WO2005113204A1

WO2005113204A1 - A device for preparing diecut blanks usable in a packaging machine

Info

Publication number: WO2005113204A1
Application number: PCT/IB2005/001555
Authority: WO
Inventors: Fulvio Boldrini; Roberto Ghiotti; Stefano Cavallari
Original assignee: Azionaria Costruzioni Macchine Automatiche A.C.M.A. S.P.A.
Priority date: 2004-05-18
Filing date: 2005-05-17
Publication date: 2005-12-01
Also published as: EP1747088A1; ITBO20040313A1

Abstract

Paper blanks used by a packaging machine to fashion liquid food containers are prepared by a device (1) comprising a die (9), an anvil (10) facing the die (9), and a motion-inducing system (13) by which the die (9) and the anvil (10) are caused to alternate one relative to the other between a first position, distanced so that a diecuttable sheet can be inserted between them, and a second position of close proximity in which the sheet is compressed and cut or scored by the die. The motion-inducing system (13) utilizes a flexible membrane (14) associated with the anvil (10), and a source of fluid power (15) by which the membrane (14) is deformed sufficiently to shift the anvil (10) between the first position and the second position.

Description

A device for preparing diecut blanks usable in a packaging machine

Technical Field The present invention relates to a device for preparing diecut blanks used in a packaging machine. Preferably, though not exclusively, the present invention is applicable to automatic machines used in the manufacture of containers suitable for preserving beverages and liquid food products such as fruit juices, water and milk.

Background Art Containers of the type in question are fashioned from flat blanks of a paper material obtained from single sheets or from a continuous strip divided into discrete lengths . The blanks are produced by a diecutting operation, that is, scored, cut and/or perforated along predetermined lines in readiness for subsequent manufacture of the container. The scoring, cutting and perforating operations in question are carried out conventionally by means of a diecutting press, composed generally of a flat bed or anvil on which to place a sheet or length of wrapping material, and a die furnished with blades by which the aforementioned cuts are made, or with steel rules by which crease lines are scored. The die and the anvil are movable one relative to the other to allow the insertion of the sheet, ready for the subsequent diecutting stroke. Accordingly, the die, or the anvil, is mounted to a platen in which motion can be induced by a pneumatic cylinder so as to allow of distancing the die from the anvil, placing the sheet and then bringing the die to bear against the anvil, applying a pressure sufficient to cut and score the sheet as intended. The rates of output achievable using in-line automatic machines of the aforementioned type are limited somewhat by the relatively low operating speed of a diecutting press as outlined above. In effect, the notable internal volume of the pneumatic press cylinder, which must fill and empty cyclically, and the not inconsiderable mass of the platen-cylinder assembly, are factors tending to slow the operation of conventional flat-bed diecutting equipment . These drawbacks might be overcome by adopting air compressors deliberately oversized in respect of the pressures needed to run the diecutting process. In this instance however, the additional capacity would be fully exploited only on the forcing stroke of the cylinder. Besides the negative cost factor, the adoption of such high power compressors also dictates that the press must be equipped with additional systems needed to control pressure during the diecutting stroke. The object of the present invention is to provide a device for preparing diecut blanks such as will be unaffected by the drawbacks mentioned above. In particular, the object of the present invention is to provide a diecutting device capable of notably fast cycle times, thereby enabling an increase in the operating speed of automatic packaging machines used for manufacturing containers .

Disclosure of the Invention The stated object is realized, according to the present invention, in a device for preparing blanks of which the features are as recited in claim 1. The invention will now be described in detail, by way of example, with the aid of the accompanying drawings, in which:

-figure 1 illustrates a portion of an automatic packaging machine for the manufacture of containers , viewed schematically in elevation, equipped with a device, for preparing blanks according to the present invention;

-figure 2 is a perspective view of the device for preparing blanks illustrated in figure 1; -figure 3 shows the device for preparing blanks as in figure 2, viewed schematically in a front elevation and part cutaway, illustrated in two operating configurations;

