequent to the position of the second clement. In a completely similar way, a “backward position” or a position “upstream” of a first element with respect to a second element is also defined when along the oriented line identified by the direction, the first element is in a preceding position with respect to the position of the second element.

In the present description, by the definition “advanced blank” is intended to mean in particular the blank of the stack closest to an outlet section of the storage device.

The Applicant has preliminarily observed that the provision of a blanks feeding unit provided with a storage device, such as for example a loading hopper, intended to contain a stack of blanks and configured to feed in succession the blanks of the stack of blanks towards a handling unit allows to obtain significant advantages in terms of efficiency and feeding speed of the blanks. In fact, the subsequent blanks are moved in rapid succession one after the other towards the handling unit.

However, the Applicant has observed that the blanks may be torn, or ripped, in the transfer from the feeding unit to the handling unit. The Applicant has verified that the damages to the blanks are particularly evident and/or frequent when the blanks have limited thickness and strength and when the dimensions and/or the number of the blanks themselves increase.

In particular, the Applicant has observed that one of the critical steps in feeding the blanks, during which the blanks may be more subject to tears, is constituted by the picking of the blanks from the feeding unit by means of the handling unit.

To this end, the Applicant has found that a stack of blanks is loaded into a loading hopper provided with a movement mechanism for moving the blanks towards an outlet section of the hopper. At the outlet section of the hopper there are provided retaining elements intended to abut the advanced blank of the stack of blanks so as to prevent the unwanted escape of the same from the hopper. For picking the advanced blank from the loading hopper, there is usually provided a handling unit provided with gripping elements intended to engage the advanced blank. The handling unit is moved towards the loading hopper so as to engage the advanced blank with the gripping elements and subsequently moved to pick up the advanced blank from the loading hopper by disengaging it from the retaining elements.

The Applicant has observed that the retaining elements must be positioned in the loading hopper so as to avoid accidental escapes of the blanks, but at the same time allow the picking of the blanks from the hopper by the handling unit.

The Applicant has verified that the most critical step for the integrity of the blank is the transfer of the blank from the loading hopper to the handling unit. In this step, in fact, distinct portions of the blank are retained by the gripping elements of the handling unit and respectively by the retaining elements of the loading hopper, which tend to keep the advanced blank integral respectively with the handling unit and the loading hopper.

The Applicant therefore imagined to modify the retaining elements by reducing the interference with the advanced blank. However, the Applicant has found that this would have entailed the need to provide for further measures in order to avoid the accidental disengagement of the advanced blank from the retaining elements. The Applicant has therefore verified that some of these measures would not have been sufficient to obviate this inconvenience.

The Applicant has found that sometimes the blanks may not be abutted correctly by the retaining elements at the outlet section of the loading hopper.

The Applicant has verified that this negatively affects the correct picking of the blanks by the handling unit, favouring tears of the blanks during the picking step, or an incorrect positioning of the blanks on the handling unit. The Applicant has further verified that when the blanks are not correctly positioned on the handling unit, an incorrect folding of the blank to form the box can be generated and, therefore, a decrease in the quality of the boxes produced.

The Applicant has noted that frequent maintenance interventions by operators are necessary to modify the relative position between advanced blank and retaining elements, for example by adjusting the position of the retaining elements in the loading hopper.

However, the Applicant has verified that these interventions considerably slow down the productivity of the packaging apparatus since it is necessary to interrupt the operation of the feeding unit during the maintenance interventions.

Furthermore, the Applicant has verified that this approach does not prevent some blanks from being damaged, or compromised, during the picking by the handling unit. In fact, the maintenance interventions are usually planned after a plurality of blanks have been damaged or torn, in order to avoid interrupting the operation of the feeding unit unnecessarily, or due to an isolated malfunction.

The Applicant has also found that as the movement speed of the blanks in the loading hopper increases, for example to increase the production capacity of the packaging apparatus, the tears or rips in the blanks occur more frequently.

The Applicant, in order to reduce the occurrence of possible tears of the blanks, has therefore imagined to act on the movement mechanism of the blanks, for example by reducing the movement speed of the blanks in the loading hopper, or also on the handling unit, for example by reducing the speed of picking of blanks from the loading hopper.

However, the Applicant has found that these solutions would have strongly limited the production capacity of a packaging plant. The Applicant therefore verified that the possibility of using such blanks movement and handling systems was limited by the productivity required of the packaging apparatuses.

The Applicant has therefore understood that in order to limit the possibility of damaging the blanks during the picking by the handling unit, it was necessary to redesign blanks feeding unit.

The Applicant has therefore understood that in order to achieve the aforementioned purpose while maintaining high production capacities, it was necessary to identify an operating mode that would allow the position of the retaining elements to be adjusted as a function of objectively detectable process parameters.

The Applicant, in particular, has intuited that the possibility of generating damages to the blanks was correlated to the pressure exerted by the blanks on the retaining elements and, therefore, that an optimal position of the retaining elements that would allow to avoid tears or damages to the advanced blank without thereby limiting the feeding speed of the blanks, had to be correlated to the pressure exerted on them by the blanks.

Finally, the Applicant has found that a method and a unit for feeding blanks that provide for retaining a stack of blanks by means of at least one retaining element intended to abut a portion of the advanced blank, to detect the thrust pressure exerted on the retaining element and to adjust the position of said retaining element, or of another retaining element if provided, based on the pressure detected in said detection step, surprisingly allow to effectively retain the blanks avoiding unwanted tears thereof and at the same time maintaining high production speeds without the need to continuously recur to the action of an operator.

