Patent ID: 12234116

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION

With reference to the accompanying drawings, the numeral1denotes a depalletizing machine for picking up and moving groups of articles S, specifically bundles of blanks, comprising a containing structure2internally provided with at least one receiving area3for a movable magazine M containing one or more groups of articles S, specifically bundles of blanks.

The machine1according to the invention is especially designed for moving groups of blanks intended for making three-dimensional containers, especially packages for loose products for the coffee market: for example, capsules or pods. More generally speaking, the invention is applicable to the production of containers for the following sectors: food, absorbent products, ceramic ware, tobacco and pharmaceutical industries, fine quality boxes or standard boxes intended to be sold empty.

Also, the term “blanks” is used to mean pieces of foldable material—for example, cardboard, cellulose, plastic or other materials—obtained by blanking or other similar process applied to a sheet or continuous web.

Preferably, as shown inFIG.4, the receiving area3is configured to contain a vertical magazine comprising an automatic, self-propelled trolley M1, on which a plurality of vertical supports M2are mounted to define one or more containing channels in which the groups of articles S are supported from below by specific supporting means M3which allow them to be stacked one above the other at a predetermined spacing.

To allow the magazine M to be inserted into the receiving area3and to remove the magazine M from the receiving area3after the groups of articles S have been picked up, the depalletizing machine1also comprises at least one access opening4.

In the embodiment illustrated in the accompanying drawings, the containing structure2is internally provided with a plurality of receiving areas3, each having respective independent access openings4for receiving respective movable magazines M. In the specific embodiment, the receiving areas3are aligned along a predominant direction of extension of the machine1; they might, however, be disposed in other configurations, not illustrated.

Preferably, the access openings4of the receiving areas3are each provided with a door, shown inFIG.1, openable independently of the others to allow a respective movable magazine M in and out. Preferably, the door may be a roll-up door or, alternatively, it may be of a type that opens by pivoting about a horizontal axis.

The depalletizing machine1may also comprise a collection zone5configured for receiving a succession of groups of articles S from the movable magazine M located in a respective receiving area3and for moving the groups of articles S towards the outside of the machine1and/or towards a processing station.

In the embodiment illustrated inFIG.2, the collection zone5is in the form of a belt conveyor or other straight conveyor with a top surface that moves in translation.

The collection zone5might be positioned adjacent to one of the receiving areas3or it might be made differently—for example, positioned at the bottom of the receiving areas3, running along the predominant direction of extension of the machine1. Furthermore, there might be a plurality of collection zones5, for example, one for each receiving area3.

Each receiving area3is preferably delimited at the side and the back by respective walls3a,3bor separator elements. Further, the receiving areas3are each provided with a pair of sensors (not illustrated) located laterally relative to the ingoing direction of the magazine M into the receiving area3through the access opening4. Preferably, the sensors are located on the side walls3aof each receiving area3, possibly also on the bottom wall3b.

The groups of articles S are moved from the magazines M to the collection zone5by means of at least one pickup head7which is movable in an upper portion of the containing structure2according to a predetermined law of motion, implemented in particular by a control unit (not illustrated). Preferably, there is only one pickup head7, shared by all the receiving areas3. However, in a variant embodiment in which there are a plurality of collection zones5or in which each receiving area3is associated with its own collection zone5, there may be one pickup head7for each receiving area3and/or for each collection zone5.

More in detail, the control unit is configured to receive from the sensors information relating to the position of the magazines M, specifically the lateral position (and, if necessary, also the longitudinal position) within the receiving areas3and to process the information to generate a suitable law of motion for the pickup head7.

Preferably, the control unit is configured for setting the predetermined law of motion for the pickup head7according to an open loop logic whereby the control unit determines a final spatial position to be assigned to the pickup head7when picking up at least one group of articles S from the movable magazine M.

More specifically, the control unit determines the spatial position to be assigned to the pickup head7as a function of the information it receives from the sensors regarding the position of the movable magazines M.

Advantageously, the possibility of varying the law of motion of the pickup head7based on the position of the magazines M in the receiving areas3allows speeding up the entire process of picking up the groups of articles S, by making it possible to prevent wasting time in unnecessary movements of the pickup head7and to simplify the process and make it economically advantageous.

