IT201800007828A1 - STACKING OR DE-STACKING MACHINE FOR TRAYS WITH SUPPORT PLATE - Google Patents

Description

DESCRIPTION

of the Italian Patent for Industrial Invention entitled:

“STACKING OR DE-STACKING MACHINE FOR TRAYS WITH

SUPPORT PLATE "

Field of technique

The present invention relates to a machine for stacking or de-stacking trays for bakery products, such as for example biscuits, croissants, sandwiches, buns and many others.

Known technique

As is known, the production of bakery products generally involves preparing a dough, dividing the dough into portions individually suitable for making a respective product, possibly letting these portions rise for a certain period of time and finally submitting the portions of leavened dough to a baking process in the oven.

As part of the industrial production of this type of food, after dividing the dough into individual portions, the latter are placed on trays, which are used to support the products during the leavening and cooking phases.

At the end of the cooking phase, the products are removed from the trays which are then reused.

To cope with any variations in the production rhythm, for example any production stoppages, after the removal of the products leaving the oven, the trays can be temporarily accumulated in a special warehouse, waiting to be placed again along the production line. afterwards.

In order to reduce the overall dimensions, inside this warehouse the trays can be arranged by stacks, in which each stack includes a plurality of overlapping trays.

For this reason, the warehouse is generally equipped with a stacking machine, suitable for overlapping the trays coming one at a time from the production line to form a stack, and with a de-stacking machine, suitable for separating the overlapping trays of a stack for enter them one at a time back on the production line.

After being stacked, the stacks of trays inside the warehouse can be handled in various ways, for example by means of belt conveyors or roller conveyors, on which the stacks of trays travel by staying directly in contact with the handling components, up to reach a storage position or be placed directly on shelves.

However, the direct contact that is made between the stacked pans and the handling and storage devices (eg shelves) means that the pans can be damaged and sometimes get dirty, decreasing the hygiene of the entire production process.

Presentation of the invention

In light of these considerations, an object of the present invention is to make available a stacking or de-stacking machine that allows to overcome the aforementioned drawback of the prior art, within the framework of a simple, rational and relatively low cost solution.

These purposes are achieved by the characteristics of the invention reported in the independent claims. The dependent claims outline preferred and / or particularly advantageous aspects of the invention.

In particular, an embodiment of the present invention makes available a stacking or de-stacking machine for baking trays, comprising:

- a horizontal support surface designed to support a stack of trays,

- an upper conveyor adapted to hold a tray in a vertically suspended position above the support surface and spaced from it, and

- a lifting device designed to move the stack of trays vertically in the space between the support surface and the upper conveyor,

in which the support surface for the stack of trays is defined by a support plate resting on a support apparatus.

In this way, the stacks of trays can be subsequently manipulated together and by means of the relative support plates, making these operations simpler and safer.

The support plates also allow you to keep the piles of trays raised by the various machine parts, protecting them and increasing the hygiene and asepticity of the entire production plant.

An aspect of the present invention provides that the support apparatus for the support plate can comprise a lower conveyor adapted to advance the support plate and stop it under the upper conveyor.

Thanks to this solution, the level of automation of the machine is advantageously increased, correspondingly reducing the manual interventions necessary for its operation.

Preferably, each support plate can be made of plastic material.

Thanks to this solution, the support plates are relatively cheap and easy to clean.

According to another aspect of the present invention, the lifting device can comprise:

- at least one pair of first support arms, cantilevered associated with a vertical support structure, parallel to each other and positioned in plan externally and on opposite sides with respect to the support surface, and

- actuator members adapted to move said first support arms in a vertical direction between a lowered position, in which they are positioned at a lower level with respect to the support surface, and a raised position, in which they are positioned at a higher level with respect to the supporting surface support.

Thanks to the presence of these cantilevered support arms, the stacking or de-stacking machine is mechanically rather simple and, above all, it is substantially open and accessible on at least three sides, guaranteeing the possibility of carrying out easy maintenance operations when necessary, as well as to perform periodic cleaning interventions to obtain a higher level of hygiene.

According to an aspect of the present invention, the lifting device can further comprise:

- a pair of second support arms cantilevered associated with the vertical support structure, parallel to the first support arms and positioned in plan externally and on opposite sides with respect to the first support arms themselves,

- first actuator members adapted to move said second support arms in a vertical direction between a lowered position, in which they are substantially at the same height as the first support arms in a raised position, and a raised position, in which they are positioned at a height greater and near the upper conveyor, e

- second actuator members adapted to move said second support arms between a closed configuration, in which they are able to support the trays, and an open configuration, in which they release the trays.

Thanks to this solution, the stacking or de-stacking operations of the trays can take place thanks to the cooperation between the first support arms and the second support arms, reducing downtime and therefore increasing the productivity of the machine.

A particular aspect of the invention provides that the second actuator members can be adapted to rotate each of said second support arms around a respective longitudinal axis.

In this way, a particularly simple solution is provided for moving the second support arms between the closed configuration and the open configuration.

According to another aspect of the invention, each of the second support arms can have a plurality of horizontally protruding teeth, which are offset and interpenetrated in plan with a plurality of protruding teeth of the closest first support arm.

This solution makes it possible to make contact surfaces available for the pans that are rather large, without the second support arms interfering with the first support arms.

According to a further aspect of the invention, the upper conveyor can be installed at the top of the vertical support structure.

In this way, a stand-alone machine is obtained that is easier to position and install within a plant.

A further aspect of the present invention provides that the upper conveyor can comprise:

- a belt sliding in a closed path comprising at least one straight and horizontal operating section, and

- a magnetic system suitable for keeping a pan suspended and adhering to a lower surface of the sliding belt in the operating section of its path. This aspect provides a safe, simple and rational way to keep the trays suspended and adhered to the upper conveyor.

Preferably, the aforesaid magnetic system can be deactivated, ie the magnetic force exerted by it can be selectively canceled or at least weakened.

