Patent Publication Number: US-11660771-B2

Title: Cutting device and method for cutting paper

Description:
BACKGROUND 
     The invention relates to a cutting device and a method for cutting paper. 
     Known cutting devices, in particular guillotine cutting devices for document finishing lines in the digital printing market, are provided with a cutting blade and a counter-blade that have to be calibrated extremely accurately to ensure consistent and complete cutting. For this purpose, the frame that holds the cutting blade and the counter-blade is designed to be as rigid as possible and the positions of both the cutting blade and the counter-blade can be adjusted relative to the frame by means of a plurality of spacers and corresponding fasteners. 
     SUMMARY OF THE INVENTION 
     A disadvantage of the known cutting devices is that each spacer has to be adjusted and fastened individually. This requires a lot of specialized knowledge, which is why the initial calibration is usually performed by a trained calibration technician. However, even for a trained calibration technician, calibration takes at least thirty minutes. However, after the initial calibration, any further calibrations are performed in the field by a technician with less experience. Such further calibrations may take considerably longer. 
     It is an object of the present invention to provide a cutting device and method for cutting paper, wherein the ease of calibration of the cutting device can be improved. 
     According to a first aspect, the invention provides a cutting device for cutting paper, wherein the cutting device comprises a cutting blade and a counter-member that cooperate to cut the paper along a cutting line, wherein the cutting device comprises a frame and wherein the cutting blade is movable relative to said frame towards and away from the counter-member in a driving direction, transverse or perpendicular to the cutting line, for cutting the paper, wherein the cutting device comprises a holder for holding the cutting blade relative to the counter-member, wherein the cutting device is further provided with a first guide and a second guide extending in or parallel to the driving direction for linearly guiding the holder, wherein the cutting device comprises one or more first fixation members for fixating at least the first guide relative to the frame, wherein the one or more first fixation members are arranged for releasing the fixation of the first guide relative to the frame, wherein the first guide, when released, is movable relative to the frame in an adjustment direction perpendicular to the cutting line and the driving direction, wherein each of the guides comprises a guide body, wherein the guide bodies of the first guide and the second guide, when released, are arranged to be rotatable relative to the frame about a first adjustment axis and a second adjustment axis, respectively, wherein each guide body comprises an eccentric section that moves eccentrically about the respective adjustment axis and that is arranged to convert the rotational movement of the guides about the respective adjustment axes into a linear movement of the holder in the adjustment direction. 
     Hence, a simple rotation of the guides about their respective adjustment axes can effectively cause a linear displacement of the holder in the adjustment direction, without the need of additional mechanical components. 
     By moving the first guide in the adjustment direction, the linear path along which the holder is guided can be adjusted. Consequently, the position of the cutting blade relative to the counter-member can be easily adjusted. Moreover, since the first guide is adjusted relative to the frame rather than the cutting blade relative to the holder, the cutting blade can be fixed securely to said holder, thereby significantly reducing the complexity of the calibration and/or reducing tolerances. 
     Preferably, the one or more first fixation members are arranged for releasing the fixation of the second guide relative to the frame, wherein the second guide, when released, is movable relative to the frame in the adjustment direction. By moving the first guide and the second guide in the adjustment direction, not only the position but also the orientation of the cutting blade relative to the counter-member in the adjustment direction can be adjusted. More in particular, when the counter-member is a counter-blade, it is possible to position the cutting blade such that at least one end thereof slightly overlaps with the counter-blade, i.e. at a negative tolerance, to obtain a scissor-like bias or tension between the cutting blade and the counter-blade. 
     In a further embodiment the holder is arranged to slide over or along the first guide and the second guide in the driving direction. The holder can thus be moved with respect to the guides while the guides are adjusted in the adjustment direction. 
     In a further embodiment the holder is provided with slotted holes through which the eccentric sections of the respective guides are received, wherein the slotted holes are elongated in a lateral direction perpendicular to the driving direction and the adjustment direction to absorb the eccentric movement of the eccentric sections relative to the holder in the lateral direction and to follow the eccentric movement of the eccentric sections in the adjustment direction. Consequently, the holder will only move in the adjustment direction and cancel out the component of the eccentric movement in the lateral direction. The holder can therefore remain in place in the lateral direction to maintain the cutting blade in proper alignment above the counter-member. 
     In a further embodiment thereof the eccentric sections of the first guide and the second guide have varying radii with respect to the first adjustment axis and the second adjust axis respectively, wherein the radii vary within a maximum adjustment range of at least half a millimeter, preferably at least one millimeter and most preferably at least two millimeters. The maximum adjustment range defines the maximum distance over which eccentric sections can displace the holder in the adjustment direction. The specified range should be sufficient to calibrate the cutting device properly. 
