EP0965526A1

EP0965526A1 - Feeding device of stacks of packaging labels or blanks, in particular on cigarette packing machines

Info

Publication number: EP0965526A1
Application number: EP99109727A
Authority: EP
Inventors: Valter Spada; Stefano Malossi
Original assignee: Sasib Tobacco SpA
Current assignee: SASIB SpA
Priority date: 1998-05-22
Filing date: 1999-05-18
Publication date: 1999-12-22
Also published as: ITSV980032A1; ITSV980032A0; IT1305962B1

Abstract

Feeding device of packaging labels or blanks, in particular on a cigarette packing machine, or similar, these labels or blanks are fed in stacks (P) tied by a tie band (F), being provided with a cutting station (T) for the tie band (F), a feeding station (3) of the stacks (P) of labels or blanks and conveyor means (2) of the stacks (P) from the cutting station (T) to the feed hopper (3). According to the invention, the conveyor means (2) of the stack (P) of labels or blanks from the cutting station (T) of the band (F) to the feed hopper that are made in shape of clamping jaws (102, 702) of the stack (P) of labels or blanks and that comprise means (6, 6') for gripping the band (F) that act only on the band (F) itself, holding this latter and leaving the stack (P) of blanks free.

Description

The invention relates to a feeding device of packaging labels or blanks, in particular to a cigarette packing machine, or similar, these labels or blanks being fed in stacks tied by a tie band, a cutting station of the tie band, being provided with a feed hopper of the stacks of labels or blanks to the packing machine and conveyor means of the stacks of labels or blanks from the cutting station to the feed hopper.
The invention has the aim to create a device of the type described at the beginning in such a manner that it becomes possible to separate with safety the cut tie bands from the corresponding stack of labels, avoiding with absolute certainty that the band itself is conveyed away from the feed area to the machine and ensuring that the same can be discharged with precision in a preset discharge station away form the feed area; all in a very simple fast and operationally safe manner without requiring the use of particularly complex and costly means.
The invention attains said aims thanks to conveyor means of the stack of labels or blanks from the cutting station of the band to the feed hopper that are made in shape of clamping jaws of the stack of labels or blanks and that comprises means for gripping the band that act only on the band itself, holding this latter and leaving the stack of blanks free.
Advantageously the clamping means are formed by suction modules that are integrated with at least one of the clamping jaws of the stack of labels or blanks. The conveyor means cooperate advantageously with stationary holding means of the stack of blanks.
The holding means of the stack of labels can be alternatively formed by the feed hopper itself or by an other operating unit foreseen also for other functions or by a unit provided for the purpose.
Said means can be made in a manner such to hold back the stack while the band is being extracted thanks to the conveyor (2) moving away from the stack (P) or the stack (P) form the conveyor itself.
The holding means of the blanks are provided in conjunction with clamping means of the said stack that can be engaged and disengaged and that cooperate with areas of the stack different from those with which the conveyor means cooperate.
In a preferred form of execution, the conveyor means are formed by the same pick up/conveyor means of the stack of blanks from the cutting station and are fitted on a carriage guided in order to carry out movements at least on one plane.
The conveyor means of the pick up/conveyor means are advantageously formed by a horizontal support ledge of the stack carried in a projecting manner by a vertical structure, while in a postion overlapping the same in a measure greater than the hight of the stack a support ledge of a pusher is provided the stroke of which is at least transversal to the support ledge, preferably perpendicular and that has at least one suction nozzle in a position coinciding with the tie band.
Advantageously, the band is provided in the middle section of the stack of blanks and the support ledge and opposite pusher extend themselves in correspondence to said area.
The holding means of the stack of blanks can be formed by walls, wings or other ledges holding the stack relative to the extraction of the same from the conveyor both in the case of a motion of the conveyor itself as well as in the case of a movement of the stack together with the holding means.
In the case of a feed hopper in which said means are integrated, the same are formed by the upper section of the vertical feed hopper that has at least on the side facing towards the support ledge, prefereably also on the opposite parallel side a recess that extends itself from the top end to an intermediate area of the hopper itself and the support ledge being oriented perpendicular to the same, while the said recesses are of dimensions greater than the support ledge.
The distance between the top edge of the hopper and intermediate plane is slightly greater than the hight of the stack and movable support means of the stack of blanks are provided in the intermediate plane that engage with the peripheral sections of the stack.
The holding means can also be formed by the clamping means of the stack. These can be connected to a cutting unit of the band in which the stack is carried prior to the cycle removing the tie band and feeding the stack itself to the machine.
In a preferred form of execution , the cutting unit provides for closure means that act on the top sides of the stack and that are supported in a projecting manner by the cutting unit itself, while the stack clamping means are carried in a projecting manner by said closure means.
The clamping means of the stack can be foreseen also in conjunction with the feed hopper and in conjunction with the holding means formed by the rest modules.
