DEPALLETIZING MACHINE FOR PICKING UP AND MOVING GROUPS OF ARTICLES

Abstract

A depalletizing machine for picking up and moving groups of articles, specifically bundles of blanks, includes a containing structure internally provided with at least one receiving area for a movable magazine containing one or more groups of articles. The machine also includes at least one access opening for allowing the magazine to be inserted into, or removed from, the receiving area. The machine also includes a collection zone configured for receiving a succession of groups of articles from the movable magazine and for moving the groups of articles towards the outside of the machine. The machine also includes at least one sensor configured for detecting a position of the movable magazine within the at least one receiving area and a pickup head configured to pick up groups of articles from the movable magazine and transferring them into the collection zone. The machine also includes a control unit configured for setting a predetermined law of motion for the pickup head as a function of at least one information item obtained from the sensor, regarding the position of the movable magazine.

Claims

1. A depalletizing machine for picking up and moving groups of articles, specifically bundles of blanks, comprising: a containing structure internally provided with at least one receiving area for a movable magazine containing one or more groups of articles, specifically one or more bundles of blanks; at least one access opening for allowing the magazine to be inserted into the at least one receiving area and for removing the magazine from the receiving area; at least one collection zone configured for receiving a succession of the groups of articles from the at least one movable magazine disposed in the at least one receiving area and for moving the groups of articles towards the outside of the machine and/or towards a processing station; at least one sensor configured for detecting a position of the movable magazine within the at least one receiving area; a pickup head movable to an upper portion of the containing structure and configured to pick up groups of articles in succession from the at least one movable magazine disposed in the at least one receiving area and for transferring the groups of articles into the collection zone; a control unit configured for setting a predetermined law of motion for the pickup head as a function of the at least one information item obtained from the at least one sensor, regarding the position of the movable magazine, the machine being characterized in that the containing structure is internally provided with a plurality of receiving areas for respective movable magazines, the receiving areas having respective independent access openings and being preferably disposed in sequence along a direction of juxtaposition, and wherein the pickup head is configured to transfer groups of articles from the receiving areas to the collection zone.

2. The machine according to claim 1, wherein the control unit is configured for setting the predetermined law of motion for the pickup head according to an open loop logic, the control unit being, more specifically, configured for determining, as a function of the at least one information item regarding the position of the movable magazine, a spatial position to be assigned to the pickup head when picking up at least one group of articles from the movable magazine.

3. The machine according to claim 1, wherein the at least one sensor comprises, for each receiving area, a first and a second sensor configured to measure a distance between the movable magazine and a respective side wall delimiting the receiving area, the first and second sensors preferably being optical sensors.

4. The machine according to claim 1, wherein the control unit is configured to disable the movement of the pickup head and preferably to generate an alarm signal when the at least one information item regarding the position of the movable magazine indicates that the movable magazine is at a position that is outside a predetermined tolerance.

5. The machine according to claim 1, further comprising a retaining device disposed inside the at least one receiving area and configured to lock the movable magazine at a predetermined position within the receiving area, wherein the retaining device comprises a first pushing element and a second pushing element disposed on opposite sides of the receiving area and mutually movable between an active position in which the first and second pushing elements extend towards the centre of the receiving area and engage respective side portions of the movable magazine in such a way as to prevent further movement of the movable magazine, and a rest position in which the first and second pushing elements adopt a withdrawn position and are disengaged from the respective side portions of the movable magazine to allow the movable magazine in and out of the receiving area, the first and second pushing elements preferably comprising pantograph-style articulated arms.

6. The machine according to claim 5, wherein the control unit is configured to disable the movement of the first and second pushing elements and preferably to generate an alarm signal when the at least one information item regarding the position of the movable magazine indicates that the movable magazine is at a position that is outside a predetermined tolerance.

7. The machine according to claim 1, wherein the pickup head is movable in translation along two horizontal axes which are transverse to each other, and along a vertical axis, and wherein the pickup head is also movable in rotation about the vertical axis.

