Cutting device with exchanging device for the cutter bar

Abstract

Cutting device for longitudinally cutting a film web, in particular a plastic film web, moved in a web plane in a transport direction into a plurality of film bands, wherein a first cutter bar provided with cutting blades is immersed with the cutting blades in a cutting position into the web plane. In order to replace the cutter bar, a second cutter bar provided with cutting blades may be immersed with its cutting blades into the web plane, wherein the first cutter bar may be moved from the cutting position into a transfer position outside of the web plane when the second cutter bar is immersed with its cutting blades into the web plane.

Claims

1. A cutting device for longitudinally cutting a film web moved in a web plane in a transport direction into a plurality of film bands, wherein a first cutter bar provided with cutting blades is immersed with the cutting blades in a first cutting position into the web plane, wherein a second cutter bar provided with cutting blades is immersible with its cutting blades in a second cutting position into the web plane and the first cutter bar is moveable from the first cutting position into a first transfer position outside of the web plane when the second cutter bar is immersed with its cutting blades into the web plane, and wherein a displacing device shifts the second cutter bar from the second cutting position in the opposite direction to the transport direction into the first cutting position, and shifting of the second cutter bar from the second cutting position takes place while the second cutter bar is in the web plane.

2. The cutting device according to claim 1, wherein the first cutter bar is moveable essentially vertically to the web plane from the first cutting position into the first transfer position and/or vice versa' and wherein the second cutter bar is movable essentially vertically to the web plane from the second cutting position into a second transfer position and/or vice versa.

3. A cutting device according to claim 2, wherein the first cutter bar is shiftable along a first guiding device essentially vertically to the web plane and the second cutter bar is shiftable along a second guiding device essentially vertically to the web plane.

4. A cutting device according to claim 3, wherein the first cutter bar and the second cutter bar are releasably attachable to a first cutter bar holder and a second cutter bar holder, respectively.

5. A cutting device according to claim 4, wherein the first cutter bar and the second cutter bar each have a respective accommodation device for accommodating a respective fastening device at the first cutter bar holder and the second cutter bar holder, respectively.

6. A cutting device according to claim 4, wherein the first cutter bar holder is slidably arranged along the first guiding device and the second cutter bar holder is slidably arranged along the second guiding device.

7. A cutting device according to claim 3, further comprising control devices for a fully automatic replacement of the cutter bars as well as for an adjustment of the guiding devices.

8. A cutting device according to claim 2, wherein a transfer carrier for receiving at least one of the cutter bars from the first transfer position or the second transfer position and/or for transferring at least one of the cutter bars into the first transfer position or the second transfer position is moveably arranged between the first transfer position and the second transfer position at a guiding device.

9. A cutting device according to claim 8, wherein the transfer carrier is shiftable along the guiding device from the first transfer position or the second transfer position into a central removal position for replacing the cutter bars.

10. A cutting device according to claim 8, wherein the transfer carrier is shiftable transversally to the transport direction as well as laterally of the film web into a lateral removal position for replacing the cutter bars.

11. A cutting device according to claim 1, further comprising an upstream web carrier as well as a downstream web carrier for guiding the film web to be cut in the web plane, wherein the cutting positions of the cutter bars are arranged between the upstream web carrier and the downstream web carrier.

12. A cutting device according to claim 11, wherein the first cutting position of the first cutter bar is arranged between the upstream web carrier and the downstream web carrier in the transport direction, immediately following the upstream web carrier.

13. A cutting device according to claim 1, wherein a shifter of the displacing device is shiftable in an axial direction in parallel to the web plane.

14. A cutting device according to claim 13, further comprising a drive for shifting the shifter of the displacing device in the axial direction in parallel to the web plane.

15. A cutting device according to claim 1, wherein a first immersion depth into the web plane of the cutting blades provided at the first cutter bar and a second immersion depth into the web plane of the cutting blades provided at the second cutter bar are respectively adjustable in height.