-figures 3a and 3b show two enlarged details of figure 3; -figure 4 shows the device for preparing blanks as in figure 2, viewed schematically in a side elevation, with certain parts in section and others cut away; -figure 5 illustrates a portion of the packaging machine as in figure 1 equipped with the device for preparing blanks according to the present invention, viewed schematically in perspective. With reference to the drawings, 1 denotes a device for preparing blanks, in its entirety, referred to in the following specification as a diecutter. The diecutter 1 as illustrated in figures 1 to 5 finds application, to advantage, in an automatic machine 2 for the manufacture of beverage and liquid food containers starting from a strip of wrapping material wound onto rolls 3. The automatic machine 2 comprises a frame 4 such as will support two shafts 5 carrying and transmitting motion to two respective rolls 3 of strip paper material, one serving as a change roll, suitable for forming the aforementioned containers . The machine also comprises feed means denoted 6, installed on the frame 4 and indicated schematically in figure 1, by which the strip 7 is decoiled from the two rolls 3 in alternation and directed toward the diecutter 1 along a predetermined feed path 8. As illustrated in figure 5, the machine 2 comprises further feed devices, located downstream of the diecutter 1 and serving to direct the emerging diecut blanks toward units (not illustrated) by which the aforementioned containers are formed. With reference in particular to figures 2, 3 and 4, the diecutter 1 comprises at least one die 9, and a respective anvil 10 positioned facing the die 9 at least when the diecutter 1 assumes an operating configuration. Figure 2 shows the diecutter 1 in a non-operating open configuration (to be described in due course) , so as to provide a clearer view of its component parts. The die 1 comprises a plurality of metal ridges 11 identifiable as cutter blades and/or steel scoring rules, mounted to a flat bed 12 and arranged in a selected pattern (figure 2) determined by the shape of the particular container in production. When the diecutter is closed and in the operating configur tion, indicated by solid lines in figures 3 and 4, the die 9 and/or the anvil 10 can be shifted by the action of motion-inducing means 13 between a first position distanced one from the other and a second position of close proximity one to another. In the first position of the diecutter 1, a sheet to be processed can be inserted between the die 9 and the anvil 10. In the second position, the sheet placed between the die 9 and the anvil 10 is pressed and scored by the action of the diecutter 1. To advantage, the motion-inducing means 13 comprise a deformable element 14 of which the underside carries the anvil 10, and means 15 by which this same element 14 is deformed in such a way as will cause the anvil 10 to shift between the first and the second position (figures 3, 3a and 3b) . In a preferred solution, the deformable element 14 consists in a flexible membrane with which either the anvil 10 or the die 9 is associated. The deformable element 14 delimits a fluid-tight chamber 16 in fluid communication with a source 17 of pressurized gas constituting part of the means 15 by which the selfsame element 14 is deformed (figures 3a and 3b) . In the preferred embodiment illustrated, it is the anvil 10 that will be associated with the deformable element 14, in this instance the flexible membrane 14 mentioned above, whereas the die 9 remains fixed. In addition, the anvil 10 is assembled from a plurality of plates 18 positioned side by side and delimiting slots 19 matched geometrically to the ridges of the die 9 (see figure 2) . More in detail, the diecutter 1 presents a housing structure 20 of substantially parallelepiped shape accommodating the die 9, the anvil 10, the deformable element 14 and the fluid-tight chamber 16. The housing structure 20 comprises a bottom portion denoted 21, secured by way of suitable mounting elements 22 to the automatic packaging machine 2, and a top portion 23 hinged to the bottom portion 21 by way of a shaft 24 extending along one side 25 of the structure 20 and establishing an axis 26 of rotation. The top portion 23 is pivotable on the axis 26 of rotation, relative to the bottom portion 21, between a closed operating configuration of the diecutter 1 (see figure 3, solid lines, and figure 4) and an open configuration assumed when the machine is not in operation (figure 3, phantom lines, and figure 2). Numeral 27 denotes a drive mechanism enabling the diecutter 1 to be opened for the purpose of changing the die 9 and the anvil 10, or performing maintenance operations (figure 3) . The drive mechanism 27 comprises a horizontal first shaft 28 located beneath the housing structure 20, extending transversely to the hinge shaft 24. The first shaft 28 presents a first end 29 affording a socket 30 engageable by a tool, so that the shaft can be rotated on its longitudinal axis 31, and a second end 32 connected by way of a coupling 33 to a first end 34 of a vertical second shaft 35, of which the second end 36 is keyed to a first gear 37 (worm) in mesh with a second gear 38 (worm wheel) keyed to the hinge shaft 24. The top portion 23 of