In other words, the Applicant has found that adjusting the position of a retaining element based on the pressure exerted by the advanced blank allows to effectively retain the blanks while avoiding the defects complained about above.

In a first aspect thereof, therefore, the present invention is directed to a blanks feeding unit.

Preferably, said unit comprises a blanks storage device for containing a stack of blanks and moving said stack along a movement direction towards an outlet section of said storage device.

Preferably, said unit comprises at least one retaining element provided at said outlet section and intended to abut an advanced blank of said stack at least at a portion of said advanced blank.

Preferably, said unit comprises a pressure sensor operatively connected to said at least one retaining element and intended to detect the pressure exerted on said at least one retaining element by said advanced blank.

Preferably, said unit comprises at least one further retaining element provided at said outlet section and intended to abut an advanced blank of said stack at least at a further portion of said advanced blank distinct from said portion.

Preferably, said unit comprises an adjusting device operatively connected to said pressure sensor and intended to adjust the position of said at least one retaining element based on the pressure detected by said pressure sensor.

Preferably, said unit comprises an adjusting device operatively connected to said pressure sensor and intended to adjust the position of said at least one further retaining element based on the pressure detected by said pressure sensor.

In a second aspect thereof, the present invention is directed to a method for feeding blanks.

Preferably said method comprises storing a stack of blanks in a storage device having an outlet section.

Preferably said method comprises moving said stack along a movement direction towards said outlet section, said stack comprising an advanced blank placed at the outlet section.

Preferably said method comprises retaining said stack of blanks at said outlet section by means of at least one retaining element intended to abut a portion of said advanced blank.

Preferably said method comprises detecting the pressure exerted on said at least one retaining element.

Preferably said method further comprises retaining said advanced blank by means of at least one further retaining element intended to abut a further portion of said advanced blank distinct from said portion.

Preferably said method comprises adjusting the position of said at least one retaining element based on the pressure detected in said detection step.

Preferably said method comprises adjusting the position of said at least one further retaining element based on the pressure detected in said detection step.

In a third aspect thereof, the present invention is directed to a control unit of a blanks feeding unit.

Preferably, said feeding unit comprises a blanks storage device for containing a stack of blanks and moving said stack along a movement direction towards an outlet section of said storage device.

Preferably, said feeding unit comprises at least one retaining clement provided at said outlet section and intended to abut an advanced blank of said stack at least at a portion of said advanced blank.

Preferably, said feeding unit comprises a pressure sensor operatively connected to said at least one retaining element and intended to detect the pressure exerted on said at least one retaining element by said advanced blank.

Preferably, said feeding unit comprises an adjusting device intended to adjust the position of said at least one retaining element based on the pressure detected by said pressure sensor.

Preferably said control unit comprises a control element operatively connected to the adjusting device so as to actuate the adjusting device to displace said at least one retaining element based on the pressure detected by said pressure sensor

The control unit preferably comprises processing elements intended to receive the signal relative to the pressure detected by the pressure sensor and to process a corresponding actuation signal for the control element to actuate the adjusting device.

In a further aspect of the invention there is provided an apparatus for packaging boxed articles comprising a blanks feeding unit according to the aforesaid first aspect.

Thanks to the invention it is possible to adjust the position of a retaining element of the advanced blank based on the pressure detected by the pressure sensor so as to position the retaining element in an optimal position that allows to effectively retain the advanced blank and at the same time avoid damages or tears of the same. By adjusting the position of a retaining element, it is possible to prevent tears or damages to the advanced blank during the picking by the handling unit, while preventing the advanced blank from disengaging from the retaining clement. For example, if the pressure detected by the pressure sensor is outside a certain range, it is possible to displace a retaining clement by positioning it so that the pressure exerted by the advanced blank on such a retaining element is within the desired range.

Advantageously, such adjustment does not interfere with the operation of the feeding unit and it is not necessary to interrupt or slow down the operation of the feeding unit itself.

Moreover, thanks to the invention, the adjustment of the feeding unit can be carried out automatically, without the intervention of the operator, greatly simplifying the adjustment operations.

In addition, acting on the retaining element optimizes the effectiveness of the adjustment because one acts directly on the interaction force between advanced blank and retaining element. Therefore, this greatly limits, or eliminates, the possibility of a blank being torn during the picking by the handling unit.

The present invention, in at least one of the aforementioned aspects, may have at least one of the further preferred features indicated below.

In some embodiments, said adjusting device is configured to displace said at least one retaining element along a first displacement direction.

In some embodiments, said adjusting device is configured to displace said at least one further retaining clement along a first displacement direction.

Preferably said first displacement direction is parallel to the movement direction of said stack.

Displacing the at least one retaining element and/or the at least one further retaining clement along a displacement direction parallel to the movement direction of the stack varies the pressure exerted by the advanced blank on the at least one retaining element and/or on the at least one further retaining element and, therefore, the force that must be overcome by the handling unit to extract the advanced blank from the storage unit.

In some embodiments, said adjusting device is configured to displace said at least one retaining element along a second displacement direction transverse to the movement direction of said stack to vary the position of said at least one retaining clement with respect to said advanced blank.

In some embodiments, said adjusting device is configured to displace said at least one further retaining clement along a second displacement direction transverse to the movement direction of said stack to vary the position of said at least one further retaining element with respect to said advanced blank.

