APPARATUS FOR FEEDING PACKAGING MACHINES WITH STACKS OF SHEET MATERIAL

Abstract: The apparatus (1) for feeding packaging machines with stacks of sheet material has a unit (10) for the removal and transfer of stacks (4) of sheet material (2) which are arranged mutually side by side on supports (6) and are individually wrapped by respective bands (5). The removal and transfer unit (10) has a head (11) which is vertically and horizontally movable and has grip elements (18, 19) for removing individual stacks (4) from the supports (6) and for transferring them to a feeding station (3) of the packaging machine. A station (20) for cutting the band (5) is arranged ahead of the feeding station (3).

Description: The present invention relates to an apparatus for feeding packaging machines with sheet material (EP-A-86 280), in particular cardboard cutouts for rigid cigarette packets. As known, cigarette packaging machines are fed with stacks of cardboard cutouts intended to constitute the outer container of the cigarette packets. The stacks of cardboard cutouts are arranged on a belt conveyor which advances with a stepwise motion so as to convey said stacks to means which transfer the individual cardboard cutouts to a processing line of the machine. The stacks of cutouts are currently arranged manually on the input conveyor of the packaging machine. The conveyor in turn supplies a tank which feeds a stripper element adapted for separating the individual cutouts to be transferred to the machine processing line. This feeding system is rather complicated and limits the productivity of the machine besides entailing a considerable cost in labor. The aim of the present invention is to solve the above described problem by providing an apparatus for feeding packaging machines with stacks of cardboard cutouts in a completely automatic manner. A further object of the present invention is to provide an apparatus which is simple in concept, safely reliable in operation and versatile in use. According to the present invention, an apparatus for feeding packaging machines with stacks of sheet material is provided, said apparatus being characterized in that it comprises a unit for the removal and transfer of stacks of sheet material which are arranged side by side on supporting means and are individually wrapped by respective bands, said removal and transfer unit having a head provided with grip elements for gripping a stack and being movable vertically and horizontally so as to be positionable at the individual stacks and subsequently movable to a station for feeding said sheet material to the packaging machine and a cutting station for cutting said wrapping band, said cutting station being arranged ahead of said station for feeding to the packaging machine. The invention is now described with reference to the accompanying illustrative, non-limitative drawings, wherein: figure 1 is a perspective view of the apparatus for feeding packaging machines; figure 2 is a front view of a detail of figure 1; figure 2′ is a plan view of the detail of figure 2; figures 3 and 4 are vertical sectional views of a further detail of figure 1 in successive operating steps; figure 5 is a side view of another embodiment of a detail of figures 3 and 4; figure 6 is a perspective view of a further embodiment of the machine; figure 7 is a plan view of a detail of figure 6; and figure 8 is a side view of the detail of figure 7. With reference to the above figures, the reference numeral 1 generally indicates an apparatus for automatically feeding stacks of sheet material, constituted by cardboard cutouts 2, to a hopper 3 which constitutes a station for feeding said cutouts 2 to a known packaging or packet-making machine. The cardboard cutouts 2 have a substantially rectangular shape which has, at its ends, respectively a tab 2a and a trapezoidal indent 2b. The cutouts 2 furthermore have appropriate folding and cutting lines which are suitable for allowing subsequent packaging operations to be performed by the packaging machine. The cutouts 2 are provided in stacks 4 which are closed by a band 5, wrapped transversely around the longitudinal sides of said cutouts. The stacks 4 of cutouts to be transferred to the packaging machine are arranged in an orderly manner on pallet-like supporting means 6. More in particular, said stacks 4 are arranged mutually side by side along said longitudinal sides, so as to form parallel rows; the rows are in turn mutually adjacent along the shorter sides of the stacks 4. The stacks 4 are furthermore arranged so as to form superimposed levels or layers. The apparatus 1 has a fixed framework 7 from the side whereof two pairs of uprights 8 are arranged symmetrically and have, at their tops, a pair of beams 9 arranged horizontally parallel. A unit for the removal and transfer of the stacks 4, generally indicated by the reference numeral 10, is horizontally movable on the beams 9. Said removal and transfer unit 10 has a head 11 which is mounted at the lower end of a vertical beam 12. The beams 9 slidably support respective sliders 13 which are mutually connected by a cross-member 14 and can be actuated by means of suitable actuation elements which are not illustrated in