8. The machine according to claim 1, wherein the pickup head comprises at least a first pair of pickup elements facing each other and a second pair of pickup elements facing each other and acting in conjunction with the pickup elements of the first pair to engage an underside surface of a group of articles supported by the movable magazine in such a way as to support the group of articles while the movable magazine is being moved to the collection zone, and wherein the pickup head comprises a retractor mechanism operating between the pickup elements of each pair to move the pickup elements of each pair according to an adjustment movement towards and away from each other along a first direction of movement, the two pickup elements of each pair being preferably adjustable independently of the pickup elements of the other pair.

9. The machine according to claim 8, wherein each of the pickup elements comprises a supporting bar, preferably vertical and, at the top, connected to the retractor mechanism and, at the bottom, provided with a lifting finger adapted to be inserted under a group of articles to be picked up, each of the pickup elements preferably being C-shaped and the pickup elements of one of the pairs having the shape of a C whose concavity is deeper than that of the pickup elements of the other pair, so as to engage a wider portion of the groups of articles.

10. The machine according to claim 8, comprising a spacing mechanism for adjusting the distance between the pickup elements of the first pair and the pickup elements of the second pair, in particular along a second direction of movement which is transverse, preferably perpendicular, to the first direction of movement, one of the pair of pickup elements being preferably fixed along the second direction of movement.

11. A method for picking up and moving groups of articles, specifically bundles of blanks, preferably implemented by a machine according to claim 1, comprising the following steps: inserting a movable magazine into a receiving area, the movable magazine carrying one or more groups of articles; detecting a position of the movable magazine within the receiving area through at least one sensor; picking up groups of articles in succession from the movable magazine disposed in the receiving area and transferring the groups of articles into the collection zone, through a pickup head; wherein the step of picking up and transferring the groups of articles is accomplished by setting a predetermined law of motion for the pickup head as a function of at least one information item regarding the position of the movable magazine obtained from the at least one sensor, specifically through an open loop control logic, and wherein the step of inserting a movable magazine into the at least one receiving area is accomplished by an automatic, self-propelled trolley.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0042] The description is set out below with reference to the accompanying drawings which are provided solely for purposes of illustration without restricting the scope of the invention and in which:

[0043] FIG. 1 shows a perspective view of a depalletizing machine of this invention;

[0044] FIG. 2 is a plan view of the machine of FIG. 1;

[0045] FIGS. 3A-3B show respective plan views of a portion of the machine in different operating configurations;

[0046] FIG. 4 shows a front view of a portion of the depalletizing machine of FIG. 1;

[0047] FIGS. 5A-5B show perspective views of a component of the machine of this invention;

[0048] FIG. 6 shows a perspective view of a preliminary operating step performed by parts of the machine of the invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION

[0049] With reference to the accompanying drawings, the numeral 1 denotes a depalletizing machine for picking up and moving groups of articles S, specifically bundles of blanks, comprising a containing structure 2 internally provided with at least one receiving area 3 for a movable magazine M containing one or more groups of articles S, specifically bundles of blanks.

[0050] The machine 1 according 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.

[0051] 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.

[0052] Preferably, as shown in FIG. 4, the receiving area 3 is configured to contain a vertical magazine comprising an automatic, self-propelled trolley M1, on which a plurality of vertical supports M2 are mounted to define one or more containing channels in which the groups of articles S are supported from below by specific supporting means M3 which allow them to be stacked one above the other at a predetermined spacing.

[0053] To allow the magazine M to be inserted into the receiving area 3 and to remove the magazine M from the receiving area 3 after the groups of articles S have been picked up, the depalletizing machine 1 also comprises at least one access opening 4.

[0054] In the embodiment illustrated in the accompanying drawings, the containing structure 2 is internally provided with a plurality of receiving areas 3, each having respective independent access openings 4 for receiving respective movable magazines M. In the specific embodiment, the receiving areas 3 are aligned along a predominant direction of extension of the machine 1; they might, however, be disposed in other configurations, not illustrated.

[0055] Preferably, the access openings 4 of the receiving areas 3 are each provided with a door, shown in FIG. 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.

[0056] The depalletizing machine 1 may also comprise a collection zone 5 configured for receiving a succession of groups of articles S from the movable magazine M located in a respective receiving area 3 and for moving the groups of articles S towards the outside of the machine 1 and/or towards a processing station.