16. A method for longitudinally cutting a film web moved in a web plane in a transport direction into a plurality of film bands by means of the cutting device according to claim 1, comprising: immersing the first cutter bar provided with the cutting blades of the first cutter bar with its cutting blades in the first cutting position into the web plane of the film web to cut the film web into the plurality of film hands, immersing the second cutter bar provided with the cutting blades of the second cutter bar with its cutting blades in the second cutting position into the web plane, wherein the cutting blades of the second cutter bar each engage in a respective space between the film bands already cut in the longitudinal direction, moving the first cutter bar from the first cutting position into the first transfer position outside of the web plane.

Description

(1) Further details, features and advantages of the invention will become obvious from the following description of an exemplary embodiment schematically illustrated in the drawings. In the drawings there is shown:

(2) in FIG. 1 to FIG. 9 respectively in side sections a temporal sequence of the automatic replacement of the cutter bars in operation of a cutting device according to the invention;

(3) in FIG. 10 in a front view a disassembled cutter bar;

(4) in FIG. 11 and in FIG. 12 respectively in a top view the cutting device illustrated in the FIGS. 1 to 9.

(5) in FIG. 13 in a sectional side view a cutting device according to the invention having control and feedback control devices for the fully automatic replacement of the cutter bars as well as for the fine adjustment of the guiding devices.

(6) The following illustrations FIG. 1 to FIG. 9 are intended to describe the replacement of cutter bars in a continuous operation of a cutting device 1. As shown, for example, in FIG. 1, a continuous flat film web 2, for example a plastic film web 2, is moved in a transport direction 3 to the cutting device 1. The transport direction 3 of the film web 2 is indicated in the illustration respectively by an arrow 3. The plastic film web 2 is cut by the cutting device 1 into a plurality of film band 4 of a defined band width. The plastic film web 2 as well as the individual parallel film bands 4 are thus moved in a web plane 5. In order to guide the film web 2 to be cut there are arranged an upstream web carrier 6, which is arranged in relation to the transport direction 3 upstream at the cutting device 1, as well as a downstream web carrier 7 at the downstream end of the cutting device 1. The two web carriers 6 and 7 are each herein embodied, for example, as guiding rolls or guiding rollers, guaranteeing a flat position of the film web 2 to be cut and of the film bands 4 already cut in the longitudinal direction, respectively, in the plane web 5. Undesired flattering or lateral offset, respectively, in particular with a fast running film web 2 are successfully prevented by the two web carriers 6 and 7 at least in this web section.

(7) In FIG. 1, which shows a cutting device 1 according to the invention in operation, a first cutter bar 10, which is provided at its underside with cutting blades 11 and which has accommodation devices 12, 14 for its fastening or adjustment, respectively, is immersed into the web plane 5 of the film web 2 at an immersion depth 13 of the cutting blades 11. The first cutter bar 10 is therein situated in an upstream cutting position 110, which is situated, viewed in the transport direction 3, immediately following the upstream web carrier 6. A second cutter bar 20, which is also provided with cutting blades 21 at its underside and which has accommodation devices 22, 24 for its fastening and adjustment, respectively, is currently situated in a transfer position 220 outside of the web plane 5.

(8) The cutting device 1 further comprises cutter bar holders 30, 40, which each have fastening devices 31, 41. Each cutter bar holder 30, 40 is slidably arranged along a guiding device 50, 60. The directions of movement 51, 61 of the cutter bar holders 30, 40 along the guiding devices 50, 60 are each indicated by double arrows 51, 61. The directions of movement 51, 61 are essentially perpendicular to the web plane 5. The cutter bars 10, 20 may each be releasably fastened at a cutter bar holder 30, 40, wherein the accommodation devices 12, 22 of the cutter bars 10, 20 are provided for accommodating the fastening devices 31, 41 at the cutter bar holder 30, 40.

