APPARATUS AND METHOD FOR MOVING A CUTTING DEVICE IN A DIRECTION PARALLEL TO THE FLOW OF PAPER MATERIAL
DESCRIPTION The present invention refers to a cutting apparatus, and in particular for perforation, of paper material and the like, and to a related method. Several documents, like, e.g., brochures and statement of expenses, bear a preferential tearing perforated region separating the informative section thereof from a module, often prefilled out, destined to a distinct use. For example, the periodic statements sent to users by telephone companies consist of a certain number of customisable informative pages, illustrating the telephone detail and ending with a prefilled out postal money order to effect the payment at the dedicated counters.
To date, suchlike documents are printed and perforated in a single station of a plant operating on a continuous flow of paper material.
In particular, a first type of station carries out a perforation in a substantially fixed position. Therefore, this station enables no continuous-cycle processing of documents bearing a perforation region on a position variable documentwise, thereby not enabling an automatic customising of the manufactured documents.
A second type of station provides instead the option of a selective perforation of the paper material, variable documentwise, said perforation being controlled by a reader of control codes reported thereon. In stations of this type the perforation is typically carried out in a direction parallel to the flow of paper material, by an idle knife mounted on a actuator apt to near and/or to move it away therefrom.
However, also the known plants of this second type and the associated perforation method entail several drawbacks, the main one lying in that said idle knife does not provide a sufficient cutting accuracy. The technical problem underlying the present invention is to provide a cutting apparatus and method, and in particular for perforation, overcoming the drawbacks abovementioned with reference to the known art.
This problem is solved by a cutting apparatus, in particular for perforation, operating on a continuous flow of paper material and the like, comprising at least one cutting device apt to cut the paper material, characterised in that it comprises parallel-moving means, apt to move said at least one cutting device in a direction substantially parallel to the flow of paper material.
According to the same inventive concept, the present invention further relates to a cutting method, in particular for perforation, operating on a continuous flow of paper material and the like, comprising a step of driving at least one cutting device providing that this device be moved, during the cutting, in a direction substantially parallel to the flow of paper material.
The present invention provides several relevant advantages. The main advantage lies in that the apparatus and the method provided enable to carry out documentwise-variable machinings with the utmost versatility and precision, in a single continuous cycle. Other advantages, features and the modes of employ of the present invention will be made apparent in the following detailed description of some embodiments thereof, given by way of a example and without limitative purposes. Reference will be made to the Figures of the attached drawings, wherein:
Figure 1 is a schematic representation in a front view of a first embodiment of a cutting apparatus according to the present invention;
Figure 2 is a perspective view of the paper material of Figure 1; Figures 3A and 3B both show a schematic representation in a plan view of a cutting station of the apparatus of Figure 1 in a rest and cutting configuration, respectively; Figures 4 A to 4E each show a schematic representation in a front view of another cutting station of the apparatus of Figure 1 in the various configurations assumed during the cutting; and
Figure 5 shows a schematic representation in a front view of a second embodiment of a cutting apparatus according to the present invention. Hereinafter, the apparatus and the method of the invention will be described with reference to the perforation of paper material. It is understood that the invention generally applies to cutting plants and methods operating on different materials.
With initial reference to Figure 1, a perforation apparatus, generally indicated with 1, operates on a continuous flow 2 of paper material or the like, outletted from a paper reel feeder, of a traditional type and not shown in the figures. In Figure 1 the direction and the verse of this flow are highlighted by a thicker line and by arrows.
In the present embodiment, the apparatus 1 provides a plurality of cutting stations, each comprising a cutting device apt to cut the paper material 2, and means for moving such device in a direction substantially parallel to the flow of paper material, as it will be detailed later on. In particular, the apparatus 1 comprises first of all four cutting stations, each indicated with 3, apt to perforate the paper material 2 according to a perforation line substantially parallel to the flow thereof, that therefore will hereinafter be referred to as parallel cutting stations. Moreover, the apparatus 1 provides two further cutting stations 4 apt to perforate the paper material 2 according to a perforation line substantially orthogonal to the flow thereof, that therefore will hereinafter be referred to as orthogonal cutting stations.
The apparatus 1 comprises a reader 5 of control signs reported onto the paper
material 2, located upstream of said cutting stations 3 and 4 with respect to the motion verse thereof.