Operatively, therefore, one or more movable magazines M containing groups of articles S stacked one above the other are inserted into respective receiving areas3. In each receiving area3, the sensors detect the lateral position of the magazine M and transmit the information to the control unit, which sets a predetermined law of motion for the pickup head7as a function of that information.

Preferably, the control unit can plan the law of motion for the pickup head7also taking into account the user's specific needs such as, for example, preferences relating to the orientation the groups of articles S should have when they are released into the collection area5or preferences relating to the order in which they are picked up in the different receiving areas3.

Once the law of motion has been processed, the pickup head7is moved between the magazines M of the different receiving areas3in such a way as to pick up the groups of articles S according to the predetermined order set by the control unit.

Preferably, the pickup head7is moved in translation along two horizontal axes X, Y, transverse to each other—defined, for example, by a gantry structure—until it is positioned above the magazine M.

Preferably, where necessary, the pickup head7is also rotated about a vertical axis Z, perpendicular to the two horizontal axes X, Y, if its orientation is not compatible with the orientation of the group of articles S to be picked up. More specifically, the rotation may be correlated with the way the groups of articles S are arranged in the magazine M, for example, in the case where the magazine M contains two or more stacks of groups of articles in which the articles of one stack are positioned at 90° or 180° relative to the articles of another stack.

Next, the pickup head7is lowered along the vertical axis Z towards the magazine M below to reach the level where the groups of articles S to be picked up are located.

To perform the pickup operation, the pickup head7comprises at least a first pair of facing pickup elements7a,7band a second pair of facing pickup elements7c,7dacting in conjunction with the pickup elements of the first pair7a,7bto engage an underside surface of the groups of articles S to be picked up from the movable magazine M in such a way as to support the groups of articles S as they are being moved from the movable magazine M to the collection area5.

In this situation, each of the pickup elements7a,7b,7c,7dis inserted into the vertical space between the group of articles S to be picked up and the group of articles S below it so that the group of articles S to be picked up can be lifted out along the containing channel of the magazine M.

Preferably, during pickup operations, to prevent impacts and/or jams between the pickup elements7a,7b,7c,7dand the structure of the magazine M, the magazine M is configured in such a way that the supporting means M3adopt a retracted position, specifically a recessed position within the vertical supports M2after the passing of an underlying group of articles S during a step of extracting. More specifically, while a group of articles S is being picked up, it strikes the supporting means M3just above it, causing them to move to the recessed position.

Advantageously, the movability of the supporting means M3prevents the pickup elements7a,7b,7c,7dof the pickup head7from being interfered with by the supporting means M3, now free of the groups of articles S.

To get a hold of the group of articles, the pickup head7, as shown inFIG.5A, also comprises a retractor mechanism9operating between the pickup elements7a,7b,7c,7dof each pair, so as to move the pickup elements7a,7b,7c,7dof each pair according to an adjustment movement towards and away from each other along a first direction of movement. In an embodiment not illustrated, the two pairs of pickup elements7a,7b,7c,7dmay define two distinct directions of non-parallel movements.

Preferably, the two pickup elements7a,7b,7c,7dof each pair are adjustable independently of the pickup elements7a,7b,7c,7dof the other pair.

Preferably, as shown inFIGS.5A and5B, the pickup elements7a,7b,7c,7deach comprise a supporting bar10, preferably vertical, connected at the top to the retractor mechanism9and having, at the bottom, a horizontal lifting finger11designed to be inserted under a group of articles S to be picked up.

Preferably, the pickup elements7a,7b,7c,7deach have the shape of a C, oriented in such a way that the concavities of the two pickup elements7a,7b,7c,7dof each pair face each other. Still more preferably, in the pickup elements7a,7b,7c,7dof one of the pairs, the concavity is deeper than it is in the pickup elements7a,7b,7c,7dof the other pair, so as to engage a wider portion of the groups of articles S.

In use, therefore, once the pickup head7has reached a position above the magazine M (or alternatively, before or while reaching the positon above the magazine M) shown, for example, inFIG.6, the pickup elements7a,7b,7c,7dare moved away from each other to allow the pickup head7to move down along the magazine until it reaches the level where the group of article S to be picked up is located. Preferably, as the pickup head7moves down, the pickup elements7a,7b,7c,7dare retracted in such a way as to occupy a position on the outside of the channel defined by the vertical supports M2of the magazine M.