the figures. The cross-member 14 slidably supports a sleeve 15 which can be actuated by an appropriate actuation element (not illustrated). A further sleeve 16 is rigidly associated with the sleeve 15 and is perpendicular thereto; the vertical beam 12 is slidably mounted in said sleeve 16 and can be actuated by a related actuation element (not illustrated). The head 11 is provided, in a downward position, with a supporting element 17 which is rotatable about a vertical axis 17′ under the control of an appropriate actuation element (not illustrated). The supporting element 17 supports grip elements constituted by pneumatic means 18 and by mechanical supporting means 19 which operate in combination with one another on the individual stacks 4. Said pneumatic means 18 are constituted by a plurality of sucker elements with a vertical axis which can be connected to a suction source which is not illustrated. Said mechanical supporting means 19 are in turn constituted by an L-shaped or fork-like element which is mounted so as to oscillate, under the control of actuation elements which are not illustrated, on a horizontal pivot 19a which is fixed to the supporting element 17. An end portion 19b of said L-shaped element is movable, as a consequence of said oscillation, between a first substantially horizontal position, at which it defines, together with said sucker elements, an accommodation seat for a stack 4, and a second inclined position of disengagement with respect to the line of action of the sucker elements. Between the position for removal of the stacks 4 from the pallet 6 and the feed hopper 3 there is a station for cutting the wrapping bands 5 which is generally indicated by the reference numeral 20 and is illustrated in detail in figures 3 and 4. The cutting station 20 has a seat for the insertion of the stack 4 which is defined by a pair of walls 21 which are intended to engage said stack at the shorter sides of the cutouts 2. Said seat has a lower opening 22 for the passage of a circular-blade cutting element 23. Said blade 23 is rotatably supported by an arm 24 which is slidable, by means of a sleeve 25, on a stem 26 which is mounted between the walls 21 below the opening 22. A suction belt 27 for the removal of the cut band is arranged to one side of the insertion seat of the stack 4. Said belt 27 wraps around a pair of rollers 28 and has a plurality of through holes 29. Below the cutting station 20 there is a container 30 into which the cut bands are conveyed with the aid of a guide 31. The operation of the described apparatus is as follows. The pallet 6, on which the stacks 4 of cutouts to be transferred to the packaging machine are arranged in an orderly manner, is inserted at the base of the fixed framework 7 of the apparatus. In this position the pallet 6 is arranged below the removal and transfer unit 10 which is movable on the beams 9. In particular, the head 11 is adapted to be moved along three orthogonal axes and can therefore be positioned exactly on the first stack 4 to be transferred and then lowered onto it. The movements of the head 11 are controlled by an appropriate known and commercially available control unit (not illustrated) which is normally used in three-axis measurement machines. The stack 4 to be transferred is gripped by the sucker elements 18, which are arranged so as to act exclusively on the band 5, and raised above its supporting plane, as shown by the broken lines 32, by an extent which is sufficient to allow the rotation of the L-shaped element 19 about the pivot 19a and the insertion of the end portion 19b below said stack, as illustrated in figure 2. The stack 4, gripped by the head 11, is moved along the transfer direction A, which is parallel to the beams 9, until it moves to the side of the cutting station 20. The stack 4 is then moved laterally above said cutting station 20, inserted in the seat defined by the walls 21 and released by the grip elements of the head 11, as shown by the broken lines 33. It should be noted that during the transfer step the stack 4 has the longitudinal sides of the cutouts 2 arranged horizontally perpendicular to the direction A. In order to allow the insertion of the stack 4 between the walls 21 of the cutting station 20, said stack is angularly rotated, by means of the supporting element 17, about the axis 17′. After the stack 4 has been inserted in the cutting station 20, the supporting arm 24 of the circular blade 23 slides, under the control of an actuation element which is not illustrated, through the opening 22, so as to cut the band 5 as illustrated in figure 3. The cut band is removed by the suction belt 27 and conveyed into the underlying container 30 with the aid of the guide 31. The stack 4, freed from the band 5, is again gripped by the grip elements 18, 19 of the head 11 and extracted from the cutting station 20. The stack 4 is subjected to a further transfer in the transfer direction A until it is vertically aligned with the feed hopper 3. The hopper 3 is defined by a plurality of angular profiled elements 34 which are arranged vertically along the vertices of a rectangle and are suitable for guiding the stacks 4. Said profiled elements 34 extend from a frame 