In this way, when necessary, the trays can be released from the upper conveyor.

In this regard, the magnetic system can comprise at least one magnet (for example a permanent magnet) and actuator members adapted to move said magnet in a vertical direction.

Thanks to this solution, the magnet can be selectively moved towards or away from the operating section of the sliding belt, by selectively varying the magnitude of the magnetic attraction force that it exerts on the trays carried.

According to another aspect of the invention, the machine can also comprise a handling device adapted to move the pan with respect to the operating section of the sliding belt in the vertical direction.

In this way the trays can be advantageously transferred between the upper conveyor and the underlying lifting device.

This handling device can comprise for example:

- at least two abutment bodies mutually coplanar and positioned in plan on opposite sides of the sliding belt, e

- actuation members adapted to move said abutment bodies in a vertical direction between a raised position, in which they are positioned at a higher level than the operating section of the sliding belt, and a lowered position, in which they are positioned at a lower level than the working section of the walking belt.

This aspect provides a relatively simple solution for handling trays.

In particular, each abutment body can comprise a deactivatable magnetic system adapted to keep the pan suspended and adherent to the abutment body itself.

In this way, the abutment bodies can advantageously accompany the trays in their movement.

Also in this case, the magnetic system can comprise at least one magnet (for example a permanent magnet) and actuator members adapted to move said magnet in a vertical direction.

According to another aspect of the invention, the actuating members of the abutment bodies can comprise at least one motor equipped with a rotating shaft and at least one thrust crank mechanism adapted to transform the rotational movement of the motor shaft into a reciprocating movement in the vertical direction. of abutment bodies.

Thanks to the drive by means of a thrust crank mechanism, the speed of the abutment bodies is variable and reaches the minimum at the points of inversion, ensuring a transfer of the trays between the upper conveyor and the particularly delicate lifting device.

Another embodiment of the present invention also makes available a system for the stacking and de-stacking of baking trays, which includes:

- a first machine as outlined above and configured to de-stack the trays of a stack,

- a second machine as outlined above and configured to stack the trays forming a stack, e

- a handling line suitable for transporting the support plates from the first machine to the second machine.

In this way, the operation of the entire system can be fully automated.

According to a preferred aspect of the invention, a brushing machine capable of brushing the empty support plates before reaching the second machine can be placed along the handling line.

Thanks to this solution, it is possible to remove dust or food residues that may have accumulated on the support plates, before they are used in contact with the trays, consequently increasing the hygiene and asepticity of the system.

A further aspect of the invention provides that a warehouse can be placed along the handling line to receive the support plates coming from the first machine, accumulate them and send them to the second machine. Thanks to this solution it is advantageously possible to create a "lung" of support plates that allows to cope with any variations in the production rate, for example by accumulating support plates when the production rates (of food products) are high or by releasing plates of support when production rates (of food products) drop.

According to an aspect of the invention, the aforementioned warehouse can comprise at least one stacker / de-stacker device of the support plates.

In this way, the support plates can also be stacked on top of each other, reducing the space they occupy and therefore the overall dimensions of the warehouse.

According to another preferred aspect of the invention, the warehouse can be placed along the handling line between the brushing machine and the second machine.

Thanks to this solution, the brushing machine will be able to clean the trays before they reach the warehouse so that they can be stacked already clean, avoiding that possible residues create a misalignment of the stack of support plates with consequent fall of the same.

According to an aspect of the invention, in which the aforementioned stacker / de-stacker device may comprise:

- a conveyor adapted to define a support surface for the support plates, - a plurality of supports,

- first actuator means adapted to move the plurality of supports between a lowered position, in which they are placed at a lower level than the support for the support plates, and a raised position in which they are placed at a higher level than said plane of support,

- second actuator means adapted to move the plurality of supports between an engagement position, in which they are able to stay in contact and support a support plate, and a disengagement position, in which they are unable to stay in contact with said support plate.

In this way, the support plates can be easily stacked on top of each other as each of them reaches the stacker / de-stacker device advancing on the conveyor.

Similarly, each stack support plate can be easily released onto the conveyor to be put back into circulation.

According to another aspect of the solution, the plurality of supports can be fixed to a frame, which is movable between the lowered position and the raised position activated by the first actuator means.

This solution has the advantage of simply coordinating the two movements of the supports.

Brief description of the figures

Further features and advantages of the invention will become evident from reading the following description provided by way of non-limiting example, with the aid of the figures illustrated in the attached tables.

Figure 1 is a plan view of the layout of a plant for managing trays according to an embodiment of the present invention.

Figures 2, 3 and 4 are as many views relating to a stack of trays.

Figure 5 is a perspective view of a stacking machine inserted in the system of Figure 1.

Figure 6 is a plan view of the machine of Figure 5.

Figure 7 is the section VII-VII of Figure 6.

Figure 8 is the section VIII-VIII of Figure 7 shown on an enlarged scale.

Figure 9 is a side view of the detail of Figure 8.

Figure 10 is the X-X section of Figure 7.

Figure 11 is an enlarged detail of Figure 10.

Figure 12 is an enlarged detail of the view indicated by XII in Figure 7.

Figures 13 and 14 are a different detail of the view indicated by XII in Figure 7, shown in two different operating configurations.

Figure 15 is the section of Figure 7 but relating to a de-stacking machine belonging to the plant of Figure 1.

Figure 16 is a plan and schematic view of the layout of a support plate management system used in the plant in Figure 1.

Figure 17 is a top view of a stacker / de-stacker device included in the management system of figure 16.

Figure 18 is the XVIII-XVIII section of Figure 17.

Figure 19 is a side view of the stacker / de-stacker device of Figure 17.

Detailed description

Figure 1 shows a plant 100 for the handling, storage and management of V trays for food products, typically for baked goods, such as biscuits, croissants, sandwiches, focaccia and many others. In particular, the trays V can be conceived to support portions of a food dough during the various processing steps necessary to obtain the aforementioned products, including for example a leavening step and / or a baking step in the oven.

