ES3014970A1 - CARDBOARD SHEET FEEDER FOR CARDBOARD BOX FORMING MACHINE FROM SUCH SHEETS AND METHOD OF FEEDING CARDBOARD SHEETS - Google Patents

Abstract

Cardboard sheet (S) feeder for a box forming machine (100) (B), wherein at the output end of a loader (10) there is fixed, during the cyclic movement of a suction mechanism (60) for extracting sheets (S), a device for separating (30) a plurality of front sheets (S) from the stack (P) comprising a friction zone (31) and a blown air outlet mouth (32) facing the same side of a loading zone of the loader (10) and arranged in the same advance section (A) of sheets (S) in the loader (10), the blown air outlet mouth (32) assisting in a subsequent separation of the edges of said plurality of front sheets (S) by blowing air between some faces of the sheets (P) as these same edges are previously separated by the friction zone (31). (Machine-translation by Google Translate, not legally binding)

Description

DESCRIPTION

CARDBOARD SHEET FEEDER FOR CARDBOARD FORMING MACHINE

CARDBOARD BOXES FROM SUCH SHEETS AND FEEDING METHOD

OF CARDBOARD SHEETS

TECHNICAL SECTOR

The technical field of the present invention is the plate feeders that prevent multiple feeding of plates for the manufacture of containers of semi-rigid sheet material, for example, cardboard, by folding a plate in a forming station of the type that includes a male or mandrel that moves with a reciprocating or oscillating movement in and out of a folding die or mold.

OBJECT OF THE INVENTION

According to a first aspect, the present invention relates to a cardboard sheet feeder for a machine for forming cardboard boxes from such sheets.

According to a second aspect, the present invention relates to a method of feeding cardboard sheets.

The term "cardboard" used throughout the present invention must be understood in a broad sense, and refers to a semi-rigid material in the form of a sheet that maintains its shape unless subjected to external forces and that has a certain rigidity when folded / bent. Said term "cardboard" of semi-rigid material in the form of a sheet includes the cases of a sheet (sheet) of corrugated cardboard (corrugated), a sheet of compact cardboard (also called cardboard cardboard, laminar cardboard, laminated cardboard or stretched cardboard), a sheet formed by a sheet of cardboard joined to one or more internal and / or external plastic sheets, a sheet that combines at least one sheet of paper and another of plastic, among others.

Preferably, each sheet or plate is die-cut with weakened fold lines to facilitate its formation into a box by folding portions of the plate around said weakened lines.

STATE OF THE ART AND TECHNICAL PROBLEM TO BE SOLVED

Document ES2914929A1, from the same owner and inventor as the present invention, discloses a cardboard box forming machine that includes a plate feeder comprising a plate loader supported by their lower edges, and a suction mechanism and a conveyor that feed the plates one by one from the loader to a forming station, which includes a core and a mold with a cavity where the core can be inserted and removed. The machine in document ES2914929A1 has a significantly improved box production speed, reaching up to 6,000 boxes per hour in each core and mold assembly, compared to 2,500 or 3,500 boxes in the state of the art. Thus, the production speed of the machine is essentially doubled for conventional box formats, for example, for conventional trays (basket-type boxes) or conventional C1-type boxes, among others.

Furthermore, the machine in document ES2914929A1 allows the formation at high speeds, in the range between 5,000 and 6,000 boxes / hour, (approximately 2,500 and 3,000 for each male and mold) of boxes known in the technical field as "topseal" boxes or trays, which are boxes with projecting flanges, folded outwards from the side walls by respective flange fold lines. These flanges or shelves are located in the upper open mouth of the cardboard box and provide a support surface, which may be closed, for example, by heat sealing or gluing with a top sheet.

However, when the machine in document ES2914929A1 is fed with cardboard sheets with certain specifications, for example, including certain materials, e.g., cardboard sheets with excessive paraffin on their faces, and/or certain cardboard sheets with a plastic coating, and/or when the machine is fed with cardboard sheets of very reduced thickness, e.g., extremely thin solid or corrugated cardboard sheets or plastic-coated paper sheets, an unwanted multiple feeding of plates occurs, i.e., the plates are inconveniently not removed from the plate loader one by one, but rather two by two or in packs of plates. Thus, the feeder is unable to counteract an adhesive effect that keeps a plate attached to one or more other plates, and the feeder is unable to separate the plates individually. All of this results in the feeder's limited versatility for working with different plates at high speeds.

This inconvenient multiple feeding of mutually adhered sheets causes the production stoppage of the machine, due to jamming of the mutually joined sheets during transport to the forming station or due to jamming of the mutually joined sheets due to the thrust of the male towards the mould.

In some cases, such double/multiple feeding of sheets has even experimentally caused the breakage of parts of the machine, for example, the core drive mechanism, when trying to force the core into several sheets at once against its mold, leaving the machine unusable until the parts are replaced by qualified personnel, having the machine stopped for long periods of time, dramatically reducing its productivity.

On the other hand, consulting documentation in the technical field, document US3527367A discloses an escape device 7 of a loader 9 for installation in a cardboard box machine to release cardboard sheets one by one in synchronism with a vacuum suction cup mechanism 5. The escape device 7 comprises a stop device 29 movable between a position facing the first output sheet and a retracted position, a spring device 38 arranged behind said stop device 29 to retain the sheets while allowing the removal of the sheets one by one, a gripping device 33 with a rough face 34, is movable by a lever mechanism between a lower position out of the path followed by the sheets in the loader (Fig. 3) and an upper vertical thrust position for controlling the weight of the sheets in the loader (Fig. 4).

In the vertical pushing position of Fig. 4 of document US3527367A, the gripping devices 33 with roughened faces 34 engage the lower edges of vertically arranged plates to push them against the upper opposite side of the magazine 9 to restrain the weight of the rest of the plates arranged behind those restrained, while a few plates 35, 36 are supported by the lower spring device 38 and an upper stop 37, the first of these supported plates being ready to be removed by the suction cups 5 with the stop device 29 in the retracted position.

In document US3527367A, for the subsequent advance of sheets towards the exit end, the gripping device 33 returns to the retracted position and the stop device 29 returns to the opposite (active) position, since the stop device 29 and the gripping device 33 always operate in opposite directions, one being active and the other inactive. The escape device 7 operates twice per revolution of a lever cam 22 or each time the vacuum venous device 5 takes a cardboard sheet from the loader.

In document WO2012082048A1, similarly to document US3527367A, it discloses a feeder 1 for a cardboard box forming machine that controls the weight of the stack of sheets on the front sheet to be removed, and comprises stop means 14, 34 at the output end 13 of the loader to hold the stack of sheets in position, by its edges, in combination with a press plate 15, 35 with a corrugated surface 15a or interaction surface 35a with protuberances, vertically movable by a cylinder 18, to apply vertical pressure on a subgroup of front sheets the stack of sheets arranged in the loader 11. The corrugated surface 15a or interaction surface 35a prevents stack collapses since it penetrates the edges of the sheets, anchoring the upper edges of the same.

In document WO2012082048A1, similarly to document US3527367A, the movement of the press plate 15, 35 between the retracted position of Fig. 2 and the pushing position of Fig. 4 is intermittent, occurring cyclically, once for each plate removed from the feeder.

Additionally, in document WO2012082048A1, the intermittent movement of the press plate 15, 35 is in synchronism with an intermittent forward movement of the plate by a ratchet mechanism associated with a conveyor comprising two conveyor belts or bands 51a, 51b moved by a cylinder associated with a ratchet mechanism and controlled independently of each other by sensors 52a, 52b. In this same sense, document WO2016046433A1 can be cited.

Thus, in both documents US3527367A and WO2012082048A1, to control the pressure exerted by the stack of plates on the first plates to be removed, the corrugated vertical pressure surfaces, to control the weight exerted by the rest of the stack of plates on the first plate or plates to be removed from the stack, are retracted to a position where they allow the stack of plates to advance towards the output end of the loader.