In this case, in correspondence to the top edge of the hopper are foreseen the said clamping means of the stack of blanks itself against the mobile support, which themselves can also be engaged and disengaged and assume like the mobile support means a position of rest in which they do not interfere with the stack inside the hopper and an active position in which they protrude inside the clearance of the hopper coming to engage with the bottom and ceiling of the stack respectively.
A further preferred form of execution provides that the vertical support structure of the support ledge has at least one suction module coinciding with the area of the band along the facing side of the stack.
Advantageously the said vertical support structure is formed by a wall rigidly connected to the support ledge and that forms an additional lateral stop wall of the stack itself.
The said vertical wall is provided on the side of the ledge opposite to the free end of the same facing towards the feed hopper.
According to a further perfectioning, the conveying means of the stack of blanks move along a vertical plane or in any case parallel to the axis of the hopper, the said conveying means being supported in a position such, that the stack of blanks is always aligned with the feed hopper with reference to only one of the directions of movement and with the cutting station of the band, in this case the cutting unit being made movable according to a direction transversal to the plane of motion of the conveyor means, while the ledge is oscillating around an axis transversal to the axis of the hopper, or else parallel to the ledge itself and at such an angle that it moves into a position of disengagement from the side supporting the stack P on the same.
In the executive form in which the support ledge is rigidly connected to the lower end of a vertical support wall, the ledge and said wall are supported oscillating together as the said vertical wall is fulcrated on the structure of the conveyor in the area of its upper horizontal extremity or parallel to the supporting ledge.
Therefore, when the band is cut, the stack P is already on the conveyor and does not need to be transferred on other conveying means in order to be taken from the cutting station to the feed hopper. Furthermore, already in the cutting station of the band the stack can be held firmly in the position of perfect reciprocal alignment of the blanks thanks to the pusher means cooperating with the supporting ledge in form of a pair of clamping jaws. The stack is then carried with a first translation in a position vertically coinciding with the mouthpiece of the hopper and thus with a translation in the axial direction of the hopper inside the upper section of the same, always keeping the pusher active. The suction cup or different suction cups are activated and also the movable support and movable pushers of the feed hopper are brought into active support and clamping position. The pusher of the conveyor is lifted and the top part of the band remains attached to the same, while a rearward angular motion disengages the ledge from the hopper and the stack firmly held in the same. The part of the band engaging with the side of the stack facing towards the conveyor is held back by the eventual suction means connected to the vertical side of the conveyor and is consequently also moved away from the stack. The conveyor is translated in inverse direction parallel to the axis of the hopper and the band is pulled off the stack with regards to the section associated with the bottom side of the stack and to the one opposite to the conveyor.
The conveyor can then carry the band cut and seperated from the stack to a discharge station provided in a suitable position with regards to the contingent arrangement of the operational parts of the machine and of the different stations.
However, when the means holding back the stack and/or the clamping means of the pack are connected to the cutting unit, then it is the said cutting unit that moves relative to conveyor means pulling off the stack firmly held on the same that hold back the cut band instead. Subsequently the conveyor moves towards a discharge station of the band to return once the same has been dropped to pick up the stack from the cutting unit and to carry and deposit it in the feed hopper.
In combination with the alternatives described above it is possible to provide a particular discharge station of the band that comprises a suction duct.
The suction duct is preferably foreseen in the track of the conveyor and in an intermediate position between the hopper and the cutting unit of the band.
According to a preferred form of execution, the suction duct is of the Venturi effect type. In particular the suction duct comprises a tubular part that terminates at the mouthpiece side with lead-in surface, while along the the said lead-in surface and in direction of the axis of the tubular part, at least in the area of the mouthpiece a laminar compressed air flow is generated that has the effect of sucking the hanging strip of the cut band against the lead in surface and into the tubular part.
In particular, the said lead in surface connects in a harmonious manner and without solution of continuity to the substantially circular entry of the tubular part starting from a free flat extremity.
The free flat extremity has a nozzle for the laminar flow that is formed by a chamber of distribution that has an exit slit turned substantially towards the mouthpiece of the tubular part.
The steps feeding the stack to the hopper are regulated by suitable sensors, as for example luminous barriers or similar.
The device according to the invention is considerably economic, in that it is completely integrated with the means that pick up the stacks and carry them to the cutting station and from this to eventual other stations and to the hopper. The suction nozzles are easy to execute, available on the market and ensure a long life and a constant and safe operation.
