ES2382098T3 - Cutting device with a common drive for clamping arm and cutting blade - Google Patents

Abstract

Device for cutting sheet piles (4) composed of paper sheets stacked superimposed, comprising a clamping arm (13) extending in the direction of the shaft (17), fixing the sheet pile (4) before cutting and comprising a cutting blade (12) that extends in the axial direction (17) and that completely cuts the stack of sheets (4) as a guillotine, comprising a common drive for the clamping arm (13) and the cutting blade (12), in such a way that the clamping arm (13) is advanced to the cutting blade (12) to fix the stack of blades (4) before the cutting blade (12) affects the stack of sheets (4), characterized by an operating side (8), from which perpendicularly to the axis direction (17) in the horizontal direction (14) * the sheet stack (4) is inserted into the machine, * the axis of the lever (11) is operated, * the cutting blade (12) is displayed along its entire length of cut and by a lever pi voter (11) pivotable in the vertical direction (9) with stumps (23) extending in the axial direction (17) as a drive unit for the clamping arm (13) and the cutting blade (12).

Description

Cutting device with a common drive for clamping arm and cutting blade.

The invention concerns a device for cutting stacks of sheets composed of paper sheets stacked superimposed. Such devices are also referred to as sheet pile cutters or paper cutting machines.

Generally, the stack of sheets to be cut is inserted into the device, adjusting it there, so that the cutting blade cuts through the stack of sheets at the desired location. After adjustment, the stack of sheets is subjected to pressure from a clamping arm in a cutting position. The tightening arm then has the function of a footstep for the stack of sheets. Then, the stack of sheets under pressure by the clamping arm will be sectioned by the cutting blade. The cutting blade can be arranged at the bottom of a pivoting lever and go through the stack of blades, cutting like a sword. Likewise, the manufacturing models are known, where the cutting blade immediately attacks through its entire width of cut, the stack of sheets, that is to say, section the stack of sheets, cutting like a guillotine.

In known cutting devices, the operation of the clamping arm on one side and the cutting blade on the other hand, is performed through separate drive units. This has the disadvantage that, in general, two different operating elements must be operated. In addition, in conventional cutting devices, these maneuvering elements must be operated, generally, from two sides of the cutting device. Therefore, the space required for the cutting device is very large. In addition, the device must be placed, so that it is easily accessible and that it can be equally operated, both by a right-handed and a left-handed person.

From EP-A-0 353 389 a cutting device with a common drive unit for the cutting blade and for the tightening arm is known, for which the parallel path of the tightening arm is illustrated for this cutting device. cutting blade and pivoting lever to operate the cutting blade.

Starting from these problems, the invention aims to optimize a cutting device of the type mentioned above with respect to its maneuverability and configure it at the same time, so that it does not require too much space. This objective is achieved by combining the features of claim 1, in an innovative manner. The dependent claims contain optimizations of the invention, partially convenient and partially innovative in themselves.

The invention is based on the idea of providing a common drive unit for the clamping arm and for the cutting blade. In this way, only one maneuvering element must be operated to keep the sheet stack in its cutting position by means of the clamping arm and, finally, to cut the sheet stack. Consequently, only a single drive unit must be operated to achieve the position of tightening and positioning of the stack of sheets, as well as the cutting operation.

The manual drive links a pivoting lever. This pivoting lever is generally mounted on a pivotally stationary retaining shaft and drives an outer carrier and thereby the clamping arm and the cutting blade through a transmission, for example, a cam gear, a movement gear curvilinear, a guide slide or rollers mounted on the pivot lever.

One side of the support surface of the device is designed as an operating side. On this operating side, both the sheet stack is inserted into the device and the pivoting lever is maneuvered during the process of tightening and cutting the sheet stack. The cutting adjustment of the stack of sheets in a horizontal direction on the support surface is also carried out from this operating side. For this purpose, a horizontally movable stop can be provided on the support surface with the aid of a spindle, in particular a ball spindle or by means of cable traction. Since only the accessibility of the operating side is required to operate the device, it can be placed, adjusting the required space considerably. For example, it can be integrated in a closet drawer

or in a space accessible only by one side.

According to claim 2, it is favorable to arrange the clamping arm and the cutting blade above the stack of sheets and the supporting surface for the stack of sheets and thus guide and store in lateral guides, so that the clamping arm and the cutting blade can move vertically in the direction of the stack of sheets. The construction component composed of the lateral guides, the clamping arm and the cutting blade, overlaps the support surface for the stack of sheets as a portal.

