CROSS-REFERENCE TO RELATED APPLICATION

The present application claims priority to German Patent Application no: 10 2019 005 949.2, filed Aug. 23, 2019, which is incorporated herein by reference in its entirety.

FIELD OF THE INVENTION

The invention relates to a roller for guiding and/or width stretching of a running material web, wherein the roller has at least one supporting body. On the outside receptacles for axially displaceable battens which grasp the material web are provided on this supporting body.

BACKGROUND OF THE INVENTION

A generic roller is known from DE 1 460 639 A. This consists of a roller body in the outer side of which grooves are formed. H-shaped profiles which are configured to be elastic are formed in these grooves. These profiles grip the material web with the outer sides. The material web can be stretched in its width by opposing displacement of the individual profiles. This roller forms the starting point of the present invention.

BRIEF SUMMARY OF THE INVENTION

The invention is based on the object of providing a roller of the type mentioned initially which is characterized by an increased functionality.

This object is achieved by the following features.

A roller according to the invention is used for guiding and/or width stretching a running material web. Guiding is to be understood in this case as the change in position of the material web transversely to its running direction, wherein the material web width in this case remains substantially unchanged. Width stretching is understood on the other hand as the stretching the material web transversely to its running direction, wherein the centre of the material web remains substantially unchanged in its position. Naturally guiding and width stretching can also be performed in combination, i.e. simultaneously. The roller has at least one supporting body which is preferably held rotatably about an axis. Receptacles for battens are provided on the outside on the supporting body, on which axially displaceable battens are held. These battens can grip the material web indirectly or directly on the outside. In order to increase the functionality of the roller, at least one undercut groove is formed on the at least one supporting body between two of the battens, which groove serves to receive at least one functional component. This at least one functional component can in principle be axially displaceable like the battens. Usually however it is sufficient to connect the at least one functional component firmly to the at least one supporting body. The at least one functional component can easily grip between two battens due to the selected position of the at least one groove and thereby reach the material web.

In particular, under restricted space conditions it is advantageous if the receptacles of the battens overlap in the radial direction with the at least one groove to receive the functional component. A fastening foot of the at least one functional component—when viewed in the radial direction—thus grips under the battens so that even under restricted space conditions, a sufficiently secure hold of the at least one functional component is achieved.

In order to be able to connect at least one functional component optimally to the roller, it is advantageous if the at least one undercut groove has at least one threaded driving channel. Thus, the at least one functional component can be easily screwed to the roller. A threaded driving channel additionally has the advantage that at least one screw can be screwed in longitudinally to the at least one undercut groove at any arbitrary point without an aligning alignment with a threaded hole being necessary.

In order to achieve a space-saving arrangement, it is additionally advantageous if the at least one groove has at least one S-shaped undercut. In this way, the space between the receptacle of the battens on the one hand and the at least one groove for receiving the functional component on the other hand can be optimally utilized. In addition, a favourable shape for easy insertion of the at least one functional component is obtained in this way.

In order that the at least one functional component can have a spreading-out effect on the material web, it is favourable if said functional component has ribs which are inclined at an acute angle to a material web running direction which grip the material web. In this way, an advantageous spreading-out device is achieved which in particular rolls out the edges of the material web and prevents any rolling in again.

Alternatively or additionally, the at least one functional component can also comprise at least one brush. In this case, it is important for several functions that the at least one brush can also grip the material web.

In particular, as a result of obliquely arranged rows of bristles of the at least one brush, a spreading-out effect is achieved. In this case, the rows of bristles can be arranged obliquely in the axial direction or similarly to the aforesaid ribs. The at least one brush thereby presses against the material web and thereby causes a frictional force which is dependent on the speed of the material web. As a result of the obliquely arranged rows of bristles, this frictional force, which is originally directed in the running direction of the material web, is divided into a component in the direction of the series of bristles and a component transverse thereto. A force directed away from the centre of the material web is thus produced, which for example can smooth out rolled-in edges. Alternatively or additionally the bristles themselves can be aligned at an acute angle to the radial direction of the roller. A force aligned transversely to the web running direction is thereby also produced.

Alternatively or additionally, the rows of bristles of the at least one brush can be arranged in such a manner that a fixing effect is obtained. This should be understood to mean that as a result of the action of the at least one brush, the material web is prevented from contracting again to its original width after leaving the roller. In order to achieve a fixing effect, an obliquely outwardly aligned row of bristles is not required. However, the bristles are preferably arranged in such a manner that they enclose an obtuse angle with the vector of the material web running direction with the result that the bristles exert a corresponding normal force on the material web without substantially impeding the running of the material web.

Alternatively or additionally, the at least one functional component can also make an electrically conducting connection between the material web and the at least one supporting body. This is particularly important in the case of insulating material webs which can be charged electro statically since surface charges can easily be diverted in this way. Such surface charges can hinder further process steps to which the material web is subjected or interfere with subsequent devices.

The at least one functional component can have at least one sliding surface for the material web. The sliding surface prevents edges of the battens from being able to press into the material web so that the material web need not be smoothed again. In particular, sensitive material webs such as natural silk, thin plastic films or thin metal films can be protected in this way and the formation of pressed-in batten edges can be prevented.

In particular, if the process step following the roller requires a smooth material web, the sliding surface of the functional component is advantageous. Alternatively or additionally, this sliding surface can also be inclined obliquely to the material web running direction in order to achieve a spreading-out effect on the material web in this way.

For the sliding surface it has proved to be favourable if said sliding surface is curved in the circumferential direction of the at least one supporting body. Preferably the sliding surface is aligned and tangential to the two neighbouring battens so that no edges which could press into the material web are formed on the surface of the roller.

Naturally the configurations of the functional components described above can also be combined in any manner in order to fulfil several functions simultaneously.

