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Title:
A SYSTEM FOR STACKING FLAT ARTICLES, SUCH AS SHEETS AND/OR PANELS, IN A RECEIVING STATION LOCATED DOWNSTREAM OF THE OUTLET OF AN OPERATING STATION OF A MACHINE, AND A METHOD FOR ACTUATING THE STACKING
Document Type and Number:
WIPO Patent Application WO/2017/208123
Kind Code:
A1
Abstract:
A method for stacking flat articles, such as sheets and/or panels, in a receiving station located downstream of the outlet of an operating station of a machine (M), comprising; detecting an inlet of an article (F) into the receiving station coming from said outlet in an advancement direction (W1); measuring the longitudinal advancement of a leading edge of the article (F) involving the receiving station; following measuring of a predetermined first portion (d1) of the advancement of the article (F), activating first means for engaging and supporting the article (F); longitudinally moving the first means for engaging and supporting, in phase relation with activation thereof, in a direction concordant to the direction of the first advancement direction (W1) and a velocity equal to the advancement velocity of the article (F); following measuring of a predetermined second portion (d2) of the advancement of the article that is greater than the first portion, activating at least second means for engaging and supporting the article in cooperation with the first means; longitudinally moving the first means for engaging and supporting, in phase relation with activation thereof, in a direction concordant to the direction of the advancement direction (W1) and a velocity equal to the advancement velocity of the article (F); centring the article with respect to an underlying loading plane (P) or head article of a stack of articles under formation thereon; deactivating the first and second means with a consequent release of the article onto the loading plane, or onto the head article of the stack.

Inventors:
GALLUCCI, Giuseppe (Via Borgo Nuovo, 111, Monte Urano, 63813, IT)
Application Number:
IB2017/053122
Publication Date:
December 07, 2017
Filing Date:
May 26, 2017
Export Citation:
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Assignee:
ELITRON IPM S.r.l. (Viale I^ Maggio 42, Monte Urano, 63813, IT)
International Classes:
B65H29/32; B65H29/24; B65H31/10
Attorney, Agent or Firm:
DALL'OLIO, Giancarlo et al. (Invention S.r.l, Via delle Armi 1, Bologna, 40137, IT)
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Claims:
CLAIMS

1. A method for stacking flat articles, such as sheets and/or panels, in a receiving station located downstream of the outlet of an operating station of a machine (M), characterised in that it comprises: a- detecting an inlet of an article (F) into the receiving station coming from said outlet in a first advancement direction (W1); b- measuring the longitudinal advancement of a leading edge of the article (F) involving the receiving station; c- following measuring of a predetermined first portion (d1) of the advancement of the article (F), activating first means for engaging and supporting the article (F); d- longitudinally moving the first means for engaging and supporting, in phase relation with activation thereof, in a direction concordant to the direction of the first advancement direction (W1) and a velocity equal to the advancement velocity of the article (F); e- following measuring of a predetermined second portion (d2) of the advancement of the article that is greater than the first portion, activating at least second means for engaging and supporting the article in cooperation with the first means; f- longitudinally moving the second means, in phase relation with activation thereof, in a direction concordant to the direction of the first advancement direction (W1) and at a velocity equal to the advancement velocity of the first means and the article (F); g- centring the article with respect to an underlying loading plane (P) or head article of a stack of articles under formation thereon; h- deactivating the first and second means with a consequent release of the article onto the loading plane, or onto the head article of a stack under formation thereon; i- moving the first and second means in a second direction (W2) opposite to the first advancement direction of the article, up to positioning the first and second means in the relative initial positions; j- re-iteration of the preceding steps.

2. The method of the preceding claim characterised in that between step g and step h there is an upward movement of the loading plane (P) up to when the plane itself, or of the head article of the stack borne thereon, intercepts the lower surface of the article (F).

3. The method of the preceding claim characterised in that the intercepting comprises raising of the article (F) engaged and supported at and by the first and second means.