[0057] In the embodiment illustrated in FIG. 2, the collection zone 5 is in the form of a belt conveyor or other straight conveyor with a top surface that moves in translation.

[0058] The collection zone 5 might be positioned adjacent to one of the receiving areas 3 or it might be made differently—for example, positioned at the bottom of the receiving areas 3, running along the predominant direction of extension of the machine 1. Furthermore, there might be a plurality of collection zones 5, for example, one for each receiving area 3.

[0059] Each receiving area 3 is preferably delimited at the side and the back by respective walls 3a, 3b or separator elements. Further, the receiving areas 3 are each provided with a pair of sensors (not illustrated) located laterally relative to the ingoing direction of the magazine M into the receiving area 3 through the access opening 4. Preferably, the sensors are located on the side walls 3a of each receiving area 3, possibly also on the bottom wall 3b.

[0060] The groups of articles S are moved from the magazines M to the collection zone 5 by means of at least one pickup head 7 which is movable in an upper portion of the containing structure 2 according to a predetermined law of motion, implemented in particular by a control unit (not illustrated). Preferably, there is only one pickup head 7, shared by all the receiving areas 3. However, in a variant embodiment in which there are a plurality of collection zones 5 or in which each receiving area 3 is associated with its own collection zone 5, there may be one pickup head 7 for each receiving area 3 and/or for each collection zone 5.

[0061] 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 areas 3 and to process the information to generate a suitable law of motion for the pickup head 7.

[0062] Preferably, the control unit is configured for setting the predetermined law of motion for the pickup head 7 according to an open loop logic whereby the control unit determines a final spatial position to be assigned to the pickup head 7 when picking up at least one group of articles S from the movable magazine M.

[0063] More specifically, the control unit determines the spatial position to be assigned to the pickup head 7 as a function of the information it receives from the sensors regarding the position of the movable magazines M.

[0064] Advantageously, the possibility of varying the law of motion of the pickup head 7 based on the position of the magazines M in the receiving areas 3 allows 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 head 7 and to simplify the process and make it economically advantageous.

[0065] Operatively, therefore, one or more movable magazines M containing groups of articles S stacked one above the other are inserted into respective receiving areas 3. In each receiving area 3, 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 head 7 as a function of that information.

[0066] Preferably, the control unit can plan the law of motion for the pickup head 7 also 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 area 5 or preferences relating to the order in which they are picked up in the different receiving areas 3.

[0067] Once the law of motion has been processed, the pickup head 7 is moved between the magazines M of the different receiving areas 3 in such a way as to pick up the groups of articles S according to the predetermined order set by the control unit.

[0068] Preferably, the pickup head 7 is 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.

[0069] Preferably, where necessary, the pickup head 7 is 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.

[0070] Next, the pickup head 7 is 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.

[0071] To perform the pickup operation, the pickup head 7 comprises at least a first pair of facing pickup elements 7a, 7b and a second pair of facing pickup elements 7c, 7d acting in conjunction with the pickup elements of the first pair 7a, 7b to 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 area 5.

[0072] In this situation, each of the pickup elements 7a, 7b, 7c, 7d is 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.

[0073] Preferably, during pickup operations, to prevent impacts and/or jams between the pickup elements 7a, 7b, 7c, 7d and the structure of the magazine M, the magazine M is configured in such a way that the supporting means M3 adopt a retracted position, specifically a recessed position within the vertical supports M2 after 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 M3 just above it, causing them to move to the recessed position.

[0074] Advantageously, the movability of the supporting means M3 prevents the pickup elements 7a, 7b, 7c, 7d of the pickup head 7 from being interfered with by the supporting means M3, now free of the groups of articles S.

[0075] To get a hold of the group of articles, the pickup head 7, as shown in FIG. 5A, also comprises a retractor mechanism 9 operating between the pickup elements 7a, 7b, 7c, 7d of each pair, so as to move the pickup elements 7a, 7b, 7c, 7d of 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 elements 7a, 7b, 7c, 7d may define two distinct directions of non-parallel movements.