By integrating the holding means of the stack with the hopper on removal of the band one obtains a reduction of the operational steps. The alternate form of execution instead has the advantage of avoiding with certainty that the band can possibly fall into the feed hopper, which would have negative influence on the correct operation of the manufacturing machine requiring the intervention of the service personell if not directly stopping the manufacturing machine itself.
The invention relates also to other features which are subject of the claims below.
The featueres of the invention and the advantages derived therefrom are better evidenced from the following description of an executive example illustrated in a non limiting manner in the enclosed drawings in which:
The Fig.s 1 to 4 illustrate schematically and in perspective a device according to the invention in combination with a cutting station of the band and a feed hopper, in four important phases of the feeding cycle of the stack and removal of the tie band.
The Fig.s 5A and 5B show a lateral view in elevation of the conveyor according to the invention in two operative positions.
The Fig. 6 is an enlarged rear view of the conveyor according to Fig. 5.
The Fig.s 7 to 11 illustrate the different phases of feeding the stack to the hopper.
The Fig. 12 illustrates a plan view from above on the mouth of the hopper.
The Fig. 13 illustrates a lateral view in elevation of the hopper.
The Fig.s 14 to 16 illustrate a view analogous to the one of the Fig.s 1 to 4, of a further form of execution of the invention.
The Fig.s 17 and 18 illustrate a view in cross-section of the cutting unit of the band provided with closure means that carry the clamping means of the stack of blanks for removal of the same from the conveyor that retains the cut band and in the open and closed position of said clamping means respectively.
The Fig.s 19 and 20 illustrate schematically a plan view from above of the closure and of the clamping means of the stack according to the preceding figures and in two operative conditions respectively.
The Fig.s 21 and 22 illustrate schematically a lateral view in cross-section of the discharge station of the band from the conveyor.
With reference to the Fig.s 1 to 4, to a packing machine, in particular a cigarette packing machine the stacks P of blanks are fed in succession thanks to conveyors 1. Pick up/conveyor means 2 pick up each stack from the conveyor 1 and carry it initially to a cutting station T in which the tie band F is cut that holds the blanks of each stack together. Subsequently the pick up/conveyor 2 carries the stack P in correspondence of a feed hopper 3 in which it deposits the stack P. The individual blanks which are sent to the folding station of the packing machine are picked up by other modules not illustrated from the bottom opening of the hopper 3.
The conveyor 1 is advantageously formed by a pair of parallel conveyor bands distanced from each other with a dimension such as to form a central longitudinal void in which the pick up/conveyor 2 can enter to pick up the stack P in the respective front position of the sequence.
The cutting station T comprises a band cutting unit 4. The discharge end of the conveyor 1, the hopper 3 and the cutting station T are arranged relative to each other in such a manner, that the pick up/conveyor can limit itself to a motion on one plan and therefore according directions with only two perpendicular components, preferably in a plane parallel to the axis of the hopper 3 and especially in a plane in which the mean axis of the stack P on the pick up/conveyor 2 extends itself in the same plane containing the axis of the hopper 3. Advantageously the pick up/conveyor 2 can furthermore rotate around the axis parallel to the axis of the hopper 3 and perpendicular to the plane of conveyance of the conveyor 1, in such a manner that the output end of the conveyor can find itself on the side of the pick up/conveyor 2 opposite to the one of the hopper 3 and the cutting unit T. Preferably the plane of motion of the pick up/conveyor 2 is vertical and transversal to the dicrection of feeding of the stacks P on the conveyor 1 and also the axis of the hopper 3 is vertical.
With reference to the figures, the pick up/conveyor 2 is mounted on a first carriage 21 sliding in horizonatl direction along a guide 22. This in turn is fitted at its extremities on carriages 23 that slide along a pair of vertical guides 24 which form a bridge like structure.
As evidenced in Fig.s 5A, 5B and 6, the pick up/conveyor 2 is formed by a horizontal ledge 102 on which the stack P is made to rest. The support ledge 102 is carried projecting on the lower end of a vertical rear stop wall 202 that is fulcrated at its upper end in a manner oscillating around an horizontal axis 302 parallel to the upper edge of said vertical rear stop plate 202.
In particular the vertical rear stop plate 202 is fixed on top to an oscillating arm 402 fulcrated with one end to the structure of the pick up/conveyor 2 and at the other end of which projecting overhanging beyond the rear stop wall is articulated the rod of a linear actuator 5. The actuator is articolated with its opposite end to a stationary stop 502.
In the central area overlapping the part of the band F extending itself along the facing side of the stack P, the rear wall has two suction pads or other suction means intended to cooperate with the top and bottom end sections of the facing part of the band F. The suction pads 6 extend themselves substantially in line with the side of the rear stop wall 202 intended to come into contact with the stack P. Above in coincidence with the support ledge 102 of the support structure of the pick up/conveyor 2 projects a fixing bracket 602 of a linear actuator 5 that is oriented in such a manner as to carry out a stroke in direction of the support ledge 102 underneath, in particular perpendicular and the rod of which drives a pusher 702 that has in a position turned towards the support ledge 102 at least one suction pad, preferably a group of suction pads 6 in a position coinciding with the part of the tie band F that extends itself along the upper side of the stack P facing towards the pusher 702.