4. The method according to claim 1 wherein a predefined velocity is imposed on the article in outlet from the operating station, characterised in that the velocity with which the first and second means draw the article in the first advancement direction (W1) is equal to the predetermined velocity.

5. A system for stacking flat articles, such as sheets and/or panels, in a receiving station located downstream of the outlet of an operating station of a machine M, characterised in that it comprises: means for detecting and measuring the longitudinal advancement of the leading edge of an article (F) crossing the inlet, in a first advancement direction (W1) of the receiving station; a frame, associated to the receiving station, supporting a guide longitudinal member (5), orientated in the direction of the first direction (W1), located above the receiving station; at least first and second means, guided and supported by the longitudinal member (5), for engaging and supporting an article (F) coming from the inlet; a loading plane (P), located below the longitudinal member, destined to receive the article, disengaged from the first and second means, directly or on the head article of a stack under formation on the plane; at least first and second devices associated to the longitudinal member (5) to which the first and second means are connectable for correspondingly drawing the first and second devices in the first direction (W1), or in a second direction (W2), opposite to the first direction; a command and control board (100), to which the means for detecting and measuring are connected, which command and control board (100), following the measuring of the advancement of the article (F) of a first portion (d1) and at least a second portion (d2) having a greater value than the preceding value, is able to activate, in sequence and in phase relation, correspondingly the first means and first devices, and the second means and second devices, with a consequent drawing of the article in the first direction (W1) with a predetermined velocity; means for detecting the centring of the article (F) with respect to the underlying loading plane (P), connected to the command and control board (100), the command and control board, following the detecting of the centring, being destined, in suitable phase relation, to deactivate the first and second devices, with a consequent halting thereof, to deactivate the first and second devices, with a consequent disengaging therefrom of the article (F), to newly activate the first and second devices in the second direction (W2), so as to reposition the first and second device and the relative first and second means, at the inlet.

6. The system of claim 5, characterised in that it comprises, a structure 3, which supports the frame, provided with a base which bears an elevator (E) and which vertically moves the loading plane (P), the structure including a transversal portion (4), or collecting zone, situated at a height (h) not greater than a height of the outlet of the operating station of the machine (M), on which the article (F) directed towards the receiving station transits.

7. The system of claim 6, characterised in that the means for detecting and measuring comprise an enabling means (A) positioned on the transversal portion

(4) , destined to detect passage of the article (F) and to enable, in phase relation, activation of a second detecting means (7), anchored to the longitudinal member

(5) , which measures a linear displacement of the article (F), for determining activation in sequence of the first and second means.

8. The system of claim 7 characterised in that the means for detecting and measuring further comprise a first detecting means (R), positioned on the transversal portion (4) upstream, with respect to the advancement direction (W1) of the article, of the enabling means (A), the first detecting means (R) being destined to detect introduction and transit of the article (F) in the receiving station and the complete exit of the article from the operating station of the machine (M).

9. The system of claim 5, characterised in that the first means and the second means respectively comprise a first and a second collecting and displacing arm

(6a, 6b), arranged transversally with respect to the longitudinal member (5), which collecting and displacing arms bear relative coupling means (60) of the article (F).

10. The system of claim 9, characterised in that the coupling means (60) comprise suction means (61), connectable to at least an aspirating source, borne by a stem (63) of an actuator (62) so as to define, for the suction means (61), a lowered operating position for abutting and engaging the article (F) and a raised non- operating position.

11. The system of claim 6 and 10, wherein motor means are provided, connected to the command and control board (100), for moving the elevator (E), and with the actuator (62) acting elastically on the suction means (61), characterised in that it comprises, a third detecting means (65), connected to the command and control board (100) and associated to the suction means (61), the motor means being destined, in phase relation with the activating of the detecting and centring means, to move the elevator (E) upwards with a consequent intercepting of the loading plane (P) or the head article of the stack under formation on the loading plane (P), against the article (F) engaged to the suction means (61) and a raising thereof, in opposition to the elastic means associated to the actuator (62), up to activation of the third detecting means (65) with a consequent deactivating of the suction means (61) and a release of the article (F), previously engaged thereto, on the underlying adjacent loading plane (P) or head article of the stack under formation thereon, the motor means, following the release, being destined to move the elevator (E) downwards, until it is lowered by a step with respect to the position the elevator (E) occupied before the raising thereof.