In this regard, each tray V can be shaped as a sheet-like body of generally planar shape, for example with a rectangular plan, which can be made of metallic material, for example of stainless steel, or of any other material suitable to withstand high temperatures and to ensure sufficient asepticity.

At least one face of each pan V can comprise a plurality of recesses for containing the individual portions of food dough.

Before being used in the production of food, the V trays can be collected in stacks, where each stack includes a plurality of V trays mutually superimposed in direct contact with each other.

As illustrated in Figures 2 to 4, each stack of trays V is preferably supported on a respective support plate S, which can be made of metallic material, for example of stainless steel, or more preferably of plastic material.

The support plates S can have a substantially planar shape, for example with a rectangular plan. Preferably, each support plate S has at least one dimension (e.g. width) smaller than a corresponding size of the trays V above and is arranged in such a way that the trays V can protrude laterally from two opposite parts of the support plate S itself.

Each support plate S can further have a countersink in correspondence of two opposite sides.

Returning to Figure 1, the plant 100 may include a warehouse, globally indicated with 105, which is suitable for hosting and storing a multiplicity of the aforementioned stacks of trays V.

For this purpose, the magazine 105 can comprise a plurality of longitudinal conveyors 110, for example roller or belt conveyors, which can be arranged parallel to each other and can be individually adapted to support a row of stacks of trays V.

All the longitudinal conveyors 110 can support the same type of trays V or they can support trays V of different shape and / or format for use in the production of different food products.

The magazine 105 can also comprise a transverse conveyor 115, oriented orthogonally with respect to the longitudinal conveyors 110, which can comprise a trolley 120 adapted to pick up a stack of trays V from any of the longitudinal conveyors 110 and to transport it to a de-stacking machine 125.

The de-stacking machine 125 is adapted to separate the trays V from the stack and to transfer them, one at a time, to an outlet conveyor 130.

The outfeed conveyor 130 can and comprise mobile support means able to define a support surface above which the trays V.

These mobile support means can be defined for example by one or more sliding belts, the upper portion of which is adapted to define the support surface for the trays V.

However, it is not excluded that, in other embodiments, the mobile support means of the outfeed conveyor 130 may be defined by a roller conveyor or other suitable systems.

By means of the outlet conveyor 130, the trays V can be introduced onto a handling line 135 which transports them to a succession of operating stations.

These operating stations (not shown in the figures) can include, for example, but not exclusively or necessarily, a brushing station, in which the trays V are cleaned, a loading station, in which the trays V are loaded with the portions of food dough , a leavening station, in which the V trays can be kept in a temperature and humidity controlled chamber to facilitate the leavening of the dough portions, a baking station, in which the V trays are placed inside an oven, and an emptying station, in which the food products obtained are removed from the trays V.

At the end of this path, the trays V can remain on the handling line 135, so as to be immediately reused in a new production cycle, or they can be diverted onto an inlet conveyor 140, which can be structurally similar to the outlet conveyor 130 described above.

The inlet conveyor 140 is adapted to transport one tray V at a time to a stacking machine 145, which is capable of overlapping the trays V so as to form a stack.

The stack of trays V obtained from the stacking machine 145 can be subsequently picked up by the transverse conveyor 115 to be placed on one of the longitudinal conveyors 110 of the warehouse 105.

According to a possible embodiment illustrated in Figure 5, the stacking machine 145 first of all comprises a horizontal support surface 150 adapted to support a stack of trays V.

The support surface 150 can be made directly available by one of the support plates S, which can be placed on a support apparatus which keeps it raised from the ground.

The support apparatus can be defined by a lower conveyor 155, which is adapted to advance a row of support plates S along a predetermined direction of advancement A, for example a straight and horizontal direction of advancement, to stop them one at a time. at a predetermined operating position.

As illustrated in figure 7, the lower conveyor 155 can comprise a pair of roller conveyors, indicated respectively with 160 and 165, which are mutually aligned, in such a way as to allow the support plates S to pass from one to the other with continuity .

Each roller conveyor 160 and 165 generally comprises a plurality of horizontal rollers, arranged transversely with respect to the direction of advancement A and coplanar with each other, and a motor 170, for example an electric motor, which, through a suitable transmission system (not shown), for example a belt transmission system is able to simultaneously rotate all the rollers of the roller conveyor around their own axis.

However, it is not excluded that, in other embodiments, the lower conveyor 155 may comprise a single roller conveyor or that one or both roller conveyors can be replaced by sliding belts or other suitable transport systems.

It is also not excluded that some embodiments may provide that, instead of the lower conveyor 155, the support apparatus of the support plate S is defined by a static element, such as a table or a fixed base.

Further embodiments could also provide that the stack of trays V is placed directly on the support apparatus, for example directly on the rollers or belts of the lower conveyor 155 or on a suitable surface of the static element, which would define them same support surface 150.

The stacking machine 145 further comprises an upper conveyor 175, which is adapted to bring a tray V into a vertically suspended position above the support surface 150 and spaced from it.

In the illustrated example, the upper conveyor 175 includes a sliding belt 180, which is able to slide in a closed path which includes at least a straight and horizontal operating section 185 which is at least partially overlapped and spaced from the support surface 150.

For this purpose, the sliding belt 180 can be wound on at least two return wheels 190 with a horizontal axis, so that its path includes a lower section, which defines the operating section 185, and an upper section, above the operating section. 185, which substantially defines the return section. The movement of the sliding belt 180 can be driven by a motor (not shown), for example by an electric motor, which is able to rotate at least one of the transmission wheels 190.

The upper conveyor 175 also comprises a magnetic system, indicated globally with 195, which is adapted to keep the trays V suspended and adhering to the lower surface of the sliding belt 180 which is located in the operating section 185, i.e. to the surface facing the underlying surface. support 150.