[0076] Preferably, the two pickup elements 7a, 7b, 7c, 7d of each pair are adjustable independently of the pickup elements 7a, 7b, 7c, 7d of the other pair.

[0077] Preferably, as shown in FIGS. 5A and 5B, the pickup elements 7a, 7b, 7c, 7d each comprise a supporting bar 10, preferably vertical, connected at the top to the retractor mechanism 9 and having, at the bottom, a horizontal lifting finger 11 designed to be inserted under a group of articles S to be picked up.

[0078] Preferably, the pickup elements 7a, 7b, 7c, 7d each have the shape of a C, oriented in such a way that the concavities of the two pickup elements 7a, 7b, 7c, 7d of each pair face each other. Still more preferably, in the pickup elements 7a, 7b, 7c, 7d of one of the pairs, the concavity is deeper than it is in the pickup elements 7a, 7b, 7c, 7d of the other pair, so as to engage a wider portion of the groups of articles S.

[0079] In use, therefore, once the pickup head 7 has reached a position above the magazine M (or alternatively, before or while reaching the positon above the magazine M) shown, for example, in FIG. 6, the pickup elements 7a, 7b, 7c, 7d are moved away from each other to allow the pickup head 7 to 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 head 7 moves down, the pickup elements 7a, 7b, 7c, 7d are retracted in such a way as to occupy a position on the outside of the channel defined by the vertical supports M2 of the magazine M.

[0080] The pickup elements 7a, 7b, 7c, 7d are then moved back towards each other so that the respective lifting fingers 11 are inserted under the group of articles S to be picked up.

[0081] In the embodiment illustrated in the accompanying drawings, the pickup elements 7a, 7b of the first pair make a movement towards each other that is smaller than the movement towards each other made by the pickup elements 7c, 7d of 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 elements 7a, 7b of the first pair support a portion of the group of articles that is less wide than the portion supported by the pickup elements 7c, 7d of the second pair.

[0082] Advantageously, adjusting the pairs of pickup elements 7a, 7b, 7c, 7d independently of each other allows the pickup head 7 to engage groups of articles S having a cross section of any shape.

[0083] Furthermore, adjusting the pairs of pickup elements 7a, 7b, 7c, 7d independently 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.

[0084] To make the pickup head 7 even more versatile in terms of the size and/or shape of the groups of articles S to be picked up, the pickup head 7 is also provided with a spacing mechanism 12 for adjusting the distance between the pickup elements 7a, 7b of the first pair and the pickup elements 7c, 7d of the second pair.

[0085] 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 elements 7a, 7b, 7c, 7d is fixed along the second direction of movement (that is, fixed to the load-bearing structure of the pickup head 7), while the other pair of pickup elements 7a, 7b, 7c, 7d is movable.

[0086] Advantageously, this adjustment mechanism 12 makes the pickup head 7 more adaptable to groups of articles S of any type.

[0087] Preferably, the pickup head 7 also comprises a downwardly facing sensor, not illustrated (for example, an analogue sensor) configured to scan an area under the pickup head 7 to 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 head 7 can be moved at a higher speed when the pickup head 7 is 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 head 7 capable 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.

[0088] 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).

[0089] To make the most of the versatility and flexibility of the pickup head 7 and to further maximize the process of picking up the groups of articles S from the movable magazines M, the machine 1 also comprises control mechanisms for controlling the position of the movable magazines M in the receiving areas 3.

[0090] To enable the movable magazines M to adopt a predetermined position inside the respective receiving area 3 so that the pickup head 7 can operate precisely, the control unit is configured to disable the movement of the pickup head 7 and 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.

[0091] 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 area 3.

[0092] The sensors are preferably optical sensors and are configured to measure a distance between the movable magazine M and a respective side wall 3a delimiting the receiving area 3. If these distances fall within the predetermined tolerance, the pickup head 7 is operated normally so it picks up the group of articles S from the magazine M and moves it towards the collection area 5 according to the method described above. On the other hand, if the distances are outside the predetermined tolerance, the pickup head 7 is not moved and the movable magazine M is repositioned manually by an operator or automatically.

[0093] Preferably, the movable magazine M is moved back into a position within the receiving area 3 manually if it is outside the tolerance by a long way.