12. The system of claim 5, characterised in that the first devices comprise at least a first carriage (81) mobile on at least a corresponding sliding guide (G) provided in the longitudinal member (5), to which the first arm (6a) is anchored by means of a prolongation (88), and in that the second means comprise at least a second carriage (82), positioned downstream according to the first advancement direction (W1) of the first carriage (81), to which the second arm (6b) is anchored by means of a prolongation (88).

13. The system of claim 12, characterised in that the first carriage 81 comprises: a guide sliding block (811), provided in the lower part of the first carriage (81), slidabiy coupled to the sliding guide (G); an anchoring (810), provided in the upper part of the first carriage (81), solidly constrained to an upper branch (Tc) of a belt (T) of activating devices and in that the second carriage (82) comprises: a guide sliding block (821), provided in the lower part of the second carriage (82), slidably coupled to the sliding guide (G); a spring clamp (820) provided in the upper part of the second carriage (82), activated by a blocking/unblocking means (C) fixed to the longitudinal member (5) and acting on the spring clamp for engaging/disengaging to and from the upper branch (Tc) of the belt (T).

14. The system of any one of the preceding claims from 5 to 13 characterised in that it comprises at least first and second sensor means (S1 , S2) associated to the longitudinal member (5) in proximity of the head zone (Z) thereof for detecting the non-operating position of the first and second devices (81 , 82). 15. The system of any one of the preceding claims from 7 to 13, characterised in that the second detecting means and the detecting and centring means are defined by an encoder which measures predefined linear advancements of the article (F) and cooperates with the command and control board (100) for: activating the first means and first devices, and the second means and second devices, with a consequent drawing of the article in the first direction (W1) with a predetermined velocity; deactivating the first means and first devices, and the second means and second devices, with a consequent centring of the article (F) with respect to the underlying loading plane (P).

Description:
A SYSTEM FOR STACKING FLAT ARTICLES, SUCH AS SHEETS AND/OR PANELS, IN A RECEIVING STATION LOCATED DOWNSTREAM OF THE OUTLET OF AN OPERATING STATION OF A MACHINE, AND A METHOD FOR ACTUATING THE STACKING FIELD OF THE INVENTION

The present invention relates to the technical sector concerning methods for stacking flat articles, such as sheets and/or panels, in a receiving station located downstream of the outlet of an operating station of a machine.

DESCRIPTION OF THE PRIOR ART

The articles, for example in outlet from a digital printer, are unloaded onto a pallet included in a receiving station adjacent to the outlet of the operating station.

The means expelling the article from the operating station advance the article and, following the advancement, the initial part thereof flexes downwards to determine intercepting on and against the upper surface of the head article of the stack positioned in the receiving station; the front edge of the article brushes against the stack and slides on the upper surface of the underlying article, causing scratches and/or abrasions thereon, and/or damage to the front edge.

To obviate this drawback one or more operators grip the article expelled from the operating station and accompany it during the advancing thereof, keeping it raised up to complete outlet from the operating station.

The operators subsequently guide the article in the descent, or fall, of the article onto the stack: the costs deriving from the use of manual labourers are clear, as the large dimensions of the articles require use of several operatives, whose productivity and reliability tend to diminish due to fatigue.

Alternatively, an extensible conveyor is positioned between the operating station and the receiving station, which unwinds in phase relation with the exit of the article from the operating station, so that the article gradually and completely comes to lie on the conveyor.

The conveyor, upon complete expulsion of the article from the operating station, retracts to as to enable the article to gradually come to rest on the stack of articles in the receiving station. The extensible conveyor is a technical solution that is particularly complex; if not properly positioned, or not in perfect cooperation with the expulsion of the article from the operating station, it can be observed that the article is not correctly unloaded into the receiving station, with a consequent damaging thereof.