The aforementioned magnetic system 195 can comprise a plurality of magnets 200, for example permanent magnets, which can be shaped like plates and can be arranged in the space between the operating section 185 and the upper return section of the sliding belt 180, in so as to exert a magnetic attraction force from the bottom upwards which, overcoming the force of gravity, keeps the trays V suspended and in contact with the lower surface of the sliding belt 180 in the operating section 185.

To avoid contamination of the V trays, the magnets 200 can be completely enclosed within a protective casing 205, which can be made for example of stainless steel.

Along the operating section 185, the sliding belt 180 is able to slide in a predetermined direction of advancement B, preferably horizontal, which can be parallel to the direction of advancement A of the lower conveyor 155 below.

With respect to this direction of advancement B, the walking belt 180 has a transversal dimension (width) which is generally smaller than the width of the trays V, so that each of them can protrude horizontally from two opposite sides of the walking belt 180 itself ( see for example fig. 6).

At least in correspondence with the portion of the sliding belt 180 which is vertically superimposed on the support surface 150, the magnetic system 195 can be of the deactivatable type, i.e. it can be selectively controlled to cancel or at least attenuate the magnetic attraction force, so that the tray V tends to fall down by gravity.

To achieve this purpose, the magnet 200 which is in the aforementioned position can be movable in the vertical direction between a lowered position (shown in Figures 7 and 8), in which it is located at a minimum distance from the operating section 185 of the walking belt 180, and a raised position (not shown), in which it is at a greater distance from the operating portion 185 of the walking belt 180.

In the lowered position, the magnet 200 is able to generate on the tray V a magnetic attraction force sufficient to hold it stably in contact with the sliding belt 180, while in the raised position this magnetic attraction force is insufficient to perform this function or is in any case attenuated.

By way of example, this movement of the magnet 200 can be obtained by means of at least one cylinder-piston assembly 210, for example of the pneumatic type. In particular, the magnet 200 can be housed inside the protective casing 205 with a certain vertical clearance and the cylinder-piston assembly 210 can be fixed outside the aforementioned protective casing 205, with the relative sliding rod which penetrates the whole and is attached to magnet 200.

In other embodiments, the magnet 200 placed above the supporting surface 150 could simply be a fixed electromagnet which is selectively powered and de-energized.

In correspondence with the portion of the sliding belt 180 which is vertically superimposed on the support surface 150, the stacking machine 145 can also comprise a handling device, indicated as a whole with 215 in figures 8 and 9, which is able to move the tray V with respect to to the operating section 185 of the walking belt 180 in the vertical direction.

In the example illustrated, this handling device 215 can comprise at least two abutment bodies 220, made for example of stainless steel, each of which makes available a contact surface 225 that is substantially flat, horizontal and facing downwards.

These two abutment bodies 220 can be positioned on the side of the sliding belt 180 and on opposite sides thereof with respect to a direction transversal to the direction of advancement B, so that their contact surfaces 225 are superimposed on the protruding portions of the tray V (see also figure 6).

Actuating members 220 are associated with the abutment bodies 220, globally indicated with 230, which are adapted to move said abutment bodies 220 in the vertical direction between a raised position (illustrated in Figure 8) and a lowered position (not shown).

In the raised position, the contact surfaces 225 of the abutment bodies 220 are positioned at a height substantially equal to or at least slightly higher than the operating section 185 of the sliding belt 180, while in the lowered position, the contact surfaces 225 are positioned at a height lower than the operating section 185 of the walking belt 180.

In both these positions, the contact surfaces 225 of the abutment bodies 220 are preferably coplanar with each other and remain coplanar even during their movement.

For each abutment body 220, the actuation members 230 can comprise for example a thrust crank mechanism 235, which can comprise a crank 240, able to rotate around a horizontal rotation axis, and a connecting rod 245, one end of which it is articulated in an eccentric position to the crank 240 and the opposite end is articulated to the respective abutment body 220, for example through a support element 250, which is in turn coupled and constrained to slide on suitable vertical guides.

In this way, the rotation of the cranks 240 is advantageously transformed into a linear reciprocating motion of the abutment bodies 220, the speed of which will have a substantially sinusoidal trend, minimum (practically zero) in correspondence with the raised position and the lowered position and maximum during the movement. run between these two positions.

The cranks 240 of the two thrust cranks 235 can be placed in rotation simultaneously by a single motor 255, for example by an electric motor, through a transmission system that connects the shaft of said motor 255 to both cranks 240.

However, it is not excluded that, in other embodiments, each thrust crank 235 may be driven by a respective motor or that there may be only one thrust crank 235 connected so as to operate both abutment bodies 220.

Each abutment body 220 preferably comprises a magnetic system, globally indicated with 260, which is generally adapted to keep the tray V adherent to the contact surface 225. This magnetic system 260 can comprise a magnet 265, for example a permanent magnet, the which can be shaped like a plate and can be inserted inside the abutment body 220 (which can be realized as a closed casing), so as to be able to exert a magnetic attraction force from the bottom upwards which, overcoming the force of gravity, keeps the tray V suspended and adhering to the contact surface 225.

Also these magnetic systems 260 are preferably of the deactivatable type, ie they can be selectively controlled to cancel or reduce the magnetic attraction force they exert on the tray V, so that the latter tends to fall downwards by gravity.

To achieve this purpose, the magnet 265 can be movable in a vertical direction, with respect to the corresponding abutment body 220, between a lowered position (shown in figure 8), in which it is located at a minimum distance from the contact surface 225, and a raised position (not shown), in which it is at a greater distance from the contact surface 225.

In the lowered position, the magnet 265 is able to generate on the tray V a sufficient magnetic attraction force to hold it stably in contact with the abutment body 220, while in the raised position this magnetic attraction force is insufficient to perform this function or in any case is attenuated.