On the other hand, document US3429570A discloses a feeder comprising means for supporting a stack of sheets by their edges (chains 42), suction cups 70 for removing the front sheets from the stack, and sheet separating elements 110, inclined downwards by about 45 degrees, mounted on arms 112. Each arm 112 is pivotally mounted on an oscillating shaft 116 articulated in spaced apart brackets 118 attached to cross bar 58. Thus, the separating elements 110 fixed on arms 112 are rocked downwards each operating cycle, by a complex mechanism of cams 120, 124 and gears, to present serrated surfaces of the separating elements 110 against the upper front corner or upper edges of the front group of sheets in the stack, to apply a downward pressure at an angle of 45 degrees. As the separating members 110 are continuously moved downward in their swing, the planks of the front plank group are separated and bowed forward to present the front plank in engagement with the suction cups 70, as shown in Fig. 3. Thus, the front plank cannot be sucked by the suction cups unless the plank is bowed (see Figs. 3 and 5) due to the separation between the non-bowed front plank and the suction cups 70 (Fig. 5), this being a very critical and failure-prone operation for planks of certain specifications, as referred to above.

Thus, document US3429570A has severe limitations when working with plates of certain specifications, such as those referred to above, since the complex mechanical linkage of the cams that balance the separation elements 110 and the critical coupling of the front plate to the suction cups 70, always with the plate arched, have a difficult and critical adjustment with the triangular adjustment plate 114, prone to failure, and in any case the machine is not capable of easily adapting to plates of different mechanical resistances, depending on their thickness and/or coating or covering material.

Furthermore, the feeder of document US3429570A, for certain types of sheets, for example for the formation of the “topseal” type boxes described above, the inclination of the saw teeth of the separating elements 110, downwards, so as to press and arch the top of the sheet, may optionally even cause an undesired bending of the sheet removed from the magazine, particularly produced around the fold line separating the upper edge of the sheet of the stack from the side wall of such upper edge, which may complicate subsequent forming operations, eventually causing frequent production stoppages or even making it impossible to form such extremely thin boxes and/or with certain layers and/or coating compounds.

Continuing with US3429570A, provision is also made for directing air streams against opposite lateral sides of the leading end of the stack (see Fig. 2) to further assist in separating adjacent sheets in the fanned and arcuate group of sheets formed by the upper separating elements 110, preventing the extraction of two or more preforms by the suction cups 70. The air jets 142, 144 are supported on supports 146 attached to and extending from the cross support bar 58. Each air jet is connected by a flexible hose 148 to a regulated source of compressed air. In use, air is discharged from the jets 142, 144 for a predetermined time each cycle of operation during the separation operation and extraction of the front sheet after which the air is discontinued.

In view of the foregoing, the technical problem to be solved is to increase the production speed of a cardboard plate feeder that supplies plates individually to a box-forming machine, for a wider range of plates, for example, when it works with plates made of certain materials, for example, cardboard plates with excess paraffin on their faces, and/or cardboard plates with a plastic coating sheet, and/or when it works with cardboard sheets of very reduced thickness, for example, extremely thin solid and/or corrugated cardboard plates or plastic-coated paper plates, which tend to produce unwanted multiple feedings of plates at high speeds. In other words, the technical problem can be established in how to increase the versatility of such a feeder at high speeds, to supply plates of very different configurations.

EXPLANATION OF THE INVENTION

To solve the drawbacks described in the previous section, according to a first aspect, the present invention presents a cardboard sheet feeder.

The cardboard sheet feeder is installed in a cardboard box forming machine from sheets of the type comprising a forming station including a core and a mold facing each other. The core can be inserted and removed into a mold cavity at least partially delimited by mold-forming devices for forming boxes by folding and joining parts of the sheet with each other.

The feeder comprises a magazine comprising a lower support for contacting lower edges of the sheets supported in the magazine, forming a stack of sheets. The magazine also comprises two side guides, one of said side guides on each side of said supported sheets, for positionally delimiting respective mutually opposite side edges of the sheets.

The lower support and the side guides delimit a loading area with a lower side, two lateral sides, and an upper side that is open or optionally delimited by an upper guide that positionally delimits the upper edges of the plates.

Furthermore, said loading area has a plate input end or site and a plate output end or site facing each other according to a plate feed direction A.

At the output end, a plurality of sheet stops are arranged, configured to retain the front sheet of the stack, to be extracted by at least one suction cup of a suction mechanism of the feeder, movable by a drive. The suction mechanism extracts the front sheets individually from the magazine and deposits them on a sheet conveyor, which supplies sheets to the forming station.

The suction mechanism can be actuated by any drive in general, for example, by way of illustration but not limitation, the drive includes an electric motor and/or a fluid dynamic cylinder, among other options, which causes the movement of the at least one suction cup between the position associated with the output end of the loader and the position on the conveyor, to extract the front plate from the loader and supply it to the conveyor.

In a manner not known in the state of the art, the present invention presents the following characteristics of the feeder.

At the output end of the magazine, a device is arranged in a fixed position during the cyclic operation of the feeder, for separating a plurality of front sheets from the stack. Thus, the position of the separating device is maintained in relation to the magazine when the suction mechanism is in automatic mode, cyclically moving by the drive, extracting sheets from the magazine and depositing them on the conveyor.

The separation device comprises a friction device and an air blowing device, strategically positioned as will be described in detail later.

The friction device includes a friction zone capable of separating edges of a plurality of front plates from each other as the plates advance in the advance direction A with the extraction of each front plate by the suction mechanism.

In some cases, the friction zone may include protrusions (irregularities or projections), for example, saw teeth, knurling, rose edges of a shaft (screw or spindle), or those included in a sanding belt, metal fibers, wood fibers and/or textile fibers, such as textile fibers used in slings, and/or a combination of these, among others.

In still other options and/or in addition to the option in the previous paragraph, the friction zone may include a rough element, for example, a plastic compound, for example, by way of illustration, but not limitation, rubber, or plastic compounds used in drag conveyor belts, which have a relatively high coefficient of friction, compared to smooth metal and/or Teflon surfaces.

Preferably, the friction zone includes protrusions or roughnesses delimited between a flat upper surface and a flat lower surface. That is, the friction zone includes an essentially flat interference area.

In an alternative and/or additional option to the preferred option in the preceding paragraph, the friction zone is an interference edge that has protuberances or roughness along its length; for example, said contact edge corresponds to the contact edge of the edges of the plates with a shaft with threaded edges, for example, a screw, a spindle, a knurled shaft, or corresponds to the elongated broken edge of saw teeth in contact with the edges of the plates. The aforementioned axes are preferably parallel to the feed direction A.

Likewise, the separation device comprises, in combination with the friction device, an air blowing device. The air blowing device includes a blown air outlet associated with a pressurizable air conduction device. The air conduction device can be pressurized by a pressurized air source, for example, by a pressurized air tank and/or an air compressor.

The air outlet vent faces the friction zone and is adjacent to it. Furthermore, the air outlet vent and the friction zone face each other on the same side of the loading zone and are arranged in the same forward section according to the forward direction A.

Thus, the air outlet and the friction area of the separation device both face the lower side, both face either one of the two lateral sides, or both face the upper side of the loading area.

Thus, the air outlet and the friction zone are not arranged one after the other according to the linear feed direction A of the sheets, but arranged transversely in the same longitudinal feed section according to the feed direction A, in order to be able to separate the edges in two phases, synergistically, in the same work area.

The air blowing outlet is configured to assist in a subsequent separation of the edges of said plurality of front plates by blowing air between some faces of the plates as these same edges are previously separated by the friction zone, in the same work area, to extract the plates one by one from the loader.

Advantageously, the fixed arrangement, on one side of the loading area, in the same working area, of the friction device and an air blowing device of the separation device, for acting on the same edges of the sheets, enables sheets of various specifications to be extracted from the loader individually at high speeds.

That is to say, advantageously, in said work zone intentionally focused in position in the present invention, on one same side of the exit end of the loading zone and in one same section of plate advance, two plate separation technologies coexist, concentrated in a positionally fixed region, acting synergistically, such that the separation provided by the friction zone is used by the air blow outlet to print a subsequent edge separation, blowing air between the faces of the plates, which allows the unitary separation of plates of a greater range of materials and thicknesses at high speeds, conferring versatility.

A number of additional optional features are described below.

In an optional advantage, the arrangement of the blown air outlet adjacent to the friction zone, in addition to helping enable the unitary extraction of plates, limits unwanted movements of the blown air outlet in at least one linear direction, for example, a direction transverse to the direction of advance, due to collisions of the upper extremities of the operator or of the plates against the blown air outlet during the plate loading operation, maintaining the relative position between the air outlet and the friction zone, focused on an effective work region or zone.

Optionally, the separation device may comprise a plurality of friction devices, each with a respective friction zone.

Optionally, the separation device may comprise a plurality of blown air outlets.