SUMMARY OF THE INVENTION

The advantage of the present invention is that it provides a system for stacking flat articles, such as sheets and/or panels, in a receiving station located downstream of the outlet of an operating station of a machine, realised by the combination of means and/or devices which enable engaging the articles in outlet from the operating station so as to stack them in a receiving station, thus obviating the drawbacks of the prior art mentioned in the preamble hereto.

The advantage of the present invention is to provide a system for stacking flat articles, such as sheets and/or panels, in a receiving station located downstream of the outlet of an operating station of a machine, realised in such a way as to be associable both downstream and upstream of a machine for processing the articles.

A further advantage of the invention is to provide a structurally simple system, in relation to the performance produced thereby, that is also extremely functional.

A further advantage of the present invention is to provide a method which enables obviating the drawbacks of the known methods concerning the stacking of flat articles, such as sheets and/or panels, in a receiving station located downstream of the outlet of an operating station of a machine.

BRIEF DESCRIPTION OF THE DRAWINGS

The above-mentioned advantages are obtained according to the contents of the claims.

The characteristics of the invention are specified in the following with particular reference to the accompanying tables of drawings, wherein:

figures 1A, 1 B are perspective views of two different operating positions of a system for stacking flat articles, such as sheets and/or panels, in outlet from a receiving station located downstream of the outlet of an operating station of a machine according to the present invention; figure 2 is a larger-scale perspective view of gripping means which are a part of the system of the invention;

figure 3 is a perspective view according to section plane Ill-Ill of figure 2, with some parts removed better to evidence others;

- figure 4 is a larger-scale view of section IV-IV of figure 3;

figures 5, 6, 7 are lateral views, in smaller scale with respect to the preceding figures, of three different operating steps of the proposed system;

figure 8 is a larger-scale view of detail D of figure 2;

figure 9 is a perspective view of detail M of figure 7, with some parts removed better to evidence others;

figure 10 schematically illustrates, as it is of known type, a command and control board with some of the more significant connections with means/devices which are part of the described system.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

With reference to the appended tables of drawings, reference number 1 denotes a system for stacking flat articles, such as sheets and/or panels, in a receiving station located downstream of the outlet of an operating station of a machine M, for example a digital printer.

The system 1 , as illustrated in figures 1A, 1B, comprises: a base structure 3, for example comprising a perimeter framework 30, which includes a plane P borne, for example, by an elevator E of known type; a transversal portion 4, or collecting zone, fixed to vertical supports 40 comprised in a side of the base structure 3 at a height "h" (figure 5) not greater than a height of the outlet of the operating station of the machine M; a floating frame 2 (figure 1A, 1 B), anchored to the base structure 3, for example comprising a pair of vertical uprights 20a, 20, solidly constrained to one of the two longitudinal sides of the base structure 3, to which corresponding cross-members 21a, 21 b are hinged at 90°; a guide longitudinal member 5, supported by the frame 2 above the plane P, comprising two facing open profiled members 50, internally of each of which a sliding guide G is fixed, connected by two transversal plates 51 and having a partial covering 52 in the head zone Z of the longitudinal member 5; collecting and displacing arms, for example three arms 6a, 6b, 6c, arranged transversally to said longitudinal member 5, each having a series of coupling means 60 of an article F in outlet from the operating station; a first detecting means R (fig. 2), for example a photocell, positioned on the transversal portion 4; an enabling means A, for example a sensor, positioned on said transversal portion 4 downstream with respect to a first advancement direction W1 of the article F, of the first detecting means R; a second detecting means 7, for example an encoder, anchored, by means of a support 70, to the longitudinal member 5, on the surface of the transversal portion 4; activating devices associated to the longitudinal member 5 for movement of the collecting and displacing arms 6a, 6b, 6c; a command and control board 100 which controls the coupling means 60 and the movement of the arms for coupling, the transport of the article F and the release of the article F onto the pallet L provided on the plane P.