     In a further embodiment thereof each guide is provided with one or more tool engagement elements to facilitate engagement of the guide with a tool for rotating the guide about the respective adjustment axis. Preferably, the one or more tool engagement elements are tool holes for receiving a lever that facilitates manual rotation of the guides. A tool may be used to securely engage the guides and to allow for accurate and/or fine adjustment of the guides relative to the frame. In the embodiment of the tool holes, a tool such as a lever can be easily inserted into one of the tool holes to manually adjust the guides. 
     In a practical embodiment thereof each guide comprises two or more tool engagement elements which are offset in a circumferential direction about the guide body. The offset provides the calibration technician with multiple options to engage the guide and allows for switching between tool engagement elements, in particular, when one of the tool engagement elements is out of reach. 
     In a further embodiment each guide comprises a reference element that indicates a special position of the respective guide. The special position may be a starting position, a default position or an optimal position. 
     In another embodiment the one or more first fixation members are located at a top end of the frame, wherein the guides are fixed to a lower end of the frame by fasteners, wherein the fasteners are fixated against rotation relative to the frame about the respective adjustment axis by the tension of a spring acting in a tension direction parallel to the driving direction, wherein the cutting device is provided with a clearance between the guide bodies and the lower end of the frame to allow the guide bodies to move in the tension direction when released by the one or more first fixation members at the top end. 
     In another embodiment the one or more first fixation members comprises a bolt, preferably a bolt with a hexagonal socket. The bolt can be used to clampingly fixate the guide relative to the frame, while functioning as bearing for rotation of the guide about the respective adjustment axis when released. 
     In another embodiment the cutting device is provided with a drive mechanism to drive the movement of the cutting blade with respect to the counter-member in the driving direction, wherein the drive mechanism comprises a first linear actuator and a second linear actuator which are arranged to act on the holder in or parallel to the driving direction. The linear actuators can reliably drive the holder and the cutting blade attached thereto in the driving direction while the guides guide the holder in said driving direction. 
     In an embodiment thereof the cutting device comprises one or more second fixation members for fixating the holder to the linearly moving parts of the linear actuators, wherein the one or more second fixation members are arranged for releasing the holder from said fixation, wherein the holder, when released, is movable relative to the linear actuators in the adjustment direction. The holder can now be moved together with the guides in the adjustment direction. The holder can be fixated again after the calibration has been completed. 
     In a further embodiment thereof each linear actuator comprises a rotatable screw and a nut that is arranged to travel linearly along the screw, wherein the one or more second fixation members are arranged for fixating the holder to and releasing the holder from the nuts of the linear actuators. The rotatable screw and the nut together form a spindle. The holder can be released from the nuts to allow for calibration at the guides, while the same nuts can be fixated again to the holder after the calibration has been completed. 
     In a further embodiment thereof the holder is movable with respect to the linear actuators in the adjustment direction within a maximum adjustment range of at least half a millimeter, preferably at least one millimeter and most preferably at least two millimeters. In other words, a tolerance or gap is provided between the linear actuators and the holder to allow for the calibration at the guides when the holder is released from the linear actuators. 
     Additionally or alternatively, the cutting blade comprises a flat or substantially flat cutting surface, wherein the driving direction is parallel or substantially parallel to said flat cutting surface. 
     According to a second aspect, the invention provides a method for cutting paper with the use of the cutting device according to any one of the aforementioned embodiments, wherein the method comprises a calibration of the cutting blade with respect to the counter-member, wherein the calibration comprises the steps of using the one or more first fixation members to release the fixation of the first guide relative to the frame and moving the first guide relative to the frame in the adjustment direction. 
     The method relates to the practical use of the previously discussed cutting device. Consequently, the method and its embodiments have the same technical advantages as the aforementioned cutting device and its respective embodiments. These advantages will not be repeated hereafter. 
     Preferably, the calibration further comprises the steps of using the one or more first fixation members to release the fixation of the second guide relative to the frame and moving the second guide relative to the frame in the adjustment direction. 
     In a further embodiment the first guide and/or the second guide are moved over small increments, wherein the calibration further comprises the step of performing a cutting stroke between the increments to check if the paper is being cut. Hence, the cutting blade may be progressively calibrated relative to the counter-member to prevent excessive adjustment that could lead to jamming, malfunction or even damage to the cutting device. 
     In an embodiment thereof the cutting blade is initially calibrated by cutting and checking the cut in a single sheet of paper, wherein, when the calibration based on the single sheet of paper has been completed, the calibration further comprises the step of cutting a stack of paper and then again cutting a single sheet of paper. The stack of paper may cause some deburring at the cutting edges that may have a negative impact on the cutting quality. After the stack of paper has been cut successfully, the calibration technician again cuts a single sheet of paper to see if said single sheet of paper is still cut consistently. If not, the abovementioned calibration steps can be repeated. 