As it is shown in Figure 2, in the present embodiment it is provided that such control signs be bar codes 51. Of course, alternative embodiments could provide any type of control signs whatsoever, e.g. the so-called OMR (Optical Marker Reader) optical codes.
The reader 5 communicates with a control unit 6 that determines, according to the data received from the reader itself, the driving of the abovementioned cutting devices. This control unit 6 manages various units of the apparatus 1, as it will be made apparent hereinafter, by data receiving/transmitting lines of traditional type not shown in the figures.
Hereinafter, each of the abovedisclosed components will be detailed, with reference to the specific embodiments given here.
First of all, always with reference to Figure 1, upstream of the control unit 6 and of the reader 5 it is provided a printing unit 7, apt to print a desired text onto the paper material 2. Preferably, the printing unit 7 provides a digital control laser printing. Usually, this printing unit 7 is already present in the plant in which the apparatus 1 according to the mvention is installed.
The printing unit 7 generally provides its own control unit, enabling to print onto the paper material 2 text, figures, and in general graphic signs of any nature whatsoever, enabling to sequentially manufacture documents of different type in a continuous processing cycle.
Moreover, the printing unit 7 may provide a section dedicated to the printing of said control signs 51 onto the paper material 2. From the printing unit 7, the paper material 2 is conveyed towards the reader
5 via a system of rolls 8 free to slide in a vertical direction, generally referred to as 'dandy rolls' by those skilled in the art. The system of rolls 8, as already in other known plants, implements a sort of paper reserve, apt to compensate changes, even rapid and sudden ones, in the feeding speed of the paper material 2 from the stations upstream to those downstream thereto. Thus, the operation of the cutting stations 3 and 4 is made independent from that of the stations located upstream of the system of rolls 8.
Preferably, the system of rolls 8 also comprises position transducing means, e.g. one or more potentiometers, communicating with the control unit 6. The reader 5 and the control unit 6 are suitably implemented with traditional hardware and software technologies, hence a further description thereof will be omitted. It will be understood that the hereto given arrangement thereof should be
construed as being purely exemplary.
Figures 3A and 3B show in greater detail one of said parallel cutting stations 3 located downstream of the reader 5. With reference to these latter figures, in the present embodiment each station 3 provides a perforation of the paper material 2 according to a substantially vertical cutting line.
As abovementioned, each cutting station 3 provides first of all a cutting device, that in turn comprises a notched circular knife 9 substantially disc-shaped and integrally revolving about a shaft 90. The latter is in turn connected, by an elastic rotary joint 10, to a first toothed pulley 11 of traditional type. The shaft 90, the elastic joint 10 and the pulley 11 implement, jointly to other members that will be described hereinafter, the abovementioned means apt to move the knife 9 in a direction substantially parallel to the flow of paper material, hereinafter referred to as first parallel-moving means.
The cutting device further comprises a substantially cylindrical contrast member 12 facing the knife 9, it also connected to a second toothed pulley 13 of traditional type by a rigid joint 14. Usually, the contrast member 12 is of casehardened type.
When the cutting device lies in a rest configuration, as it is shown in Figure 3 A, between the circular knife 9 and the contrast member 12 a vertical gap is defined in which the paper material 2 flows.
Moreover, the knife 9 and the shaft 90 are connected, in correspondence of the latter, to moving means 14 apt to move the knife 9 in a direction substantially orthogonal to the flow of paper material 2. Hence, hereinafter said means 14 will be referred to as orthogonal-moving means. The orthogonal-moving means 14 comprises an electromagnetic actuator 15, in particular of linear type and based on the use of an electromagnet, controlled by the control unit 6. The actuator 15 in turn comprises a stator integral to an outer frame of the apparatus 1, schematically shown and indicated with 100 in Figure 3 A, and a movable member fixed to a framework 16. The latter is in turn fastened, as abovementioned, to the shaft 90.
The means 14 further comprises elastic return means 17, located between the framework 16 and the frame 100 and apt to accumulate elastic energy during the cutting of the paper material 2 by the knife 9, as it will be detailed hereinafter, with reference to the operation modes of the apparatus 1. In particular, in the present embodiment the elastic means are two helical compression springs, them also indicated with 17, each wound in correspondence of a respective rod of the framework 16 and apt to abut the frame 100.