Each coupling means 60, as illustrated in figure 8, comprises suction means 61 , connected to an aspiration source and, possibly, also to a compressed air source (not illustrated), borne by a stem 63 of a corresponding pneumatic actuator 62, defining a lowered position (figure 8) of abutment and coupling of an underlying article F transiting on the transversal portion 4 and a raised non-operative position.

Each coupling means 60 is, further, provided with a third detecting means 65, for example a sensor, associated in a known way to the actuator 62, which detects any upwards displacements of the suction means 61 , as will be described in the functioning of the proposed system.

The activating devices comprise two belt conveyors, identical to one another, positioned in opposite positions correspondingly in the profiled members 50 of the longitudinal member 5, moved in synchrony by means of a motor J; in the accompanying figures, only one of the conveyors is illustrated, to be precise, the drive pulley U (figure 3) splined on the shaft B (which also draws the pulley, not illustrated, of the other conveyor) and the driven pulley U1 (figure 9), the shaft B being activated by the motor J, and the upper branch Tc of the relative conveyor belt T.

By means of the motor, the upper branches Tc of the conveyors are activated, in synchrony, in the first advancement direction W1 and in the opposite second advancement direction W2.

The activating devices further comprise: a pair of first carriages 81 , each of which is coupled, by an anchoring 810, to the upper branch Tc of a corresponding belt T, and is inferiorly guided by a guide sliding block 811 slidably coupled to a corresponding sliding guide G (see fig. 3); a pair of second carriages 82 and a pair of third carriages 83 arranged in an ordered way downstream, with respect to the first advancement direction W1 , of the first pair of carriages 81.

Each of the carriages 82, 83, of the two last couples is inferiorly provided with a relative guide sliding block 821 , 831 , slidably coupled to a corresponding sliding guide G; the connecting of the carriages to the upper branch Tc of the relative belt T is actuated, in a removable manner, by a corresponding spring clamp 820, 830, activated by a blocking/unblocking means C (for example a known pneumatic cylinder) fixed to the profiled member 50.

The corresponding first, second, third arms 8a, 8b, 8c, are fixed by means of prolongations 88 to the first, second and third carriages 81 , 82, 83.

The stacking system of articles 1 is positioned in outlet from an operating station of a machine M, so that the transversal portion 4 flanks the outlet zone of said operating station, for example as illustrated in figures 5-7.

A pallet L is positioned on the plane P; the position of the plane P and therefore the pallet L is regulated by the elevator E, the movement means of which, of known type and not illustrated, are connected to the command and control board 100.

In this way the pallet L is moved between a series of positions (detected in a known way) of maximum raising corresponding to the empty pallet, to a final position of minimum raising corresponding to the full pallet L for enabling, time by time, the transferring of the article F from the outlet zone of the operating station, first onto the pallet and, thereafter, onto the stack under formation.

In an initial condition the collecting and displacing arms are flanked in proximity of the head portion Z of the longitudinal member 5, so that the first, second and third sensor means S1 , S2, S3 (fig. 5) detect the non-operative position of each corresponding carriage 81 , 82, 83, and, consequently, of the collecting and displacing arms; the coupling means 60 are also arranged in the non-operating position.

The article F exits the outlet zone of the machine M and starts to advance longitudinally on the transversal portion 4, there to be detected initially by the first detecting means R and, thereafter, by the enabling means A, which following complete covering thereof enables the second detecting means 7 which begins measuring the effective linear displacement of the article F: the longitudinal extension of the article F has been subdivided into four consecutive portions di, d 2 , d 3 , d 4 , being the first, second, third and fourth.

Following a predefined initial displacement of the article F corresponding to the first portion d1 , the coupling means 60 of the first arm 6a are activated on the leading edge thereof, so that the suction means 61 pass from the non-operating position to the operating position so as to abut the upper surface of the underlying article F transiting on the transversal portion 4.

In phase relation, the coupling means 60 of the first arm 6a are connected to the aspiration source, and the motor J is activated by the command and control board 100; it follows that the article F is coupled to and drawn in the first direction W1 with a velocity that is equal to the advancement velocity of the article F in outlet from the operating station of the machine; the first arm 6a, therefore, starts advancing along the longitudinal member 5, supporting the initial part of the article F in outlet from the operating station.