the diecutter 1 is locked in the closed position by means of a bolt 39 extending parallel to the hinge shaft 24 and positioned on the side of the housing structure 20 (see figure 2) opposite to that occupied by the hinge axis 26. In the closed position, the locking bolt 39 passes through holes 40 in the top portion 23, and through holes 41 in respective blocks 42 associated rigidly with the bottom portion 21. Likewise in the closed position, the blocks 42 of the bottom portion locate in corresponding recesses 43 presented by the top portion 23, in such a way that the holes 40 and 41 align coaxially one with another. The top portion 23 of the structure 20 houses the anvil 10, the deformable element 14 supporting the anvil 10, and the fluid-tight chamber 16, whilst the bottom portion 21 of the selfsame structure 20 houses the die 9. As illustrated in figures 2, 3, 3a, 3b and 4, the die 9 is mounted to a top face 44 of the bottom portion 21, whilst the flexible membrane 14 is mounted to a bottom face 45 of the top portion 23. More exactly, and as discernible from figures 3a and 3b, the aforementioned bottom face 45 presents an undercut portion 46 of substantially rectangular outline, enclosed by and combining with the flexible membrane 14 to create the fluid-tight chamber 16. The top portion 23 further comprises a platen 47 disposed substantially in contact with the flexible membrane 14 and affording a mounting surface for one or more removable plates 18 making up the anvil 10. To ensure the movement of the platen 47 will be suitably guided when the diecutter 1 is in the closed operating configuration, the peripheral edges 48 of the flexible membrane 14 are paired with a surround frame 49 of which the opposite longitudinal sides overlap the platen 47 in part. As illustrated in figure 3b, the frame 49 presents one or more guide pins 50 disposed at right angles to the anvil 10 and engaging slidably in respective holes 51 afforded by the platen 47. When the membrane 14 is deformed by an increase in pressure internally of the chamber 16, the platen 47 shifts vertically downwards, guided by the pins 50. Also located between the surround frame 49 and the platen 47, as illustrated in figure 3a, are one or more springs 52 favouring the return of the flexible membrane 14 to a condition (undeformed) corresponding to the first position of the anvil 10. Advantageously, the fluid-tight chamber 16 will be of relatively limited volume so that it can fill and empty swiftly and thus guarantee high speed motion of the anvil 10. To this end, the chamber 16 extends substantially over the entire area of the flexible membrane 14. As indicated in figures 2 and 3, in order to enable communication between the fluid-tight chamber 16 and the source 17 of pressurized gas, and allow the chamber 16 to empty, the diecutter 1 also comprises an inlet duct 54 and an outlet duct 55 connecting with the chamber 16. The ducts 54 and 55 in question are incorporated into the housing structure 20. Figure 3 shows only one of the two ducts 54 and 55, the other being structurally identical and extending symmetrically to the duct illustrated, relative to a longitudinal plane of symmetry passing through the diecutter 1. The inlet duct 54 and outlet duct 55 each comprise a first leg 56 located in the bottom portion 21 of the housing structure 20, and a second leg 57 located in the top portion 23 of the structure 20. The first leg 56 of the inlet duct 54 extends vertically between a first end 58, connected by way of a first solenoid valve 59 to the source 17 of pressurized gas, or to a plenum containing a supply of the gas (not illustrated) , and a second end 60 emerging at the top face 44 of the bottom portion 21. The second leg 57 of the inlet duct 54 extends parallel with the anvil 10 between a first end 61 emerging at the bottom face 45 of the top portion 23 and a second end 62 emerging into the fluid-tight chamber 16. When the top portion 23 is closed over the bottom portion 21, the first end 61 of the second leg 57 and the second end 60 of the first leg 56 are in fluid communication one with another. The two legs 56 and 57 are thus connected together when the diecutter 1 assumes the operating configuration (solid lines in figure 3) and disconnected when the diecutter 1 assumes the open configuration (figure 2, and phantom lines in figure 3) . The outlet duct 55 is structurally identical to the inlet duct 54 save for the fact that the first end 58 of the first leg 56 is in fluid communication, by way of a second solenoid valve not illustrated in the drawings, with the surrounding atmosphere or with extractor means denoted 63. The adoption of extractor means 63, illustrated schematically by a block in figure 2, will enable the chamber 16 to be emptied more quickly and thus allow a swifter return of the anvil 10 after each forcing stroke. As indicated in figure 4, the housing structure 20 is furnished with an infeed opening 64 through which the sheet for processing enters the device, and an outfeed opening 65 from which the diecut sheet leaves the device. More exactly, the two openings 64 and 65 consist in slits delimited by the top portion 23 and the bottom portion 21 of the housing structure 20 when in the closed operating configuration. The paper material, whether