In this way it is, for example, possible to vary the interference between the at least one retaining element or the at least one further retaining element and the blank, i.e. the extension of the portion, or respectively of the further portion, of blank abutted by the retaining clement or by the further retaining element. It is, for example, possible to reduce the interference between the at least one retaining element or the at least one further retaining element and the blank in case of tears or damages to the advanced blank or, conversely, to increase the interference in case of ineffective retention of the advanced blank.

It is also possible to vary the area of the blank in which the at least one retaining element or the at least one further retaining element abuts the blank, for example based on the dimensions and/or shape of the blank. In this way it is possible to effectively retain blanks of various shapes and dimensions.

In some embodiments, said second displacement direction is perpendicular to the movement direction.

Preferably said at least one retaining element is positioned so as to abut said advanced blank at an edge portion thereof.

Preferably said at least one further retaining element is positioned so as to abut said advanced blank at a further edge portion thereof.

This positioning makes it possible to simplify the operations of picking the blanks by the handling unit while effectively retaining the blanks.

In some embodiments, said at least one retaining element is positioned so as to abut said advanced blank at a central portion thereof.

In some embodiments, said at least one further retaining element is positioned so as to abut said advanced blank at a central portion thereof.

In such a version the at least one retaining element and/or the at least one further retaining element are spaced apart by an edge portion of the blank. Such positioning is advantageous, for example, for small sized blanks and/or with determined handling units, in particular with feeding units that pick up the blank by moving it in a direction transverse to the movement direction. In this case it is possible to effectively retain a blank even with a small number of retaining elements.

Preferably, said portion at which said at least one retaining element abuts said advanced blank is defined on an advanced face of said advanced blank.

Preferably said further portion at which said at least one further retaining element abuts said advanced blank is defined on an advanced face of said advanced blank.

Said at least one retaining element and/or said at least one further retaining element abut said blank on the advanced face, that is, on the face directed towards the outlet section of the storage device and facing away from the stack.

In some embodiments, said second displacement direction is transverse to the edge of the edge portion and/or of the further edge portion on which the at least one retaining clement or, respectively, the at least one further retaining element is provided.

In some embodiments, said second displacement direction is parallel to the edge of the edge portion and/or of the further edge portion on which the at least one retaining clement or, respectively, the at least one further retaining element is provided.

By varying the position of the at least one retaining element or of the at least one further retaining element, it is possible to effectively retain blanks also with dimensions and shapes different from each other.

Said second displacement direction is preferably parallel to the edge of the edge portion and of the further edge portion on which the at least one retaining element or respectively the at least one further retaining element is provided.

Preferably said adjusting device is configured to displace said at least one retaining element and/or said at least one further retaining element along three distinct displacement directions orthogonal to each other.

In some embodiments, said adjusting device is configured to make said at least one retaining element oscillate about a rotation axis perpendicular to said movement direction to vary the orientation of said at least one retaining element with respect to said advanced blank.

In some embodiments, said adjusting device is configured to make said at least one further retaining element oscillate about a further rotation axis perpendicular to said movement direction to vary the orientation of said at least one further retaining element with respect to said advanced blank.

In this way, the extension and the shape of the portion and/or of the further portion of the advanced blank abutted by the at least one retaining clement or respectively by the at least one further retaining element is varied.

In some embodiments, said feeding unit comprises a plurality of retaining elements intended to abut said advanced blank in distinct portions thereof.

In this way, said advanced blank is abutted in distinct portions of the advanced face thereof.

In this way, the retention of the advanced blank is improved without compromising the picking of the advanced blank by the handling unit. The provision of a plurality of retaining elements allows to limit the dimensions of the individual retaining elements and/or the interference of the individual retaining elements with the advanced blank, facilitating the picking of the blank by the handling unit without risking accidental falls of the advanced blank.

Preferably, said plurality of retaining elements comprises said retaining element and said further retaining element.

Preferably each retaining element of said plurality of retaining elements is displaceable.

Preferably said plurality of retaining elements comprises a first plurality of retaining elements automatically displaceable by means of said adjusting device and a second plurality of retaining elements manually displaceable by means of the action of an operator.

In this way, the retention of the advanced blank is improved without excessively complicating the feeding unit.

In some embodiments, said adjusting device is configured to displace all the retaining elements of said feeding unit.

In this way, a highly versatile feeding unit is obtained which allows to optimize the retention of the blank, also in the presence of deformations of the blanks, while minimizing the need for intervention by the operator.

Preferably said adjusting device comprises a plurality of adjusting elements, each adjusting element of said plurality of adjusting elements being configured to displace a retaining element of said first plurality of retaining elements.

Preferably said control unit comprises a plurality of control elements operatively connected to each adjusting element so as to actuate each adjusting element to displace the corresponding retaining clement.

Preferably, the retaining elements of the plurality of retaining elements are positioned on a same plane defined as the retention plane of the advanced blank.

Preferably said movement direction is perpendicular to said retention plane.

Preferably, said plurality of retaining elements comprises at least two retaining elements positioned at a same edge of said advanced blank, in a position spaced apart from each other.

Each blank comprises two distinct faces, an advanced face turned towards the outlet section of the storage device, and an opposed backward face facing away from the outlet section of the storage device.

Each blank preferably comprises a plurality of folding lines dividing the blank into a plurality of panels, each pair of adjacent panels being oscillatable about a respective folding line separating them. Preferably, the folding lines are configured so that a plurality of central panels and a first and a second plurality of lateral panels are identified in the blank, the panels of the first and second plurality of lateral panels are positioned on opposite laterals with respect to the central panels. Preferably said plurality of central panels comprises an upper panel and a lower panel.