(9) A transfer carrier 70 is intended to receive at least one of the cutter bars 10, 20 from a lateral transfer position 210, 220 or vice versa to transfer at least one of the cutter bars 10, 20 again into a lateral transfer position 210, 220. The transfer carrier 70 is movably arranged between two lateral transfer positions 210, 220, which are situated herein each above the web plane 5. The transfer carrier 70 thereto has fastening devices 71, which engage accommodation devices 14, 24 of the cutter bars 10, 20 dedicated to this purpose for holding or guiding, respectivelycomparable with the fastening devices 31, 41 of the two cutter bar holders 30, 40. Each cutter bar 10, 20, hence, has accommodation devices 12, 22 for attachment at the cutter bar holders 30, 40 as well as further accommodation devices 14, 24 for attachment at the transfer carrier 70. The transfer carrier 70 is movably arranged at a guiding device 80. According to the respective embodiment, the transfer carrier 70 thus may be moved back and forth in the direction of movement 81 in parallel to the film web 2 or the web plane 5, respectively, which is indicated in the figures as double arrow 81, between the two lateral transfer positions 210 and 220, and it may be moved into a central removal position 230, which is situated at any position between the transfer positions 210 and 220, for removing a cutter bar 10, 20 to be replaced. The transfer carrier 70 may be especially conveniently moved in addition in a transversal movement 82 of the transfer carrier 70 laterally to the film web 2 and transversally to the transport direction 3, respectively, by means of which a further lateral removal position 240 of the transfer carrier 70 is obtained, which is situated laterally offset next to the film web 2. In this embodiment variant the access to the cutter bar 10, 20 to be replaced is further improved, and replacing the cutter bar may take place especially conveniently and rapidly. The lateral transversal movement 82 of the guiding device 80 is indicated in the illustrations FIG. 7 as well as FIG. 11 or FIG. 12, respectively, as a double arrow 82. The central removal position 230 of the transfer carrier 70 is illustrated in FIG. 11. FIG. 12 shows the transfer carrier 70 in the further lateral removal position 240, which is situated laterally next to the film web 2 arranged underneath.

(10) FIG. 6 illustrates the action of a displacing device 90, which is intended to move a cutter bar 10, 20, with the plant in operation, from a downstream cutting position 120 in the web plane 5 in the opposite direction to the transport direction 3 of the film web 2 into an upstream cutting position 110. For the sake of clarity, the displacing device 90 is depicted only in FIG. 6, being omitted in the further side views FIG. 1 to FIG. 5 as well as FIG. 7 to FIG. 9. In FIG. 6 the direction of movement of a shift 91 of the shifter 93 of the displacing device 90 is indicated as a double arrow 91. The displacing device 90 ensures that herein the cutter bar 20 is moved in an axial direction 92 in parallel to the web plane 5. For this reason, herein two shifters 93, for example, engage each laterally at the cutter bar 20 to be shifted and move this in the direction of the arrow 91 in the opposite direction to the transport direction 3. The shifters 93 are moved using a drive of the displacing device 90, e.g. using a linear drive 94 or a spindle drive. In this embodiment there is ensured that it is that cutter bar 10, 20, which is currently engaged in the web plane 5 of the film web 2 with the cutting blades 11, 21 thereof, that may be moved from the downstream cutting position 120 into the opposite upstream cutting position 110, with the plant in operation, without the cutting profile of the film bands 4 being impeded or ruptures of the bands being caused. Within the scope of the invention there may also be used other comparable embodiments of displacing devices 90.

(11) The cycle of replacement of the cutter bars 10, 20 in a continuous operation of a cutting device 1 is herein described by way of the exemplary embodiment shown in the illustrations FIG. 1 to FIG. 9 as follows: If the cutting blades 11 of the first cutter bar 10 are already blunt in the cutting position 110 in FIG. 1, then the cutter bar 10 has to be replaced. For this reason, there is already positioned a prepared new second cutter bar 20 in the transfer position 220.