A paper flow conveyor roll 43, that in the present embodiment is of idle type, is interposed between the last parallel cutting station 3 and the first orthogonal cutting station 4.
Figure 4A schematically shows the main components of each orthogonal cutting station 4. With reference to this latter Figure, in each station 4 the paper material 2 is subjected to a perforation accordmg to a substantially horizontal cutting line.
Each cutting station 4 comprises a revolving drum 18 bearing a pair of knives 19 having a substantially linear contour, them also notched. The knives 19 are longitudinally secured onto the side wall of the drum 18, in correspondence of diametrically opposed portions thereof.
The station 4 further comprises a contrast member 20 having a coating made of soft-rubber, so as to enable sinking of the knives 19 therein without being damaged. Preferably, due to reasons that will be made apparent hereinafter, the contrast member 20 has a diameter, indicated with a reference arrow 200, substantially greater than that of the drum 18, indicated with a reference height 180.
A variant embodiment provides that one or more orthogonal cutting stations have each two or more side-by-side knife-bearing drums, having fixed or variable distance between their axes. This variant embodiment is particularly indicated for the manufacture of bills, and also when an operative cycle provides two side-by-side paper flows.
With further reference to Figure 1, the apparatus 1 further comprises an actuator 21 for dragging the paper material 2, optionally controlled by the control unit 6, that is very summarily sketched in said Figure. In the present embodiment, the dragging actuator 21 is of electromechanical type, e.g. a rotary electromagnetic motor of known type.
Moreover, by driving means 22, them also of traditional type and shown hatched in Figure 1, the dragging actuator 21 sets in rotation both toothed pulleys 1 1 and 13 of each parallel cutting station 3, i.e. the circular knife 9 and the contrast member 12 of said station 3, as well as the contrast member 20 of each orthogonal cutting station 4.
Said driving means 22 may comprise, e.g., toothed pulleys and belts of known type. These are sized so that the peripheral speed of said contrast members 12 and 20 and of the circular knives 9 substantially coincide with the linear speed of the flow of paper material 2.
As it is schematically shown in Figure 1, the drums 18 of each orthogonal cutting station 4 are instead moved each by a dedicated rotary actuator 23, controlled
by the control unit 6 and it also of known type.
Hence, in each orthogonal cutting station 4, the rotary actuator 23, jointly to the drum 18 - knives 19 system, implements second parallel-moving means, apt to generate a motion of the knives 19 in a direction substantially parallel to the flow of paper material 2.
Hereinafter, with reference to all of the heretointroduced Figures, the operation modes of the cutting apparatus 1 will be illustrated.
First of all, with reference to Figure 1, it will be understood that when the apparatus 1 is operative, the dragging actuator 21 moves the paper material 2 and concomitantly it determines the rotation of the circular knives 9 and of the contrast members 12 of the parallel cutting stations 3 and of the contrast members 20 of the orthogonal cutting stations 4.
Dragged by the actuator 21, the paper material 2 outletted from the printing station 7 goes through the system of rolls 8 and flows in front of the reader 5. Said transducing means of the system of rolls 8 enable a feedback control by the control unit 6 of the speed of the dragging actuator 21 and an adjustment of said speed according to the speeds of the stations upstream of the system of rolls 8.
If the reader 5 detects signs 51 onto the paper material 2, it transmits related control signals to the unit 6. Accordingly, the latter in turn commands the driving of the orthogonal-moving means 14 of one or more parallel cutting stations 3 and/or that of the rotary actuator 23 of one or more orthogonal cutting stations 4.
In the absence of driving commands by the unit 6 to the orthogonal-moving means 14 of a certain parallel cutting station 3, the related knife 9 remains in the abovementioned rest configuration, substantially detached from the flow of paper material 2, as it is shown in Figure 3A.
Instead, when the control unit 6 commands the driving of the orthogonal- moving means 14, the electromagnetic actuator 15 thereof nears the circular knife 9 to the paper material 2, until letting it sink therethrough, and therefore in the contrast member 12, as it is shown in Figure 3B. It will be understood that, by virtue of the elastic rotary joint 10, the circular knife 9 can anyhow receive a rotary motion from the pulley 11 even in said cutting configuration, unlike the known knives that can be operated merely in a direction orthogonal to the flow of paper material.