Preferably said plurality of retaining elements comprises at least an upper retaining element, intended to engage said upper panel. Said upper retaining element abuts said advanced face at said upper panel.

Preferably said plurality of retaining elements comprises at least a lower retaining element, intended to engage said lower panel. Said lower retaining element abuts said advanced face at said upper panel.

Preferably said plurality of retaining elements comprises at least a first and a second lateral retaining element intended to engage respectively at least one lateral panel respectively of said first and said second plurality of lateral panels. Said lateral retaining elements abut said advanced face at said at least one lateral panel.

Preferably, said plurality of retaining elements comprises a first plurality of lateral retaining elements, the retaining elements of the first plurality of lateral retaining elements being intended to engage at least two distinct lateral panels of said first plurality of lateral panels.

Preferably, said plurality of retaining elements comprises a second plurality of lateral retaining elements, the retaining elements of the second plurality of lateral retaining elements being intended to engage at least two distinct lateral panels of said second plurality of lateral panels.

In this way, the retention of the advanced blank is improved.

By displacing the lateral retaining elements it is possible to adjust their position so that they retain distinct lateral panels of the same plurality of lateral panels.

In some embodiments, said at least one retaining element comprises a laminar body.

In some embodiments, said at least one further retaining element comprises a laminar body.

Preferably, said laminar body is sized so as to engage a percentage comprised between about 20% and about 100%, preferably between about 20% and about 50% of the length of said edge.

Preferably, said laminar body is sized so as to engage a percentage comprised between about 2% and about 50%, preferably between about 2.5% and about 25%, of a surface of the advanced blank on which said at least one retaining element or said further retaining element is provided.

Preferably, said laminar body comprises a rounded edge configured to guide said advanced blank when it is extracted by means of said feeding unit from said feeding unit.

In some embodiments, said feeding unit comprises a plurality of pressure sensors and preferably a pressure sensor of said plurality of pressure sensors is operatively associated with said at least one retaining element, a further pressure sensor being associated with said at least one further retaining element.

Preferably, each pressure sensor of said plurality of pressure sensors is associated with a corresponding retaining element of said plurality of retaining elements.

In this way, each pressure sensor detects the pressure exerted on a distinct retaining element.

Preferably each pressure sensor of said plurality of pressure sensors is mounted on a corresponding retaining element of said first plurality of automatically displaceable retaining elements.

Preferably, said feeding unit comprises a movement device for moving said stack along said movement direction.

Preferably, said feeding unit comprises an operating device for operating the movement speed of said movement device.

Preferably said movement device comprises a plurality of movement elements intended to interact with distinct flank portions of said blanks.

Preferably said movement elements are distinct from said retaining elements. Said movement elements and said retaining elements are actuatable independently of each other.

The movement elements are intended to interact with the blanks to move them along the movement direction and to follow this movement along the movement direction.

The retaining elements are configured to abut the advanced blank so as to counteract a displacement of the same along the movement direction.

This allows to improve the movement of the blanks and their retention. This also makes it possible to improve the adjustment made with the adjusting device. Preferably, said operating device is provided with an operating element for operating the movement speed of at least one of said movement elements.

Preferably, said operating device is provided with a plurality of operating elements for operating the movement speed of each movement element of said plurality of movement elements.

In one version said feeding unit comprises a further movement device, placed upstream with respect to said movement device in the movement direction of said stack.

Preferably said further movement device is actuated at a further movement speed different from said movement speed of said movement device. Preferably, said further movement speed is lower than said movement speed, to a most preferred extent said further movement speed is slightly lower than said movement speed.

Preferably, said further movement device comprises a further plurality of movement elements intended to interact with distinct flank portions of said blanks.

Preferably, said plurality of movement elements and/or said further plurality of movement elements comprises an upper movement element and a lower movement device which are intended to interact respectively with an upper flank and a lower flank of said blanks.

The lower movement device comprises a first and a second lower movement element.

Preferably said plurality of movement devices comprises at least a first and a second lateral movement device which are intended to interact with opposed lateral flank portions of said blanks.

Preferably, each lateral movement device comprises a first and a second lateral movement element which are intended to interact with distinct lateral flank portions of said blanks.

Preferably at least one movement element of said plurality of movement elements and/or of said further plurality of movement elements comprises a belt movement element.

Preferably each lateral movement element comprises a belt movement element.

The belt movement member extends in a direction parallel to the movement direction of the stack while engaging a plurality of blanks of the stack of blanks. This allows to improve the movement of the blanks of the stack of blanks allowing a more precise positioning of the blanks. In particular, the positioning of the advanced blank at the outlet section is improved.

Preferably at least one movement clement of said plurality of movement elements and/or of said further plurality of movement elements comprises a wheeled movement clement, preferably a toothed wheel.

Preferably, a single operating device for operating the movement speed of said movement elements is provided.

In this way, the movement elements of said plurality of movement elements are operating simultaneously. This simplifies the operation of the feeding unit.

Preferably, a plurality of operating elements is provided, each operating element of said plurality of operating elements being intended to operate the movement speed of a movement element. In this way, the movement elements are operated independently of each other and the operation of the feeding unit is optimized.

Preferably said control unit comprises a control device operatively connected to said operating device for adjusting the movement speed of at least one movement element of said movement device.