(12) As illustrated in FIG. 2, the second cutter bar 20 comprising the cutter bar holder 40 is then moved in the direction of movement 61 essentially vertically downwards along the guiding device 60 until this second cutter bar 20 is immersed with the cutting blades 21 thereof in a cutting position 120 into the web plane 5 of film bands 4. At this point, the first cutter bar 10 as well as the second cutter bar 20 are in cutting positions, wherein the cutting blades 11, 21 of both cutter bars 10, 20 are immersed into the web plane 5 of the film web 2 at an immersion depth 13, 23. The position 120 for immersion of the cutting blades 21 of the second cutter bar 20 is herein, viewed in the transport direction 3, downstream of the cutting position 110 of the first cutter bar 10.

(13) When immersing the cutting blades 21 of the second cutter bar 20, there has to be ensured that the cutting blades 21 are introduced exactly into the cutting gap of the cutter bar 10 in order to avoid damage to the film bands 4. On the one side, the distance between the individual cutting blades 11, 21 at the cutter bar 10, 20 is defined by spacers between the blades, and, on the other side, the position of the cutter bar 10, 20 is determined respectively by accommodation devices 12, 22, for example accommodation bores 12, 22, at the cutter bar 10, 20 and by the respective fastening devices 31, 41, for example centering pins 31, 41, of the utter bar holders 30, 40. In this way there is guaranteed that the position of the cutting blades 11, 21 of the cutter bars 10, 20 always corresponds exactly in the longitudinal cutting direction of the film web 2 to the spaces between the film bands 4each independent of the respective cutting position 110, 120.

(14) In FIG. 3 there is shown that subsequently the first cutter bar 10, which has become blunt, is moved from its cutting position 110 with the cutter bar holder 30 along the guiding device 50 in the direction of movement 51 essentially vertically upwards into the transfer position 210. The cutting blades 21 of the first cutter bar 10 are thus not situated in the web plane 5 anymore. The second cutter bar 20 alone, hence, assumes the cutting function in the cutting position 120. Following the blade replacement, the first cutter bar 10 may then be removed according to the embodiment of the cutting device 1 either directly from the transfer position 210, or the first cutter bar 10 is received by the transfer carrier 70, which is depicted in FIG. 4.

(15) For this reason, the centering pins as fastening devices 71 of the transfer carrier 70 are then guided into the accommodation devices 14, which are dedicated exclusively for the replacement of the cutter bar, e.g. the accommodation bores 14, the attachment of the cutter bar 10 at the cutter bar holder 30 is released, and the cutter bar 10 is transferred to the transfer carrier 70. The transfer carrier 70 is moved with the blunt cutter bar 10 along the guiding device 80 in the direction of arrow 81 into a central removal position 230, and it may then be conveniently reached and removed from the cutting device 1. In order to further facilitate the replacement of the cutter bars 10, 20, it is further provided within the scope of the invention that the transfer carrier 70 may be moved, according to embodiment, in addition also in the direction of movement 82 transversally or laterally, respectively, to the transport direction 3 of the film web 2 out of the cutting device 1, by means of which this further lateral removal position 240 laterally above the film web 2 may be reached especially easily and conveniently. The lateral direction of movement 82 of the guiding device 80 of the transfer carrier 70 may be seen, for example, in FIG. 11 or in FIG. 12, wherein FIG. 11 shows the transfer carrier 70 in a central removal position 230 and FIG. 12 shows the transfer carrier 70 in a further lateral removal position 240.

(16) The empty cutter bar holder 30 is then moved without the cutter bar 10 again essentially vertically in the direction of movement 51 along the guiding device 50 downwards into the cutting position 110, which is illustrated in FIG. 5.