In another configuration of the invention according to claim 3, it is provided that the clamping arm simultaneously conforms to the cutting knife housing. In this way, it is sufficient with the common drive unit, first to move the clamping arm in the direction of the sheet stack so as to simultaneously bring the cutting blade to the sheet stack. For the vertical path from the rest position to the cutting position, then only the tightening arm must be moved, the cutting blade automatically moved.

In another configuration according to claim 4, the cutting blade is mounted on a guide slide in the clamping arm. The guide slide in the clamping arm is formed, in this case, by two guide grooves that extend diagonally to the longitudinal axis of the clamping arm. In each of the guide grooves a guide pin engages respectively, which in turn is connected to the cutting blade. In this way, the cutting blade is guided vertically in the clamping arm towards the stack of blades.

According to claim 5, this other configuration is developed, such that the movement of the cutting blade is carried out against the pressure of a spring element. In this way, it is guaranteed that after cutting through the stack of sheets, the cutting blade moves back to its resting position opposite the clamping arm. The cutting blade edge in the retracted rest position does not project beyond the lower edge of the clamping arm, so that the clamping arm itself assumes at the same time the function of a cut protection on the device.

The protective or cover covers according to claim 6, ensure the cutting device against unintentional manipulation by the operator. They serve to protect the entire cutting mechanism outwards and thus reduce the risk of injury to the operator.

The same purpose satisfies the reciprocal safety lock of the knife holder and the lid cover according to claim 7. With the knife holder fully open in its resting position, it is possible to engage a bolt kinematically coupled to the lid cover, as an incident bolt. , in an existing cavity in the knife holder, thus blocking the knife holder in its inactive position. If, on the contrary, the cover covers are closed and the knife holder pressed down in a vertical direction by means of the pivoting lever, the bolts seated in the knife holder prevent the cover covers from being involuntarily opened, thus avoiding possible injuries for the operator.

Based on the manufacturing example described below, the invention will be explained in more detail. It is shown in:

Figure 1a, a perspective view of the cutting device in the rest position,

Figure 1b, a front view on the operating side and the cutting mechanism in the rest position,

figure 2a, shows the device of figure 1a with the pivoting lever partially pivoted down and the clamping arm moved vertically towards the stack of sheets,

figure 2b, the position shown in figure 2a of the cutting mechanism in front view according to figure 1a,

figure 3a, the device according to figure 1a with clamp arm on the stack of sheets,

figure 3b, front view of the cutting mechanism according to figure 1b in the position of the clamping arm according to figure 3a,

Figure 4a, a perspective view of the device according to Figure 1a, at the beginning of the cutting process in a stack of paper already partially sectioned,

Figure 4b, the front view of the cutting mechanism in the position of the device shown in Figure 4a,

Figure 5a, a perspective view of the device according to Figure 1a in the final cutting position with a fully sectioned sheet stack,

figure 5b, the front view of the cutting mechanism according to figure 1b in the final cutting position according to figure 5a,

Figure 6, a perspective view of a manufacturing model of the cutting device with protective cover and cover in closed operating state,

Figure 7, the manufacturing model shown in Figure 6 with the covers open,

Figure 8, an oblique view from below on the side of the worktable away from the support surface,

Figure 9, a side view of the manufacturing model shown in Figure 6 of the cutting device with the lid cover closed,

figure 10, the view of the cutting device according to figure 9, but, with open cover covers,

Figure 11, a side view of a manufacturing model of the cutting device, shown partially sectioned with retracted cutter bar,

Figure 12, the manufacturing model shown in Figure 11 with the cutter bar ejected,

Figure 13, an exploded view of the knife holder, the pivoting lever and the clamping arm and Figure 14, the view exploded according to Figure 13, viewed in the viewing direction XIV in Figure 13.

The cutting device is basically composed of a work table 1, and a cutting mechanism 2 placed on the work table 1. The work table 1 has a support surface 3 for the stack of sheets 4. The surface of support 3 is laterally surrounded by a clamping frame 5. The clamping frame 5 itself is composed of square profiles 6 and angular joints 7 that splice these square profiles 6. The square profiles 6 can be made of plastic or metal, in particular light metal. The angular joints 7 can be of a soft plastic and have angular splice tabs, which project into the hollow square profiles 6, so that the projected tabs within the square profiles 6 form a tongue and groove type splice. A particularly stable clamping frame 5 has been imposed and therefore, which maintains the shape when cutting, consisting of square profiles 6 made of steel pipes and angular joints 7 of zinc injected cast iron. The angular joints 7 are designed as molded parts and are formed of a metal alloy, particularly zinc injected cast iron.