Preferably, the separating device is arranged fixed to one end of the lower support element located at the outlet end of the charger. Thus, in this preferred embodiment, the air outlet and the friction zone specifically face the underside of the charging area.

Advantageously, the arrangement of the separation device fixed at the end of the lower support element causes the plates to be separated on the lower side of the loading area, side where the weight of each plate falls on the friction zone, the weight of the plates themselves facilitating the separation by friction between the lower edges of the plates.

Optionally and/or additionally, the separating device may be fixed at one end of the side guides and/or at one end of an optional upper guide at the outlet end of the magazine which positionally delimits the upper edges of the plates, each of these ends being located at the outlet end of the magazine.

Optionally and/or complementarily, the feeder comprises a plurality of separation devices as referred to above.

In one option, the feeder comprises two separating devices, one fixed at each end of each side guide.

In one option, the feeder comprises two separating devices, one fixed at the end of the lower support and another fixed at the end of an upper guide.

In another option, the feeder comprises the four separation devices of the two previous options.

Preferably, the friction device is arranged in said fixed position in a removably manner by a fixing and releasing device.

Preferably, the feeder further comprises one or more additional separating devices arranged in fixed positions, removably by a respective securing and releasing device, at the outlet end of the magazine. Each separating device further comprises a respective smooth area. In the feeder, each securing and releasing device of each additional separating device enables two interchangeable working positions. In a first interchangeable working position, the friction area is secured to the side of the loading area to contact the plurality of face plates, while in a second interchangeable working position, the smooth area is secured to the side of the loading area, configured to contact the plurality of face plates.

Advantageously, the additional separating devices are each positioned in either the first or second working position, giving the machine greater versatility when working with a wider range of plates at high speeds.

Preferably, the feeder comprises a pair of separating devices positioned in respective working positions, facing each other on two mutually opposite sides of the loading area. Thus, one separating device in the first working position faces the lower side and another separating device in the first or second working position faces the upper side of the loading area of the magazine, and/or one separating device in the first working position faces the lateral side and another separating device in the first or second working position faces the other lateral side of the loading area of the magazine.

Advantageously, this facing arrangement of separation devices facilitates the unitary separation of a wide variety of plates at high speeds.

Other optional features of the feeder and their associated advantages are described below with reference to the figures.

According to a second aspect, to overcome the drawbacks of the previous section, the present invention presents a method for feeding cardboard sheets.

Each of the fed sheets comprises a lower edge, two mutually opposite side edges, and an upper edge.

In the method, the plates are fed by a plate feeder and are initially supported on a lower support of a feeder magazine forming a stack of plates guided laterally by two magazine side guides, one on each side of the stack.

In a manner not known in the state of the art, the method of the present invention comprises the steps of:

- employing a device for friction and blow separation of a plurality of front plates from the stack of the feeder, arranged in a fixed position at the plate output end of the loader during an automatic movement of a suction mechanism of the feeder that extracts the front plates from the stack one by one by suction with at least one suction cup; and

- separating the front plates from the stack by acting by friction and blowing on the same edges of the front plates with the separation device, this separation comprising the steps of:

- separating the edges of the plurality of face plates of the stack from each other by a friction device including a friction zone as the plates advance in a forward direction A at the plate outlet end with the extraction of each face plate from the outlet end by at least one suction cup of the suction mechanism, and

- separating the edges of said plurality of front plates by blowing air between some faces of the plates by means of a blown air outlet associated with a pressurizable air conducting device, as these same edges are previously separated by the friction zone, in the same work zone in a section according to the direction of advance A, extracting the plates one by one from the loader.

Advantageously, in said work zone intentionally focused in position in the present invention, on one same side of the exit end of the loading zone and in one same section of plate advance, two plate separation technologies coexist, concentrated in one same positionally fixed region, acting synergistically, such that the separation provided by the friction zone is used by the air blow outlet to print a subsequent edge separation, blowing air between the faces of the plates, which allows the unitary separation of plates of a greater range of materials and thicknesses at high speeds, conferring versatility to the feeding.

Optional features of the method and the advantages associated with them are described below with reference to the embodiments in the figures.

BRIEF DESCRIPTION OF THE DRAWINGS

To complement the description being made of the object of the invention and to help better understand the characteristics that distinguish it, a set of drawings is included in this descriptive report, as an integral part thereof, in which the following has been represented for illustrative and non-limiting purposes:

Fig. 1 is a front top perspective view of two cardboard sheet feeders installed on the same cardboard box forming machine, according to a first embodiment;

Fig. 2 is a top perspective view of a plate for forming a conventional type of tray;

Fig. 3 is a top perspective view of a plate for forming a topseal type of tray;

Fig. 4 is a rear top perspective view of Fig. 1;

Fig. 5 is a rear top perspective view of a stack of plates as shown in Fig. 2 and where the direction of advance of plates in the loader towards the output end is indicated;

Fig. 6 is a rear top perspective view of a stack of plates as shown in Fig. 3 and where the direction of advance of plates in the loader towards the output end is indicated;

Fig. 7 is a front top perspective view of the plate feeder of Fig. 1, also showing the machine conveyor;

Fig. 8 is an enlarged view of section V of Fig. 7;

Fig. 9 is an enlarged view of section VI of Fig. 7;

Fig. 10 is a cut-away side view of Fig. 7 in which some elements have been omitted for the sake of a better understanding of the invention, and also represents a second embodiment of the feeder;

Fig. 11 is a side view similar to that of Fig. 10, now with the at least one suction cup of the suction mechanism in the position associated with the conveyor;

Fig. 12 is a front top perspective view of the pushing device supported on the lower support and of a separating device fixedly arranged at the end of the lower support according to any one of the embodiments of Figs. 7 or 10;

Fig. 13 is a front top perspective view of the end of the lower support with separation device of Fig. 12;

Fig. 14 is a rear bottom perspective view of Fig. 13;

Fig. 15 is a corresponding view with an alternative embodiment of Fig. 13, where now the separating device is in the second interchangeable working position and fixed at the end of the lower support of Fig. 18;

Figs. 16, 17, 18 and 19 are respective schematic front views of a feeder, frontally showing the output end of the loader and the friction device, corresponding to a third, fourth, fifth and sixth embodiments, respectively;

Figs. 20 and 21 are top and bottom perspective views, respectively, of a part of the separation device of Fig. 13;

Fig.22 is a side view of the part in Fig.20;

Fig. 23 is a sectional view along section B-B of Fig. 22;

Fig.24 is a perspective view of Fig.23;

Fig.25 is a top view of the part in Fig.20;

Fig. 26 is a sectional side view along the D-D section of Fig. 25;

Fig.27 is a front top perspective view of Fig.26;

Fig. 28 is a top perspective view of a second embodiment of the separation device, fixed at the end of the lower support, analogously to Fig. 12;

Fig. 29 is a bottom perspective view of Fig. 28;

Figs. 30 and 31 are top and bottom perspective views, respectively, of a third embodiment of the separating device, in the first working position, fixed to the end of the lower support in the same way as Fig. 12;

Fig. 32 is a top view of the separation device of Fig. 30;

Fig. 33 is a sectional side view along the E-E section of Fig. 32;

Fig. 34 is a top perspective view of the third embodiment of the separating device, in the second working position, fixed at the end of the lower support of Fig. 18;

Fig. 35 is a top perspective view of a fourth embodiment of the separating device arranged in a fixed position at the end of the lower support;

Figs. 36 and 37 are top and bottom perspective views, respectively, of a fifth embodiment of the separating device, fixed to the end of the lower support in the same way as Fig. 12;

Fig. 38 is a partially sectioned side view of the separation device of Fig. 36;

Fig. 39 is a top view sectioned along the F-F section of Fig. 38;

Figs. 40 and 41 are top and bottom perspective views, respectively, of a sixth embodiment of the separating device, fixed to the end of the lower support in analogy to Fig. 12;

Fig. 42 is a partially sectioned side view of the separation device of Fig. 36;

Fig. 43 is a top view sectioned along the section G-G of Fig. 42;

Fig. 44 is a top perspective view of a seventh embodiment of the separating device, fixed at the end of the lower support of the magazine analogously to Fig. 12;

Fig.45 is the top view of Fig.44;

Fig. 46 is a top perspective view of an eighth embodiment of the separating device, fixed at the end of the lower support of the magazine analogously to Fig. 12;

Fig.47 is the top view of Fig.46;

Fig. 48 is a top perspective view of a ninth embodiment of the separating device, fixed at the end of the lower support of the magazine analogously to Fig. 12;

Fig. 49 is the top view of Fig. 48, partially cut away;

Fig. 50 is a top perspective view of a tenth embodiment of the separating device, fixed at the end of the lower support of the magazine analogously to Fig. 12;

Fig. 51 is the top view of Fig. 50;

Fig. 52 is a top perspective view of an eleventh embodiment of the separating device, fixed at the end of the lower support of the magazine analogously to Fig. 12;

Fig. 53 is the top view of Fig. 52;

Figs. 54 and 55 are respective enlarged side views of the feeder with a separation device analogous to that shown in Figs. 28 and 29, showing part of the feeder's operating sequence, and where only the plurality of front plates of the stack have been represented; and

Figs. 56 to 59 are respective enlarged side views of the first and second embodiments of the feeder of Figs. 7 to 14, showing part of the feeder's operating sequence, and where only the plurality of front plates of the stack have been represented.