The control unit preferably comprises processing elements intended to receive a signal relative to the pressure detected by the pressure sensor and to process a corresponding actuation signal for the control device to vary the movement speed of at least one movement element of said movement device based on the pressure detected by said pressure sensor.

Preferably said control unit comprises a plurality of control elements operatively connected to each adjusting element so as to actuate each adjusting element to displace a corresponding displaceable retaining element.

Preferably said control elements are configured to position said automatically displaceable retaining elements on the retention plane of the advanced blank.

Preferably, the feeding unit comprises a setting device for setting the position of one or more of the movement devices based on the dimensions and the shape of the blanks of the stack to be moved.

Preferably said feeding unit comprises a control unit comprising a control element operatively connected to the adjusting device for actuating the adjusting device to displace said at least one retaining element.

The control unit preferably comprises processing elements intended to receive the signal relative to the pressure detected by the pressure sensor and to process a corresponding actuation signal for the control element to actuate the adjusting device.

Preferably said control unit comprises operating elements operatively connected to the adjusting device so as to actuate the adjusting device to displace the at least one retaining element and/or the at least one further retaining element based on the pressure detected by said pressure sensor.

The control unit preferably comprises processing elements intended to receive the signal relative to the pressure detected by the pressure sensor and to process a corresponding actuation signal for the control element to actuate the adjusting device.

In some embodiments, said control unit is configured to emit an alarm signal if the pressure detected by said pressure sensor is outside a desired pressure range.

Preferably said alarm signal is an audible or visual signal.

In some embodiments, said control unit is configured to block said movement device if the pressure detected by said pressure sensor is outside a further desired pressure range.

Preferably said adjusting comprises translating said at least one retaining element to vary the position of said at least one retaining element with respect to said advanced blank.

Preferably said adjusting comprises translating said at least one further retaining clement to vary the position of said at least one further retaining element with respect to said blank.

Preferably said adjusting comprises oscillating said at least one further retaining clement about a rotation axis perpendicular to said movement direction.

Preferably said adjusting comprises displacing said at least one retaining element along a displacement direction parallel to the movement direction.

Preferably said adjusting comprises displacing said at least one further retaining clement along a displacement direction parallel to the movement direction.

Preferably said adjusting further comprises displacing said at least one retaining clement along a displacement direction transverse to the movement direction to vary the position of said at least one retaining element with respect to said advanced blank.

Preferably said adjusting further comprises displacing said at least one further retaining clement along a displacement direction transverse to the movement direction to vary the position of said at least one further retaining element on said advanced blank.

Preferably said retaining comprises retaining said advanced blank at least at one edge portion of said advanced blank.

Preferably said adjusting further comprises displacing said at least one retaining clement along a displacement direction transverse to the movement direction along an edge portion of said advanced blank to vary the position of said at least one retaining clement on the advanced blank.

Preferably said adjusting further comprises displacing said at least one further retaining element along a displacement direction transverse to the movement direction along an edge portion of said advanced blank to vary the position of said at least one further retaining element on the advanced blank.

Preferably said adjusting further comprises displacing said at least one retaining element along a displacement direction transverse to the movement direction transversally to the edge portion to vary the interference of said at least one retaining element with the advanced blank.

Preferably said adjusting further comprises displacing said at least one further retaining element along a displacement direction transverse to the movement direction transversally to the edge portion to vary the interference of said at least one further retaining element with the advanced blank.

Preferably said adjusting comprises oscillating said at least one retaining element around a rotation axis positioned perpendicularly to said movement direction.

Preferably said adjusting comprises oscillating said at least one further retaining element around a rotation axis positioned perpendicularly to said movement direction.

Preferably said adjusting independently comprises adjusting each retaining element of said plurality of retaining elements.

This improves the retention of the blank, allowing an optimal adjustment of the position of the individual retaining elements.

Preferably said method comprises moving said stack along said movement direction by means of at least one movement device.

Preferably said operating comprises varying the movement speed of said at least one movement device to vary the movement speed of said stack along said movement direction.

Preferably said adjusting is provided during said movement.

Preferably said adjusting and said varying are performed independently of each other.

Preferably said adjusting comprises positioning said at least one retaining element so that the pressure exerted on said at least one retaining element and said at least one further retaining element is substantially the same.

Preferably said adjusting comprises positioning said at least one further retaining element so that the pressure exerted on said at least one retaining element and said at least one further retaining element is substantially the same.

Preferably said adjusting comprises positioning said at least one retaining element and/or said at least one further retaining element so that they are positioned on the same plane, identified as a retention plane of said advanced blank.

Preferably said movement device comprises moving said stack along said movement direction at a first movement speed by means of a movement device and further moving said stack along said movement direction at a second movement speed different from said first movement speed by means of a further movement device placed upstream of said movement device. Preferably said first movement speed is greater than said second movement speed, to a most preferred extent said first movement speed is slightly greater than said second movement speed.

It should be specified that some steps of the method described above may be independent of the order of execution reported. In addition, some steps may be optional. In addition, some steps of the method may be performed repetitively, or they may be performed in series or in parallel with other steps of the method.

