DE29518877U1 - Device for determining the state of rotation of a pressure roller - Google Patents

Description

The subject of the present innovation is a device according to the introductory part of the main claim.

As is well known, in paper processing machines, printing machines, machines for combining packaging films, machines for extruding plastic films, for winding and cutting, the squeezing group (sometimes also called a drawing group, pressure group, laminating group) is formed by a metal drive roller against which a pressure roller is pressed, which consists of a shaft on which a cylinder nest is arranged, which is covered on its surface with a layer of soft material, typically rubber. This pressure roller (hereinafter simply called a rubberized roller) rotates together with the metal roller and, thanks to its interaction with it, has the task of taking the film on which the processing is carried out and allowing it to move further.

The pressure that builds up between the two rollers can reach such excessive levels that it becomes a risk of serious accidents for workers. This risk is further increased by the fact that the rotational state of the rollers, whether at low or high speed, cannot be easily determined due to the uniformity of the colour of the rubber rollers or rubberised rollers (which are usually coloured black).

In order to protect the worker, some machines are equipped with protection and safety devices to stop the machine in case of emergency; these safety devices are

however, it is removed during the machine adjustment phase, which represents a critical moment for the worker who is in close contact with the slow-moving group: in fact, accidents during this phase, leading to serious injuries to the workers, are frequent.

The aim of the present innovation is to create a device associated with at least one of the rollers of the embossing group, in particular the rubberized roller, which makes it possible to make the rotation of said rollers easily visible and recognizable.

A further aim is to create a device that is easy to implement, but optically extremely effective.

Another goal is to create a device that can be manufactured at a reasonable cost and that does not affect in any way the functionality of the rubberized roller and thus the performance of the embossing group.

These and other objectives apparent to the person skilled in the art are achieved by a device in accordance with the appended claims.

For a better understanding of the present innovation, the attached drawing is presented for purely exemplary explanation and without limitation of the innovation, in which:

Figure 1 shows a rubberized roller provided with a device according to the innovation;

Figure 2 illustrates another embodiment of the innovation.

In the drawings, 1 generally indicates a roller consisting of a shaft 2 and a cylindrical member 3 covered with a layer of soft material, usually rubber. The colour of this rubber layer is usually black.

According to the innovation, the rubberized roller has within its layer 4 a helical body 5 which has a color contrasting with the color of the rubber layer 4. For example, if the latter is black, the body 5 has a yellow color.

The helical body is inserted into a seat 7 formed in the layer 4 in such a way that the thickness of this layer is not modified. This body preferably has a width of between 1 and 3 cm depending on the diameter D and the length L of the roller; the body is made of a material equivalent to that of the layer 4 (for example rubber) and has the same physical properties as the material of the latter (i.e. the same grinding, hardness, etc.).

The helical body 5 can describe a single helix on the roller (as in Figure 1) or two or more (as in Figure 2); their pitch or thread also depends on the diameter D and the length L of the roller.

Thanks to the innovation, during the rotation of the roller 1, the helical body 5 creates a significant visual effect, as a continuously unwinding helical line appears on the roller 1. This effect is highly visible and allows the rotation to be observed even from a distance.

the pressure roller and consequently the functional state of the squeezing group of which it forms a part.

Two variants of the innovation have been described. Others are also possible (such as the one in which a wavy ring-shaped decoration is present on the roller 4, which is arranged in the area of one or more ring zones of the roller); in any case, all these variants are to be considered as being within the scope of the present innovation.

Claims (5)

PROTECTION CLAIMS 1. Device for determining the rotational state of a pressure roller (1), in particular of a squeezing group of a paper processing machine or printing machine, the roller (1) having a shaft (2) on which a cylindrical element (3) made of soft material, such as typically rubber, is arranged, characterized in that it has a body 5 which is inserted into the rubber layer (4) and has a color contrasting with the color of the layer (4) and occupies at least part of the layer, so that during the rotation of the roller an easily recognizable optical effect is produced which indicates the aforementioned rotation. 2. Device according to claim 1, characterized in that the body (5) is arranged in a corresponding seat (7) provided in the rubber layer (4) of the roller (1) in such a way that the thickness of this layer is not changed. 3. Device according to claim 1, characterized in that the body (5) has the shape of a helix on the surface of the rubber layer (4). 4. Device according to claim 1, characterized in that the body (5) has a width between 1 and 3 cm. 5. Device according to claim 1, characterized in that the body (5) has the same physical and geometric properties as those of the rubber layer (4) of the pressure roller (1).