DETAILED EXPOSURE OF IMPLEMENTATION METHODS / EXAMPLES

According to a first aspect, the present invention relates to a cardboard sheet (S) feeder for a machine (100) for forming cardboard boxes (B) from sheets (S).

Figs. 1, 4, 7, 10 and 11 show that the cardboard sheet (S) feeder is installed on the chassis (1) of a machine (100) for forming cardboard boxes (B) from sheets (S) of the type comprising a forming station including a core or head (not shown) and a mold facing each other. The core is insertable and removable in a cavity (95) of the mold delimited at least partially by forming devices (96) of the mold for forming boxes (B) by folding and joining some parts of the sheet (S) with others.

In Figs. 1, 4, 7, 10 to 12, 16 to 19 and 54 to 59, the feeder comprises a magazine (10) comprising a lower support (11) for contacting lower edges (CI) of the plates (S) supported in the magazine (10), forming a stack (P) of plates (S) shown in Figs. 5 or 6.

Likewise, the loader (10) comprises two lateral guides (12), one of said lateral guides (12) being on each side of said supported plates (S), to positionally delimit respective mutually opposite lateral edges (CL) of the plates (S), better shown in Figs. 4 to 6 and 15 to 19.

In the figures, the lower support (11) comprises a support surface, for example, of one or more plates, although alternatively it may comprise two elongated bars with a circular section whose upper parts define edges contained in a virtual support plane or surface.

Alternatively and/or complementarily, the lower support (11) comprises at least one chain, belt or drag band (not shown) movable by a drag drive to advance the plates (S) of the stack (P).

In one option, for example, the moving advance of the chain, belt or band is controlled by a ratchet mechanism (not shown), similarly to that disclosed in document WO2012082048A1, mentioned in the section on the state of the art of the present invention.

The lower support (11) and the lateral guides (12) delimit a loading area or cavity in the shape of a parallelepiped, with a lower side, two lateral sides, and an upper side that is open or optionally delimited by an upper guide (13) that positionally delimits the upper edges (CS) of the plates (S).

Furthermore, said loading zone, for example, shown in Figs. 4 and 7, has a plate inlet end or site (S) and a plate outlet end or site (S) facing each other in a forwarding direction (A) of the plates (S). That is, the parallelepiped-shaped loading zone has a plate inlet mouth and a plate outlet mouth facing each other.

Thus, the loading area of the magazine (10) houses a stack (P) of plates (S), for example, as shown in Fig. 5 or 6.

Figs. 2, 3, 5, 6 and 15 to 19 show that each plate (S) comprises a bottom panel (F) delimited by four fold lines connected to respective four side panels (PL).

In Figs. 3 and 6, each plate (S) comprises flange extensions (R) connected by flange fold lines (LR) to the end portions of the side panels (PL).

The lower edges (CI), upper edges (CS) and side edges (CL) of the plates (S) correspond to the distal edges of the side panels (PL) in Figs. 2, 5 to 16 to 18.

The lower edges (CI), upper edges (CS) and lateral edges (CL) of the plates (S) correspond to the distal edges of the flange extensions (R) in Figs. 3, 6 and 19.

The sheets (S) may optionally have side flaps (SL), as shown in Figs. 2 and 3, connected to the side panels (PL) by fold lines, for joining some side panels (PL) of the sheet (S) with others forming side walls in the formed box (not shown).

Figs. 8, 10, 11 and 16 to 19 show that at the output end of the loading area there is arranged a plurality of plate stops (40) configured to retain the front plate (S) of the stack (P) to be extracted by at least one suction cup (61) of a suction mechanism (60) of the feeder movable by a drive (62).

The suction mechanism (60) extracts the front plates individually from the loader until they are positioned on a plate conveyor (80), which supplies the plates with a transport pusher (81) in a guided manner between two transport guides (82) towards the forming station, as shown in Figs. 7, 10 and 11.

The suction mechanism (60) is movable by any drive (62) in general, for example, the drive includes a rotating electric motor that can be of the conventional type or of the type that forms part of a servomotor, as shown in Figs. 4, 7 and 10.

In an alternative and/or complementary option, not shown in the figures, the drive (62) includes a fluid dynamic cylinder, for example, a pneumatic cylinder.

The preferred suction mechanism (60) of Figs. 7 to 11 is analogous to the suction mechanism described in the Spanish patent application ES2914929A1, already granted, from the same owner and inventor as the present application.

It should be noted that the embodiment of Figs. 4 and 7 shows two feeders, and the respective suction mechanism (60) of each of them is driven by a common drive (62), although in another option each suction mechanism (60) of each feeder may be driven by a respective individual drive (62).

Figs. 7, 10 and 11 show that the drive (62) is configured to cause movement of the at least one suction cup (61) between the position associated with the output end of the magazine (10) of Fig. 10 and the position on the conveyor of Fig. 11, to extract the front plate (S) from the magazine (10) and supply it to the conveyor (80).

Common to all embodiments of the figures, although explicit reference is made here to Figs. 7 to 14 of the first and second embodiments of the feeder, at the output end of the loader (10) there is arranged, in a fixed position during the movement of the suction mechanism (60), a device (30) for separating a plurality of front plates (S) from the stack (P).

In one option, the fixed positioning of the separation device (30) is with screw elements (35b, 36) inserted into holes (33, 37) as shown in Figs. 7 to 14, 28 to 34 and 36 to 59, which will be described in greater detail later.

In another option of Fig. 35, the separation device (30) is in said fixed position thanks to the fact that it forms an integral part of the lower support (11), or alternatively (not shown) of the lateral guide (12) or of the upper guide (13), for example, by its union by welding or by machining of the friction zone (31) on the ends of the delimiting elements of the loading zone located at the plate exit end of the loader (10).

Thus, the position of the separation device is kept unchanged with respect to the loader (10) when the suction mechanism (60) is in motion in automatic mode, that is, cyclically, by the drive (62).

Common to all embodiments of the figures, the separation device (30) comprises a friction device and an air blowing device, in combination, strategically positioned as will be described in detail later.

The friction device includes a friction zone (31) capable of separating edges of a plurality of front plates (S) from each other as the plates (S) advance in the forward direction (A) with the extraction of each front plate (S) by the suction mechanism.

In the embodiments of Figs. 7 to 51 and 54 to 59, the friction zone (31) includes protuberances (irregularities or projections), for example, saw teeth.

Preferably, the pitch between saw teeth (distance between consecutive peaks or valleys) is approximately the same size as the thinnest sheet being fed, for example, between 0.75 and 1.5 mm, or between 1 and 2 mm, among other options. For example, if the thinnest sheet being fed is 1 mm thick, the pitch between teeth is 1.5 mm.

Preferably, the friction region (31) of Figs. 7 to 51 and 54 to 59 includes saw-tooth-shaped protuberances that are delimited between an upper flat surface where the peaks of the teeth are contained, and a lower flat surface where the valleys of the teeth are contained. That is, the friction region (31) of Figs. 7 to 51 and 54 to 59 includes an essentially planar friction or interference area.

In the option of Figs. 50 and 51, each of the two friction zones (31) of the separation device (30) comprise an interference edge that has protuberances along its length; in this case, each of said interference or contact edges corresponds to the broken and elongated edge, according to the direction of advance (A), of saw teeth in contact with the edges of the plates (S).

In the option of Figs. 52 and 53, each of the two friction zones (31) of the separation device (30) includes an interference edge that has along its length some protuberances, in this case, said interference or contact edge corresponds with the contact edge of the edges of the plates (S) with an axis with threaded edges, for example, a screw or bolt. The aforementioned axes are parallel to the direction of advance (A) so that the thread edges are essentially perpendicular to the direction of advance (A).