The movement of each magnet 265 can be obtained by means of one or more cylinder-piston assemblies 270, for example of the pneumatic type. In particular, each magnet 265 can be housed inside the respective abutment body 220 with a certain vertical clearance and the cylinder-piston assemblies 270 can be fixed outside the abutment body 220, with the relative sliding rod which penetrates the whole and is attached to magnet 265.

In other embodiments, each magnet 265 could simply be a fixed electromagnet that is selectively powered and de-energized.

As illustrated in Figure 10, the stacking machine 145 also comprises a lifting device, globally indicated with 275, which is able to move the trays V vertically in the space between the support surface 150 and the upper conveyor 175.

The lifting device 275 can comprise a pair of first support arms 280, each of which extends mainly along a horizontal longitudinal axis X.

The longitudinal axes X of the first support arms 280 are preferably parallel to each other and can be parallel to the direction of advancement A of the lower conveyor 155.

In particular, the first support arms 280 can be positioned to the side and on opposite sides of the lower conveyor 155, in such a way that the width of the lower conveyor 155 is completely contained, in plan, in the space between this pair of first support arms. support 280.

The first support arms 280 can be cantilevered associated with a vertical support structure 285, which can be substantially shaped like a portal which is placed astride the lower conveyor 155 and at the top of which the upper conveyor 175 can be installed.

As illustrated in Figure 12, each of the first support arms 280 can comprise an upper wall 290 adapted to make available a substantially flat, horizontal and upward facing contact surface 295, which can extend substantially for the entire length of the relative support arm 280.

The upper wall 290 of each support arm 280 can protrude from the top of a vertical stiffening wall 300, extending outwards, i.e. away from the space between the two support arms 280.

The distance separating the inner edges of the support arms 280, i.e. the edges of the upper wall 290 closest to each other, is generally less than the width of the trays V, so that the contact surfaces 295 are able to support them in support.

To increase the amplitude of the contact surfaces 295, it is however preferable that the upper part 290 of each support arm 280 has an outer edge substantially comb-shaped, i.e. comprising a plurality of horizontally protruding teeth interspersed with empty spaces (see fig. .11).

Actuator members, generally indicated 305 in Figure 7, are associated with the first support arms 280, which are adapted to move said support arms 280 in the vertical direction between a raised position and a lowered position (not explicitly shown in the figures).

In the lowered position, the contact surfaces 295 of the first support arms 280 are positioned at a lower height with respect to the support surface 150, while in the raised position, the aforementioned contact surfaces 295 are positioned at a higher level with respect to the support surface 150 but preferably lower than the operating section 185 of the sliding belt 180.

In both these positions, the contact surfaces 295 of the first support arms 280 are preferably coplanar with each other and remain so even during their movement.

As illustrated in Figure 7, for each support arm 280, the actuator members 305 can comprise at least one vertical guide installed in the support structure 285, to which a carriage 310 carrying the support arm 280 is slidingly associated, and a chain or drive belt 315 adapted to drag the carriage 310 to slide along the vertical guide.

The driving chains or belts 315 of the first support arms 280 can be operated simultaneously by a single motor 320, for example by an electric motor, through a suitable transmission system.

The lifting device 275 can further comprise a pair of second support arms 325, which mainly extend along a respective horizontal longitudinal axis Y and can be cantilevered associated with the support structure 285.

The longitudinal axes Y of the second support arms 325 are preferably parallel to each other and parallel to the longitudinal axes X of the first support arms 280.

In particular, the second support arms 325 can be positioned on opposite sides with respect to the pair of first support arms 280, so that the latter are completely contained, in plan, in the space between the second support arms 325.

As illustrated in Figure 13, each of the second support arms 325 can comprise an upper wall 330 adapted to make available a substantially flat, horizontal and upward facing contact surface 335, which can extend substantially for the entire length of the relative support arm 325.

The upper wall 330 can protrude from the top portion of a support rod 340, extending inwards, i.e. approaching the other support arm 325.

The distance separating the inner edges of the second support arms 325, i.e. the edges of the upper wall 330 closest to each other, is preferably less than the width of the trays V, so that the contact surfaces 335 are able to support them. in support.

To increase the width of these contact surfaces 335, it is however preferable that said inner edges of the second support arms 325 are substantially comb-like, or that they have a plurality of horizontally protruding teeth interspersed with empty spaces (see fig. 11 ).

In particular, it is preferable that the protruding teeth of each support arm 325 are offset, in plan, with respect to the protruding teeth of the closest first support arm 280, so as to substantially overlap the empty spaces of the latter, of which substantially have a complementary shape.

Associated with the second support arms 325 are first actuator members, globally indicated with 345 in Figure 7, which are adapted to move said second support arms 325 in the vertical direction between a raised position (shown in Figure 7) and a lowered position (not explicitly shown in the figures).

In the lowered position, the contact surfaces 335 of the second support arms 325 are positioned substantially at the same height (and therefore coplanar with) the contact surfaces 295 of the first support arms 280, when the latter are in the raised position.

This position can be reached, without having to reduce the dimensions of the contact surfaces 335 and / or 295, thanks to the fact that the protruding teeth of the support arms 325 and 280 are offset and complementary to each other, thus being able to penetrate vertically without interference. .

In the raised position, the contact surfaces 335 of the second support arms 325 are instead at a higher level than the previous one but in any case preferably lower than the operating section 185 of the sliding belt 180 and substantially equal to the level reached by the abutment bodies 220, when the latter are in the lowered position.

In both these positions, the contact surfaces 335 of the second support arms 325 are preferably coplanar with each other and remain so even during their movement.

As illustrated in Figure 7, for each of the second support arms 325, the first actuator members 345 can comprise at least one vertical guide installed in the support structure 285, with which a carriage 350 carrying the support arm 325 is slidingly associated, and a driving chain or belt 355 adapted to drag the carriage 350 to slide along the vertical guide. The driving chains or belts 355 of the two support arms 325 can be operated simultaneously by a single motor 380, for example by an electric motor, through a suitable transmission system.