sheeted, or preferably the continuous strip 7 decoiling from the rolls 3 toward the infeed opening 64, is directed into the diecutter 1 by a feed device 66 consisting in a pair of rollers 67 and 68 contrarotating about respective axes 70 and 71 at a point near the infeed opening 64. A first roller 67, set in rotation by drive means not illustrated, operates in conjunction with a second roller 68 to advance the strip 7 along a direction denoted D, feeding it between the die 9 and the anvil 10. The feed device 66 also comprises tension means 69 by which the roller 68 uppermost is biased permanently toward the roller 67 beneath. More exactly, the second roller 68 is mounted to a slide 72 capable of movement vertically on a track 73 transverse to the axis 71 of the roller. The tension means 69 consist in a pair of coil springs installed vertically between the track 73 and the slide 72 in such a way as to push the second roller 68 downwards against the first roller 67. Finally, the diecutter 1 according to the invention comprises a cut-off blade 74 of which the function is to divide the continuous strip 7 into single sheets. The blade 74 is mounted near the outfeed opening 65 so as to separate the diecut portion of the strip 7. As discernible in figure 4, the blade 74 extends parallel to the outfeed opening 65 and, being mounted to the platen 47 and anchored thus to the flexible membrane 14, is operated through the deformation of the selfsame membrane 14 occasioned by the rise and fall of fluid pressure in the chamber 16. As illustrated in figure 5, the device 1 further comprises a horizontal shelf 75 located downstream of the outfeed opening 65, interposed between the die 9 and a belt conveyor 76 running transversely to the aforementioned feed direction D and equipped with respective means by which to take up the single blanks and transfer them to further devices located downstream, by which the containers are formed. In operation, the continuous strip 7 decoiling from the rolls 3 is advanced by the feed means 66 toward the diecutter 1 and inserted between the rollers 67 and 68 of the feed device 66 (figures 1 and 4) . The first roller 67 is driven intermittently, timed in such a way as to position the strip 7 above the die 9 and beneath the anvil 10 and then pause for the duration of the diecutting cycle. More exactly, one step in the rotation of the first roller 67 and the second roller 68 causes a given portion of the strip 7 to be directed through the infeed opening 64 and positioned between the die 9 and the anvil 10. The two rollers 67 and 68 are then immobilized, and as the portion of strip 7 remains motionless on the die 9, the first solenoid valve 59 opens, the second solenoid valve remaining closed, and pressurized gas is allowed to flow into the fluid-tight chamber 16 through the inlet duct 54. The immediate rise in pressure has the effect of deforming the flexible membrane 14 and forcing the anvil 10 down onto the portion of the strip 7, with the result that the selfsame portion is impressed by the die 9. At the same time, the blade 74 descends and cuts the diecut portion from the strip 7, generating a single blank that emerges from the outfeed opening 65 of the diecutter 1. Thereafter, the first solenoid valve 59 closes and the second valve opens, allowing the gas to escape from the chamber 16 with or without the aid of the aforementioned extractor means 63, the membrane 14 reassumes the at-rest position and the anvil 10 returns to the first position, distanced from the die 9. The return stroke of the anvil 10 is assisted by the springs 52 interposed between the surround frame 49 and the platen 47. At this point the cycle repeats, and the newly diecut portion of the strip 7 is transported away from the diecutter 1 toward the downstream devices. Should the need arise to replace the die 9 and the anvil 10 or carry out maintenance on the equipment, it will be sufficient to withdraw the bolt 39 from the respective holes 40 and 41 and, applying a tool to the socket 30, rotate the first shaft 28 of the drive mechanism 27 about its longitudinal axis 31. The rotation thus induced will be transmitted through the coupling 33 and the second shaft 35, causing the top portion 23 of the housing structure 20 ultimately to rotate on the hinge axis 26 and lay the structure open. With the housing structure 20 in the open position, advantageously, the fluid circuit formed by the ducts 54 and 55 is broken and the chamber 16 cannot be pressurized. The problems encountered with the prior art are overcome, according to the present invention, and the stated objects duly realized. In effect, significantly fast cycle times can be achieved with the diecutter according to the present invention, so much so that the operating speed of automatic machines for manufacturing containers can be increased. In practice, the compact dimensions of the pressurized chamber and the low inertia of the platen combine to allow a considerable increase in the speed with which the anvil is displaced, while maintaining the co pressive force on the diecut material within an acceptable range, and without the need for complex control systems. In addition, the diecutting device disclosed is simple in construction, and consequently reliable and compact .