     Additionally or alternatively, the cutting blade comprises a flat or substantially flat cutting surface, wherein the driving direction is parallel or substantially parallel to said flat cutting surface. 
     The various aspects and features described and shown in the specification can be applied, individually, wherever possible. These individual aspects, in particular the aspects and features described in the attached dependent claims, can be made subject of divisional patent applications. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention will be elucidated on the basis of an exemplary embodiment shown in the attached schematic drawings, in which: 
         FIG.  1    shows an isometric view of a cutting device for cutting paper according to a first embodiment of the invention; 
         FIG.  2    shows a front view of the cutting device according to  FIG.  1   ; 
         FIG.  3    shows a cross section view of the cutting device according to line III-III in  FIG.  1   ; 
         FIG.  4    shows a view from below of the cutting device according to  FIG.  1   ; 
         FIG.  5 A- 5 D  shows a cross section views of the cutting device according to line V-V in  FIG.  2   ; 
         FIG.  6    shows a cross section view of the cutting device according to line VI-VI in  FIG.  2   ; 
         FIG.  7    shows a view from below of an alternative cutting device for cutting paper according to a second embodiment of the invention; 
         FIG.  8    shows a front view of a further alternative cutting device for cutting paper according to a third embodiment of the invention; 
         FIG.  9    shows a cross section view of the alternative cutting device according to the line IX-IX in  FIG.  8   ; and 
         FIG.  10    shows a cross section view of a further alternative cutting device according to a fourth embodiment of the invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIGS.  1 - 6    show a cutting device  1  according to a first exemplary embodiment of the invention. The cutting device  1  is arranged for shearing, trimming or cutting paper  9 , in particular stacks of paper or booklets  90 , for example in a document finishing line for the digital printing market. A document finishing line may comprise one or more of the cutting devices  1 , i.e. to enable one-side, two-side or three-side trimming. 
     As shown in  FIG.  1   , the cutting device  1  comprises a housing or a frame  2  and a knife or a cutting blade  3  that is movably supported with respect to said frame  2  for cutting along a cutting line C. The cutting device  1  further comprises a counter-member in the form of a counter-knife or counter-blade  4  that is arranged in a stationary position at or along the cutting line C to cooperate with the movable cutting blade  3  to cut the paper  9 . In this exemplary embodiment, the counter-knife  4  is mounted to the frame  2 . 
     The cutting device  1  according to the first exemplary embodiment of the invention operates as a guillotine cutter. As such, the cutting blade  3  is movable in a driving direction D perpendicular to the cutting line C towards and away from the counter-blade  4  for cutting the paper  9 . In this exemplary embodiment, the driving direction D is vertical or substantially vertical. Hence, the cutting blade  3  is movable in a vertically downward cutting stroke and a vertically upward return stroke. The cutting blade  3  is angled at an oblique angle to the cutting line C to progressively cut the paper  9  along the cutting line C. In contrast, the counter-blade  4  extends parallel or substantially parallel to the cutting line C. 
     As best seen in  FIG.  6   , the cutting blade  3  comprises a flat or substantially flat cutting surface  31  that faces the counter-blade  4  when the cutting blade  3  moves across the cutting line C. The driving direction D is preferably parallel or substantially parallel to said flat cutting surface  31 . The cutting blade  3  further has a front surface  32  that tapers towards the cutting surface  31  to form an upper cutting edge  30 . Said upper cutting edge  30  is angled at an oblique angle to the cutting line C. As such, the upper cutting edge  30  has a lowest point that is closest to the counter-blade  4  in the driving direction D and a highest point that is further away from the counter-blade  4  in the driving direction D. In this exemplary embodiment, the front surface  32  is beveled to form a sharp chisel grind  33  together with the flat cutting surface  31 . It will be apparent to one skilled in the art that other blade configurations are also possible and that the scope of the present invention is not limited to the configuration as shown. 
     In this exemplary embodiment, the counter-blade  4  is formed as a rectangular strip that is secured to the frame  2  by bolts or other suitable fasteners at or along the cutting line C in a position opposite to the cutting blade  3 . The counter-blade  4  forms a lower cutting edge  40  that extends parallel or substantially parallel to the cutting line C. The counter-blade  4  may be slightly beveled at the cutting edge  40 . Optionally, as shown in  FIG.  2   , the counter-blade  4  may be provided with a support member  41  for supporting the spine  91  of a booklet  90 , as schematically shown in  FIG.  2   . The support member  41  may be an integral part of the counter-blade  4  or may be mounted on the counter blade  4  with suitable fasteners. The support member  41  has a concave support surface  42  that is arranged to closely match and/or support the curvature of the spine  91  in place and thereby improve the cutting quality at said spine  91 . In particular, paper snippets may be prevented at the spine  91 . 