The pickup elements7a,7b,7c,7dare then moved back towards each other so that the respective lifting fingers11are inserted under the group of articles S to be picked up.

In the embodiment illustrated in the accompanying drawings, the pickup elements7a,7bof the first pair make a movement towards each other that is smaller than the movement towards each other made by the pickup elements7c,7dof the second pair. In effect, in the embodiment illustrated in the accompanying drawings, the cross sectional plan shape of the groups of articles S to be picked up is substantially like a cross in which the pickup elements7a,7bof the first pair support a portion of the group of articles that is less wide than the portion supported by the pickup elements7c,7dof the second pair.

Advantageously, adjusting the pairs of pickup elements7a,7b,7c,7dindependently of each other allows the pickup head7to engage groups of articles S having a cross section of any shape.

Furthermore, adjusting the pairs of pickup elements7a,7b,7c,7dindependently of each other allows supporting the groups of articles S at specific points of their cross section, such as, for example, the points most subject to bending or points having particularly complex shapes.

To make the pickup head7even more versatile in terms of the size and/or shape of the groups of articles S to be picked up, the pickup head7is also provided with a spacing mechanism12for adjusting the distance between the pickup elements7a,7bof the first pair and the pickup elements7c,7dof the second pair.

More specifically, this adjustment is along a second direction of movement, transverse, preferably perpendicular, to the first direction of movement. Preferably, one of the pairs of pickup elements7a,7b,7c,7dis fixed along the second direction of movement (that is, fixed to the load-bearing structure of the pickup head7), while the other pair of pickup elements7a,7b,7c,7dis movable.

Advantageously, this adjustment mechanism12makes the pickup head7more adaptable to groups of articles S of any type.

Preferably, the pickup head7also comprises a downwardly facing sensor, not illustrated (for example, an analogue sensor) configured to scan an area under the pickup head7to check for the presence of the magazine M and/or the presence of the group of articles on the magazine M. That way, the pickup head7can be moved at a higher speed when the pickup head7is far from the groups of articles (rapid approach movement) and slowed down only when it is near the groups of articles (gripping movement). This feature also makes the pickup head7capable of automatically detecting the height at which the top group of articles in the magazine M is located, which may vary according to how full the magazine M is, and for optimizing process times while working in conditions of utmost safety.

This also allows checking for the presence/absence of the groups (magazine/channel loaded or empty), and to check (by continuous monitoring) for the presence of the group of articles picked up during transfer from the magazine to the collection zone (to ensure that no load has been lost in transit (and preferably generating an alarm signal if there has).

To make the most of the versatility and flexibility of the pickup head7and to further maximize the process of picking up the groups of articles S from the movable magazines M, the machine1also comprises control mechanisms for controlling the position of the movable magazines M in the receiving areas3.

To enable the movable magazines M to adopt a predetermined position inside the respective receiving area3so that the pickup head7can operate precisely, the control unit is configured to disable the movement of the pickup head7and preferably to generate an alarm signal when the information regarding the position of the movable magazine M indicates that the movable magazine M is at a position that is outside a predetermined tolerance.

More in detail, the signal indicating that the magazine M is incorrectly positioned relative to the predetermined tolerance comes from the sensors mounted in each receiving area3.

The sensors are preferably optical sensors and are configured to measure a distance between the movable magazine M and a respective side wall3adelimiting the receiving area3. If these distances fall within the predetermined tolerance, the pickup head7is operated normally so it picks up the group of articles S from the magazine M and moves it towards the collection area5according to the method described above. On the other hand, if the distances are outside the predetermined tolerance, the pickup head7is not moved and the movable magazine M is repositioned manually by an operator or automatically.

Preferably, the movable magazine M is moved back into a position within the receiving area3manually if it is outside the tolerance by a long way.

Instead, if the position adopted by the magazine differs only a little from the correct position, it is repositioned automatically or locked at its position by activating push bars which are configured to engage the side of the magazine M, specifically to push the magazine M towards or away from the side walls3aof the receiving area3, or to lock the side of the magazine M in position, respectively.

The machine1may also comprise at least one proximity sensor (not illustrated) mounted in a bottom wall3bdelimiting the receiving area3and configured to issue a signal when the movable magazine M is at a predetermined distance from the bottom wall3b.