Figure 1b shows the front view on the operating side 8 according to the display arrow marked 8 in Figure 1a. From the support surface 3, projecting outwards in the vertical direction 9, guide rails 10. The guide rails 10 form on one side, the end supports for the pivoting lever 11 pivotable in the vertical direction 9. Furthermore, on the guide rails 10 The cutting blade 12 and the clamping arm 13 are mounted vertically 9 in a movable way. In figure 1b the fact that the clamping arm 13 protrudes 9 vertically with its lower edge of the cutting blade 12 is recognized in FIG. direction to the stack of blades 4, so that the clamping arm 13 covers the cutting edge of the cutting blade 12, such that the clamping arm 13 is simultaneously effective as a cut protection for the cutting blade 12.

In the horizontal direction 14 it extends at a right angle to the vertical direction 9. The stack of sheets 4 is movable at will in the horizontal direction 14 on the support surface 3 of the worktable 1. To position the stack of sheets 4 on the support surface 3 is provided with the horizontal stop 15. In addition, another adjustable stop is provided on the support surface 3 not shown in the plane and which limits the displacement capacity of the stack of sheets 4 in the horizontal direction 14.

With the help of the pivoting lever 11, the clamping arm 13 and the cutting blade 12 can be moved vertically against the pressure of the spring elements 16. The longitudinal axis, both of the cutting blade 12, as well as of the cutting arm tighten 13, extends in the axial direction 17. The axial direction 17 extends perpendicularly on its side, both with respect to the vertical direction 9 and the horizontal direction 14. Compared to the rest position in Figures 1a and 1b, the pivoting lever 11 in figure 2a and 2b is already slightly pivoted downward in the vertical direction 9 in the direction of the stack of blades 4, so that both the vertical distance between the lower edge of the cutting blade 12, and between the arm of tightening 13 with respect to the stack of sheets 4 is significantly reduced. In addition, the spring elements 16 have already reduced their bending capacity somewhat. Figures 3a and 3b show the tightening arm 13, after reaching its final tightening position. In that final tightening position, the tightening arm 13, sits firmly on the stack of sheets 4, fixing it in its position both in the horizontal direction 14 and in the axial direction 17. In this cutting position of the device, the cutting blade 12, continues in its initial position in relation to the clamping arm 13, where the lower edge of the clamping arm 13 exceeds as before, the cutting edge of the cutting blade 12 in the vertical direction 9 as a cut protection . Furthermore, in Figure 3b it can be seen that the spring elements 16 are significantly decompressed.

The cutting operation itself, in which the cutting blade 12 enters the stack of sheets 4, completely sectioning it, can be seen particularly well in Figures 4b and 5b. In the manufacturing model shown in the figures, the clamping arm 13, is slidably guided with its ends in each case, in one of the two guide rails 10 in the vertical direction 9. The cutting blade 12 is in turn guided slidably again in the clamping arm 13 in the vertical direction 9. The vertical guidance of the cutting blade 12 in relation to the guide rails 10, is therefore carried out directly through the clamping arm 13. To do this, the arm of tightening 13 has a guide groove 18 that extends diagonally with respect to the vertical direction 9 and the axial direction

17. This guide groove 18 is minimally visible in Figure 4b and in Figure 5b it is displayed very clearly. To fully section the stack of sheets 4, the clamping arm 13 according to the tightening position shown in Figures 3a and 3b, rests on the stack of sheets 4. Starting from this tightening position corresponding to the cutting position of the device of cutting, the cutting blade 12 is driven diagonally over two guide grooves 18, both in the vertical direction 9 downwards, and also in the axial direction 17 of the cutting edge of the cutting blade 12. In Figures 4b and 5b , only one of the two guide grooves 18 is shown. The guide groove disposed at the end of the opposite clamping arm 13 in the axial direction 17 is covered by the cutting blade 12 in the drawing. The cutting blade 12 performs in Fig. 4b, both a movement in the vertical direction 9 downwardly entering the stack of blades 4, and to the left in the axial direction 17. Thus, a cutting movement is performed, in which the cutting edge of the cutting blade 12 is no longer covered by the lower edge of the clamping arm 13, thus being able to section the sheet stack 4. In Figure 4b it can be clearly seen that the sheet stack 4 is approximately sectioned in its medium vertical level. The spring elements 16 with respect to the tightening position shown in Figure 3b are more decompressed. Finally, in Figure 5b it can be recognized that the stack of sheets 4 is completely sectioned, whereby the cutting blade 12 is directly supported with its cutting edge on the support surface 3 of the worktable 1. In this final cutting position can be seen on the right side of figure 5b, that the cutting blade 12 relative to the clamping arm 13 that supports it, is displaced to the left in axial direction 17 around the value of the axial path