The features and the advantages of the present solution will become clearer from the detailed description of an embodiment thereof, illustrated by way of non-limiting example, with reference to the appended drawings in which:

FIG. 1 is a schematic perspective view of an embodiment example of a blanks feeding unit in accordance with the present solution;

FIG. 2 is a view of the feeding unit of FIG. 1 without blanks;

FIG. 3 is a further enlarged perspective view of the feeding unit of FIG. 1 provided with a blank;

FIG. 4 is an enlarged view of a detail of the feeding unit of FIG. 2;

FIG. 5A and 5B are respectively an enlarged perspective and sectional view of the detail of FIG. 4;

FIG. 6 is a schematic sectional figure of a blank usable in the feeding unit of FIG. 1.

In the appended Figures, a blanks feeding unit 7 made in accordance with the present solution is indicated as a whole with 100. The feeding unit 100 is preferably used in an apparatus for packaging boxed articles, or in general in forming apparatus in which it is provided to form a box by folding a blank. In a preferred version, the feeding unit is to be used in a packaging apparatus of the “wrap-around” type, performing the packaging by folding a blank around an article to be packaged so as to form a box containing the article.

The feeding unit 100 comprises a ground support frame 5 and a loading hopper 1, or other storage device, intended to receive and contain a stack of blanks 7 and a movement device 2 intended to move the stack of blanks 7 along a movement direction F towards an outlet section 3 of the loading hopper 1.

In the attached figures, a single blank is shown for clarity's sake, i.e. the advanced blank 7 of the stack of blanks, i.e. the blank positioned at the outlet section 3 of the loading hopper 1.

The loading hopper 1 can be made in ways known in the sector and, therefore, will not be described in greater detail below. In the version shown, the loading hopper 1 is configured so that the movement direction F is parallel to a horizontal axis Y, however, in other versions, the blanks can be moved along a movement direction parallel to a vertical axis or also along a movement direction transverse to both the horizontal and vertical axis.

Each blank 7, better visible in FIG. 6, is made of cardstock and has two opposed substantially planar faces S having substantially larger dimensions than the dimensions of the thickness of the blank. The blank is positioned in the stack so that one face, defined as the advanced face, is directed towards the outlet section of the storage device, and an opposed face, defined as the backward face, faces away from the outlet section of the storage device.

The blank 7 has a substantially quadrangular shape, delimited by two opposed lateral flanks 12, 13, a lower flank 11 and an upper flank 14. The flanks of the blank can be defined as a plurality of non-continuous portions, in particular the lateral flanks are defined by distinct flank portions of distinct lateral panels, as better clarified below.

The terms lower and upper refer to the embodiment described below and, in particular, depend on the positioning of the blank in the loading hopper 1, however, it is evident that this distinction has a purely conventional character.

The blank 7 has a thickness comprised between 0.4 and 0.8 mm, in this case about 0.5 mm, and is suitably shaped to form a box when suitably folded. For this purpose, a plurality of folding lines 70 are obtained on the blank 7 which divide the blank 7 into a plurality of panels intended to form, alone or in combination with each other, the different faces of the box. The folding lines 70 are preferably creases and each pair of adjacent panels is oscillatable about a respective folding line 70 separating them. In particular, a plurality of central panels, a first plurality of lateral panels and a second plurality of lateral panels are identified in the blank 7. The panels of the first and second plurality of lateral panels are positioned on opposite laterals with respect to the central panels. The number and the shape of the panels of the blank depend on the shape and on the dimensions of the box to be formed.

The plurality of central panels comprises an intermediate panel 7C, a first and a second panel 7A, 7B respectively extended on two opposed sides of the intermediate panel 7C, a lower panel 7D positioned so that the first panel 7A is interposed between the upper panel 7D and the intermediate panel 7C, and a lower panel 7E positioned so that the second panel 7B is interposed between the lower panel 7E and the intermediate panel 7C.

Each plurality of lateral panels comprises, in the version shown, the same number of panels whereby only one will be described in detail, and the corresponding panels will be indicated with the same numerical references.

Each plurality of lateral panels comprises a first lateral panel 71, placed at the upper panel 7D, a second lateral panel 72, placed at the first panel 7A, a third lateral panel 73 placed at the intermediate panel 7C and a fourth lateral panel 74, placed at the second panel 7B.

The lateral panels can have different dimensions from each other, both in length and width, these dimensions depending on the shape and on the dimensions of the various faces of the box to be formed.

Each lateral panel 71-74 has a width, indicated as the extension of each lateral panel 71-74 from the folding line 70 with the corresponding central panel 7A-7D, which depends on the dimensions of the box to be formed. In the version shown, the second lateral panel 72 and the fourth lateral panel 74, i.e. the lateral panels placed at the first panel 7A and the second panel 7B, have the same width “L” which is greater than the width “L1” of the first 71 and the third lateral panel 73. In general, the lateral panels can each have a different width from each other. The outer edges of the lateral panels, i.e. the edges opposed to the respective central panel, define the respective lateral flanks 12, 13 of the blank.

The lower flank 11 is provided at the lower panel 7E, the upper flank 14 is provided at the upper panel 7D and the lateral flanks 12, 13 at the lateral panels 71-74.

The stack of blanks is formed by a plurality of blanks 7 flanked one another so that the faces S of two adjacent blanks face each other. In particular, the backward face of a blank is adjacent to the advanced face of the flanked blank.

The movement device 2 moves the stack of blanks 7 along the movement direction F so that the various blanks of the stack 10 are subsequently brought at the outlet section 3 of the loading hopper 1. At each instant, therefore, an advanced blank 7 is identified in the loading hopper 1, and shown in FIGS. 1 and 3 defined as the blank of the stack 10 of blanks closest to the outlet section 3 and intended to be picked up by the loading hopper 1 by means of a handling unit not shown in the Figures.