Common to all embodiments of the figures, although explicit reference is made here to Figs. 7 to 14 of the first and second embodiments of the feeder, the separation device (30) comprises, in combination with the friction device, an air blowing device. The air blowing device includes a blown air outlet mouth (32) associated with a pressurizable air conducting device (33, 34, 34a, 35).

The air conducting device (33, 34, 34a, 35) is pressurizable by a source of pressurized air, for example, by a pressurized air boiler and/or an air compressor (not shown in the figures) to which it is connected in a pneumatic circuit.

Optionally, the air that passes through the blown air mouth (32) may be blown in synchronism with the suction mechanism (60) through a detector device (65, 66, 67), monitored or not, of the rotation of the shaft of the electric motor corresponding to the actuator (62) of the suction mechanism (60) or of the rotation of a shaft driven by the electric motor, for example, the shaft (63) of a reducer (63), among other shafts driven by the drive (62).

In one option, Figs. 10 and 11 show that the detector device (65, 66, 67) includes a cam (66) coupled to the movement of the rotation axis of the electric motor, specifically coupled to an axis moved by it, for example to the axis (63) of a reducer (63) coupled to the electric motor (62), which sends a signal to a control unit through a detector associated with the cam (66), for example, an inductive detector (67), to blow air for a predetermined time when the suction cup (61) approaches and/or is at the outlet end of the charger (10) and to cut off the blown air after said predetermined time.

In another alternative or complementary option, Figs. 10 and 11 show that the detecting device (65, 66, 67) includes a monitored detecting device, for example a rotational encoder (65) that directly or indirectly monitors the rotation of the rotation shaft of the electric motor of the drive (62) of the suction mechanism (60), to blow air for a predetermined time when the suction cup (61) approaches and/or is at the outlet end of the loader (10) and to cut off the blown air after said predetermined time.

In yet another option, the air passing through the blown air mouth (32) may be blown continuously in the automatic (cyclic) mode of operation of the feeder, during the cyclic movement of the suction mechanism (60).

Likewise, for all embodiments, for example, in Figs. 7 to 14, the blown air outlet (32) is oriented towards the friction zone (31) and is adjacent to the friction zone (31). Likewise, the blown air outlet (32) and the friction zone (31) face each other on the same side of the loading zone and are arranged in the same advance section according to the advance direction (A).

Thus, in each separation device (30) of all embodiments of the figures, the air outlet (32) and the friction zone (31) both face the lower side (Figs. 7 to 14), both face any one of the two lateral sides or both face the upper side (Fig. 18) of the loading zone.

It is noted that the embodiments of Figs. 7 to 14 have six separation devices, (30) one on the bottom side, one on the top side, and two on each lateral side of the loading area.

It is noted that the embodiments of Figs. 16, 17 and 19 have a separating device, (30) on the lower side, i.e. arranged fixed at one end of the lower support element (11) located at the outlet end of the magazine (10).

It is noted that in Fig. 18 it has a separation device, (30) on the upper side, where the air outlet (32) and the friction zone (31) are both facing the upper side.

Thus, in each separation device (30) of all the embodiments of the figures, the air outlet (32) and the friction zone (30) are not arranged one after the other according to the linear advance direction (A) of the plates, but are arranged transversely in the same advance section according to the longitudinal advance direction (A), in order to be able to separate the same edges in two phases, synergistically, in the same work zone, as can be seen for example in Figs. 28 and 29, and also in Figs. 33 and 35 to 59.

In this way, in each separation device (30) of all the embodiments of the figures, the air blowing outlet (32) is configured to assist in a subsequent separation of the edges of said plurality of front plates (S) by blowing air between some faces of the plates (P) as these same edges are previously separated by the friction zone (31), in the same work zone, to extract the plates (S) one by one from the loader (10).

Continuing with the feeder options of Figs. 12 to 34, each air conducting device (33, 34, 34a, 35) includes a hole (33) formed in a piece and an air tube (34, 34a) in communication with the hole (33) of the piece, and the blown air outlet mouth (32) corresponds with a free end mouth of the hole (33).

In the embodiment of Figs. 12 to 14 and 20 to 27, the air conducting device (33, 34, 34a, 35) includes a plurality of holes (33) formed in one piece, both longitudinal and transverse, which allow the exchange of the position of the flexible air tube (34) at the sides or the bottom or top of the piece, by changing the position of plugs (33a), for example, materialized in bolts, set screws or plastic plugs.

In the embodiment of Figs. 30 to 34, the air conducting device (33, 34, 34a, 35) includes a plurality of holes (33) formed in a piece and a plurality of air tubes (34, 34a) in communication with the plurality of holes (33) of the piece, and each blown air outlet mouth (32) corresponds with a free end mouth of each hole (33).

In the feeder options of Figs. 12 to 14 and 20 to 34, a set screw (35a) secures the connection of the air connector (35) to the distal end of the air conducting device (33, 34, 34a, 35) materialized in one or more holes (33) formed in one piece.

In the feeder options of Figs. 35 to 43, in the air blowing device, the air conducting device (33, 34, 34a, 35) includes a pneumatic connector (35) and a flexible air tube (34) connected to a proximal end of the pneumatic connector (35). In addition, the blown air outlet mouth (32) corresponds with the free mouth (35b) of the distal end of the pneumatic connector (35). It should be noted that the pneumatic connector (35) is also considered here an air conducting device (33, 34, 34a, 35) that conducts air between the connection ends thereof.

In the feeder options of Figs. 35 to 45, each separation device (30) comprises a through hole (39) of at least one piece crossed by a distal end of the air conducting device (33, 34, 34a, 35).

In the feeder options of Figs. 35 to 43, it further comprises a fixing screw (35a) for fixing the distal end of the air conducting device (33, 34, 35, 36), for example, the end of the air tube (34, 34a) or of the air connector (35), which passes through the through hole (39) formed in at least one piece.

Advantageously, said through hole (39) additionally limits the unwanted movements of the previously mentioned blown air outlet mouth (32), conferring robustness and reliability to the unitary feeding of a wide range of plates (S) at high speeds.

In the feeder options of Figs. 44 to 53, in the air blowing device, the air conducting device (33, 34, 34a, 35) includes a rigid air tube (34a). In addition, the blown air outlet mouth (32) corresponds to the free mouth of the distal end of the rigid air tube (34a).

In addition, in Figs. 44 to 53, the air conducting device (33, 34, 34a, 35) includes air tubes materialized in flexible air tubes (34) connected to the rigid air tubes (34a).

Preferably, for example, in Figs. 7 to 14, 16, 17, 19, 28 and 33 and 35 to 59 the separating device (30) is fixedly arranged at one end of the lower support element (11) located at the outlet end of the loader (10), with the air blow outlet (32) and the friction zone (31) facing the lower side of the loading zone to separate the lower edges (CI) of the plates (S).

Optionally and/or complementarily, Figs. 8, 10 and 11 show that the separation device (30) may be fixed at one end of the side guides (12) located at the outlet end of the magazine (10) arranged to separate the side edges (CL) of the plates (S).

Optionally and/or complementarily, Figs. 7, 10, 11 and 18 show that the separating device (30) may be fixed at one end of an optional upper guide (13) at the outlet end of the magazine (10) which positionally delimits the upper edges (CS) of the plates (S), the end of an upper guide (13) located at the outlet end of the magazine (10) being arranged to separate the upper edges (CS) of the plates (S).

In the embodiments of Figs. 16, 17 and 19, the feeder comprises a single separation device (30) fixed to the lower support (11).

In the embodiment of Fig. 18 and in the embodiments of Figs. 7 to 14, the feeder comprises one or more additional separating devices (30) such that the feeder comprises a plurality of separating devices (30).

In the embodiments of Figs. 7 to 14 and 18, the feeder comprises two separating devices, one fixed at the end of the lower support (11) and another fixed at the end of the upper guide (13).

In the embodiments of Figs. 7 to 14, the feeder further comprises two separating devices, one fixed at each end of each side guide (12).

More specifically, in the embodiments of Figs. 7 to 14, the feeder comprises four separating devices (30), two fixed at each end of each side guide (12), the feeder thus having six separating devices in total arranged fixed at the outlet end of the loading area of the magazine (10).