As evidenced from in the Fig. 5A, the angular movement of the support ledge 102 and vertical rear stop wall 202 assembly is such, that the free end of the support ledge 102 can be carried into a laterally staggered position and distanced from the edge of the bottom support side of the stack P and consequently in a position of non interference with the same. This allows the stack P to be picked up or deposited by the conveyors 1 or in the hopper 3 thanks to a single substantially vertical motion of the pick up/conveyor 2, once the support ledge 102 has been angularly moved in position of disengagement of the stack P itself.
The support ledge 102 and the rear stop wall 202 are of such dimensions that the stack P protrudes beyond the same at least from the lateral edges.
With reference to the Fig.s 7 to 13, the feed hopper 3 is formed by a tubular part, vertical with an internal conduit 103 shaped substantially corresponding to the lay-out shape of the blanks that form the stacks P. The feed hopper 3 has a shape complementary to the one of the blanks that is slighly wider in correspondence to the top end and narrows to the dimensions of the blank in direction of the bottom discharge end 203. The walls of the hopper 3 do not come into contact with the edges of the blanks over their entire extension but only with some axial bands of preset width and with predefined position. The said bands are indicated with 63, 603' and 603''. The position of the said axial bands of contact of the hopper with the blanks is dependent on the shape of the actual blanks. For a typical blank for forming rigid packets, the hopper has inclined contact and centering surfaces along the longer sides of the actual blank and in correspondence of the top and bottom ends of the blanks. Advantageously the vertical contact bands 603' and 603'' of the hopper 3 in correspondence of the top and bottom ends of the blanks make contact with the angled sections of the blank and form between themselves correspondingly angular guides and that partially overlap the blank at the top end and at least partially and for a short section at the end connecting with the longer side and with a side having at least one component paralell to the said longer side. In this particular case, on a top end the blank has a central rectangular wing 12 and the contact bands form substantially a U shaped guide, while in correspondence to the opposite end the two longer sides of the blank extend themselves beyond the central section of the corresponding top end form on each side triangular wings 13 which engage with complementari vertical guides 603''' of the hopper.
The contact bands of the hopper 3 with the blank are therefore formed by ribs 603 or guides in form of a channel, or with angled transversal sections and all substantially with inclined contact faces in order to narrow the inner space of the hopper from the feed opening to the one of discharge.
Above a set level from the discharge opening 203, the same extends itself upwards only in correspondence of the two side walls parallel to the lateral edges of the support ledge and rear stop wall 102, 202. In the executive example illustrated the walls 303 of the hopper corresponding to the end sides of the stack P extend themselves upwards and with them the guides 603', 603'' and 603''' that overlap the corner sections of the blank on the end sides, thus forming in the top section of the hopper 3 surfaces holding the stack P relative to a motion in direction of oscillation of the support ledge 102. Between the two guides or the two upper extensions, there is a recess opened at the top at least in the wall facing towards the pick up/conveyor 2 and preferably also in the additional wall parallel to this one. Said recesses or openings allow the pick up/conveyor 2 to bring the stack inside the top part of the hopper 3.
Advantageously the difference in the level between the top one and the intermediate one is greater than the hight of the stack P and the movable means of support of the stack P in the rest position are provided slightly distanced from the plane defined by the top edge of the lower part of the hopper completely closed or substantially completely closed.
This allows to obtain sufficient vertical space to permit the ledge 102 to carry out the motion of oscillation without interfering with the stack of blanks in the lower section of the hopper 3 itself.
The movable support means of the stack P in the upper part of the hopper 3 and that support the said stack P in a position raised from the stack P of blanks underneath, can be made in any manner and are formed advantageously by small L shaped ledges supported in an oscillating manner in correspondence to the free end of a branch of theirs, in a manner such to arrange itself horizontally and protruding on the inside of the hopper 3 in active position of the same and to be withdrawn to the position of non interferance with the stack P in the hopper in their inactive position. The small ledges are driven by a linear actuator 5'' eventually thanks to return levers 105.
It is possible to foresee any number of said movable support means of the stack P in the upper part of the hopper according to the shape, the dimensions of the blank and the weight of the stack itself.
In correspondence to the top edge of the hopper 3 at the extensions of the sides of same are provided pusher means 803 of the stack P against the movable small ledges 703. Also these means are formed by oscillating parts, as for example oscillating levers that are fulcrated around an axis parallel to the corresponding extension of the wall 303 of the hopper 3 in correspondence to their middle section. The pushers 803 can be oscillated in active position of abutment against the end of the stack P adjacent to the extension of the corresponding wall 303 and in inactive position in which they are outside the opening defined by the hopper 3. This takes place in a manner analogous to the motion of the small movable support ledges 703.
