Web Guiding Device and Device for Processing a Web of Material

Abstract

The invention relates to a web guiding device (3) for guiding a material web (2), in particular a film web, with a first and a second frame element (31, 32), which are pivotably mounted on a first spindle (33) in respective first end areas (311, 321), are connected via a rotatably mounted web guide roller (34) in respective second end areas (321, 322) and are connected via a second spindle (35) which is connected to the first spindle (33) by means of a fixing element (37).

Claims

1. A web guiding device for guiding a film web, with a first and a second frame element, which are pivotably mounted on a first spindle in respective first end areas, are connected via a rotatably mounted web guide roller in respective second end areas and are connected via a second spindle which is connected to the first spindle by means of a fixing element.

2. The web guiding device according to claim 1, wherein the web guide roller and/or the second spindle are attached to the frame elements by means of pivoting bearings.

3. The web guiding device according to claim 2, wherein the pivoting bearings are formed as pivoting ball bearings.

4. The web guiding device according to claim 1, wherein the second spindle is arranged between the first spindle and the web guide roller.

5. The web guiding device according to claim 4, wherein a ratio between the distance from the second spindle to the first spindle and the distance from the second spindle to the web guide roller is from 1:3 to 1:10.

6. The web guiding device according to claim 1, wherein the fixing element is arranged movable in axial direction on the first spindle.

7. The web guiding device according to claim 6, wherein the fixing element can be fixed to the first spindle by means of a fastening element.

8. The web guiding device according to claim 7, wherein, in an operational position of the web guiding device, the fixing element is fixed centrally to the first spindle between the first and the second frame element.

9. The web guiding device according to claim 1, wherein the fixing element is mounted floating on the second spindle.

10. The web guiding device according to claim 9, wherein the fixing element is mounted on the second spindle by means of a bearing bushing.

11. The web guiding device according to claim 10, wherein an inner diameter of the bearing bushing is 5% to 20%, larger than an outer diameter of the second spindle.

12. The web guiding device according to claim 9, wherein a sliding resistance can be set between the fixing element and the second spindle by means of a further fastening element.

13. A device for processing a a film web, with a web guiding device according to claim 1.

14. The device according to claim 13, wherein the first spindle of the web guiding device is firmly fixed to the frame of the device.

15. The device according to claim 13, wherein the web guiding device is arranged such that, in an idle state and/or in the case of symmetrical application of force to the web guide roller, the web guide roller of the web guiding device is arranged perpendicular to a conveying direction of the material web and in the conveying plane of the material web.

16. The device according to claim 13, wherein the device is formed as a hot embossing device, and/or as a printing device.

Description

[0035] The invention is now explained in more detail with reference to embodiment examples. There are shown in

[0036] FIG. 1 A perspective view of an unwinding device for a material web with an embodiment example of a web guiding device for compensating for an oblique drawing-in of the web;

[0037] FIG. 2 A side view of the unwinding device according to FIG. 1;

[0038] FIG. 3 A front view of the web guiding device of the unwinding device according to FIG. 1;

[0039] FIG. 4 A side view of the web guiding device according to FIG. 3 in the case of symmetrical drawing-in of the web;

[0040] FIG. 5 A side view of the web guiding device according to FIG. 3 in the case of asymmetrical drawing-in of the web on the left side;

[0041] FIG. 6 A side view of the web guiding device according to FIG. 3 in the case of asymmetrical drawing-in of the web on the right side.

[0042] FIGS. 1 and 2 show the part of a device 1 for processing a material web 2, responsible for the web provision. The material web 2 is provided on a reel 21 which is held on a roller 11 of the device 1. Via a plurality of deflection rollers 12 which are arranged fixed firmly and rotatably to a frame 13 of the device 1, the unwound material web 2 is guided to the processing section. The actual processing device, for example a printing or embossing station, is not shown in the figures.

[0043] If, when a new reel 21 is inserted, the material web is introduced obliquely, when the material web 2 is drawn in this results in different tensile forces on the opposite sides 22, 23 thereof. This can lead to tears in the web, which make it necessary to stop the device 1.

[0044] In order to prevent this, the device 1 comprises a web guiding device 3. This comprises two frame elements 31, 32, which are pivotably mounted on a first spindle 33 with their respective end areas 311, 321. The spindle 33 is fixed with one end area 331 to the frame 13 of the device 1 and is not itself rotatable.