(17) As shown in FIG. 6, the attachment of the second cutter bar 20, which is situated at the cutter bar holder 40 in a lateral cutting position 120, is released, and the cutter bar 20 is then shifted by two shifters 93 of the displacing device 90 in the shifting direction 91 or in the axial direction 92, respectively, and then transferred to the cutter bar holder 30, which is situated in the preferred cutting position 110. According to embodiment, there may arranged, for example, also only one shifter 93 or, as is the case herein, several shifters 93 in a displacing device 90, which, e.g., will engage the two opposite ends of the cutter bar 20 and thus enable a parallel shift 91 of the respective cutter bar to be shifted.

(18) The shifter 93 of the displacing device 90 is therefore driven herein by means of a linear drive 94 in order to move the cutter bar 20 in the opposite direction to the transport direction 3 of the film web 2 along the web plane 5 as precisely as possible to the cutter bar holder 30 into the cutting position 110. Therein it is of uttermost importance that the cutter bar 20 is guided exactly in parallel to the cutter bar holder 40 or exactly in the longitudinal direction of the film web 2, respectively, so that the film bands 4 are also cut exactly during this shifting process. The cutter bar 20 is transferred to the fastening devices 31 of the cutter bar holder 30 and attached thereto accordingly.

(19) In FIG. 7 the first cutter bar 10 that has become blunt is still in a central removal position 230 at the transfer carrier 70.

(20) FIG. 8 illustrates the cutting device 1, after the transfer carrier 70 has been emptied and the first cutter bar 10 that has become blunt has been removed for replacing the device.

(21) According to FIG. 9 the cutter bar holder 40 is subsequently moved from the cutting position 120 in the direction of movement 61 along the guiding device 60 essentially vertically upwards into the lateral transfer position 220, where the transfer of a new cutter bar optionally by the transfer carrier 70 or by direct placement or attachment, respectively, at the cutter bar holder 40 in the lateral transfer position 220 may be performed. The first cutter bar 10 having newly sharpened or replaced cutting blades 11 and/or the further additional cutter bar having new cutting blades, which is not depicted, may then be optionally used and attached at the cutter bar holder 40, as this is depicted in FIG. 1. In this way, by way of the example shown herein of an embodiment variant of the cutting device 1 according to the invention, a complete cycle of blade replacement is described, with the plant being in operation, analogously followed by another cycle of blade replacement.

(22) In order to make use of the entire blade or a larger blade section of the cutting blades 11, 21, respectively, the position of the cutting blades 11, 21 may be varied with increasing wear in the immersion depth 13, 23 thereof in respect to the web plane 5. This may, for example, be achieved by way of height adjustment of the cutter bar holders 30, 40 or also by way of traverse drums. The cutting angle of the cutting blades 11, 21 in respect to the web plane 5 in this way remains advantageous and, in contrast to rotational cutter bars, also unchanged even in the case of a height adjustment of the immersion depth 13, 23.

(23) FIG. 10 shows in a front view a disassembled cutter bar 10 having a plurality of cutting blades 11, which are each arranged distributed at the same intervals over the length of the cutter bars. As accommodation devices 12 or 14, respectively, for accommodating the fastening devices 31, 41 of the cutter bar holder 30, 40 or of the fastening devices 71 of the transfer carrier 70, respectively, herein there are intended accommodation bores 12, 14. By way of the spatial offset arrangement of the accommodation devices 12 for accommodating the fastening devices 31, 41 of the cutter bar holders 30, 40 in respect to the accommodation devices 14 for accommodating the fastening devices 71 of the transfer carrier 70 there is ensured a friction-free transfer of the cutter bars 10, 20 from the lateral transfer positions 210, 220 to the transfer carrier 70. During transfer, hence, the fastening devices 31 or 41, respectively, of the respective cutter bar holders 30 or 40, respectively, may then simultaneously with the fastening devices 71 of the transfer carrier 70, engage the respective cutter bar 10, 20. The further cutter bar 20 having cutting blades 21 as well as accommodation devices 22 or 24, respectively, has the same construction as the cutter bar 10 shown herein.

