DE9303547U1 - Device for cutting web-shaped material - Google Patents

Description

Patent Attorneys *" Dipl.-ing. Harald Ostnga Dipl.-ing. Bernd Sonnet

Wuppertal-Barmen · Stresemannstrasse 6-8

Authorized by the European Patent Office

Patent Attorneys Ostriga & Sonnet ■ PO Box 201327 ■ D-5600 Wuppertal 2

W/Kn

Applicant: Service Technology.

Wolfertz GmbH Windhövel 2a

5600 Wuppertal 2

Designation

of the invention: Device for cutting web-

shaped material

The invention relates to a device for cutting web-shaped material made of plastic, paper or the like, in particular carpet webs, into a plurality of strips, with a drive unit which jointly drives a shaft carrying knife disks and, in the opposite direction, a guide/transport roller arranged at a distance and provided with circumferential grooves, with each groove interacting with an opposite knife disk.

Such a device for cutting paper webs into longitudinal strips is known, for example, from DE-PS 30 70 34. This device essentially consists of a knife roller and a paper guide roller. Circular knives are individually attached and anchored to the knife roller with spacer discs in between. Sharply turned discs are attached to the paper guide roller at such a distance and secured by screwing that grooves or grooves are formed at regular intervals.

Postgiro account Crc-Jit-und Vollcs'iank "OnAM Cimmefbank AG Telephone (0202) 557040

Essen Wi;^rtal B.-rmcn V uppc^l-Barmen Fax (0202) 593708

(BLZ. &Iacgr;&Lgr;01&Pgr;&Ogr;43) 44504-431 (BI-Z 3.(060098) 301 KVI 024 (bt-7. 33040001) 4O34R23 &Tgr;&EEgr;&ggr;&lgr; 8591 274 mp> d

Service-Technik Wolfertz GmbH

The paper strips are produced by the circular knives always being in close contact, like scissors, with the sharp edges of the grooves or slots of the paper guide roller, thus virtually shearing off the material.
5

Such a device has the disadvantage that, due to the direct interaction of the surface of the screwed-in disks with the circular blades, both parts wear out over time and have to be replaced at regular intervals. In addition, the cleanliness of the cutting area leaves much to be desired due to the interaction of two cutting surfaces lying on top of one another.

Ultimately, changing the cutting width with the known device can only be accomplished in a relatively complex and time-consuming manner.

The object of the invention is therefore to create a new device for cutting web-shaped material, the cutting tools of which are subject to less wear and at the same time produce better cutting results.

The solution to this problem arises essentially from the features of the characterizing part of claim 1, according to which each knife disk is arranged to dip into the groove interior without contact, and that a gear is arranged between the drive unit and the shaft or the guide/transport roller, which drives the knife disks with a higher peripheral speed than the guide/transport roller.

Service-Technik Wolfertz GmbH

The device according to the invention has the significant advantage that the cutting disks can move without contact within a circumferential groove of the transport roller and, due to the higher peripheral speed of the cutting disks compared to the transport roller, can cut the material laid over the circumferential groove like a bridge into the desired strip width. Because in the invention two cutting surfaces do not interact with one another, the web-shaped material can be cut much more finely and cleanly and there is almost no wear on the cutting disks and the transport roller.

The device according to the invention also has the advantage that it can be used to cut a wide variety of web-shaped materials, whereby in each case a very clean cutting edge is created due to the cutting effect of the knife disks - in contrast to the more shearing effect in the prior art.

An advantageous embodiment of the device according to the invention is further characterized in that the transmission ratio of shaft to roller is 4:1 and the diameter ratio of the knife disks to roller is 3:1. This transmission/diameter ratio results in a 25% higher peripheral speed of the knife disks compared to the roller surface, which produces the advantageous cutting effect of the knife disks.

Service-Technik Wolfertz GmbH

A particularly advantageous embodiment of the invention is further characterized in that the knife disks are arranged detachably/movably on the shaft and that the shaft can be raised at least by a stroke that is greater than the immersion depth of the knife disks in the circumferential grooves.

This device according to the invention makes it possible to simply adjust the strip width by increasing the center distance between the shaft and the roller so that the knife disks emerge from the grooves, whereby they can be easily moved to a new position by loosening the knife disk fastening. After the knife disks have been fastened to the new position and the knife disks arranged on the shaft have been lowered into the grooves, the device can be put back into operation.

Finally, the invention also includes a device in which the stroke of the shaft is smaller than the tooth immersion depth of the gears driving the shaft and the transport roller. This embodiment has the additional advantage that it reliably prevents the gear from blocking when the shaft is lowered due to the teeth of the opposing gears coming into contact with one another.

Further advantages of the invention emerge from further subclaims and from the following description of an embodiment. They show:
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Service Technology Wolfertz GiabH

Fig. 1 is a front view of a device for cutting web-shaped material,

Fig. 2 is an enlarged view of the dot-dash area of the device according to Fig. 1 and marked II.

Fig. 3 is an enlarged view of the dot-dash area marked III of the device according to Fig. 2.

In the drawings, a device for cutting web-shaped material is designated overall by the reference number 10.

The device 10 has a machine table 11 which carries a motor 12, a gear 13, a transport/guide roller 14 and a shaft 15 with knife disks 16 arranged thereon.

The transport roller 14 is mounted in the machine table 11 in such a way that it protrudes slightly from a table surface 17. The transport roller 14 is provided with circumferential grooves 18 at regular or irregular intervals, which have distances a of 2 mm, 5 mm or 10 mm from each other, for example, and whose width b is 1.1 mm and depth c is 3 mm (see in particular Fig. 3). Above the transport roller 14, the shaft 15 is mounted, which carries knife disks 16, which can be anchored in a desired position on the shaft 15 by means of clamping screws (not shown). Between each two knife disks 16, there is approximately

Service-Technik Wolfertz GmbH

A so-called hold-down device 19 is arranged, which is constructed in an angled manner and serves to press web-shaped material 24 to be cut onto the table surface 17. The hold-down devices 19 are arranged in the same way as the knife disks 16, but on a separate guide rod 20 by means of clamping screws so that when the strip width changes, each hold-down device 19 can be moved parallel to the movement of the knife disks 16.