Both the movable small ledges 703 as well as the pushers 803 have an arrangement and extension such, that they cooperate with parts of the stack P away from the support ledge 102 of the pick up/conveyor 2 and therefore the said parts do not interfere with each other.
One or more sensors 8, 8' detect the filling level of the hopper and according to this filling level control the activation of the pick up/conveyor 2 means in that it request the feeding of a new stack or places the pick up/conveyor in waiting position.
As evidenced in the Fig.s 1 to 4 and 7 to 12, the operation of the device according to the invention is the following. The pick up/conveyor 2 takes a stack to the cutting station T where the tie band F is cut. Subsequently the said pick up/conveyor prepares to convey the stack P to the hopper 3. The sensors 8 detect the filling level of the hopper 3 and if the same is lower than the level of the small movable support ledges 703, the new stack P is inserted in the upper part of the hopper 3 with a motion of vertical alignment of the pick up/conveyor 2 with the top opening of the hopper 3 and a subsequent vertical motion of descent. The small support ledges 703 are activated and the stack P is supported in addition to the pick up/conveyor 2, or the ledge 102 by the said small support ledges 703. In these sequencies of conveyance of the stack P the pusher of the pick up/conveyor 2 is activated and moved in condition of compression of the stack P against the support ledge 102, that is to retain the stack on the ledge 102, as well as to hold the band to avoid that the stack perfectly aligned should be subjected to deformations.
In the lowered position of the pick up/conveyor 2 with the stack P in the hopper 3 and in position of resting on the small movable ledges 703 the pushers 803 that additionally hold the stack P are first activated and subsequently the pusher of the pick up/conveyor is lifted from the stack in inactive position. The suction cups 6 and 6' are activated at the same time, so that the band is held against the corresponding part of the pick up/conveyor 2 and moved away from the stack that instead is held back in position by the small support ledges 703 and by the pushers 803.
The pusher of the pick up/conveyor 2 moves away dragging with it the corresponding part of the band F and the same thing happens with the parts of the band F facing towards the vertical rear stop wall 202 when the ledge 102 and the said wall are moved angularly backwards. The support ledge 102 will be on the outside of the hopper 3 and in a position completely disengaged from the stack P. At the same time the band F is partially extracted from above and below also from the opposite side of the stack P, whether during the oscillation of the support ledge 102 or during the subsequent motion of lifting of the pick up/conveyor 2.
Advantageously during the return stroke of the pick up/conveyor 2 to the conveyor 1 in order to pick up the following stack P, the same is made to pass in correspondence of one discharge station S, as for example a collecting container or a suction conduit in which the band F is also simply left by the pick up/conveyor, interrupting the suction of the suction cups 6, 6'.
A preferred example of the means of discharge or rejection of the bands from the conveyor 2 are illustrated in the Fig.s 21 and 22. Said figures illustrate two cycles of the operation of discharge or rejection of the band F from the conveyor 2. The means of discharge or rejection are formed by a tubular conduit, preferably with a cylindrical section 30 of which only the end piece that is the pick up mouthpiece of the band F. Said tubular conduit extends itself towards the conveyor 2 with a plate 31 that without solution of continuity starts with a section in form of a circular sector or else arched correspondingly to the curvature of the tubular part 30 and ends substantially flat in correspondence to the free extremity. On the said extremity, the plate of conveyance 31 has a nozzle 32 for the emission of a jet of air under pressure G with a laminar extension substantially parallel to the surface of conveyance 31 and in the direction of the mouthpiece of the tubular part 30. The nozzle 32 has a chamber of distribution 132 that has a slit 232 on the side turned towards the mouthpiece of the tubular part 30. This one is of a lenght substantially corresponding to the width of the surface of conveyance 31. The concentrated laminar flow causes a suction action on the hanging strip 33 of the band F against the plate of conveyance 31 and drags the same into the tube when the part of the band held by the nozzles 6' of the conveyor 2 is released. The band F is therefore pushed and sucked into the tubular part 30 that leads to a removable container for collection not illustrated in detail.
The position of the means of rejection or of dicharge of the band F can be provided in any position along the run of the conveyor 2. As illustrated in the Fig.s 14 to 16, preferably the means of rejection or of discharge are provided in the intermediate position between the hopper 3 and the cutting unit T.
With reference to a variant of the invention, the withdrawal of the band F from the stack P of blanks is carried out in the cutting station itself.
In this case, as illustrated in the Fig.s 17 to 20, the cutting unit has a box 104 for housing a rotary knife 304 engaging through an opening 404 with the band F. The box 104 has runners sliding on guides 35 that are oriented in a direction perpendicular to the face of the stack P and of the band F on the conveyor 2 turned toward the cutting unit 4. In the front position and protruding , the box 104 has a pair of movable closing modules 36 that are carried by an upper stirrup 37 integral with a carriage 38 mounted on guides 39 and driven in a sliding manner by a linear actuator 40. The two closing modules 36 engage with the top sides of the stack P of blanks and have the function to aligne the blanks themselves on said top sides of the stack. Each is carried by its own stirrup 37 integral with a carriage 38. The actuator 40 is formed for example by a pneumatic cylinder or by a pair of opposing pneumatic cylinders that act in moving away from and moving close to until the closure modules 36 abut with same to the corresponding top sides.