35 for supporting the stack 4 which is arranged above a known stripper element which is suitable for separating the individual cutouts to be transferred to the processing line of the packaging machine. The removal of the other stacks 4 from the pallet 6 and their transfer to the feeding hopper 3 are subsequently performed in a similar manner. The described apparatus allows, in summary, to feed packaging machines with stacks of cutouts of sheet material in a fully automatic manner. In particular, the apparatus according to the invention performs the transfer of individual stacks, achieving operating speeds which are adequate for those of conventional packaging machines. It should be noted that the apparatus allows to directly feed the feeder hopper 3 of the packaging machine, with obvious advantages in terms of constructive and operative simplicity with respect to known devices in which said feeding occurs by means of the interposition of conveyor belts. By operating with the stacks wrapped by bands, the risk of cutouts arranged incorrectly upon the removal of the stacks from the pallet-like supporting means is furthermore eliminated. It is also possible to store on a fixed ledge 36 an appropriate reserve of stacks from which it is possible to draw during the replacement of the emptied pallets 6 so as to not interrupt the operation of the packaging machine. The ledge 36 extends above the cutting station 20 transversely to the transfer direction A. Figure 5 illustrates a different embodiment of the means for cutting the bands 5 which has a cutting blade 37 actuated with a reciprocating motion below the stack 4 by an actuation element or actuation means which are not illustrated. Said blade 37 extends, with a profile which increases in height, from a horizontal lamina 37a which is intended to insert between the lower base of the stack 4 and the band 5; the subsequent advancement of the blade 37 causes the cutting of the band 5. Figures 6 to 8 illustrate a further embodiment of the means for cutting the bands 5 which has a cutting element generally indicated by the reference numeral 38. Said cutting element 38 is arranged ahead of the feeding station 3 and is suitable for operating at a step of advancement of the stack 4 along a direction B which is transverse to the transfer direction A. The cutting element 38 comprises a blade 39 which is fixed, in an adjustable position, transversely to a lever 40. Said lever 40 is rotatable about a vertical pivot 41 on a bracket 42 which is rigidly associated with an upright 8 of the fixed frame 7, and is biased at one end by a spring 43; at the opposite end, the lever 40 supports a pair of rollers 44 which are rotatable about a vertical axis 44′. The stack 4, gripped by the grip elements 18, 19 of the head 11, is moved in the advancement direction B, which is parallel to the cross-member 14, toward the feeding station 3. It should be noted that in this advancement step the stack 4 keeps the longitudinal sides of the cutouts 2 horizontally perpendicular to the direction A. During advancement in the direction B, the slide of the stack 4 engages the rollers 44, causing the rotation of the lever 40 in contrast with the spring 3. In this manner the blade 39 is rotated in a position which is perpendicular to the advancement direction B of the stack 4 and cuts the band 5. The band 5 is cut proximate to the base of the stack 4, and this allows to reduce the hanging portion of said cut band 5. It is obviously possible to arrange the cutting element 38, as an alternative, so as to cut the band 5 at the lower surface of the stack 4. After cutting the band 5, the stack 4 continues to be advanced in the direction B until it is moved into vertical alignment with the feeding hopper 3. Upon transfer of the stack 4 into the hopper 3, the band 5 is retained by the sucker elements 18. The head 11 then performs the return stroke, during which the band 5 is allowed to fall into the container 30 by interrupting the connection of the sucker elements 18 to the suction source. In order to prevent the suckers 18 from also retaining the upper cutout of the stack 4, in particular if the band is made of relatively porous paper, it is possible to provide the use of further pneumatic means 45, constituted by a pair of sucker elements fixed to the L-shaped element 19, with axes which are parallel to the end portion 19b. The sucker elements 45 operate on one side of the band 5 and are intended to retain said band 5 upon the opening of the L-shaped element 19. In the practical embodiment of the present invention, the materials employed, as well as the shapes and dimensions, may vary according to the requirements. Thus, for example, the actuation elements may be constituted by any suitable conventional actuation means and transmission means, such as, e.g., electric motors and kinematic transmission members. Where technical features mentioned in any claim are followed by reference signs, those reference signs have been included for the sole purpose of increasing the intelligibility of the claims and accordingly such reference signs do not have any limiting effect on the scope of each element identified by way of example by such reference signs.