It will also be understood that the cutting parameters like e.g. the initial instant of nearing of the knife 9 to the paper material 2, i.e. the instant of driving the electromagnetic actuator 15, the contact time between the knife 9 and the paper material 2, i.e. the perforation length, and the rotation speed of the knife 9, are
determined by the control unit 6 according to the type of document to be manufactured, e.g. to the thickness and/or the substance number thereof, and of the actual speed of the flow of paper material 2.
The use of an electromagnetic actuator of the abovementioned type as orthogonal moving actuator enables to attain a high precision in the length and in the position of the perforation. In fact, this type of actuator, also by virtue of its low inertia, provides very rapid response times, providing a high perforation force.
During said nearing and cutting motion, the elastic return means 17 are compressed, thereby accumulating elastic energy. When the cutting time interval commanded by the control unit 6 has elapsed, the actuator 15 is disabled, in particular turning off the power supply to the electromagnet thereof, and the return means 17 determines the near-instantaneous moving away of the knife 9 from the paper material.
As it is shown in Figure 4B, in the absence of a driving command by the control unit 6 to the rotary actuator 23 of a certain orthogonal cutting station 4, the drum 18 remains in a rest configuration in which the two knives 19 are aligned on a plane that is substantially parallel to that of the paper material 2 flowing thereunder. When the unit 6 commands a perforation in a horizontal direction in a station 4, the related actuator 23 determines a revolution of about 180° of the drum 18, so that a knife 19, having run an angle of about 90°, cut the underlying paper material 2, sinking into the contrast member 20 as it is shown in Figures 4C and 4D.
In the first fraction of the rotary motion, the actuator 23 can be controlled by the unit 6 so that the drum 18 have a motion accelerated for a predetermined degree, indicated with a reference height 190 in Figure 4C, and in particular until just prior to the contact with the paper material 2. Then, and until just after the end of the perforation, the actuator 23 can keep a constant steady speed and such that the peripheral speed of the drum 18 substantially coincide with the linear speed of the paper flow, to then decelerate in the end fraction of the course.
At the end of said rotation, the drum 18 returns in a rest configuration analogous to the initial one, as it is shown in Figure 4E.
At the subsequent horizontal perforation command, the rotary actuator 23 will determine a new rotation of the drum 18 analogous .to the preceding one. Hence, the paper material 2 will be cut by the other knife 19.
It will presently be understood that alternative embodiments could provide the drum of the orthogonal cutting station to bear any one number of knives, also with regard to the minimum horizontal perforation pitch required. Moreover, different stations may have drums bearing a different number of knives, so as to
drive the one or the other station according to said minimum pitch for a certain machining cycle.
It will be appreciated that the greater diameter 200 of the contrast member 20 with respect to the diameter 180 of the drum 18 prevents a markedly localised wear of the former, because each time the knife 19 sinks therein in correspondence of a different peripheral portion thereof.
In this case as well, the cutting parameters like, e.g. the instant of start of the revolution of the drum 18, i.e. of the actuator 23, and the contact time between the knife 19 and the paper material 2 are determined by the control unit 6 according to the type of document to be manufactured and to the current flow speed of the paper material 2.
It will presently be appreciated that the option of driving the cutting knives, by said first and second parallel-moving means, in a direction substantially parallel to the flow of paper material prevents the knives from tearing the paper upon penetrating therein, remarkably improving the machining accuracy with respect to the known systems.
In particular, the fact that the peripheral speed of the contrast members 12 and 20 and, above all, of the circular knife 9 and of the linear knives 19, substantially coincides with that of the flow of paper material 2 markedly improves the machining quality and enables to precisely operate on a continuous flow of paper material. In fact, said knives 9 and 19 meet almost no resistance when penetrating into the paper material 2 in a direction transversal to that of penetration, not having to overcome the flow inertia.
Moreover, said control by the unit 6 of all the cutting parameters of the apparatus 1 enables to adjust the speed of motion of the knives 9 and 19 to the speed of the paper flow, and therefore to the production speeds of the entire plant.