19. Furthermore, it can be seen that the vertical distance between the lower edge of the clamping arm 13 on one side and on the other hand, of the knife holder 21 that supports the cutting blade 12, in the cutting position shown in Figure 5b in comparison to the initial position according to figure 1b and the tightening position according to figure 3b, is significantly reduced.

The operating mode of the device is done very simply exclusively from the operating side

8. Both to hold the stack of sheets of 4 in the cutting position, as well as to section the stack of sheets 4, it is only necessary to press down the pivoting lever 11 in the vertical direction 9. Due to its structural design, the The cutting device has to be accessible only by the operating side 8, so that the remaining sides of the device can be covered by cabinet walls or the like. In addition, the device can be easily operated with one hand and only one forward stroke is required with the pivoting lever 11 in the vertical direction 9 to keep the stack of sheets 4 in its cutting position and to fully section it. After cutting, the pivoting lever 11 automatically returns to its initial position due to the spring pressure of the spring elements 16. Throughout the entire cutting operation, the cutting blade 12 is visible throughout its length in axial direction 17 from the operating side 8, so that the operator always has the entire cutting line in front of his sight during the cutting operation.

Due to this arrangement, in which the operator always has the complete cutting line in front of his sight, it is also possible to have an indication of laser cutting in the area of the cutting line. With this indication of laser cutting it is possible to project the cutting line on the top sheet of the stack of sheets 4 to be cut. In a preferred manufacturing model, a control panel 25 with an activation button 26 is provided for the indication of laser cutting. In addition, the control panel 25 presents an operating display 27 for laser cutting, as well as a control pilot of the cover cover 28 for cover covers still to be explained, a signaling pilot 29 for the activated clamping arm 13 and an additional signaling pilot 30 for the cutter blade 12 activated. In one configuration of the invention, the control lamp of the cover cover 28 is illuminated in red, the signaling pilot 29 yellow and the signaling pilot 30 green. As can be seen from the illustration in figure 6, the control panel 25 clearly visible from the operating side 8, is placed in the cover 31 that covers the cutting mechanism.

The manufacturing model of the device shown in Figure 6, comprises a worktable 1 with a support surface 3. The support surface 3 rests on a support frame 5, which in turn is held by square profiles 6 and by angular joints 7 which connect these square profiles 6. As can be seen in the illustration in figure 8, the worktable 1 rests on rubber feet 32, which in turn are provided with suction cups. Using the rubber feet 32 or the suction cups formed on the rubber feet, it is possible to place and lock the work table 1 on the work surface of a subordinate table. The locking is carried out simply by firm suction of the suckers of the rubber feet 32. In another configuration, one or more rubber feet 32 are adjustable in height in order to balance and be able to adjust the position of the worktable.

The manufacturing model shown in Figures 6, 7 and 8 of the cutting device, has, as mentioned, the protective cover 31 covering the cutting mechanism 2. In this way, it is effectively prevented that the mechanism is mistakenly picked up cutting 2, thus reducing the risk of injury. In addition, the cutting mechanism 2 is protected by means of the protective cover 31, against external dirt or possible damage. The protective cover 31 is constructed to be removable and is composed of two cover halves 33.

In a consistent continuation of the idea of isolating the cutting blade 12 from the outside world as far as possible to avoid any risk of injury, two additional covers 34 are provided that cover that part of the work surface 3 in the closed state in the closed state. resting the pile of sheets 4 to cut. The cover covers 34 are pivotally mounted on the protective cover 31 or on the guide rails 10 for the cutting mechanism 2. Figure 6 shows the closed working position of the cover covers 34, while in figure 7 , the stack of sheets 4 and the open cover covers 34 are shown for complete accessibility of the support surface 3. Through the control panel 25, the operator can verify that the cover covers 34 have been properly closed. In this case, the control light 28 does not light up precisely. With the lid cover open, the control light illuminates red to warn the operator that the lid covers 34 must be properly closed before the cutting operation.