Second actuator members, generally indicated 360, are further associated with the support arms 325, which are adapted to move the support arms 325 between a closed configuration (shown in figure 13) and an open configuration (shown in figure 14).

In the closed configuration, the upper walls 330 are arranged so that their internal edges are separated by a distance less than the width of the trays V, allowing them to support the latter in support. In the open configuration, the distance between said internal edges is instead greater than the width of the trays V so as to be able to release them.

In the illustrated example, this movement is obtained by rotating each support arm 325 downward about its respective longitudinal axis Y, thus moving it from the position in which the relative upper wall 330 is substantially horizontal as described above to a position in which the upper wall 330 is substantially vertical.

Naturally, in order for this rotary movement to be effective for the intended purposes, the distance between the longitudinal axes Y of the support arms 325 must be greater than the width of the trays V.

To operate each support arm 325 (see fig. 11), the second actuator members 360 can comprise an articulated joint 365 adapted to connect the support arm 325 to the relative carriage 350 along the longitudinal axis Y, and at least one group piston cylinder 370, for example of the pneumatic type, which is mounted on the carriage 350 and and is connected to the support arm 325 eccentrically with respect to the longitudinal axis Y, so that an extension / shortening of the piston cylinder unit 370 results in a rotation of the arm support 325.

Inside the plant 100, the stacking machine 145 described above is arranged in such a way that the upper conveyor 175 is partially superimposed on the inlet conveyor 140 (see fig.7).

In the example illustrated, the operating section 185 of the sliding belt 180 is partially superimposed on the support plane defined by the inlet conveyor 140 and separated from it by a vertical distance substantially equal to or slightly greater than the thickness of a tray V.

In this way, the trays V which come one at a time from the inlet conveyor 140 are attracted by the magnetic system 195 and remain adherent to the operating section 185 of the sliding belt 180.

The trays V are thus transported by the sliding belt 180 and stopped one at a time in the operating position in which each of them is vertically superimposed on the support surface 150.

When the first tray V reaches this position, the second support arms 325 are in the closed configuration and in the raised position, so as to be at the minimum distance from the operating section 185 of the sliding belt 180.

At this point, the abutment bodies 220 of the handling device 215 are activated to move from the raised position to the lowered position, coming into contact with the portions of the tray V which protrude laterally from the sliding belt 180 and pushing them downwards.

In this phase, the magnetic systems 260 associated with the abutment bodies 220 can be activated, so as to retain the tray V, while the magnetic system 195 associated with the last section of the sliding belt 180 can be deactivated, allowing the detachment of the tray V .

When the stripping bodies 220 reach their lowered position, the tray V is substantially in contact with the second support arms 325 or at a short distance from them, so that the magnetic systems 260 can also be deactivated, releasing the tray V on the second arms support 325.

In this regard, it should be noted that, thanks to the actuation by means of the thrust cranks 235, the speed of the abutment bodies 220 at their raised and lowered position is minimal, ensuring a very delicate grip and release of the tray V.

Subsequently, the second support arms 325 are lowered by an amount substantially equal to the thickness of the tray V while the abutment bodies 220 are returned to the raised position.

At this point the upper conveyor 175 starts up again to bring a new tray V into the operating position and the cycle is repeated identically as before, with the only difference that the new tray V will be placed and released directly on the previous tray V.

This cyclic operation continues until the second support arms 325, with a certain number of trays V stacked on them, reach their lowered position.

At this moment, the first support arms 280 are in or are brought into a raised position, so as to be substantially coplanar with the second support arms 325, which are moved in an open configuration as described above, so as to release the trays. V resting on the first support arms 280.

At this point, the stacking process resumes in the same way described above, with the only difference that the support and progressive lowering function, previously performed by the second support arms 325, is now performed by the first support arms 280.

This stacking process proceeds until a complete stack is obtained on the first support arms 280, after which the first support arms 280 are brought into the lowered position.

In this way, the first support arms 280 pass alongside and below the support surface 150, in this case the support plate S, releasing and resting on it the stack of trays V.

In the meantime, the second support arms 325 can be moved again to the raised position and brought back to the closed configuration, so that, while the first support arms 280 lower and release the stack of trays V on the support surface 150, the first V trays from the next stack can be stacked on the second support arms 325 in the same manner as before, saving time.

In any case, after a stack of trays V has been released onto the supporting surface 150, the lower conveyor 155 is activated, so as to move said stack P away from the operating position and bring a new empty support plate S to this operating position .

The first support arms 280 are then returned to the raised position to repeat the operations previously described.

Turning now to the de-stacking machine 125 illustrated in Figure 15, this machine can be structurally identical to the stacking machine 145 and simply be operated in reverse.

In practice, the unstacking process can begin with the first support arms 280 in the lowered position and with the lower conveyor 155 which advances a stack of trays V, possibly supported by the relative support plate S, until it stops in position. operating above the first support arms 280. At this point, the first support arms 280 can be raised so as to lift the stack of trays V from the support surface 150, in this case with respect to the support plate S, until it reaches the a position in which the tray V placed at the top of the stack P is substantially at the same height as the abutment bodies 220 of the handling device 215 in the lowered position.

In this way, by activating the magnetic systems 260, the abutment bodies 220 can hold the tray V and, moving towards the raised position, bring it into contact with the operating section 185 of the sliding belt 180.

At this point, the magnetic systems 260 of the abutment bodies 220 can be deactivated, while the magnetic system 195 associated with the sliding belt 180 is activated so as to retain the tray V.

Also in this case, thanks to the actuation by means of the thrust cranks 235, the gripping and release of the tray V by the abutment bodies 220 is particularly delicate.

Thereafter, the walking belt 180 can be set in motion, so as to move the tray V away from the operative position.

In this regard, the unstacking machine 125 is arranged so that the operating section 185 of the sliding belt 180 is partially superimposed on the output conveyor 130, so that, when the tray V passes the terminal end of the sliding belt 180 it can remain directly in resting on the outfeed conveyor 130.