Preferably, Figs. 7 to 14, 28 to 34 and 36 to 59 show that each friction device (31) of each separation device (30) is arranged in said fixed position in a removably manner by a fixing and releasing device (36, 37).

The fixing and releasing device (36, 37) includes at least one screw element (36) and a hole (37) in which the screw element (36) is insertable and removable, to fix and release the friction device (31) with respect to the output end of the loader (10) in tasks of adapting the feeder to different plates, for example, to replace the friction device (31) with another, for example, with different protuberances, and/or with different roughness, and/or with a different coefficient of friction.

Preferably, as shown for example in the embodiment of Figs. 18 and 30 to 34, the feeder further comprises one or more additional separating devices (30) arranged in fixed positions, removably by a respective fixing and releasing device (36, 37), at the outlet end of the loading zone of the magazine (10).

In this preferred option of Figs. 18 and 30 to 34, each separation device (30) further comprises a respective smooth area (38).

Also in this preferred option of Figs. 18 and 30 to 34, in the feeder, each fixing and releasing device (36, 37) of each additional separating device (30) enables two interchangeable working positions.

In a first working position, shown in Figs. 30, 31 and 33, the friction zone (31) is fixed on the side of the load zone to contact the plurality of front plates (S).

In a second working position shown in Fig. 34 and in the separation device (30) on the lower side of Fig. 18, the smooth area (32) is fixed on the side of the loading area, configured to contact the plurality of front plates (S).

Optionally to the previous preferred option, the embodiments of Figs. 7 to 14 and 18 show that the feeder comprises a pair of separation devices (30) positioned in respective working positions, mutually facing each other on two mutually opposite sides of the loading area of the loader (10).

In the embodiments of Figs. 7 to 14 and 18, a separating device (30) positioned in the first working position (Figs. 7 to 14) or in the second working position (Fig. 18) faces the lower side of the loading area of the magazine (10). Furthermore, in the embodiments of Figs. 7 to 14 and 18, another separating device (30) positioned in the first working position faces the upper side of the loading area of the magazine (10), fixed at the end of the upper guide (13).

Furthermore, in the feeder of the first and second embodiments of Figs. 7 to 14, a separating device (30) positioned in the first working position faces the lateral side of the loading area of the magazine (10), and another separating device (30) positioned in the first working position faces the other lateral side of the loading area of the magazine (10).

Optionally, for example, in Figs. 13 to 15 and 31 to 34, the smooth area (32) and the friction area (31) are arranged on two opposite sides of the same piece fixed at the outlet end of the magazine (10), for example, at the end of the lower support (11).

Preferably, in the feeder embodiments of Figs. 8 to 14, 17, 18 and 28 to 59 one plate stop (40) of the plurality of plate stops (40) is fixed immediately after the separation device (30) on the same side of the loading zone, so that this plate stop (40) retains the edge of the front plate (S) previously separated from the plurality of front plates (S) by the separation device (30).

Advantageously, this relative arrangement between plate stop (40) and separation device (30) facilitates the unitary separation of a wide variety of plates at high speeds.

Contrary to the previous preferable option, in Figs. 16 and 19 the plate stops (40) are fixed on the lateral sides of the loading area while the separating devices (30) are fixed on the lower sides.

In addition, Figs. 12 to 15, 28 to 35 and 54 to 59 show that each plate stop (40) is fixed by an additional screw (44), while Figs. 36 to 47 show that each plate stop (40) can alternatively be fixed by the fixing and releasing device (36, 37) itself.

In one option, in Figs. 13 to 15 and 54 to 59, the plate stop (40) fixed immediately after the separation device (30) is a roller stop rotating around a fixed axis (41), which is in turn mounted on a supplementary support (42) fixed by the supplementary screw (44), to assist with said rotation in the separation of the front plates (S) with extreme specifications at high speeds.

In another option, in Figs. 28 to 53, the plate stop (40) fixed immediately after the separation device (30) is a nail-type stop fixed by an additional screw (44) or by the fixing and release device itself (36, 37).

Optionally, in the embodiments of Figs. 11 to 14 and 57 to 59, the feeder further comprises a secondary plate stop (45), fixed immediately after the plate stop (40) of the plurality of plate stops (40) that is fixed immediately after the separation device (30), on the same side of the loading zone.

Advantageously, the separation device (30), plate stop (40) and secondary plate stop (45), arranged one immediately after the other on the same side of the loading area of the loader (10), act synergistically to allow working at even higher speeds with plates (S) of different specifications.

Optionally, Figs. 12 to 14 and 56 to 59 show that each secondary plate stop (45) is fixed by a secondary screw (47), for example, to the end of the lower support (11).

In addition, the feeders of embodiments 7 to 35 and 40 to 59 comprise a friction device (30) including one or more friction zones (31) and a plurality of air outlets (32). Each air outlet (32) is adjacent to a respective or common friction zone (31). In addition, the one or more friction zones (31) and the plurality of air outlets (32) face the same side of the loading zone and are arranged in the same advance section according to the advance direction (A).

Advantageously, this number of air blow outlets (32) and their arrangement with respect to the friction zones (31) facilitates the unitary separation of a wide variety of plates (S) at high speeds, since the plurality of outlets acts as a redundant device to ensure the unitary separation of plates (S).

Preferably, in the feeders of Figs. 7 to 19, 30 and 35 to 59, the friction device comprises a secondary friction zone (31a), located immediately before the friction zone (31) according to the advance direction (A), configured to previously separate the same edges of the plates (S) to be subsequently separated by the friction zone (31) and by the blown air mouth (32).

Advantageously, the secondary friction zone (31a), the friction zone (31) and the blown air mouth (32) act synergistically to achieve an effective separation of the front plates (S) to be extracted unitarily by the at least one suction cup, using a separation on the same edges of the plates (S) in three phases, positioned on the same side of the loading zone and focused on the same work zone, with high reliability and robustness to work with different plates (S) at high speeds.

Optionally, the feeder in Figs. 54 and 55, as a group of plates (S), not shown, advance along the advance direction (A) on the secondary friction zone (31a), the edges, for example the lower edges (CI), may be separated by the secondary friction zone (31a) from each other instantaneously, and although the edges of some of the plates (S) of the plurality of plates (S) may remain in contact again, they are subsequently separated by the secondary friction zone (31a) with the advance of the plates (S), the edges being able to experience relative oscillating movements between edges, which introduce air between the faces of the plates (S) reducing the adhesion effect between plates (S), so that when reaching the most extreme advance position where the friction zone (31) and the blown air mouth (32) are located, the group of plates (S) corresponds with the plurality of front plates (S), which are more easily separated with each other, by the action of the last friction section (the friction zone (31)) in cooperation with the blowing of the blown air mouth (32).

The embodiment of Figs. 28 and 29 lacks said secondary friction zone (31a).

Preferably, Figs. 1, 4, 7, 10 to 12 and 15 to 19 show that the feeder further comprises a pushing device (14) including two pushing members (15) mounted on a sliding carriage (16) capable of sliding along the forward direction (A) of plates (P).

Figs. 12 and 15 to 18 show that each pusher member (15) is arranged on a respective lateral side of the separating device (30) in the forward direction (A), the two pusher members (15) being configured to push the stack (P) supported in the magazine (10) into contact with two mutually opposite side panels (PL) of the rear plate (S) of the stack (P). Example stacks (P) are shown in Figs. 5 and 6 relative to the forward direction (A).

Advantageously, with this lateral arrangement of the pusher members (15) with respect to the separation device (30) according to the advance direction (A), (arrangement not centered, not aligned), the line of thrust force on the plates (S) of the stack (P) of each pusher member (15) is parallel but not aligned (not collinear) with the line of friction force caused by the friction zone of the separation device (30) on the plates (S) at the edges, for example, at the lower edges (CI). This lateral arrangement of the pusher members (15) facilitates the separation of the edges of the plurality of front plates (S) with the separation device (30) by friction and blowing.

Optionally, Fig. 12 shows that the pushing device (14) further comprises a tensioning cable (18) provided with distal and proximal ends. The distal end is mounted in a fixed position supported on the sliding support (16), and the distal end (18a) is fixed at a fixed position point during operation of the feeder in automatic mode.

Optionally, the distal end is mounted inside a body (17) supported on the sliding support (16) that houses the tensioning cable wound to a greater or lesser extent depending on the number of plates (S) supported in the magazine (10). The distal end is fixed to the lower support (11) as shown in Fig. 12, or in another option (not shown in the figures) the distal end is fixed to one or both of the side guides (12) or to the upper guide (13).