Figure 9 shows a side view of the cutting device. In figure 9 you can see the work table 1 with lid covers 34 closed. In the illustration in Figure 9, the housing of the cover covers 34 in the cutting mechanism 2 can be seen. The cover covers 34 are connected by a guide arm 35 to the cutting unit 2. Each guide arm 35 it has a guide curve 36. The guide curve 36 acts on a control cam 37. The control cam 37 in turn acts on a horizontally movable bolt 38 14

From the illustration of figure 10, in particular from the detailed illustration it can be seen that the guide curve 36 with the cover cover 34 open, horizontally displaces 14 the control cam 37 and therefore the bolt 38, such that it it falls into a cavity 39 lock type in the knife holder 21, thereby forming an incidence lock of the cavity 39, which locks the knife holder 21 and therefore the cutting blade 12 in a vertical direction 9. With the help of the lock incidence composed of bolt 38 together with cavity 39, cutting blade 12 and with cutting blade 12 itself, the knife holder 21 complete with the cover covers 34 open is locked in its inactive retracted position. In this way, accessibility to the cutting blade 12 is effectively prevented with the cutting mechanism open. Only when the cover covers 34 are again in their closed position illustrated in FIG. 9, is it possible to move the blade holder 21 vertically 9 and therefore, the cutting blade 12, thus effectively protecting the cutting blade 12 from tampering with the outside, using the cover covers 34

Since the bolts 38 during the cutting operation cannot fall into the cavity 39, but instead rest against the outer side of the knife holder 21, they prevent the bolts 38 in cooperation with the knife holder 21, an accidental opening of the cover covers 34 during the cutting operation. In this way, the bolts 38 not only secure the knife holder 21 and therefore, the cutting blade 12 with the cover covers 34 open, but also prevent accidental opening of the cover covers 34 during the cutting operation. Accordingly, it is thus a reciprocal safety lock of the knife holder 21 and the cover 34.

In a further configuration of the invention, a cutting bar 40 is provided in the area of the cutting mechanism 2 on the support surface 3 of the working table 1. The cutting bar 40 is the counterpart of the cutting blade 12, when it has completely sectioned the stack of sheets 4. The cutter bar 40 is fixed on the support surface 3. The support surface 3 has, in this case, two clamping jaws 41 opposed and oriented in a horizontal direction 14. The bar Cutting 40 is simply inserted between the jaws 41. The cutting bar 40 is a typical wear piece, which after a certain number of cuts with the cutting blade 12 must be exchanged. To facilitate this periodic replacement of the cutting bar 40, an ejector lever 42 is provided, at which end an ejector 43 is fixed. On the support surface 3 of the worktable 1, a through opening 44 is arranged. through the through-opening 44, only the ejection force, indicated by arrow P, must be exerted on the eject lever 42. Then, the eject lever 42 ejects the cutter bar 40 from its clamp, using the ejector 43. The ejection force indicated by the arrow P, can be exerted, for example, by a screwdriver or other pointed object through the through opening 44, on the ejection lever 42. Accordingly, the ejector 43 then ejects the cutting bar 40 in the vertical direction 9 towards the support surface 3. With the cover covers 34 open, the cutter bar 40 can be easily removed and replaced with an unused spare part.

Finally, Figure 13 shows an exploded view of the knife holder 21 having attached thereto, a cutting blade 12, and of the end of the pivoting lever 11 acting on the knife holder 21, as well as the clamping arm 13. In the figure 13 the two guide pins 22 can clearly be seen, by means of which the knife holder 21 and therefore the cutting blade 12 are guided in the inclined guide grooves 18 of the clamping arm 13. The guide grooves 18 can be clearly seen in the illustration exploded in figure 14, showing the illustration of figure 13 from the opposite perspective, that is, in the direction of visualization according to arrow XIV in figure 13. In figures 13 and 14, the stumps 23 are clearly visible, with which the pivoting lever 11 is pivotally mounted on the corresponding support projections on the guide rails 10. Furthermore, in figure 13 and figure 14 the ac rollers can be seen actuation 24 on the pivoting lever 11, by means of which the pivoting lever 11 activates the cutting mechanism 2. This roller drive is as indicated above - only one variant for the cutting mechanism 2. The same applies to the guide of the knife holder 21 on the clamping arm 13, formed by the guide pins 22 and the guide grooves 18 Also in this case a roller guide is possible, which can be advantageous especially for heavy cutting equipment.