Advantageously, the proximity sensor prevents the magazine from being pushed too far into the receiving area3and making it difficult or even impossible for the pickup head7to carry out pickup operations.

In another embodiment, alternatively to the bottom sensor, the receiving area3comprises a mechanical stop member which stops the trolley M1of the magazine M when it reaches the end of its stroke in the receiving area3.

In use, therefore, when the magazine M is placed inside the receiving area3, the sensors are activated in order to detect whether or not the position of the movable magazine M falls within a predetermined tolerance. If it does, the information regarding the position of the magazine M is sent to the control unit so it can process the law of motion for the pickup head7and adjust the pickup elements7a,7b,7c,7d. If it doesn't, on the other hand, the magazine M is repositioned within the receiving area3manually or automatically.

Advantageously, thanks to the sensors mounted in the receiving areas3, the pickup head7does not make unnecessary movements towards receiving areas3whose magazines M are badly positioned and from which it would be unable to pick up the groups of articles S they contain.

Advantageously, pickup cycle times are considerably reduced because while one magazine M is being moved to the correct position inside a receiving area3, another magazine M may be emptied by the pickup head7without having to stop the machine.

To prevent the movable magazine M from moving after it has adopted the predetermined position, the machine1also comprises a retaining device, located inside each receiving area3and configured to lock the movable magazine M at that position in the receiving area3.

As shown inFIGS.3A and3B, the retaining device comprises a first pushing element8aand a second pushing element8b, located on opposite sides3aof the receiving area3and movable relative to each other between an active position and a withdrawn position.

At the active position, the first and second pushing elements8a,8bextend towards the centre of the receiving area3and engage respective side portions of the movable magazine M to prevent the magazine from moving further.

At the rest position, on the other hand, the first and second pushing elements8a,8badopt a withdrawn position and are disengaged from the respective side portions of the movable magazine M to allow the movable magazine M in and out of the receiving area3.

Operatively, the first and second pushing elements8a,8bare activated by the control unit after the position of the magazine M in the receiving area3has been detected by the first and the second sensor.

However, if the first and second sensors detect that the magazine M is badly positioned, the control unit disables the movements of the first and second pushing elements8a,8band preferably generates an alarm signal.

In the preferred embodiment, if the incorrect position of the magazine M differs just a little from a predetermined tolerance, the control unit nevertheless moves the first and second pushing elements8a,8bfrom the rest position to the active position in order to correct the position of the movable magazine by a pushing action of the first and/or the second pushing element8a,8bon the trolley M1of the magazine M.

In other words, in the embodiment illustrated in the accompanying drawings, if the magazine M is badly positioned, repositioning is carried out automatically by the first and the second pushing element8a,8bimparting a sideways push on the trolley M1of the movable magazine M so that the distances between the magazine M and the side walls3aof the receiving area3are all the same or, in any case, within a predetermined range of values. In this situation, the first and the second pushing element8a,8bimpact against the trolley M1of the magazine M to correct its position within the receiving area3and then lock the magazine M at the predetermined position.

In the embodiment shown in the accompanying drawings, the first and the second pushing element8a,8bcomprise articulated pantograph arms which, at the withdrawn position, are preferably fully recessed in the side wall3aof the receiving area3.

In another embodiment not illustrated, the first and second pushing elements8a,8bcomprise push bars.

The invention achieves the above-mentioned aims by eliminating the drawbacks of the prior art.

The presence of two or more receiving areas allows the pickup head to work on one magazine while another is being fed.

The pickup point of the pickup head changes according to the receiving area, leaving other parts of the machine unencumbered.

As each group of blanks is withdrawn from the magazine, access to those below is made possible.

The possibility of controlling the law of motion of the pickup head7optimizes the machine and makes it fast and able to avoid “wasted” movements, that is, movements in which no group of articles S is picked up from the magazines M.

The presence of sensors configured to check the position of the magazine M in the receiving area3contributes to speeding up and optimizing the pickup process.

The possibility of adjusting the mutual position of the pickup elements7a,7b,7c,7dallows managing groups of articles S having different shapes and sizes in cross sectional plan, without having to dismantle all or part of the pickup head7.

Advantageously, the pickup head7acts in conjunction with the magazine M described above, specifically with the supporting means M3, in such a way as to prevent it from impacting in any way against the magazine M itself or the groups of articles S to be picked up.