In the meantime, the first support arms 280 can be raised by an amount substantially equal to the thickness of a tray V, so as to bring the next tray V into a position suitable for being gripped by the abutment bodies 220 and repeat the previous cycle.

This cyclic operation takes place while the second support arms 325 are in an open configuration, so as not to interfere with the trays V, and continues until the first support arms 280 reach their raised position.

At this moment, the second support arms 325 are in or are brought into a lowered position and in a closed configuration, so as to be substantially coplanar with the first support arms 280, resulting vertically below the stack of remaining trays V in order to to be able to support them.

At this point, the de-stacking process resumes in the same way described above, with the only difference that the support and progressive lifting function, previously performed by the first support arms 280, is now performed by the second support arms 325 .

The de-stacking process proceeds until the last tray V of the stack is released on the upper conveyor 175, after which the second support arms 325 can be returned to the lowered position and in the open configuration.

Meanwhile, the first support arms 280 can be moved back to the lowered position, so that, as the second support arms 325 lift up and release the last V trays to the upper conveyor 175, a new stack of V trays can be brought in operating position from the bottom conveyor 155, saving time.

In any case, after a stack of trays V has been raised with respect to the corresponding support plate S, the lower conveyor 155 can also be activated to remove the empty support plate S.

As illustrated in Figure 16, by means of the lower conveyor 155, the empty support plates S can be introduced one at a time on a handling line 500 adapted to transfer them from the de-stacking machine 125 back to the stacking machine 145, so as to be able to be reused.

This handling line 500 can comprise a series of conveyors, for example roller conveyors or belt conveyors or belts, variously arranged in succession to each other.

For example, the handling line 500 comprises a roller conveyor T equipped with a series of rollers R, homologous to each other, placed side by side along a direction of advancement of the support plates S and able to provide a support surface for the support plates S themselves.

For example, the R rollers are side by side and not in contact so that a gap is created between two consecutive R rollers.

Along the handling line 500, in correspondence with the roller conveyor T, a magazine 505 can be placed, which is able to receive the empty support plates S coming from the de-stacking machine 125, accumulate them for a certain period of time and, when necessary , send them back to the stacking machine 145.

In this way, it is possible to create a basin of support plates S which allows to cope with any variations in the production rate of the plant 100.

Inside the warehouse 505, the support plates S can be collected in a stack so as to take up less space.

In the illustrated embodiment, the magazine 505 can therefore comprise a single stacker / de-stacker device 515 for the support plates S, illustrated in Figures 17 to 19, which is selectively adapted to stack the support plates S or to de-stack the support plates S, stack them as needed.

The stacker / de-stacker device 515 first of all comprises a substantially horizontal frame 520, positioned below the roller conveyor T of the handling line 500.

The 520 frame can be rigid, for example made of a metallic material such as stainless steel.

The frame 520 is movable between a lowered position in which it is located at a maximum distance from the support plane for the support plates S defined by the roller conveyor T and a raised position in which it is located at a minimum distance from said support plane.

To make this movement between the lowered position and the raised position stable and safe, the frame 520 can be slidingly coupled to a support structure 525 equipped with suitable guiding members.

The stacker / de-stacker device 515 further comprises a first actuator 530 adapted to set the frame 520 in motion between the lowered position and the raised position and vice versa.

In the illustrated embodiment, the first actuator 530 is configured as a motor, for example an electric motor, which is able to rotate one or, more preferably, at least two cams 535 which are placed under the frame 520.

In particular, the cams 535 are placed in contact with the frame 520, for example each at a respective end of the frame 520 itself, so that by rotating they are able to move it between said lowered position and said raised position and vice versa.

As illustrated in Figure 18, the stacker / de-stacker device 515 further comprises at least one pair of rods 540 which substantially rise vertically from the frame 520.

The rods 540 can be shaped like rigid bars provided with a lower end which is movably fixed to the frame 520 and with a free upper end.

In particular, the lower end can be hinged to the frame 520 so that each rod 540 can rotate with respect to a substantially horizontal hinge axis and parallel to the direction of advancement of the support plates S on the roller conveyor T.

Each rod 540 is interposed between two consecutive rollers R of roller conveyor T, i.e. it develops substantially vertically in the interspace made between two consecutive rollers R, with the second end of rod 540 extending above the support surface of the plates S.

The rods 540 are spaced apart and aligned along a substantially horizontal alignment direction and perpendicular to the respective hinge axes.

In particular, each rod 540 is placed in proximity to a respective end of the frame 520 so that the distance between the rods 540 is substantially equal to the width of a plate S or slightly greater.

Each rod 540 has at its free upper end a support 545 adapted to contact the support plates S.

The support 545 can be substantially shaped as an "L" -shaped body, that is, it can have two mutually perpendicular sections, of which a first section, which is fixed parallel to the rod 540, and a second section which protrudes overhanging and extends in horizontal direction.

Specifically, the support 545 is fixed to the rod 540 so that, when the frame 520 is in the lowered position, the second protruding portion is placed at a lower level than the support plane for the support plates S defined by the roller conveyor T .

However, it is not excluded that, in other embodiments, the support 545 can be made in a monolithic body with the rod 540.

The stacker / de-stacker device 515 comprises second actuator means adapted to rotate each rod 540 around the corresponding hinge axis between an engagement position (shown in figure 18), in which the rod 540 is substantially vertical, and a position of disengagement (not shown), in which the rod 540 is inclined so that the second end is moved away from a longitudinal centreline of the roller conveyor T.

In practice, in the disengagement position, the second end of each rod 540 is misaligned with respect to the first end and moved towards the outside of the roller conveyor T.

The second actuator means can comprise a plurality of hydraulic cylinders 550, each of which is provided with a first end fixed to the frame 520 and with a second end fixed to a respective rod 540.

However, it is not excluded that, in other embodiments, the second actuator means may comprise any other actuator suitable for moving the rods 540 in the manner described above.