[0045] At the opposite end areas 312, 322, the frame elements 31, 32 are connected to each other via a web guide roller 34, over which the material web 2 is guided during operation of the device 1.

[0046] A further spindle 35 also connects the frame elements 31, 32 and runs parallel to the spindle 33 and to the web guide roller 34. Both the spindle 35 and the web guide roller 34 are linked to the frame elements 31, 32 with pivoting ball bearings 36. The spindle 35 and the web guide roller 34 can thus not only rotate about their respective extension spindles but are also tiltable with respect to the frame elements 31, 32.

[0047] The spindle 35 is, in addition, connected to the spindle 33 by means of a fixing element 37. The fixing element 37 consists of two halves 371, 372, which can be fixed against each other by means of screws 373 and 374 and which have respective holders 375, 376 for the spindles 33, 35. The spindle 35 is held with a sliding bushing 38 in the fixing element 37, the inner diameter of which is preferably 5% to 20%, particularly preferably 10% to 12% greater than the outer diameter of the spindle 35.

[0048] Depending on the clearance of the holders 375, 376 and according to the tightening force of the screws 373, 374, it is thus also possible to determine how firmly the fixing element 37 is located on the spindles 33, 35.

[0049] If the screws 373, 374 are loosened, the fixing element 37 can be moved on the spindles 33, 35. The figures show the fixing element 37 in a sideways position. During the operation of the device 1 it is expedient to position the fixing element 37 centrally on the spindles 33, 35, such that the respective distances from the fixing element to the frame elements 31, 32 are substantially equal and differ from each other preferably by no more than 20%, particularly preferably by no more than 10%. The desired symmetrical alignment of the web guide roller 34 with respect to the material web 2 is thus ensured.

[0050] If the material web 2 is inserted obliquely into the device 1, the tensile forces which act on the material web 2 are not symmetrical. The tensile force and web speed therefore differ for the two sides 22, 23 of the material web.

[0051] As soon as the material web 2 is guided over the web guide roller 34, different forces thus also act on the opposite sides of the web guide roller 34. The frame elements and the second spindle can now act as levers which transmit these forces to the fixing element 37. This results in a torque about the fixing element 37.

[0052] As the first spindle 33 is mounted firmly with the end area 331, no movement of the spindle 33 itself results thereby. As can be seen in FIGS. 5 and 6 however, the frame elements 31, 32 can pivot about the spindle 33 and be deflected relative to their equilibrium position shown in FIG. 4. The spindle 35 and the web guide roller 34 can follow this movement and, because of their mounting by means of the pivoting ball bearings 36, can thereby be tilted at an angle to the spindle 33 and thus also at an angle to the original web guidance plane.

[0053] In other words the web guide roller 34 can thus follow the asymmetrical forces caused by a material web 3 inserted obliquely. The web guide roller 34 is further deflected until the forces acting on its end areas are again equal, i.e. no more torque is transmitted to the fixing element 37. The more rapidly running side edge of the material web 2 is hereby braked and the slower running side edge of the material web 2 accelerated. The oblique drawing-in of the material web 2 is thus corrected and the material web 2 runs evenly through the device 1. In the course of this correction the web guide roller 34 again returns to the neutral position shown in FIG. 4 and remains therein, so long as the material web 2 continues to run straight.

[0054] Overall, a simple correction of an oblique drawing-in of the web can thus be achieved, which requires no active adjusting or sensor devices. The device is thus particularly cost-effective and fail-safe.

LIST OF REFERENCE NUMBERS

[0055] 1 Device

[0056] 11 Roller

[0057] 12 Deflection roller

[0058] 13 Frame

[0059] 2 Material web

[0060] 21 Reel

[0061] 22 Side edge

[0062] 23 Side edge

[0063] 3 Web guiding device

[0064] 31 Frame element

[0065] 311 End area

[0066] 312 End area

[0067] 32 Frame element

[0068] 321 End area

[0069] 322 End area

[0070] 33 First spindle

[0071] 331 End area

[0072] 34 Web guide roller

[0073] 35 Second spindle

[0074] 36 Pivoting ball bearing

[0075] 37 Fixing element

[0076] 371 Half

[0077] 372 Half

[0078] 373 Screw

[0079] 374 Screw

[0080] 375 Holder

[0081] 376 Holder

[0082] 38 Bushing