Moreover, the fact that said control unit 6 determines also the instant of driving the parallel and the orthogonal-moving means in order to carry out a certain perforation further improves the machining precision. This may be better understood considering that typically, by virtue of the aboveillustrated specific moving means, the circular knife as well as the linear ones have a substantially constant time of travelling the space separating them, in the rest configuration, from the flow of paper material, i.e. a constant time, starting from this configuration, to begin the perforation of the material. Hence, the driving of said means should be anticipated in case of high dragging speeds of the paper material, and retarded in case of lower dragging speeds.
Advantageously, in the case of the orthogonal-moving means the control unit
also determines the instant of deactivation for the electromagnet of the related actuator. This instant can be computed by the control unit taking into account, as already for the instant of driving, both the instantaneous velocity of the paper material and the removal times associated to the actuator and to the type of return means employed.
It will now be better appreciated that the apparatus of the invention is extremely versatile, enabling a selective perforation of the documents, and thereby enabling to manufacture different documents, and in particular with different perforation requirements, in a continuous operating cycle. In particular, this is due to the presence of both the control sign reader, recognising the paper portion onto which a perforation is required, and a plurality of cutting stations, located in series and each having parallel or orthogonal cutting devices that are movable independently from those of the other stations.
To this end, it will be understood that the knives of the different parallel cutting stations, as well as those of the different orthogonal cutting stations, can be not aligned, so as to carry out perforations having thereamong a certain predetermined distance in a direction transversal to the direction of the flow.
It will also be appreciated that the heretodescribed structure of the apparatus of the invention, and in particular the vertical and the horizontal arrangement of in- series cutting stations, makes the same apparatus extremely compact, enabling the installation thereof also in small spaces.
Moreover, the heretodescribed apparatus is suitable to a modular embodiment, with any one number of parallel and orthogonal cutting stations.
Figure 5 refers to a second embodiment of the invention, in which a perforating apparatus 101 differs from that of the abovedisclosed first embodiment in that it comprises only two orthogonal cutting stations, each indicated with 40 and in all analogous to the abovedescribed ones, and no parallel cutting station.
The apparatus 101 also provides a system of rolls 80, it also analogous to the abovedescribed one, that in this case is located just upstream of the first cutting station 40.
The apparatus 101 further comprises, according to the invention, a reader 50 and a control unit 60, them also analogous to the heretodescribed ones.
According to another preferred embodiment, the apparatus of the invention comprises only one or more parallel cutting stations, and no orthogonal cutting station. In this case, the apparatus provides an actuator for dragging the paper material, located immediately downstream to the last parallel cutting station.
According to a further embodiment, instead of being provided with a
dedicated actuator for dragging the paper material, the apparatus can also use that of other working stations located upstream or downstream thereof. This applies, e.g., in the case in which a printing system requiring a tensioning of the paper material be envisaged. The present mvention also provides a cutting method, implementable with the abovedescribed apparatus. This method mainly comprises the steps of reading control signs reported onto the paper material, e.g. by a reader as the abovedescribed one, and selectively drive at least one cutting device according to the control signs detected. Preferably, the step of driving the cutting device provides that the latter be moved, during the cutting, in a direction substantially parallel to the flow of paper material, at a speed substantially coincident to that of said flow. This motion of the cutting device can be rotary, as that disclosed with regard to the cutting stations of the abovedescribed apparatus. According to this method, the cutting device preferably carries out a cutting in a direction substantially parallel to the flow of paper material, e.g. in a substantially vertical direction, and also a cutting in a direction substantially orthogonal thereto, e.g. in a substantially horizontal direction.
It will presently be understood that the hereto described structure of the cutting apparatus of the invention, comprising a plurality of operating stations arranged in series, each having parallel and/or orthogonal-moving means of a operating tool independently controlled from station to station, is also applicable to apparatuses of a different type, merely replacing the cutting tool with a different working tool. The same holds true for the related method. E.g., this structure is applicable to an apparatus for applying an adhesive on a continuous flow of paper, plastics or the like material, with a pad replacing the abovedescribed knives.
The present invention was hereto described with reference to preferred embodiments thereof. It is understood that there may be other embodiments falling within the same mventive kernel, all encompassed in the protective scope of the appended claims.