Claims

1) A device for preparing diecut blanks usable in a packaging machine, comprising at least one die (9) , at least one anvil (10) facing the die (9) , and motion-inducing means (13) by which the at least one die (9) and the at least one anvil (10) are caused to alternate between a first position, distanced one from the other, in which a diecuttable sheet can be inserted between the selfsame die (9) and anvil (10) , and a second position of proximity one to another, in which the sheet positioned between the die (9) and anvil (10) is pressed and scored and/or cut, characterized in that the motion-inducing means (13) comprise a deformable element (14) associated at least with the die (9) or with the anvil (10) , and means (15) by which the deformable element (14) is deformed and the die (9) and/or the anvil (10) caused to shift between the first position and the second position.

2) A device as in claim 1, wherein means (15) by which the deformable element (14) is deformed comprise at least a source (17) of pressurized gas.

3) A device as in claim 1 or 2, wherein the deformable element (14) consists in a flexible membrane . 4) A device as in claim 2 or 3, wherein the deformable element (14) delimits a fluid-tight chamber (16) in fluid communication with the source (17) of pressurized gas.

5) A device as in claim 4, further comprising an inlet duct (54) through which the pressurized gas is admitted to the fluid-tight chamber (16) , and an outlet duct (55) through which the pressurized gas is exhausted from the fluid-tight chamber (16) .

6) A device as in claim 5, wherein the inlet duct

(54) is in fluid communication with the source (17) of pressurized gas and the outlet duct (55) communicates with the surrounding atmosphere.

7) A device as in claim 5, wherein the inlet duct (54) is in fluid communication with the source (17) of pressurized gas and the outlet duct (55) communicates with extractor means (63) .

8) A device as in claim 1, wherein the deformable element (14) is associated with the anvil (10) .

9) A device as in claim 4 or 6, comprising a structure (20) housing the die (9) , the anvil (10) , the deformable element (14) and the fluid-tight chamber (16) . 10) A device as in claim 9, wherein the housing structure (20) presents a top portion (23) and a bottom portion (21) .

11) A device as in claim 10, wherein the top portion (23) of the structure (20) houses the anvil (10) , the deformable element (14) associated with the anvil (10) and the fluid-tight chamber (16) , and the bottom portion (21) houses the die (9) .

12) A device as in claim 1 or 11, wherein the anvil (10) consists in a plurality of plates (18) arranged side by side and delimiting slots (19) matched in shape to the die (9) .

13) A device as in claim 12, wherein the top portion (23) of the housing structure (20) is hinged to the bottom portion (21) and pivotable between a closed operating configuration and an open configuration.

14) A device as in claims 9 to 13, wherein the housing structure (20) presents an infeed opening (64) and an outfeed opening (65) through which the strip (7) is directed.

15) A device as in claim 14, further comprising a cut-off blade (74) mounted in close proximity to the outfeed opening (65) , by which the continuous strip (7) is separated into single sheets. 16) A device as in claim 13, where claim 9 is dependent on claim 5, comprising an inlet duct (54) composed of a first leg (56) located in the bottom portion (21) of the housing structure (20) and a second leg (57) located in the top portion (23) of the housing structure (20) , wherein the two legs (56,

57) are connected one to the other when the diecutter (1) is in the closed operating configuration, and disconnected one from the other when the diecutter (1) is in the open configuration.

17) A device as in claim 13, where claim 9 is dependent on claim 5, comprising an outlet duct (55) composed of a first leg (56) located in the bottom portion (21) of the housing structure (20) and a second leg (57) located in the top portion (23) of the housing structure (20), wherein the two legs (56, 57) are connected one to the other when the diecutter (1) is in the closed operating configuration, and disconnected one from the other when the diecutter (1) is in the open configuration.

18) An automatic machine for manufacturing containers, comprising at least one device for preparing diecut blanks as in claims 1 to 17.

19) A machine as in claim 18, comprising at least one shaft (5) serving to carry and induce motion in a roll (3) of diecuttable material, and feed means (6) by which the material is directed toward the diecutter (1) .