     As further shown in  FIG.  6   , the cutting device  1  comprises a holder  5  for holding the cutting blade  3  relative to the counter-blade  4 . In this example, the cutting blade  3  is securely attached to the holder  5  by means of bolts or other suitable fasteners. Preferably, the rear of the surface  31  of the cutting blade  3  is arranged in direct abutment with the holder  5 , i.e. without spacing, adjustment or calibration means, to reduce and/or eliminate tolerances between the cutting blade  3  and the holder  5 . 
     As best seen in  FIG.  4   , the cutting device  1  is provided with one or more guides  61 ,  62  extending in the driving direction D for linearly guiding the holder  5 , with the cutting blade  3  attached thereto, in said driving direction D. In this example, the cutting device  1  comprises a first guide  61  and a second guide  62  which are spaced apart from each other, preferably at opposite ends of the holder  5 . 
     In a preferred embodiment of the invention, the one or more guides  61 ,  62  double as calibration members for calibrating the position of the cutting blade  3  relative to the counter-blade  4 . In particular, as shown in  FIG.  3   , each guide  61 ,  62  comprises a guide body  60  that extends in the driving direction D between opposite parts of the frame  2 , in this example being the upper end  21  and a lower end  22  of the frame  2 , respectively. The holder  5  is arranged to be freely slide over or along said guide body  60  in the driving direction D. The cutting device  1  comprises one or more first fixation members  81 , or first fixators  81 , for fixating the guide bodies  60  of the first guide  61  and the second guide  62  relative to the frame  2 . The one or more first fixation members  81  may be bolts, clamps or other suitable fasteners. The one or more first fixation members  81  are arranged for releasing the fixation of the guide bodies  60  relative to the frame  2 , i.e. by loosening or unclamping. In this example, the one or more first fixation members  81  are bolts with a hexagonal socket that can be loosened and tightened with the use of a hex key  8 , as shown in  FIG.  1   . When released, the guide body  60  is movable relative to the frame  2  in an adjustment direction A perpendicular to the cutting line C and the driving direction D, thereby displacing the holder  5  and the cutting blade  3  attached thereto relative to the counter-blade  4 . 
     In the exemplary embodiment as shown in  FIG.  6   , the guide bodies  60  of the first guide  61  and the second guide  62 , when released, are arranged to be rotatable relative to the frame  2  about a first adjustment axis X 1  and a second adjustment axis X 2 , respectively. In particular, each guide body  60  comprises one or more concentric sections  63  that connect the guide body  60  concentrically about the respective adjustment axis X 1 , X 2  to the frame  2 . In this example, the concentric sections  63  are located at the top and the bottom of the guide body  60  at or near the upper end  21  and the lower end  22  of the frame  2 . The guide body  60  is provided with concentrically located, threaded bores at the respective concentric sections  63  for threaded connection to one of the bolt-shaped first fixation members  81 . Hence, said one first fixation member  81  concentrically connects to the guide body  60  and/or defines the adjustment axis X 1 , X 2  of the respective guide  61 ,  62 . Preferably, the frame  2  comprises one or more bearing surfaces to concentrically receive the concentric sections  63  and to ensure reliable rotation of said concentric sections  63  about the respective adjustment axis X 1 , X 2  relative to the frame  2 . 
     Each guide body  60  further comprises an eccentric section  64  that is eccentric with respect to the one or more concentric sections  63  and/or the respective adjustment axis X 1 , X 2 . As such, each eccentric section  64  is arranged to travel an eccentric path or moves eccentrically about the respective adjustment axis X 1 , X 2  with at least a component in the adjustment direction A. The radii of the eccentric section  64  with respect to the respective adjustment axis X 1 , X 2  vary within a maximum adjustment range R of at least half a millimeter, preferably at least one millimeter and most preferably at least two millimeters. Hence, each eccentric section  64  can effectively cause a displacement in the adjustment direction A within the specified range. 
     As best seen in  FIGS.  5 A- 5 D , the holder  5  is provided with slotted holes  51 ,  52  through which the eccentric sections  64  of the respective guides  61 ,  62  are received. The slotted holes  51 ,  52  are elongated in a lateral direction L perpendicular to the driving direction D and the adjustment direction A to absorb the eccentric movement of the eccentric sections  64  relative to the holder  5  in the lateral direction L and to closely follow the component of the eccentric movement of the eccentric sections  64  in the adjustment direction A. Consequently, the holder  5  moves with the eccentric movement of the eccentric sections  64  in the adjustment direction A only. In other words, the interaction between the slotted holes  51 ,  52  and the eccentric sections  64  effectively converts the rotational movement of the guides  61 ,  62  about the respective adjustment axes X 1 , X 2  into a linear movement of the holder  5  in the adjustment direction A. 