Means for clamping the stack P of blanks indicated overall with 41, 42 are connected with the closure modules 36. Said means are formed by a pair of pushers acting in opposite direction to one another carried respectively by the upper stirrup 37 that supports the closure module 36 and by an end stirrup 43 mounted on the free extremity of the corresponding closure module 36.The pusher modules, for example of the type that can be activated hydraulically or pneumatically are generally driven and have a linear actuator 141, 142 and a pressure head 241, 242. Advantageously the pressure head is shaped in such a manner that affects only the end sections on the end sides of the stack P in correspondence of which the band F is not foreseen. The said sections are shown sketched with the reference number 44 in Fig. 20. The pushers or at least the linear actuators 141, 142 can be of any type easily available on the market as a preassembled module.
The operation of the executive variant relative to Fig.s 17 to 20 is analogous to what previously described. In this case, the conveyor 2 reaches the cutting station T. The cutting station is brought forward towards the conveyor 2 as indicated by the arrow 45. The procedure of cutting the band is carried out. Subsequently the procedures of stack alignment are carried out activating amongst others also the closure modules 36 which are brought into contact with the end sides of the stack P. In this position the pushers 41 and 42 are withdrawn and in position of alignment with the section of the stack P 44 against which they are to act. On completion of the stack alignment, the pushers 41, 42 are activated that close on the stack P holding it in position. The suction cups 6, 6' of the conveyor 2 are activated contemporaneously. The cutting unit is moved back in direction of the arrow 46 along the guides 35, while the conveyor 2 stands still. Therefore the stack P is removed from the conveyor 2. At the end of the stack P removal stroke, the conveyor 2 with the cut band moves to the reject or discharge station previously described. It leaves the band F which is carried away and returns to pick up the stack P from the cutting unit 4. This takes place in ways analogous and contrary to what previously described. When the stack P is again without a band F on the conveyor 2, this one moves into position to deposit the stack P into the hopper 3. The operations of depositing the stack P of blanks into the hopper 3, take place substantially in a manner corresponding to or any case substantially analogous to what described with reference to the preceding executive example, however, the steps relative to the removal of the band F are missing as this has already taken place previously.
According to a further perfectioning that is also evidenced in the Fig.s 14 to 16, the device according to the invention can be provided additionaly in combination with an emergency buffer reservoir 11 that is formed for example, but not necessarily by a band conveyor analogous to the one of the feeding conveyor 1. The conveyor 11 can be driven in the two directions to be able to collect stacks of blanks F still tied with the bands as well as eventually already without bands and to be able the feed the same again to a station of pick up/deposit 50 by the conveyor 2.
To allow for easy pick up and deposit of the stacks by the conveyor 2, in the station 50 of pick up and deposit an elevator 51 is foreseen formed by a plate shaped like a comb with at least two recesses 151 completementary to a conveyor band 52 formed by a pair of parallel bands. The band 52 also can be driven in the two running directions and that constitute the end extension of the buffer band 11. The two recesses 151 form three fingers or wings 251 of the elevator 51 suitable to support the stack in the section of the protruding extremities of the ledge 102 of the conveyor 2 and in a central area to avoid warping of the stack. In this case, the ledge 102 of the conveyor 2 is made in shape of a fork, or of two parts separated from each other that from a central recess for housing the finger or the central wing 251 of the elevator 51. The elevator 51 furthermore comprises a vertical guide 351 on which it is mounted in a sliding manner thanks to a runner 451, while the vertical movement is driven by suitable actuators. Advantageously, such a construction can be formed by a prefabricated linear actuator of the type obtainable on the market. The stacks P that are placed on the storage/conveyor 11 can be furnished with or lacking bands and can be positioned on the same by the pick up/conveyor 2 for example during the dwell time of the feeding cycle of the machine or during stop cycles of the machine. It is also possible to provide a manual loading cycle carried out by the service personell. In case of interruption of the feeding, for example for replacing the pallet on which the stacks are arranged or in case the feeding conveyor 1 stops, the pick up/conveyor 2 picks up one or more stacks from the storage conveyor 11. This takes place by activating the conveyor 11 and 52 in direction of movement of the stacks P towards the elevator 51. The elevator 51 carries the stack received from the conveyor band 52 in the upper position of pick up by the conveyor 2. According to whether the stacks are still equipped with the band F or not, the conveyor carries the same to the cutting station T or directly into the hopper 3. The feeding procedure of the stacks P to the buffer band 11 is inverse to the one described of the pick up.
Naturtally the invention is not limited to what described and illustrated but can be amply varied aboveall constructively, the whole without abbandoning the informative principle explained above and claimed hereafter.