As can be understood from figures 17 and 19, in the illustrated embodiment, the stacker / de-stacker device 515 preferably comprises two pairs of rods 540 shaped as explained above.

The pairs of rods 540 are parallel to each other and placed at a distance along the direction of advancement of the support plates S on the roller conveyor T.

In particular, the pairs of rods 540 are placed at a distance at least slightly less than the length of the support plate S.

In practice, the operation of the stacker / de-stacker device 515 is as follows.

During the stacking step a first support plate S reaches the stacker / de-stacker device 515, while the frame 520 is in the lowered position with the rods 540 in the engagement position.

At this point, by means of the first actuator 530, the frame 520 is brought into the raised position, so that the supports 545 of the rods 540 contact the plate S, substantially in correspondence with four edges thereof, lifting it from the support surface provided by the roller conveyor T.

When a second support plate S reaches the stacker / de-stacker device 515, the frame 520, by means of the first actuator 530, is lowered until the first support plate S is substantially in contact and resting on the second plate support S.

In this position, the second portion of each support 545 is received in the space between the flaring of the second support plate S and a lower surface of the first support plate S.

At this point, the rods 540, by means of the respective hydraulic cylinder 550, are brought into the disengagement position, leaving the first support plate S stacked on the second.

The frame 520 is then lowered until reaching the lowered position and the rods 540 returned, by means of the respective hydraulic cylinder 550, to the engagement position.

The frame 520 is then raised as previously described, so as to lift from the roller conveyor T the stack consisting of the first and second support plates S.

The procedure described above is then repeated when a third support plate S arrives, and so on until a complete stack of support plates S of the desired height is created.

In the de-stacking phase, the operation of the stacker / de-stacker device is as follows.

Initially, the stack of plates S is raised from the support plane defined by the roller conveyor T, supported by the rods 540 in the engagement position and by the frame 520 in the raised position.

At this point, the frame 520 is lowered, by means of the first actuator 530, until a first support plate S, the one placed on the bottom of the stack, rests on the roller conveyor T.

The rods 540, by means of the respective hydraulic cylinder 550, are then brought into the disengagement position, after which the frame 520, by means of the first actuator 530, is raised up to a height such that the second section of the supports 545 is substantially coplanar with the flaring of the first support plate S placed on the roller conveyor T.

At this point, the rods 540 are returned to the engagement position, by means of the respective hydraulic cylinders, so as to slide into the aforementioned flaring and therefore place themselves under a second support plate S which rests on the first.

The frame 520 is then further raised until it reaches the raised position, so as to raise the second support plate S and therefore all the support plates S stacked thereon.

The roller conveyor T is then operated so as to advance the first support plate S which rests on the roller conveyor T, before the frame 520 is lowered again, by means of the first actuator 530, to place the second support plate S is resting on the roller conveyor T.

The procedure is then repeated, one support plate S at a time, until the stack of support plates S is completely unstacked.

Returning to the diagram in figure 16, along the handling line 500 can also be placed a brushing machine 510 suitable for cleaning the support plates S, in order to increase the hygiene of the entire system 100.

This brushing machine 510 can comprise for example brushing members, typically but not exclusively rotating brushes, which are adapted to brush the support plates S which advance on the handling line 500.

Preferably, the brushing machine 510 can be placed along the handling line 500 upstream of the magazine 505, in such a way that the support plates S are stacked already clean and ready for a new use.

Obviously, a technician in the field can make numerous changes of a technical-applicative nature to everything described above without thereby departing from the scope of the invention as claimed below.

Claims (1)

CLAIMS 1. A stacking or de-stacking machine for baking trays (V), comprising: - a horizontal support surface (150) suitable for supporting a stack of trays (V), - an upper conveyor (175) adapted to hold a tray (V) in a position suspended vertically above the support surface (150) and spaced from it, and - a lifting device (275) adapted to move the stack of trays (V) vertically in the space between the support surface and the upper conveyor (175), characterized by the fact that said support surface (150) is defined by a support plate (S) resting on a support apparatus 2. A machine according to claim 1, wherein said support plate (S) is made of plastic material. 3. A machine according to claim 1 or 2, in which the support apparatus comprises a lower conveyor (155) adapted to advance the support plate (S) and to stop it under the upper conveyor (175). 4. A plant (100) for the stacking and de-stacking of trays (V) for baked goods, comprising: - a first machine (125) according to any one of the preceding claims for unstacking the trays (V) of a stack, - a second machine (145) according to any one of the preceding claims for stacking the trays (V) forming a stack, and - a handling line (500) adapted to transport the support plates (S) from the first machine (125) to the second machine (145). A plant (100) according to claim 4, in which a brushing machine (510) adapted to brush the empty support plates (S) before reaching the second machine (145) is placed along the handling line. 6. A plant (100) according to claim 4 or 5, in which along the handling line (500) there is a magazine (505) suitable to receive the support plates (S) coming from the first machine (125), to accumulate them and to send them to the second machine (145). A plant (100) according to claim 6, wherein said magazine (505) comprises at least one stacker / de-stacker device (515) of the support plates (S). A plant (100) according to claim 7, in which the magazine (505) is placed along the handling line (500) between the brushing machine (510) and the second machine (145). An installation (100) according to claim 7, wherein the stacker / de-stacker device (515) comprises: - a conveyor (T) able to define a support surface for the support plates (S), - a plurality of supports (545), - first actuator means (530) adapted to move the plurality of supports (545) between a lowered position, in which they are placed at a lower height than the support for the support plates (S), and a raised position in which they are placed to a height higher than said support surface, - second actuator means (550) adapted to move the plurality of supports (545) between an engagement position, in which they are able to contact and support a support plate (S), and a disengagement position, in which are not able to stay in contact with said support plate (S). A plant (100) according to claim 9, wherein the plurality of supports (545) is fixed to a frame (520), which is movable between the lowered position and the raised position operated by the first actuator means (530) .