     In this example, as best seen in  FIGS.  3  and  4   , each guide  61 ,  62  is provided with one or more tool engagement elements  65 ,  66  to facilitate engagement of the guide  61 ,  62 , or tool engagers  61 ,  62 , with a tool for rotating the guides  61 ,  62  about the respective adjustment axes X 1 , X 2  with the use of (manual) tools. In particular, in this example, the one or more tool engagement elements  65 ,  66  are tool holes  65 ,  66  for receiving a pin or a lever  83 ,  84  that facilitates manual rotation of the guides  61 ,  62 . Preferably, each guide  61 ,  62  comprises two or more tool engagement elements  65 ,  66  which are offset in a circumferential direction about the guide body  60  to receive or engage the same tool, i.e. the lever  83 ,  84 , in different angular positions around the respective adjustment axis X 1 , X 2 . Hence, the lever  83 ,  84  may be inserted into one of the tool holes  65 ,  66  even if the other tool hole  65 ,  66  is rotated out of reach. Alternatively, the guides  61 ,  62  may be adjusted mechanically by adjustment drives (not shown). The adjustment may even be automated with the use of one or more sensors (not shown) that detect the relative position of the cutting blade  3  with respect to the counter blade  4  as a result of the adjustment. 
     Optionally, each guide  61 ,  62  may comprise a reference element  67 , i.e. a marking, a recess or a protrusion, that indicates a special position of the respective guide  61 ,  62 . Such a special position may be the position in which the guides  61 ,  62  position the cutting blade  3  at a distance in which the upper cutting edge  30  and the lower cutting edge  40  are maximally spaced apart from the counter-blade  4  in the adjustment direction A. Note that the maximum spacing between the cutting blade  3  and the counter-blade  4  does not necessarily correspond to the maximum adjustment range R of the guides  61 ,  62  in the adjustment direction A. Instead, it is preferred to have the cutting blade  3  closer to the counter-blade  4  than said maximum adjustment range R at said maximum spacing, such that the position of the cutting blade  3  can be calibrated relative to the counter-blade  4  within the maximum adjustment range R that overlaps with the counter-blade  4 . Consequently, when the cutting blade  3  and/or the counter-blade wear down, part of the maximum adjustment range R remains unused to compensate accordingly. In this example, the upper cutting edge  30  is spaced apart maximally from the lower cutting edge  40  in the adjustment direction A at a distance of approximately half a millimeter. Hence, with a maximum adjustment range R of for example one millimeter, the position of the cutting blade  3  can be adjusted over half a millimeters beyond the counter-blade  4  within the maximum adjustment range R. 
     As shown in  FIGS.  2 ,  3 ,  4  and  6   , the guides  61 ,  62  are fixed to the lower end  22  of the frame  2 , by suitable fasteners  85 , preferably bolts. In this exemplary embodiment, the fasteners  85  fixated against rotation relative to the frame  2  about the respective adjustment axis X 1 , X 2  by a suitable spring  86 , e.g. a cupped spring or a disc spring. In particular, the spring  86  tensions the fastener  85  relative to the frame  2  in a tension direction T, parallel to the driving direction D. As shown in  FIG.  6   , a small clearance Z is provided between the guide body  60  and the lower end  22  of the frame  2  in the driving direction D to allow the respective guide body  60  to be moved relative to the frame  2  in the tension direction T when the one or more first fixation members  81  at the top end  21  of the frame  2  release the fixation of the guide bodies  60  relative to the frame  2 . This reduces the tension on the springs  86 , which allows the guide bodies  60  to rotate about the respective adjustment axes X 1 , X 2  without the need to manually interact with the fasteners  85  at the lower end  22  of the frame  2 . 
     As shown in  FIGS.  3  and  4   , the cutting device  1  is provided with a drive mechanism  7  to drive the movement of the cutting blade  3  in the driving direction D towards and away from the counter-blade  4 . The drive mechanism  7  comprises a first linear actuator  71  and a second linear actuator  72  extending in or parallel to the driving direction D. The first linear actuator  71  and the second linear actuator  72  are arranged for acting in or parallel to the driving direction D on the holder  5  and/or the cutting blade  3 . The drive mechanism  7  is further provided with a motor  73  and a transmission element  74  that connects the motor  73  to the first linear actuator  71  and the second actuator  72 . By using a single motor  73  common to or shared by both linear actuators  71 ,  72 , said linear actuators  71 ,  72  can be mechanically synchronized. In particular, the transmission element  74  can be mechanical, i.e. a chain or a toothed belt, to connect the motor  73  to each of the linear actuators  71 ,  72  in a fixed ratio which is the same for both linear actuators  71 ,  72 . More in particular, the transmission element  74  is arranged to interconnect the first linear actuator  71  and the second linear actuator  72  in a 1:1 ratio. Hence, the transmission element  74  acts as a synchronization element. Preferably, the drive mechanism  7  comprises a main sprocket wheel  75  that is directly connected to the motor  73  and that drives the chain or belt-like transmission element  74 . The drive mechanism  7  further comprises a plurality of idler wheels  76 ,  77  of the same size that output the rotation of the main sprocket wheel  75  to both linear actuators  71 ,  72  in an equal ratio. 