The second detecting means 7 continues to measure the effective linear displacement of the article F and with the detecting of the second predefined portion d 2 , having a higher value with respect to the first portion d1 , both the coupling means 60 of the second arm 6b (as described for the coupling means of the first arm 6a) and the spring clamps 820 of the second carriages 82 are activated in phase relation and are closed by the blocking/unblocking means C so as to be coupled to the upper branches Tc of the corresponding transmission belts T: the second arm 6b will advance in the first advancement direction W1 , with a velocity that is equal to the velocity of the article F, supporting the article F, in cooperation with the coupling means 60 of the first arm 6a, during the exiting thereof from the operating station.

The second detecting means 7 continues to measure the effective linear displacement of the article F in outlet from the operating station. With the detecting of the third predefined advancement d 3 of the article F, having a greater value than the second portion d 2, both the coupling means 60 of the third arm 6b (as described for the coupling means of the first arm 6a) and the spring clamps 830 of the third carriages 83 are activated in phase relation and are closed by the blocking/unblocking means C so as to be coupled to the upper branches Tc of the corresponding transmission belts T causing the advancement of the third arm 6c, with a velocity that is equal to the velocity of the article F, supporting the article F, in cooperation with the coupling means 60 of the second arm 6a, 6b, during the complete exiting thereof from the operating station.

The terminal portion of the article F is then detected by the first detecting means R and then by the enabling means A; the article F has exited from the operating station.

The second detecting means 7, following a further final displacement of the article F corresponding to the fourth portion d 4 which terminates with the trailing edge of the article, is deactivated, which leads to, for technical reasons known to the expert in the sector, the deactivating of the conveyors and the consequent centring of the article F with respect to the underlying plane P.

Following the centring of the article F, the elevator E is activated to displace the plane P upwards to determine the intercepting of the upper surface of the pallet L (first article unloaded), or of the head article of a stack, against the lower surface of the article F supported by the arms on the plane P: with this intercepting, the coupling means 60 react elastically for enabling the raising of the article F and the suction means 61.

The third detecting means 65 associated to each coupling means 60 detect the upwards displacement of the stem of the corresponding suction means 61 and the command and control board 100 deactivates the aspiration source so that the coupling means 60 of the first, second and third arms 81 , 82, 83 release the article F on the pallet, or on the head article of the stack of articles which was previously formed: in order to optimise this release, the activation of the compressed air source can be operated in phase relation with the deactivating of the aspiration source acting on the coupling means 60.

In phase relation with the disengaging of the suction means 61 from the article F, the elevator E is lowered by a step (i.e. by an amount equal to the thickness of the article F) with respect to the position that it occupies before raising thereof.

Following the release of the article F the command and control board 100 manages the coupling means 60 of the arms, to reposition the suction means 61 in the non-operating position and to activate the transmission means so as to draw the relative upper branches Tc of the belts in the second direction W2: the third, second and first carriages 83, 82, 81 , which support the third, the second and the first arm 6c, 6b, 6a are repositioned in the collecting zone, and detected in sequence by corresponding third sensor means S3, S2, S1 , located in the head zone Z of the longitudinal member 5.

Covered by the third sensors S3, the spring clamps 830 of the third carriages 83 are deactivated by the blocking/unblocking means C so as to release the third carriages 83 from the upper branches Tc in order to position the third arm 6c in the non-operating position; covered by the second sensor means S2, the spring clamps of the second carriages S2 are deactivated by the blocking/unblocking means C so as to release the second carriages 82 from the upper branches Tc in order to position the second arm 6b in the non-operating position and, lastly, covered by the first sensor means S1 by the first carriages 81 the command and control board 100 deactivates the conveyors: the system is newly ready to couple to and support a further article F in outlet from the operating station of the machine M.