Claims

1. Feeding device of labels or blanks for packaging, in particular to a cigarette packing machine, or similar, the said labels or blanks being fed in stacks (P) secured by a tie band (T), a cutting station (T) for cutting the tie band (F), a feed hopper (3) of the stacks (P) of labels or blanks and conveyor means (2) of the stacks (P) from the cutting station (T) to the feed hopper (3) being provided, characterized by the fact that the conveyor means (2) of the stack (P) of labels or blanks from the cutting station (T) of the band (F) to the feed hopper that are shaped like clamping jaws (102, 702) of the stack (P) of labels or blanks and that comprises gripper means (6, 6') of the band (F) that act only on the band (F) itself, holding back the latter and freeing the stack (P) of blanks.

2. Device according to claim 1, characterized by the fact that the gripper means (6, 6') are formed by suction modules that are integrated with at least one of the clamping jaws (702) of the stack (P) of labels or blanks after the cutting of the band (F) itself.

3. Device according to claims 1 or 2, characterized by the fact that the conveyor means (2) cooperate with stationary holding means (603', 603'', 603''') of the stack (P) of blanks that are made in such a manner to hold the stack while the band is extracted thanks to the moving away of the conveyor (2) from the stack (P) or of the stack (P, 4) from the conveyor (2) itself.

4. Device according to one or more of the preceding claims, characterized by the fact that the holding means (603', 603'', 603''') are formed or integrated in a feed hopper (3) of a manufacturing machine, in a separate operational unit or in a cutting unit (4) of the band (F).

5. Device according to one or more of the preceding claims, characterized by the fact that the means holding back the stack (P) of blanks are formed by or foreseen in combination with clamping means (703, 803; 41, 42) of the stack (P) of blanks.

6. Device according to one or more of the preceding claims, characterized by the fact that the clamping means (703, 803; 41, 42 of the said stack (P) that can be activated and deactivated and cooperate with the sections of the stack (P) different from the ones with which cooperate the conveyor means (2) and at the ouside of the extension of the band (F).

7. Device according to one or more of the preceding claims, characterized by the fact that the conveyor means are formed by the same pick up/conveyor means (2) of the stack (P) of blanks from a pick up station (1) to a cutting station (T) and are mounted on a carriage (21) guided (22, 23, 24) in order to carry out a movement on at least one plane.

8. Device according to one or more of the preceding claims, characterized by the fact that the conveyor means or the pick up/conveyor means (2) are formed by horizontal support ledges (102) of the stack (P) carried protruding by a vertical structure (202), while in a position overlapping the same at a distance greater than the hight of the stack (P) a pusher (5, 702) is provided the stroke of which is at least transversal to the support ledge (102), preferably perpendicular, and that has in a position coinciding with the band (F) at least one suction nozzle, one suction cup, or other suction means (6').

9. Device according to one or more of the preceding claims, characterized by the fact that the support ledge (102) and the opposite pusher (702) extend themselves in correspondence of the band (F) that is preferably provided in the middle section of the stack (P) of blanks, transversally to the major axis.

10. Device according to one or more of the preceding claims, characterized by the fact that the ledge (201) of the pick up/conveyor (2) is shaped like a fork and has a recess in the middle that extends itself at least partially between the two front sides or from side to side.

11. Device according to one or more of the preceding claims, characterized by the fact that the stationary means holding the stack (P) of blanks are formed by side walls, wings or other parts of abutment that hold back the stack (P) relative to a movement of the pick up/conveyor (2).

12. Device according to one or more of the preceding claims, characterized by the fact that the stationary means holding the stack (P) of blanks are formed by the upper section of a vertical feed hopper (3) that has at least on the side facing the support ledge (102), preferably also on the opposite parallel side, a recess that extends itself from the top end to an intermediate section of the hopper (3) itself and perpendicular to the sane is oriented the support ledge (102), while the said recess or recesses are of a dimension greater than the support ledge (102) or of the conveyor (2).

13. Device according to one or more of the preceding claims, characterized by the fact that the distance between the top edge of the hopper (6) and the intermediate plane is slightly greater than the hight of the stack (P) and movable support means (703) of the stack (P) of blanks are provided in the section of the intermediate plane that cooperate with the peripheral sections of the stack.

14. Device according to one or more of the preceding claims, characterized by the fact that in correspondence to the top edge of the hopper (3) clamping means (803) of the pack (P) of blanks are provided against the movable means of support (703), the said means can themselves be activated and deactivated and take up a position of rest the same as the movable means of support (703) in which they do not interfere with the stack (P) inside the hopper (3) and come to engage with the bottom and the ceiling of the stack (P) respectively.

15. Device according to one or more of the preceding claims, characterized by the fact that the vertical structure is formed by a wall (202) rigidly connected to the support ledge (102) and that form an additional lateral stop wall of the stack (P) itself.

17. Device according to the claim 16, characterized by the fact that the said vertical wall (202) is provided on the side of the ledge (102) opposite to the free end of the same that is turned towards the feed hopper (3).