     As shown in  FIGS.  2  and  4   , the main sprocket wheel  75  and the idler wheels  76 ,  77  at the spindles  71 ,  72  are rotatable about wheel axes W 1 , W 2 , W 3  parallel or substantially parallel to the driving direction D. Hence, the transmission of the rotation of the main sprocket wheel  75  to the idlers wheels  76 ,  77  can all occur in the same plane, perpendicular to said driving direction D. 
     Preferably, the main sprocket wheel  75  is connected to the idler wheels  76 ,  77  in a ratio of at least 2:1, preferably at least 2.5:1 and most preferably at least 3:1. 
     Preferably, the motor  73  is an electro-motor, in particular an electric servo-motor. Hence, the position of the motor  73  can be very accurately determined and/or controlled. 
     In this exemplary embodiment, the linear actuators  71 ,  72  are mechanical linear actuators, in particular spindles. As such, each linear actuator  71 ,  72  comprises a screw  78  that is arranged to be rotated by the transmission element  74  and a nut  79  that travels linearly along the screw  78  as the screw  78  rotates. The screws  78  of the linear actuators  71 ,  72  extend parallel to the guides  61 ,  62  in the driving direction D. 
     As shown in  FIGS.  2 - 4   , the holder  5  is fixed to the linearly moving parts of the linear actuators  71 ,  72 , in this example to the nuts  78 , with the use of one or more second fixation members  82 , or second fixators  82 . The one or more second fixation members  82  may be bolts, clamps or other suitable fasteners. The one or more second fixation members  82  are arranged for releasing the fixation of the holder  5  relative to the nuts  78 , i.e. by loosening or unclamping. In this example, the one or more second fixation members  82  are bolts with a hexagonal socket that can be loosened and tightened with the use of the same hex key  8  that is used to loosen and tighten the one or more first fixation members  81  at the guides  61 ,  62 . When released, the holder  5  is movable relative to the nuts  79  in the adjustment direction A to facilitate the aforementioned adjustment of the guides  61 ,  62  in said adjustment direction A. In particular, it can be observed in figures SA-SD that the holder  5  is movable with respect to the linear actuators  71 ,  72  in the adjustment direction A within the maximum adjustment range R, as shown in  FIG.  6   . 
     A method for cutting paper with the use of the aforementioned cutting device  1  will now be explained with reference to  FIGS.  1 - 6   . 
     When cutting paper, it is important to calibrate the position of the cutting blade  3  with respect to the counter-blade  4 . When the cutting blade  3  is too far spaced apart from the counter-blade  4 , the paper will not be cut. When the cutting blade  3  is too close to the counter-blade  4 , the cutting device  1  may become jammed. Moreover, the cutting blade  3  and the counter-blade  4  preferably are not at a constant distance along the cutting line C. In other words, their upper cutting edge  30  and lower cutting edge  40  should not be parallel. Ideally, the cutting blade  3  is calibrated so that the lowest point of its upper cutting edge  30  is as close as possible to the lower cutting edge  40  of the counter-blade  4 , without making contact. In contrast, the highest point of the upper cutting edge  30  should slightly overlap with the lower cutting edge  40  to create a small tension or bias between the cutting blade  3  and the counter-blade  4  during the cutting. 
     In the prior art cutting devices, calibration required specialized knowledge and above all; time. Calibration took at least half an hour or more, depending on the experience of the calibration technician. With the cutting device  1  according to the present invention, the calibration can be performed within a few minutes. 
     As shown in  FIG.  1   , the one or more first fixation members  81  are loosened, i.e. by untightening the bolts with the hex key  8 , to release the fixation of guides  61 ,  62  relative to the frame  2 . Additionally, the one or more second fixation members  82  are loosened, i.e. by untightening the bolts with the same or another hex key  8 , to release the fixation of the drive mechanism  7 , and in particular the nuts  79  thereof, with respect to the holder  5 . The holder  5  is now no longer fixated with respect to the guides  61 ,  62  and the drive mechanism  5 . Consequently, the respective positions of the guides  61 ,  62  can be adjusted and the holder  5 , with the cutting blade  3  attached thereto, can freely follow the movement of the guides  61 ,  62  during said adjustment. 
     As shown in  FIG.  4   , a tool is coupled to, insertable in and/or arranged to engage one of the one or more tool engagement elements  65 ,  66  at one of the guides  61 ,  62  to adjust the position of said one guide  61 ,  62 . In this example, a first lever  83  is inserted into one of the tool holes  65 ,  66  at the first guide  61 . The same first lever  83  may also be used to engage the one of the tool holes  65 ,  66  at the second guide  62 . Instead, a second lever  84  may be used to adjust the positions of the guides  61 ,  62  simultaneously. Preferably, the guides  61 ,  62  are initially moved into a special position, i.e. the position marked by the reference element  67 . In said special position the cutting blade  3  is at a distance maximally spaced apart from the counter-blade  4  in the adjustment direction A. Alternatively, the calibration may be initiated from any position, i.e. the current position of the cutting blade  3 . 