(24) FIG. 11 shows in a top view the cutting device 1 that is depicted in the illustrations FIG. 1 to FIG. 9. In the centre of the illustration there is depicted the transfer carrier 70, which may be moved back and forth in the direction of movement 81 between the two lateral transfer positions 210 and 220 in order to serve in the removal position 230 shown herein for accommodating a cutter bar 10, 20 to be replaced.

(25) FIG. 12 relates to the view depicted in FIG. 11 following the transfer of the cutter bar 10 to the transfer carrier 70. This transfer carrier 70 has already been shifted from the central removal position 230 in a lateral direction of movement 82 transversally to the transport direction 3 in order to provide for an especially convenient replacement of the cutter bar 10 attached thereto in this laterally shifted removal position 240, which is shifted laterally to the film web 2 situated underneath.

(26) Further control and/or feedback control devices, which are necessary for a fully automatic replacement of the cutter bar as well as for the fine adjustment of the guiding devices, are not depicted in the schematic illustrations of FIG. 1 to FIG. 12 for the sake of clarity.

(27) In FIG. 13, there is shown a cutting device 1 according to the invention having control devices 300 and feedback control devices 310 for the fully automatic replacement of the cutter bars 10, 20 as well as for the fine adjustment of the guiding devices 50, 60. By way of the control devices 300 as well as the feedback control devices 310, which are connected with the guiding devices 50, 60 by way of signal lines 320, there is guaranteed that the guiding devices 50, 60 are continuously adjusted in an exact way in particular at high transport speeds of the film web 2 and, hence, that a highly exact cutting profile of the film bands 4 as well as an optimal cutting course of the cutting blades 11, 21 is guaranteed. By way of the fully automatic replacement of the cutter bars 10, 20 there is guaranteed a continuous, interruption-free operation of the cutting device 1 even in the case of high web speeds of the film web 2. The control devices 300 and the feedback control devices 310, respectively, may include, if required, any devices such as, for example, one or several cameras, for optically monitoring the cutting profile of the film bands. As soon as the camera detects any irregularities in the cutting profile, there is initiated an automatic replacement of the cutter bars. Similarly, the control device 300 and/or the feedback control device 310 may include one or several computing devices intended for data acquisition and/or data analysis.

(28) The invention is not limited to the embodiments depicted in the illustrations. Within the scope of the invention it is also conceivable to move the cutter bars into transfer positions for the blade replacement, which transfer positions are arranged, for example, due to spatial reasons underneath the web plane and/or laterally of the film web. Within the scope of the invention it is also conceivable to releasably attach the cutter bars directly at the guiding devices in order to provide for an especially compact movement of the cutter bars between the respective cutting positions and transfer positions by way of the guiding devices. In this way, for example, an especially compact constructed embodiment of a cutting device may be realised, which works without a transfer carrier between the two transfer positions and in which the cutting positions of the cutter bars are arranged closely or directly next to each other.

LIST OF THE REFERENCE NUMBERS

(29) 1 cutting device 2 film web 3 transport direction of the film web (direction 4 of arrow) 4 film band 5 web plane 6 upstream web carrier (guiding roll) 7 downstream web carrier (guiding roll) 10 (first) cutter bar 11, 21 cutting blade 12, 22 accommodation device for the cutter bar holder 13, 23 immersion depth of the cutting blade into the web plane 14, 24 accommodation device for the transfer carrier 20 (second) cutter bar 30, 40 cutter bar holder 31, 41 fastening device 50, 60 guiding device 51, 61 direction of movement of the cutter bar holder (double arrow) 70 transfer carrier 71 fastening device 80 guiding device 81 direction of movement of the transfer carrier (double arrow) 82 transversal movement of the transfer carrier (double arrow) 90 displacing device 91 shifting direction (double arrow) 92 axial direction of the displacing device 93 shifter 94 linear drive 110 (upstream) cutting position 120 (downstream) cutting position 210, 220 (lateral) transfer position 230 (central) removal position 240 (lateral) removal position 300 control device 310 feedback control device 320 signal line