Optionally, the plate feeder of Fig. 12 shows that the pushing device (14) comprises a positioning device (26, 27, 28, 29) supported on the sliding support (16), configured to modify the separation distance between pushing members (15) according to a direction transverse to the longitudinal plate advance direction (A).

For example, Fig. 16 shows a transverse separation distance between pusher members (15) that is smaller than the transverse separation distance between pusher members (15) shown in Fig. 19.

In the example of Fig. 18, the transverse separation distance between pusher members (15) is greater than that of Figs. 16 and 19.

Advantageously, the positioning device (26, 27, 28, 29) of the pushing device (14) contributes to increasing the versatility of plates (S) to be supplied by the feeder at high speeds.

Optionally, Fig. 12 shows that the positioning device (26, 27, 28, 29) comprises screws (29) insertable into holes (27) to fix and release the transverse position of the pusher members (15) along the holes (27).

Additionally, Fig. 12 shows that said holes (27) are elongated holes made in arms (26) where the pusher members (15) are mounted and which pivot around pivots (28) to modify the relative transverse position between pusher members (15).

In another option, not shown in the figures, the positioning device comprises a spindle (not shown) mounted on the sliding support (16). Auxiliary carriage supports (not shown) are coupled to the spindle, which support the pusher members (15), such that when the spindle rotates, the pusher members (15) modify the aforementioned transverse distance between them, moving along the spindle.

In yet another option, not shown in the figures, the positioning device comprises a crossbar (not shown) fixed on the sliding support (16). Auxiliary carriage supports (not shown) are coupled to the crossbar, which support the pusher members (15), such that by releasing some screw elements (not shown) the auxiliary carriages slide along the crossbar to modify the position of the pusher members (15).

Preferably the pushing device (14) is supported on the lower support (11) as shown in Figs. 7 to 12, although in an option not shown in the figures it may be supported on one or both of the side guides and/or on the upper guide (13).

Optionally, Fig. 12 shows that the pushing device (14) further comprises a guiding device including rollers or rollers (19) rotatably mounted on the sliding support (16) to slide the pushing device (14) along the forward direction (A), for example, on the lower support (11).

In addition, Fig. 12 shows that the sliding support (16) includes side parts that fit into the lower support (19) to guide the pusher device (14) along the forward direction (A).

Preferably, in Figs. 10 to 12 the pushing device (14) is supported on the lower support (11) and the pushing device (14) is in turn mounted on an upper end of a linear guide (23) of a linear positioning device (23, 24, 25) to modify the vertical position of the lower support (11).

Advantageously, the specific mounting of the pushing device (14) on the linear positioning device (23, 24, 25) contributes to increasing the versatility of plates (S) to be supplied by the feeder at high speeds.

Optionally, in Figs. 10 to 12, the linear positioning device (23, 24, 25) comprises auxiliary hardware (25), for example, a threaded shaft of a hardware element, for example, a screw, bolt, handle, etc. Said threaded shaft is insertable in an auxiliary hole (25) to fix and release the linear guide (23), movable along the auxiliary hole (25) in adjustment tasks, positioning the lower support (11) fixed at the end of the linear guide (23) in a desired vertical position.

Thus, for example, in Figs. 10 and 16 to 19 it can be seen that the lower separation device (30) mounted on the lower support (11) can adopt different height positions with the linear positioning device (23, 24, 25).

In another option, not shown in the figures, the linear positioning device comprises a rotating spindle (not shown) that has two carriage supports mounted on it, a carriage support fixed to the lower support (11) and another carriage support fixed to a fixed point of the chassis (1).

Optionally, Figs. 1, 4 and 16 to 19 show that the side guides (12) are mounted on side guide supports (22) capable of sliding along at least one transverse guide (21) to modify the transverse separation distance between the side guides (12). Advantageously, this contributes to increasing the versatility of sheets (S) to be supplied by the feeder at high speeds.

Optionally, the at least one transverse guide (21) comprises a spindle (Figs. 16 to 19) or a plurality of spindles (Figs. 1 and 4).

Preferably, in Figs. 1, 4, 7, 10 and 11 the lower support (11) has a diagonal inclination with respect to the vertical direction (Z), and the diagonal inclination is downwards towards the outlet end of the loader (10), providing a downward diagonal inclination of the plates (S) of the stack (P) with respect to the vertical direction (Z), so that for each plate (S), the upper edge (CS) is further forward than the lower edge (CI) along a horizontal direction parallel to the ground plane, as additionally shown in Figs. 5, 6 and 54 to 59.

Advantageously, the aforementioned diagonal inclination favors the plates (S) of the stack (P) being arranged one after the other, pressed against each other, by gravity and by the pushing device (14) in combination, against the plate stops (40), which favors a controlled, robust and reliable separation between edges by the separation device (30) thanks to the controlled positioning of the plates (S) that form the stack (P), resulting in enabling a feeding at high speeds of plates (S) with a greater range of different properties.

In an alternative and/or complementary option, not shown in the figures, the plurality of plate stops (40) includes an upper plate stop (40) and a lower plate stop (40), the upper stop being further forward than the lower stop (40) according to the advance direction (A), providing a diagonal inclination of the plates of the stack (P) with respect to the vertical direction (Z), so that for each plate (S), the upper edge (CS) is further forward than the lower edge (CI).

All embodiments of the figures, for example, Figs. 10 and 11, show that the plurality of plate stops (40) are contained in the same plane perpendicular to the direction of advance (A), with some plate stops (40) not being further forward than others according to the direction of advance (A).

According to a second aspect, the present invention presents a method for feeding cardboard plates (S) by means of a plate feeder (S).

Each of the fed plates (S) comprises a lower edge (CI), two mutually opposing side edges (CL), and an upper edge (CS). The plates (S) may be as described in the first aspect of the present invention in relation to Figs.

2 and 3.

The fed plates (S) are initially supported on a lower support (11) of a magazine (10) of the feeder forming a stack (P) of plates (S) guided laterally on the side edges (CL) by two side guides (12) of the magazine (10), one on each side of the stack (P), as shown in Figs. 1 to 6 and 16 to 19.

The method comprises the step of using a device (30) for separating by friction and blowing a plurality of front plates (S) from the stack (P) of the feeder, arranged in a fixed position, at the plate output end of the loader (10) during an automatic mode movement of a suction mechanism (60) of the feeder that extracts with at least one suction cup (61) one by one the front plates (S) from the stack (P) by suction, as shown in Figs. 10, 11 and 54 to 59.

Likewise, the method comprises the steps of separating the front plates (S) from the stack (P) by acting by friction and blowing on the same edges of the front plates (S) with the separation device (30), as shown in Figs. 54 and 55, where the lower edges (CI) of the plurality of front plates (S) are acted upon.

Alternatively and/or complementarily, the separation of plates (S) is carried out by friction and blowing on the side edges (CL) as shown in Figs. 1, 4, and 7 to 11, or by friction and blowing on the upper edges as shown in Fig. 18.

In the embodiment of Figs. 54 and 55, the aforementioned separating step comprises the step of separating the lower edges (CI) of the plurality of front plates (S) of the stack (P) from each other by a friction device that includes a friction zone (31) as the plates (S) advance in a forward direction (A) at a plate output end with the extraction of each front plate (S) from the output end by at least one suction cup (61) of the suction mechanism (60).

Continuing with Figs. 54 and 55, the aforementioned separation step also comprises the stage of separating the lower edges (31) of said plurality of front plates (S) by blowing air between some faces of the plates (P) by means of a blown air outlet (32) associated with a pressurizable air conducting device (33, 34, 34a, 35) (see, for example, Fig. 13, 30 or 52).

This blow separation of Figs. 54 and 55 is produced as these same lower edges (CI) are previously separated by the friction zone (31), in the same work zone in a section according to the direction of advance (A), extracting one by one the plates (S) from the loader (10).

Optionally, in Figs. 54 to 59, the aforementioned separation step also comprises the stage of separating the plates (S) from the stack (P) with a secondary friction zone (31a) prior to their positioning at the output end, which facilitates the subsequent separation by friction and by blowing as the plates are previously separated by friction.

Optionally, in the event that the feed speed is to be further increased for plates (S) of different specifications and/or to increase feeder reliability at high speeds, the method comprises the step of assisting in the separation of the front plate (S) by retaining the plate (S) adjacent to the front plate (S) with a plate stop (40) arranged at the exit end of the loading zone on the same side as the separation device (30), as can be represented in Fig. 57.