     Now, the calibration may start in accordance with the steps as described below and as shown in  FIGS.  5 A- 5 D . 
       FIG.  5 A  shows the situation with the guides  61 ,  62  in a position in which the cutting blade  3  is maximally spaced apart from the counter-blade  4 .  FIG.  5 B  shows the situation in which the position of the lowest end of the upper cutting edge  30  is adjusted towards the lower cutting edge  40  by turning the second guide  62  clockwise or counter-clockwise about the second adjustment axis X 2 . Based on experience, the calibration technician may already know the amount of rotation required to approximate the optimal position of the second guide  62 . Alternatively, small increments may be used. Between each increment, the calibration technician may perform a cutting stroke on a single sheet of paper  9  to check if said single sheet of paper  9  is already being cutting by the lowest end of the upper cutting edge  30 . As soon as the upper cutting edge  30  starts to cut the paper  9  at the lowest end, as shown in  FIG.  5 B , the second guide  62  is in position and should no longer be adjusted. Preferably, the one or more first fixation members  81  associated with the second guide  62  may be tightened or fastened again with suitable tools to fix the position of the second guide  62  relative to the frame  2 . 
       FIG.  5 C  shows the situation in which the calibration technician has started to adjust the position of the first guide  61 . Again, based on experience, the calibration technician may already know the amount of rotation required to approximate the optimal position of the first guide  61 . Alternatively, small increments may be used. Between each increment, the calibration technician may perform a cutting stroke to check if the paper  9  is already being cutting by the highest end of the upper cutting edge  30 . With each increment, the cut in the paper  9  will progressively increase in length until the upper cutting edge  30  cuts along the cutting line C across the entire width of the paper  9 .  FIG.  5 C  shows the situation in which the paper  9  is only cut half-way across the width.  FIG.  5 D  shows the situation in which the paper  9  is cut completely, which is an indicator that the first guide  61  is now properly positioned and/or that the upper cutting edge  30  is properly calibrated with respect to the lower cutting edge  40 . When the first guide  61  is properly positioned, the one or more first fixation members  81  associated with the first guide  61  may be tightened or fastened again with suitable tools to fix the position of the first guide  61  relative to the frame  2 . 
     Optionally, the calibration technician may perform an additional check in which a stack of paper  90 , as for example shown in  FIG.  1   , is cut. The stack of paper  90  may cause some deburring at the cutting edges  30 ,  40  that may have a negative impact on the cutting quality. After the stack of paper  90  has been cut successfully, the calibration technician again cuts a single sheet of paper  9  to see if said single sheet of paper  9  is still cut consistently. If not, the abovementioned calibration steps are repeated. 
     Finally, the one or more second fixation members  82  are tightened or fastened with suitable tools to fixate the position of the drive mechanism  7  with respect to the holder  5  in its newly calibrated position. The cutting device  1  according to the invention is now calibrated and ready for cutting. 
     When cutting through a stack of paper  90 , as shown in  FIG.  1   , the cutting blade  3  is subjected to a load travelling along its obliquely angled upper cutting edge  30 . This causes uneven loads on the linear actuators  71 ,  72 . However, the transmission element  74  as shown in  FIG.  4    ensures that both linear actuators  71 ,  72  are driven at the same speed, thereby synchronizing their operation. Hence, skewing, misalignment and/or tension between the cutting blade  3 , the linear actuators  71 ,  72  and/or the guides  61 ,  62  can be reduced or even prevented. 
       FIG.  7    shows an alternative cutting device  101  according to a second exemplary embodiment of the invention. The alternative cutting device  101  differs from the previously discussed cutting device  1  in that it features an alternative drive mechanism  107  with a first motor  171  and a second motor  172  for driving the movement of the first linear actuator  71  and the second linear actuator  72 , respectively, in the driving direction D. Consequently, each linear actuator  71 ,  72  has its own motor  171 ,  172 . The linear actuators  71 ,  72  may therefore be driven directly. The alternative drive mechanism  107  further comprises a mechanical synchronization element  174  to synchronize the linear actuators  71 ,  72 . In particular, the mechanical synchronization element  174  is arranged to interconnect the first linear actuator  71  and the second linear actuator  72  in a 1:1 ratio. In this example, the synchronization element  174  is a chain or a toothed belt. The chain or toothed belt engages with idler wheels  176 ,  177  at the respective linear actuators  71   72  and interconnects said idler wheels  176 ,  177  in a 1:1 ratio. In this manner, the synchronization element  174  can prevent that one of the linear actuators  71 ,  72  rotates faster than the other, i.e. as a result of uneven loads on the cutting blade  3 . 