Claims: Apparatus (1) for feeding stacks (4) of sheet material to packaging machines, comprising a removal and transfer unit (10) having a head (11) provided with grip elements (18, 19) for gripping a sheet material and being vertically and horizontally movable characterized in that said removal and transfer unit (10) is a unit for the removal and transfer of stacks (4) of sheet material (2) arranged side by side on supporting means (6) and individually wrapped by respective bands (5), said head being positionable at the individual stacks (4) and subsequently movable to a station (3) for feeding said sheet material to the packaging machine, and that the apparatus comprises a cutting station (20) for cutting said wrapping band (5), said cutting station being arranged ahead of said feeding station (3). Apparatus according to claim 1, characterized in that said head (11) of the removal and transfer unit (10) is mounted at the lower end of a vertical beam (12) which is slidable on a sleeve (16), rigidly associated with a further sleeve (15) arranged perpendicularly thereto and being in turn slidable on a cross-member (14) supported, at its ends, by means of respective sliders (13), on a pair of parallel beams (9). Apparatus according to claim 1 or 2, characterized in that said grip elements comprise pneumatic means (18) intended to act on said band (5). Apparatus according to claim 3, characterized in that said grip elements comprise mechanical supporting means (19) which cooperate with said pneumatic grip means (18). Apparatus according to claim 4, characterized in that said mechanical supporting means (19) are mounted so as to oscillate on a horizontal pivot (19a) and comprise an end portion (19b) for supporting said stack (4). Apparatus according to claims 3 to 5, characterized in that said grip elements (18, 19) are supported by said head (11) with the interposition of a support (17) which is rotatable about a vertical axis (17′). Apparatus according to any one of the preceding claims, characterized in that said cutting station (20) comprises a seat for the insertion of the stack (4), said seat being defined by walls (21) and having a lower opening (22), and a cutting element which is slidable through said opening (22). Apparatus according to claim 7, characterized in that said cutting element is constituted by a circular blade (23) which is supported by an arm (24) which is slidable below said opening (22). Apparatus according to claim 7, characterized in that said cutting element is constituted by a blade (37) which is movable with a reciprocating motion and extends, with a profile which increases in height, from a horizontal lamina (37a) which is suitable for inserting itself between the lower surface of the stack (4) and the band (5) to be cut. Apparatus according to any one of claims 7 to 9, characterized in that a suction belt (27) for the removal of the cut band (5) is provided on one side of said cutting station (20). Apparatus according to claim 1, characterized in that said cutting station (20) comprises a cutting element (38) which is intended to operate during a step of advancement of the stack (4) in the direction of said feeding station (3). Apparatus according to claim 11, characterized in that said cutting element (38) comprises a blade (39) which is fixed transversely to a lever (40) which is stressed, at one end, by spring means (43) and is provided, at the opposite end, with roller elements (44) intended to engage the side of the stack (4) during said advancement step. Apparatus according to claims 4 and 11, characterized in that said mechanical supporting means (19) have further pneumatic means (45) suitable for acting on one side of the stack (4) and intended to retain the cut band (5) upon the insertion of said stack (4) in said feeding station (3). Apparatus according to any one of the preceding claims, characterized in that said feeding station is constituted by an input hopper (3) of a cigarette packaging machine. Apparatus according to any one of the preceding claims, characterized in that it comprises a fixed ledge (36) for storing a reserve of stacks (4), to be drawn from in the steps of replacement of the emptied supporting means (6).

Inventors: NERI, ARMANDO, TURRA, MARIO
Applicants: G.D. SOCIETA PER AZIONI
Application year: 1990
Main classification: B65B43
IPC codes: B65B69, B65B43, B65H1