Optionally and/or in addition to the preceding paragraph, the method comprises the step of assisting in the separation of the front plate (S), by retaining the plate (S) adjacent to the front plate (S) with a secondary plate stop (45) arranged at the exit end of the loading zone on the same side as the separation device (30), positionally adjacent to the plate stop (40), as shown in Figs. 57 to 59.

The scope of the present invention is given by the following claims.

Claims (19)

1. - Cardboard sheet (S) feeder for a machine (100) for forming cardboard boxes (B) from sheets (S), the feeder comprising a loader (10) comprising a lower support (11) for contacting lower edges (CI) of the plates (S) supported in the loader (10) forming a stack (P) of plates (S), and two lateral guides (12) one on each side of said supported plates (S), for positionally delimiting respective mutually opposite lateral edges (CL) of the plates (S), the lower support (11) and the lateral guides (12) delimiting a loading area with a lower side, two lateral sides and an upper side, and with an input end of plates (S) and an output end of plates (S) mutually facing each other according to a direction of advance (A) of plates (S), a plurality of plate stops (40) being arranged at the output end configured to retain the front plate (S) of the stack (P) to be extracted by at least one suction cup (61) of a suction mechanism (60) of the feeder movable by a drive (62); characterized in that at the output end of the loader (10) there is arranged, in a fixed position in the movement of the suction mechanism (60), a device for separating (30) a plurality of front plates (S) from the stack (P), the separation device (30) comprising: a friction device including a friction zone (31) capable of separating edges of a plurality of front plates (S) from each other as the plates (S) advance in the advance direction (A) with the extraction of each front plate (S) by the at least one suction cup (61), in combination with an air blowing device, including a blown air outlet mouth (32) associated with a pressurizable air conducting device (33, 34, 34a, 35), the blown air outlet mouth (32) being oriented towards the friction zone (31) and being adjacent to it, the blown air outlet mouth (32) and the friction zone (31) being facing one side of the loading zone and arranged in the same advance section according to the advance direction (A), the blown air outlet mouth (32) being configured to assist in a subsequent separation of the edges of said plurality of front plates (S) by blowing air between some faces of the plates (P) as these same edges are previously separated by the friction zone (31), in the same work zone, to extract the plates (S) one by one from the loader (10). 2. - Cardboard plate feeder (S) according to claim 1, wherein the separation device (30) is fixed at one end of the lower support element (11). 3. - Cardboard plate feeder (S) according to any of the preceding claims, wherein the friction device (31) is arranged in said fixed position in a removably manner by a fixing and releasing device (36, 37). 4. - Cardboard plate (S) feeder according to claim 3, further comprising one or more additional separating devices (30) arranged in fixed positions, removably by a fixing and releasing device (36, 37), at the output end of the loader (10), each separating device (30) further comprising a respective smooth area (38), and wherein each fixing and releasing device (36, 37) of each additional separating device (30) enables two interchangeable working positions: a first working position in which the friction area (31) is fixed on the side of the loading area to contact the plurality of front plates (S), and a second working position in which the smooth area (32) is fixed on the side of the loading area, configured to contact the plurality of front plates (S). 5. - Plate feeder (S) according to claim 4, comprising a pair of separation devices (30) positioned in respective working positions, mutually facing each other on two mutually opposite sides of the loading area. 6. - Cardboard plate (S) feeder according to any of the preceding claims, wherein the friction device comprises a secondary friction zone (31a), located immediately before the friction zone (31) according to the advance direction (A), configured to previously separate the same edges of the plates (S) subsequently separated by the friction zone (31) and by the blown air mouth (32). 7. - Cardboard plate (S) feeder according to any of the preceding claims, wherein the friction device (30) includes one or more friction zones (31) and a plurality of blown air outlets (32), each blown air outlet (32) being adjacent to a friction zone (31), and the one or more friction zones (31) and the plurality of air outlets (32) being facing the same side of the loading zone and arranged in the same advance section according to the advance direction (A). 8. - Cardboard plate feeder (S) according to any one of the preceding claims, wherein the air conducting device (33, 34, 34a, 35) includes an air tube (34, 34a) and wherein the blown air outlet mouth (32) corresponds to the free mouth of the distal end of the air tube (34, 34a). 9. - Cardboard sheet (S) feeder according to any one of claims 1 to 7, wherein the air conducting device includes a pneumatic connector (35) and an air tube (34, 34a) connected to a proximal end of the pneumatic connector (35), and wherein the blown air outlet mouth (32) corresponds to the free mouth (35b) of the distal end of the pneumatic connector (35). 10. - Cardboard plate feeder (S) according to any of the preceding claims, comprising a through hole (39) traversed by a distal end of the air conducting device (33, 34, 34a, 35). 11. - Cardboard plate feeder (S) according to claim 9, further comprising a fixing screw (35a) for fixing the distal end of the air conducting device (33, 34, 34a, 35) passing through the through hole (39). 12. - Cardboard plate (S) feeder according to any of claims 1 to 7, wherein the air conducting device (33, 34, 34a, 35) includes a hole (33) formed in a piece and an air tube (34, 34a) in communication with the hole (33) of the piece, and the blown air outlet mouth (32) corresponds with a free end mouth of the hole (33). 13. - Cardboard plate (S) feeder according to any of the preceding claims, wherein a plate stop (40) of the plurality of plate stops (40) is fixed immediately after the separation device (30) on the same side of the loading area, so that it retains the edge of the front plate (S) previously separated from the plurality of front plates (S) by the separation device (30). 14. - Cardboard plate (S) feeder according to claim 13, further comprising a secondary plate stop (45), fixed immediately after the plate stop (40) of the plurality of plate stops (40) that is fixed immediately after the separation device (30), on the same side of the loading area. 15. - Cardboard plate (S) feeder according to any one of the preceding claims, further comprising a pushing device (14) including two pushing members (15) mounted on a sliding carriage (16) capable of sliding along the forward direction (A) of plates (P), one arranged on each side of the separation device (30) according to the forward direction (A), the two pushing members (15) being configured to press the stack (P) supported in the magazine (10) into contact with two mutually opposite side panels (PL) of the rear plate (S) of the stack (P). 16. - Cardboard plate (S) feeder according to claim 15, wherein the pushing device (14) comprises a positioning device (26, 27, 28, 29) supported on the sliding support (16), configured to modify the separation distance between pushing members (15) according to a direction transverse to the advance direction (A). 17. - Cardboard plate (S) feeder according to claim 16, wherein the pushing device (14) is supported on the lower support (11), which is in turn mounted on an upper end of a linear guide (23) of a linear positioning device (23, 24, 25) to modify the vertical position of the lower support (11). 18. - Cardboard plate (S) feeder according to claim 15, 16 or 17, wherein the lower support (11) has a diagonal inclination, downwards towards the output end of the loader (10), providing a downward diagonal inclination of the plates in the stack (P) with respect to the vertical direction (Z). 19. - Method for feeding cardboard sheets (S) by means of a sheet feeder (S), wherein each sheet (P) comprises a lower edge (CI), two side edges (CL) mutually opposite, and an upper edge (CS), supported by its lower edge (CI) on a lower support (11) of a magazine (10) of the feeder forming a stack (P) of sheets (S) guided laterally by side edges (CL) by two side guides (12), the method being characterized in that it comprises the steps of: employing a device (30) for separating by friction and blowing a plurality of front plates (S) from the stack (P) of the feeder, arranged in a fixed position, at the plate output end of the loader (10) during an automatic mode movement of a suction mechanism (60) of the feeder that extracts with at least one suction cup (61) one by one the front plates (S) from the stack (P) by suction; and separating the front plates (S) from the stack (P) by acting by friction and blowing on the same edges of the front plates (S) with the separation device (30), this separation comprising the steps of: - separating the edges of the plurality of front plates (S) of the stack (P) from each other by a friction device including a friction zone (31) as the plates (S) advance in a forward direction (A) at a plate outlet end with the extraction of each front plate (S) from the outlet end by at least one suction cup (61) of the suction mechanism (60), and - separate the edges of said plurality of front plates (S) by blowing air between some faces of the plates (P) by means of a blown air outlet (32) associated with a pressurizable air conducting device (33, 34, 34a, 35), as these same edges are previously separated by the friction zone (31), in the same work zone in a section according to the direction of advance (A), extracting one by one the plates (S) from the loader (10).