[0094] 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 walls 3a of the receiving area 3, or to lock the side of the magazine M in position, respectively.

[0095] The machine 1 may also comprise at least one proximity sensor (not illustrated) mounted in a bottom wall 3b delimiting the receiving area 3 and configured to issue a signal when the movable magazine M is at a predetermined distance from the bottom wall 3b.

[0096] Advantageously, the proximity sensor prevents the magazine from being pushed too far into the receiving area 3 and making it difficult or even impossible for the pickup head 7 to carry out pickup operations.

[0097] In another embodiment, alternatively to the bottom sensor, the receiving area 3 comprises a mechanical stop member which stops the trolley M1 of the magazine M when it reaches the end of its stroke in the receiving area 3.

[0098] In use, therefore, when the magazine M is placed inside the receiving area 3, 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 head 7 and adjust the pickup elements 7a, 7b, 7c, 7d. If it doesn't, on the other hand, the magazine M is repositioned within the receiving area 3 manually or automatically.

[0099] Advantageously, thanks to the sensors mounted in the receiving areas 3, the pickup head 7 does not make unnecessary movements towards receiving areas 3 whose magazines M are badly positioned and from which it would be unable to pick up the groups of articles S they contain.

[0100] Advantageously, pickup cycle times are considerably reduced because while one magazine M is being moved to the correct position inside a receiving area 3, another magazine M may be emptied by the pickup head 7 without having to stop the machine.

[0101] To prevent the movable magazine M from moving after it has adopted the predetermined position, the machine 1 also comprises a retaining device, located inside each receiving area 3 and configured to lock the movable magazine M at that position in the receiving area 3.

[0102] As shown in FIGS. 3A and 3B, the retaining device comprises a first pushing element 8a and a second pushing element 8b, located on opposite sides 3a of the receiving area 3 and movable relative to each other between an active position and a withdrawn position.

[0103] At the active position, the first and second pushing elements 8a, 8b extend towards the centre of the receiving area 3 and engage respective side portions of the movable magazine M to prevent the magazine from moving further.

[0104] At the rest position, on the other hand, the first and second pushing elements 8a, 8b adopt 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 area 3.

[0105] Operatively, the first and second pushing elements 8a, 8b are activated by the control unit after the position of the magazine M in the receiving area 3 has been detected by the first and the second sensor.

[0106] 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 elements 8a, 8b and preferably generates an alarm signal.

[0107] 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 elements 8a, 8b from 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 element 8a, 8b on the trolley M1 of the magazine M.

[0108] 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 element 8a, 8b imparting a sideways push on the trolley M1 of the movable magazine M so that the distances between the magazine M and the side walls 3a of the receiving area 3 are all the same or, in any case, within a predetermined range of values. In this situation, the first and the second pushing element 8a, 8b impact against the trolley M1 of the magazine M to correct its position within the receiving area 3 and then lock the magazine M at the predetermined position.

[0109] In the embodiment shown in the accompanying drawings, the first and the second pushing element 8a, 8b comprise articulated pantograph arms which, at the withdrawn position, are preferably fully recessed in the side wall 3a of the receiving area 3.

[0110] In another embodiment not illustrated, the first and second pushing elements 8a, 8b comprise push bars.

[0111] The invention achieves the above-mentioned aims by eliminating the drawbacks of the prior art.

[0112] The presence of two or more receiving areas allows the pickup head to work on one magazine while another is being fed.

[0113] The pickup point of the pickup head changes according to the receiving area, leaving other parts of the machine unencumbered.

[0114] As each group of blanks is withdrawn from the magazine, access to those below is made possible.

[0115] The possibility of controlling the law of motion of the pickup head 7 optimizes 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.

[0116] The presence of sensors configured to check the position of the magazine M in the receiving area 3 contributes to speeding up and optimizing the pickup process.

[0117] The possibility of adjusting the mutual position of the pickup elements 7a, 7b, 7c, 7d allows managing groups of articles S having different shapes and sizes in cross sectional plan, without having to dismantle all or part of the pickup head 7.

[0118] Advantageously, the pickup head 7 acts 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.