       FIG.  8    shows a further alternative cutting device  201  according to a third exemplary embodiment of the invention. The further alternative cutting device  201  differs from the previously discussed cutting device  1 ,  101  in that its driving direction D extends obliquely or transverse to the cutting line C. In particular, the alternative driving direction D as shown in  FIG.  8    is at an angle H in a range of thirty to eighty degrees with respect to the cutting line C, more preferably in a range of forty to sixty degrees and most preferably at an angle H of approximately forty-five degrees. 
     The further alternative cutting device  201  further differs from the previously discussed cutting devices  1 ,  101  in that it features an alternative cutting blade  203  and counter-member  204  configuration. While the counter-member  204  is still supported in a substantially level or horizontal orientation and supports the paper  9  along a substantially level or horizontal cutting line C, the alternative cutting blade  203  moves at the oblique driving direction D towards the counter-member  204  and has an upper cutting edge  230  that extends parallel or substantially parallel to the cutting line C. 
     As a result of the oblique driving direction D, the alternative cutting blade  203  travels towards the cutting line C with a component in the vertical direction and a component in the horizontal direction, parallel to the cutting line C. The upper cutting edge  230  thus makes a sawing movement through the stack of paper  90  rather than a vertical guillotine cutting movement. This allows the alternative cutting blade  203  to saw through thicker stacks of paper  90 . 
     To accommodate the alternative cutting blade  203  moving at the oblique driving direction D, an alternative frame  202  is provided with an upper end  221  that is angled to match the oblique driving direction D and a lower end  222  that supports the counter-member  204  at the cutting line C. The further alternative cutting device  201  is provided with an alternative drive mechanism  207  that has linear actuators  271 ,  272  arranged at the same angle H to the cutting line C as the oblique driving direction D. In other words, the linear actuators  271 ,  272  are arranged to act in or parallel to the oblique driving direction D. Apart from the orientation, the alternative drive mechanism  207  may function similarly to the drive mechanisms  7 ,  107  of the previous embodiments of the invention. 
     Note that one side of the frame  202  is now considerably longer than the other side. The guides  61 ,  62  may remain the same length as in the previous embodiments of the invention, as they only need to provide guidance at the location of the holder  5 . Optionally, the length of the linear actuators  271 ,  272  may be increased to increase the length of the cutting stroke. The length of the guides  61 ,  62  may be increased accordingly. Hence, the thickness of the stacks of paper  90  that can be cut is in principle only limited by the geometrical limitations of the available space. 
     The combination of the oblique driving direction D and the linear actuators  271 ,  272  acting in or parallel to said oblique driving direction D results in a sawing action during which the load on the alternative cutting blade  230  remains substantially constant at any depth during the cutting, regardless of the thickness of the stack of paper  90  that is being cut. Hence, the maximum thickness of stacks of paper that can be cut is in principle limitless. 
     In this alternative embodiment, the counter-member  204  forms a flat counter-surface  240  at the cutting line C that cooperates with the alternative cutting blade  203  to cut the paper  9 . The cutting process may leave snippets of paper  9  or other paper residue on the counter-surface  240 . In conventional cutting devices, these paper snippets have to be removed manually. In the present invention, the counter-member  204  is pivotable relative to the lower end  222  of the frame  202  about a pivot axis P to drop the paper snippets from the counter-surface  240 , i.e. into a waste bin below the cutting device  201 . The pivoting may be user-activated or automatically activated after a predetermined number of cuts. The automatic activation may be performed by a pushing member  205 , i.e. a mechanical finger, that pushes down on the counter surface  240  at the same side of the pivot axis P as the cutting line C to force the counter-member  204  into a drop position. 
     Alternatively, as shown in a further alternative cutting device according to a fourth embodiment of the invention, the counter-member  304  may be driven in rotation about the pivot axis P by a drive  306 , i.e. a servo-motor. Also in this case, the counter-member  304  is pivotable relative to the lower end  322  of the frame  302  about a pivot axis P to move into an active position (shown in dashed lines) and a drop position (shown in solid lines) relative to the cutting blade  303 . In this particular example, the transmission from the drive  306  to the counter-member  304  is an eccentric drive comprising a crank shaft  307  that is driven in rotation by the drive  306  and an arm or a finger  305  driven by said crank shaft  307 . The finger  305  is connected to the counter-member  304  at a distance from the pivot axis P so that it may act as a lever on the counter-member  304 . 
     It is to be understood that the above description is included to illustrate the operation of the preferred embodiments and is not meant to limit the scope of the invention. From the above discussion, many variations will be apparent to one skilled in the art that would yet be encompassed by the scope of the present invention.