In the version shown, the movement device 2 comprises a plurality of conveyor belts intended to move and guide the blanks towards the outlet section 3, however in other versions not shown other movement devices known in the sector and suitable for moving blanks can be used. In particular, in the version shown, the movement device 2 comprises a pair of lower conveyor belts 21 intended to engage the lower flank 11 of the blanks 7, a first 23 and a second lateral conveyor belt 24 intended to engage opposed lateral flanks 12, 13 of the blanks 7 and at least one upper conveyor belt, not shown in the Figures, intended to engage the upper flank 14 of the blanks 7.

The two lower conveyor belts 21 define the movement plane for the blanks 7.

In the version shown, considering a Cartesian reference system, in which the axis Z defines a vertical axis, the movement plane of the blanks is a horizontal plane XY and the movement direction F is a horizontal direction parallel to the axis Y.

The feeding unit 1 further comprises a plurality of retaining elements 50 provided at the outlet section 3 of the loading hopper 1 and intended to abut the advanced blank 7 to retain it in the feeding unit 1 and prevent accidental falls thereof. The retaining elements of the plurality of retaining elements 50 are intended to abut the advanced blank 7 at portions of the advanced face S suitably positioned on the advanced blank 7, as better clarified below.

In the version shown, the plurality of retaining elements 50 comprises a lower retaining element 51, intended to retain the advanced blank 7 at an edge portion of the lower flank 11, an upper retaining element 52, intended to retain the advanced blank 7 at an edge portion of the upper flank 14 and two pairs of lateral retaining elements intended to abut respectively the lateral flanks 12, 13 of the advanced blank 7. The retaining elements of the plurality of retaining elements 50 are configured to project onto the advanced face S of the advanced blank 7.

Each pair of lateral retaining elements comprises a first lateral retaining element 53 and a second lateral retaining element 54 spaced apart from each other along the vertical axis Z. According to the present solution, the first lateral retaining element 53 and the second lateral retaining element 54 are positioned so as to engage distinct lateral panels of the advanced blank 7.

In the version shown, the first lateral retaining element 53 and the second lateral retaining element 54 are intended to abut respective edge portions respectively of the second lateral panel 72 and of the fourth lateral panel 74 of the first and second plurality of lateral panels.

In the version shown, the lower 51, upper 52 retaining elements and the second lateral retaining elements 54 of the plurality of retaining elements 50 are structurally and functionally similar, whereby only one will be described in detail, indicating any differences subsequently.

With specific reference to FIGS. 4, 5A-5B, each retaining element 51, 52, 54 comprises a body 55 provided with a plate 56 on which the blanks 7 slide, a plate 58 from which a retaining appendage 57, arranged perpendicularly to the plate 56, protrudes and intended to abut and retain the advanced blank 7 in a respective edge portion to retain it in the feeding unit 100. The retaining appendage 57 is made integrally with the plate 58, or fixed thereto.

The plate 58 is displaceable with respect to the plate 56 in both directions of a displacement direction F2, indicated in FIG. 5B, as better explained below.

The lower 51, the upper 52 retaining element and the second lateral retaining elements 54 are each provided with a single retaining appendage which is shaped as a tooth 57 protruding from the corresponding plate 56.

Inside the body 55 there is provided a pressure sensor 30 operatively connected to the tooth 57 and intended to detect the pressure exerted on the tooth 57 by the advanced blank 7.

Inside the body 55 there is also provided an adjusting device 40 operatively connected to the pressure sensor 30 and intended to adjust the position of the plate 58 of the corresponding retaining element based on the pressure detected by the pressure sensor 30.

The pressure sensor 30 comprises a hinging body 30A hinged at the pin 34 to the body 55 of the retaining element and a stem 31 extended between opposed longitudinal ends 31A, 31B. The first longitudinal end 31A of the stem 31 is fixed to the hinging body 30a, while the second longitudinal end 31B is free.

The pressure sensor 30 also comprises an end stroke element 33 having two opposed walls 33A, 33B defining a seat inside which the second longitudinal end 31B of the stem 31 is displaceable.

The adjusting device 40 comprises a pushing element 42 fixed to the stem 31 in an intermediate position between the two longitudinal ends 31A-31B and provided with a spring 32.

As the pressure exerted by the advanced blank 7 on the retaining appendage 57 increases, the latter is pushed with greater force away from the plate 56, in the direction indicated by the arrow F′ in FIG. 5B. This causes a rotation of the hinging body 30A about the pin 34 counterclockwise. Following this rotation, the free end 31B of the stem 31 rotates counterclockwise until it abuts against a wall 33A of the end stroke element 33 and the stem 31 exerts a greater thrust force on the spring 32.

This variation in the force exerted by the spring 32 is detected and the adjusting device 40 can act by displacing the plate 58 away from the plate 56 in the direction indicated by the arrow F′.

In this way the pressure exerted by the advanced blank 7 on the retaining appendage 57 is brought back to a desired range.

The adjusting device 40, therefore, moves the plate 58, and in particular the retaining appendage 57, based on the pressure detected by the pressure sensor 30. Preferably, the adjusting device is configured to move the retaining appendage 57 so as to bring the pressure back within a desired range.

Preferably the pressure range is comprised between about 0.1 g/mm² and about 10 g/mm², preferably between about 0.2 g/mm² and about 5 g/mm².