The unloading of the article F on the plane P, alternatively to what is described in the foregoing, can take place with a release of the article F starting from the head portion up to the trailing portion thereof; the following are then deactivated in sequence: the coupling means 60 of the first arm 6a; then the coupling means 60 of the second arm 6b and, lastly, the coupling means 60 of the third arm 6c so as to determine a gradual release of the article F onto the pallet L, or onto the head article of the stack created.

The release of the article F on the plane P can, alternatively, take place with the simple deactivating of all the coupling means 60 associated to the first, second and third arm 6a, 6b, 6c, so that the article F is released by force of gravity to fall onto the pallet L, or onto the head article of the formed stack.

The system for stacking flat articles in a receiving station located downstream of the outlet of an operating station of a machine M, has particularly advantageous characteristics; the system enables the anchoring, support and displacing of articles F from the operating station on a pallet, or stack of articles, with the simple activation, in sequence, of the coupling means 60 of the first, second and third arm 6a, 6b, 6c, and the displacement of the arms as described in the foregoing. The enabling means A positioned downstream of the first detecting means R enables enabling the second detecting means 7 which will measure the effective linear displacement of the article F so as to determine the activation of the coupling means 60 of the first, second and third arm 6a, 6b, 6c at predefined distances from the leading edge of the article F; in the described embodiment the activation in sequence of the coupling means 60 and, thereafter, the movement of the relative arms enables coupling the article F on the leading edge, in the central portion and at the trailing edge thereof.

Considering the large dimensions of the articles, during the advancing thereof any downwards flexion thereof is prevented, avoiding dragging of the lower surface against the upper surface of the pallet, or the head article of a stack of articles supported by the pallet, which would possibly cause damage thereto.

The upwards movement direction of the elevator E determines the intercepting of the upper surface of the pallet L, or of the head article of a stack, against the lower surface of the article F supported on the plane P with a consequent raising of the article F and the coupling means 60.

Following the detecting of the raising, the command and control board 100 deactivates the coupling means and the article F is released onto the pallet, or onto the head article of a stack, preventing air from becoming trapped between the two surfaces, which air would cause displacement of the article with respect to the pallet L, or of the head article of a stack (bubble effect).

In the description the raising is detected by the sensor 65; an expert in the sector can apply further prior art for the raising and the entity thereof.

The fact that the longitudinal member is coupled to the floating frame 2 is advantageous as any damage to the article F and the longitudinal member 5 is prevented in a case of malfunctioning of the elevator E.

In a further embodiment, the movement of the support arms can be set by the article F, as it is expelled from the operating station using known methods. The arms will be pushed in the first advancement direction W1 ; this is not obstructed as the carriages can freely slide along the guides and, following the release of the article F on the pallet or on the stack of articles F formed, be repositioned in proximity of the outlet of the operating station of the machine M manually or with suitable dragging means.

In a different embodiment, not illustrated, the terminal portion of the article F is detected by the first detecting means R and then by the enabling means A; the second detecting means 7 are disabled.

Following the detections and deactivating, the activating devices remain active so as to determine the detection of the first carriages 81 of the first arm 6a by corresponding detecting means and the centring in the profiled members 50.

The detecting and centring means detect the first carriages 81 and the command and control board 100 blocks the transmission means, in this way determining the centring of the article F with respect to the underlying pallet, or stack of articles: the articles will be release and perfectly stacked.

Note that the system of the invention can alternatively be positioned in inlet of an operating station of a machine; the system must be positioned in such a way that the transversal portion 4 is by the inlet portion of the machine and, by appropriately intervening on the command and control board 100 to control the elevator, the activating of the coupling means, the movement of the support arms and the displacement, it is possible to couple each head article F of a stack of articles to be processed so as to position the head article F in abutment to the transversal portion 4, then to be guided in inlet to the operating station of the corresponding machine.

It is of further note that blocking/unblocking means can be associated to the first carriages, which perform the same function, as described in the foregoing, as the blocking/unblocking means associated to the second and third carriages.

It is understood that the above has been described by way of example and that technical-functional variants of the proposed system are considered to fall within the protective scope of the invention as claimed in the following.