The oblique spring elements in the manufacturing examples in Figure 1 through 5b, produce the formation of a sufficient frictional force between the contact surfaces. These contact surfaces produce the conversion of the pressure force induced by the pivoting lever 11 and exerted on the knife holder 21 through the guide pins 22, at the clamping pressure by the clamping arm 13 on the sheet stack 4 To complete, it should be mentioned that the spring elements 16 can also extend parallel to each other obliquely. The V-shaped arrangement of the spring elements shown in Figures 1 through 5b is only one possible variant.

The main advantage of the apparatus is the arrangement of the cutting blade 12 on the operative side 8 of the apparatus, which allows an optimized display on the stack of sheets 4 to be cut, also allowing the assembly of the laser cutting indication.

List of reference symbols

1 Worktable

2 Cutting mechanism

3 Support surface

4 Pile of leaves

Clamping frame 6 Square profile 7 Angular joint 8 Operator side 9 Vertical direction

Guide rail 11 Pivot lever 12 Cutting blade 13 Tightening arm 14 Horizontal direction

Horizontal stop 16 Spring element 17 Axial direction 18 Guide groove 19 Axial path

Vertical distance 21 Blade holder 22 Guide pin 23 Stub 24 Drive roller

Control panel 26 Activation button 27 Operation display 28 Cover cover control pilot 29 Tightening arm signaling pilot

Pilot of signaling of the cutting blade 31 Protective cover 32 Rubber foot 33 Half of cover 34 Cover of cover

Guide arm 36 Guide curve 37 Control cam 38 Bolt 39 Cavity

Cutting bar 41 Clamp 42 Ejection lever 43 Ejector 44 Through opening

Claims (7)

1. Device for cutting sheet piles (4) composed of paper sheets stacked superimposed, comprising a clamp arm (13) extending in the direction of the shaft (17), fixing the sheet pile (4) before cutting and comprising a cutting blade (12) that extends in the axial direction (17) and completely cuts the stack of blades (4) as a guillotine, comprising a common drive for the clamping arm (13 ) and the cutting blade (12), such that the clamping arm (13) is advanced to the cutting blade (12) to fix the stack of blades (4) before the cutting blade (12) affects the stack of sheets (4), characterized by an operating side (8), from which perpendicularly to the axis direction (17) in the horizontal direction (14)

•

 the stack of sheets (4) is inserted into the machine,

•

 the axis of the lever (11) is operated,

•

 the cutting blade (12) is displayed throughout its entire cutting length and

by a pivoting lever (11) pivotable in the vertical direction (9) with stumps (23) extending in the axial direction (17) as a drive unit for the clamping arm (13) and the cutting blade (12). 2. Device according to claim 1, characterized in that

•

 the stack of sheets (4) rests on a support surface (3),

•

 the clamping arm (13) and the cutting blade (12) are movably mounted on vertical guides (10) in the vertical direction (9) and

•

 the vertical guides (10), the clamping arm (13) and the cutting blade (12), overlap the support surface (3) as a portal.

3.

 Device according to one of claims 1 or 2, characterized in that the cutting blade (12) is movably mounted on the clamping arm (13).

Four.

 Device according to claim 3, characterized by guide grooves (18) in the clamping arm (13) and by guide pins (18) that engage in guide grooves (18) in the cutting blade (12) to guide the cutting blade (12) on the clamping arm (13) in the vertical direction (9) on the stack of sheets (4).

5.

Device according to claim 3 or 4, characterized in that the cutting blade (12) is movable against the pressure of a spring element (16) through the pivoting lever (11) with respect to the clamping arm (13).

6.

 Device according to one of claims 1 to 5, characterized by

•

 a protective cover (31) covering the cutting unit (2) and / or

•

 one or more cover covers (34) covering the support surface (3) of the work table (1) and therefore the stack of sheets (4) arranged on the support surface (3).

Device according to one of claims 1 to 6, characterized by a reciprocal safety lock of the knife holder (21) and of the cover (34), such that the cover (34) is pivotally mounted. in the cutting mechanism (2) through a guide arm (35), a guide curve (36) being molded in the guide arm (36) to guide a control cam (37), which moves a bolt (38) in the horizontal direction (14), and because in the knife holder (21) there is arranged a cavity (39) whose inactive state of the knife holder (21) is aligned with the bolt (38), such that the bolt (38 ) inhibits the mobility of the knife holder (21) in the vertical direction (9) and because when the knife holder (21) is activated, the bolt (38) rests on the knife holder (21) in such a way that the mobility of the guide arm (35) to block the cover covers (34) is suppressed in its closed position.