In Fig. 2, the gear 13 that drives the shaft 15 and the transport roller 14 together, as well as the interaction of an exemplary knife disk 16 with a circumferential groove 18, are shown in enlarged form. The shaft 15 is driven by a chain wheel 21 and the transport roller 14 by a pinion 22 arranged on the shaft 15 and a gear 23 from the same motor 12 (not shown in Fig. 2). In order to achieve a 25% higher peripheral speed of the knife disks 16 in the exemplary embodiment, the ratio of the diameter D-] of the knife disks to the diameter D2 of the transport roller is 3:1 and the transmission ratio of the pinion 22 to the gear 23 is 4:1.

During the cutting process, the material to be cut, in particular a strip-like carpet remnant - shown schematically in Fig. 3 and designated with the reference number 24 - is placed on the table surface 17 in such a way that one side edge of the material 24 rests against a guide 25 (see Fig. 1). After manually pushing the material 24 into the cutting area, the material 24 is fed into the cutting area by the counter-rotating movement of the transport roller 14 and the knife disks 16.

Service-Technik Wolfertz GmbH

area, whereby each strip of material can be automatically wound up after cutting.

As shown in particular in Fig. 2 and 3, the material 24 to be cut rests like a bridge over the grooves 18 on the surface of the transport roller 14, with the cutting disks 16 positioned so that they are arranged without contact approximately centrally between the groove walls 26 and above the groove base 27. A cutting effect is achieved due to the 25% higher peripheral speed of the cutting disks 16. The cutting edge produced is very clean, since it is a cutting process and not, as in the prior art, a shearing of the material 24 between two interacting cutting surfaces.

In the exemplary embodiment, the knife disks 16 have an immersion depth t of less than 3 mm (see Fig. 3), because the groove depth c in the exemplary embodiment is 3 mm and contact between the knife disks 16 and the groove base 27 is to be prevented. In order to change the strip width, it is necessary for the shaft 15 to be raised via a toggle lever device (not shown) to such an extent that the knife disks 16 are arranged completely outside the circumference of the transport roller. This means that the shaft 15 and thus the knife disks 16 must be raised by a stroke h that is greater than the immersion depth t and compensates for any inaccuracies in the transport roller surface. However, by raising the shaft 15, the intermeshing teeth of the pinion 22 and gear 23, which have a tooth immersion depth ζ of 4 mm, are also moved apart. Since the teeth of pinion 22 and

Service-Technik Wolfertz GmbH

If the gear 23 is to be prevented, the tooth immersion depth ζ must be greater than the stroke h of the shaft 15 so that even after the shaft 15 has been raised, the opposing teeth of the pinion 22 and gear 23 are still in engagement. When the shaft 15 is lowered again, it is therefore not possible for the individual teeth to line up with one another and for the gear 13 to become blocked.

Claims (11)

Service-Technik Wolfertz Grr.bH Claims 1. Device for cutting web-shaped material made of plastic, paper or the like, in particular carpet webs, into a plurality of strips, with a drive unit which drives a shaft carrying knife disks and, in the opposite direction, a guide/transport roller arranged at a distance and provided with circumferential grooves, wherein each groove interacts with an opposite knife disk, characterized in that each knife disk (16) is arranged so as to dip into the interior of the groove without contact, and in that a gear (13) is arranged between the drive unit (12) and the shaft (15) or the guide/transport roller (14), which drives the knife disks (16) with a greater peripheral speed than the guide/transport roller (14). 2. Device according to claim 1, characterized in that the transmission ratio of the shaft (15) to the roller (14) is 4:1 and the diameter ratio of the knife disks (16) to the roller (14) is 3:1. 3. Device according to claim 1 or 2, characterized in that the knife disks (16) are detachably mounted on the shaft (15) are arranged and that the shaft (15) can be raised at least by a stroke (h) which is greater than the immersion depth (t) of the knife disks (16) in the circumferential grooves (18).
30 Service-Technik Wolfertz Gn.bH - !0 4. Device according to one of the preceding claims, characterized in that the distance from the shaft (15) to the roller (14) can be increased by means of a toggle lever device or the like before the knife disks (16) are moved. 5. Device according to one of the preceding claims, characterized in that the intermeshing gears (22, 23) of the shaft (15) and roller (14) have a tooth immersion depth (z) of approximately 4 mm. 6. Device according to one of the preceding claims, characterized in that the stroke (h) of the shaft (15) is smaller than the tooth immersion depth (z) of the gears (22, 23) driving the shaft (15) and the roller (14). 7. Device according to one of the preceding claims, characterized in that each knife disk (16) can be fastened to the shaft (15) by means of at least one clamping screw. 8. Device according to one of the preceding claims, characterized in that between the knife disks (16) respectively detachable/slidable hold-down devices (19) are arranged on a guide rod (20) running parallel to the shaft (15). 9. Device according to one of the preceding claims, characterized in that a plurality of pierced grooves (18) are arranged at regular or irregular intervals (a) in the roller (14). Service-Technik Wolfertz Gn.bH 10. Device according to claim 9, characterized in that the grooves (18) have a distance of, for example, 2 mm, 5 mm or 10 mm (a). 11. Device according to one of the preceding claims, characterized in that the grooves (18) have a width (b) of 1.1 mm and a depth (c) of 3 mm.