In particular, in the version shown, the adjusting device 40 allows the plate 58 to be displaced in both directions in a displacement direction F2 parallel to the movement direction F so as to increase/decrease the pressure exerted by the advanced blank 7 on the retaining element 51-54. The adjusting device 40 can move the retaining element 51-54 in a direction concordant to the movement direction F to reduce the pressure exerted on the retaining element or vice versa exerted on the retaining element in a direction contrary to the movement direction F to increase the pressure exerted on the retaining element and retain, for example more firmly, the advanced blank 7.

Each first lateral retaining element 53 is provided with a plurality of retaining appendages 57A mutually spaced along the vertical axis Z. The provision of a plurality of retaining appendages 57A allows to improve the grip of the blanks even of different dimensions from each other.

Each retaining appendage 57A of the first lateral retaining elements 53 is shaped as a lamina 57A having a width comprised between about 5 mm and about 30 mm, preferably between about 12 mm and about 17 mm.

Apart from the differences indicated above, the structure and the operation of the lateral retaining elements 53 is similar to the structure and to the operation of the other retaining elements and will not be described in detail.

In other versions, the retaining appendages of the retaining elements 51-54 can be displaced along a second displacement direction perpendicular to the movement direction F, for example to vary the engagement position of the retaining element 51-54 with the advanced blank 7, or to vary the interference of the retaining element with the advanced blank 7.

The retaining elements 51-54 may be displaced along the edge portion of the advanced blank 7 on which the retaining elements 51-54 are engaged. This makes it possible to improve the grip of the advanced blank 7 by positioning the retaining elements in a suitable position even in case of deformations of the advanced blank or of irregularly shaped blanks.

The retaining elements can be displaced transversely with respect to the edge portion on which they are engaged. This makes it possible to optimize the grip of the advanced blank even in case of variations in shape or dimensions of the same.

In a version not shown, the adjusting device is configured to oscillate the retaining element along an oscillation axis perpendicular to the movement direction.

In this way, it is possible to move the retaining appendage away from/towards the advanced blank by reducing/increasing the pressure exerted between the advanced blank and the retaining element.

In some versions of the feeding unit not shown in the Figures, automatically displaceable retaining elements and manually displaceable retaining elements may be provided.

The manually displaceable retaining elements can be used as reference elements to adjust the position of the automatically displaceable retaining elements.

The retaining elements 51-54 are configured so as to be positioned on a same plane defined as the retention plane of the advanced blank.

Preferably said retention plane is perpendicular to the movement direction F of the blanks.

In one version, the pressure sensors can be operatively connected to a single control unit that takes care of displacing one or more retaining elements through a corresponding adjusting device.

The feeding unit is also provided with an operating clement not shown in the Figures for operating the movement speed of one or more of the movement elements.

The adjusting device and the operating clement are independent of each other so that the retaining elements can be displaced in a released and independent manner from the movement elements. This allows the retaining elements to be displaced, if desired, while the movement elements are in operation without interfering with the movement elements and, therefore, without interfering with the movement of the blanks. Similarly, varying the movement speed of one or more of the movement elements does not affect the position of the retaining elements.

In a version not shown the feeding unit is provided with a control unit operatively associated with the retaining elements to vary the position of the retaining elements.

In one version the control unit is operatively associated with the movement elements to vary the speed and/or the position of the movement elements.

The feeding unit 100 operates according to the following manners.

First of all, a stack of blanks is loaded into the loading hopper 1 and the blanks 7 are moved along the movement direction F by means of the movement device. The feeding unit 100 is arranged to move the blanks 7 along the movement direction F up to an outlet section 3 of the loading hopper 1, so that the advanced blank 7 can be picked up by a blank handling unit, not shown in the Figures. The handling unit is provided with gripping elements intended to engage the advanced blank 7 to pick it up from the loading hopper 1 and transport it towards subsequent processing units, such as, for example, a blank folding unit. The handling unit can be displaced by means of suitable movement mechanisms so as to be brought at the outlet section 3 of the loading hopper 1 so that the gripping elements can engage the advanced blank 7.

After the gripping elements of the handling unit have grasped the advanced blank, the handling unit is moved away from the feeding unit to disengage the advanced blank 7 from the retaining elements 51-54 and hence from the feeding unit. The movement mechanism of the handling unit can be chosen based on process requirements, any movement mechanism used in the sector can be used.

When the pressure exerted by the advanced blank 7 on a retaining element 51-54 and in particular on its retaining appendage is outside a predetermined pressure range, the adjusting device provides for displacing one or more retaining elements, for example along a displacement direction parallel to the movement direction so as to restore the desired pressure.

If the detected pressure is less than the desired range, the advanced blank may not be effectively retained and, therefore, fall or be displaced. Conversely, if the pressure exerted on the retaining element was excessive, it would become difficult to remove the advanced blank from the feeding unit. In this case, tears of the advanced blank could occur, especially at the retaining element on which there is a high pressure.

By displacing the retaining elements it is possible to restore the desired pressure.

This adjustment does not interfere with the operation of the feeding unit and there is no need to interrupt or slow down the operation of the feeding unit itself. Moreover, thanks to the invention, such adjustment can be carried out automatically without the intervention of the operator, greatly simplifying the adjustment operations.

In addition, by acting on the retaining element, the adjustment efficiency is optimized because the interaction between the advanced blank and the retaining element is immediately adjusted. This greatly limits or eliminates the possibility of a blank being torn during the picking with the handling unit.