18. Device according to one or more of the preceding claims, characterized by the fact that the conveyor means (2) of the stack (P) of blanks move along a vertical plane or in any case parallel to the axis of the hopper (3), the said conveyor means (2) being supported by (21, 22, 23, 24) in such a way, that the stack (P) of blanks is always aligned with the feed hopper (3) with reference to only one of the directions of movement while the ledge (102) is oscillating around an axis transversal to the axis of the hopper (3), that is parallel to the ledge (102) itself and at an angle such to move in position of disengagement from the side the stack (P) is supported on the same.

19. Device according to one or more of the preceding claims, characterized by the fact that the support ledge (102) is rigidly connected to the lower extremity of the vertical stop wall (202) and the ledge (102) and the said wall are supported oscillating together the said vertical wall being fulcrated on the structure of the conveyor in the area (302, 402) of its upper extremity around a horizontal axis or parallel to the support ledge (102) itself.

20. Device according to one or more of the preceding claims, characterized by the fact that the holding means (41, 42) are formed by clamping jaws associated with the cutting unit (4) and are movable in position of operational readiness and in active position.

21. Device according to the claim 20, characterized by the fact that the clamping means (41, 42) are provided on each of the two closing parts (36) carried on the cutting unit (4) and with a function of alignment of the blanks of the stack and said clamping means (41, 42) are alternatively brought in position of readiness in alignment with the areas (44) of the stack (P) with which they are to engage and in position of rest of the closing parts 36.

22. Device according to one or more of the preceding claims, characterized by the fact that the cutting unit (4) is mounted (204, 35) movable relative to the conveyor (2) at the the cutting station and in the clamped condition of the stack (P) the cutting unit constitutes the part withdrawing the stack from the conveyor (2).

23. Device according to one or more of the preceding claims, characterized by the fact that the conveyor or the pick up/conveyor (2) are provided in combination with means of collection and rejection (30, 31, 32) for the bands (F) cut and removed from the stack.

24. Device according to the claim 23, characterized by the fact that the said means of collection and reject or discharge of the bands (F) are formed by a suction conduit (30).

25. Device according to the claim 24, characterized by the fact that the suction conduit (30) is of the Venturi effect type.

26. Device according to the claims 24 or 25, characterized by the fact that the suction conduit comprises a tubular part (30) that terminates on the mouthpiece side with a lead-in and conveying surface (31), while along the said surface (31) and in direction of the axis of the tubular part (30), at least in the section of the mouthpiece of the same is generated (32) a laminar air jet (G), under pressure.

27. Device according to the claims 24 to 26, characterized by the fact that the lead-in surface (31) connects in a smooth manner and without solution of continuity with the substantially circular mouthpiece of the tubular part (30) starting from a substantially flat free extremity and in correspondence to which a blow nozzle (32) is provided.

28. Device according to one or more of the preceding claims 24 to 27, characterized by the fact that the blow nozzle (32) comprises a distribution chamber (132) connected to a pressure source and an output slit (232) turned towards the mouthpiece of the tubular part (30) and extends itself at a small distance from the surface of lead-in or of conveyance (31).

29. Device according to one or more of the preceding claims 24 to 28, characterized by the fact that the station of discharge or reject of the bands (F) is provided in the run of the conveyor (2) and aligned with the feed hopper (3), as well as in the intermediate position between the same and the cutting station (T) of the band.

30. Device according to one or more of the preceding claims, characterized by the fact that the intermediate plane of support of the stack (P) inserted in the upper part of the hopper (3) is foreseen at a certain distance from the remaining lower part of the stack (P) of blanks in the feed hopper (3).

31. Device according to one or more of the preceding claims, characterized by the fact that the feed steps of the stack (P) to the hopper (3) are controlled by suitable sensors (8, 8' 8''), as for example luminous barriers or similar.

32. Device according to one or more of the preceding claims, characterized by the fact that in addition to the feed hopper (3) a buffer reservoir (11) can be provided in combination for a certain number of stacks already freed or still equipped with the band (F) and that are picked up by the conveyor when for example the storage upstream or the cutting unit or any other problem causes the flow of stacks to be interrupted.

33. Device according to one or more of the preceding claims, characterized by the fact that the conveyor (2) also constitutes the loading unit of the stacks on the buffer (11).

34. Device according to the claims 32 or 33, characterized by the fact that the buffer (11) if formed by a band drivable in the two directions of motion and has an extension conveyor band (52) itself also drivable in the two directions of motion cooperating with an elevator (51) that takes the stacks (P) one at the time from a loading/unloading station from or to the pick up/conveyor (2) to a loading/unloading station from or to the conveyor band (11, 52).

35. Device according to one or more of the claims 32 to 34, characterized by the fact that the conveyor band (52) is formed by a pair of parallel bands distanced from each other, while the elevator has a support plane with two recesses (151) complementar to the extremities associated with the bands (52) that form three wings or fingers (251), while the ledge (102) of the conveyor (2) is made in shape of a fork or has a center recess complementary to the center wing or finger (251) of the support plane of the elevator (51).