Advancing material of indeterminate length – Threading device – With means to pull lead-end
Reexamination Certificate
1999-12-08
2002-07-30
Mansen, Michael R. (Department: 3653)
Advancing material of indeterminate length
Threading device
With means to pull lead-end
C226S091000, C226S095000, C226S172000
Reexamination Certificate
active
06425513
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the invention
The present invention relates to a device for the transfer of a threading strip or a material web in a machine for the production and/or processing of the material web, from a pick-up area to a transfer area along a web travel path, and a method for the transferring of a threading strip or a material web.
2. Description of the related art
Devices and methods of the type addressed here are already known (DE 40 37 661 C1). These are utilized in machinery for the production and/or the conversion of a material web and serve to transfer the material web, or a strip which has been slit off the web, also referred to as threading strip, from a pick-up area to a transfer area. During start-up of the machinery, or following a web break, the threading strip or the material web in its entire width, are guided along a web travel path that is established by the guide arrangements and/or the processing units. This process is also known as threading. The known apparatus includes a rope guide arrangement whereby two points converge in a so-called rope nip at the beginning of the rope guide arrangement. The threading strip/material web is led into rope nip which is located in a pick-up area and is held between the ropes. The threading strip/material web is carried together with the ropes along the web travel path into a transfer area in which the threading strip/material web is transferred into a downstream unit in the machine. The transfer takes place at reduced or full machine speed, which may be 2,000 m/min. or higher. In fact, the ropes which are used for the transfer often run at even higher speeds than the machine speed. It has proven disadvantageous that the threading strip/material web in many instances cannot be held securely by the ropes, thus getting lost during the transfer. The result is that the transfer process must often be repeated several times, until a successful transfer of the threading strip/material web from the pick-up area to the transfer area is concluded. However, web breaks occur frequently after the transfer, due to the fact that the threading strip/material web oscillates while being put under tension in a longitudinal direction, thereby enabling them to run back into the ropes where they are destroyed. These multiple attempts to achieve a successful transfer increase machine down times and thereby decrease productivity.
SUMMARY OF THE INVENTION
The present invention provides an apparatus and a method which ensures a reliable transfer of a threading strip or a material web, even at high machine speeds.
The at least one pick-up apparatus of the present invention, for the purpose of transferring the threading strip/material web from the pick-up area to the transfer area, is movable essentially along the web travel path at a speed that is lower and preferably considerably lower than the operating speed with which the threading strip/material web travels through the machine during the transfer process. Consequently, a high degree of operational reliability is assured. In the context of the present invention the term “web travel path” relates to the path which is projected by the production and/or conversion process of the material web, or by the guide assemblies and or processing units. The threading strip/material web, for example, is carried over rolls, through roll presses, over device surfaces, over/through processing devices, over/through measuring devices and/or on belts whose location inside the machine determine or establish the web travel path. The pick-up apparatus is moved along the web travel path at a lower speed than the threading strip/material web whose speed during the transfer process is consistent with the machine speed. With the assistance of the pick-up apparatus, the threading strip/material web is guided out of the web travel path, sideways for example, at the location at which the pick-up apparatus is positioned in the machine. Since the relocation speed of the pick-up apparatus is lower, preferably considerably lower than the running speed of the threading strip/material web, it is impossible for the material web to wrap onto the pick-up apparatus. Threading of the strip/web is therefore also possible at very high machine speeds since the transfer speed, that is the relocation speed, of the pick-up apparatus is variable independently from the operating. speed of the machine.
A preferred embodiment of the transfer device is an apparatus in which the pick-up assembly is movable in the direction of the web travel and in an opposite direction thereto. This permits open travel of the pick-up apparatus. Consequently, the pick-up apparatus does not have to be directed in a circle in order to relocate it from the transfer area to the pick-up area. Instead, it can be brought back to the pick-up area in a direction opposite to the direction of web travel. The relocation speed and direction of the pick-up apparatus would preferably be variable between the two transfer processes.
A particularly favored embodiment of the invention provides that the relocation speed during a transfer process is variable and preferably adjustable. Viewed in a direction of web travel, the threading strip/material web can therefore travel at different speeds in different sections. This provides for a relatively fast and reliable transfer since in the area of a processing unit or guide arrangement over/through which the threading strip/material web is carried or threaded, the already relatively low relocation speed may be further reduced.
A preferred embodiment of the transfer device provides a pick-up apparatus that is movable or guided either in the vicinity of the web travel path or outside the web travel path. The travel path of the pick-up apparatus may, for example, be adjusted to the arrangement of the threading strip that has been slit from the material web. The threading strip is slit from the material web either from a web edge or from a material web segment between the web edges. The pick-up apparatus may also be guided in the center of the web travel path. If the material web is transferred in its entire width from the pick-up area into the transfer area, then the pick-up apparatus may also be located, in this instance, in or outside the area of the web travel path. If the pick-up apparatus is located outside the web travel path, then it is designed such that its range of influence extends into the web travel path, at least into the area in which the threading strip/material web is to be guided.
A guide including at least one guide element is assigned to the pick-up apparatus. An advantageous embodiment of the invention provides that the at least one guide element is in the form of rope, belt, chain or similar device. Such a guide elements may be stationary, meaning they may be mounted rigidly, so that the pick-up apparatus can travel (for example, on the guide elements) along the path that is projected by the guide elements, while the guide elements are stationary. A different embodiment provides that the guide element(s) is (are) driven by a drive, so that the pick-up apparatus that is mounted on the guide element can travel along the path that is projected by the guide element(s). It is also feasible that the pick-up apparatus may move relative to the movable guide element.
In accordance with another design variation, the at least one guide element is provided in the form of a roll, preferably a profile roll. The pick-up apparatus can, therefore, be moved with the assistance of rolls which are located along the web travel path and whereby at least some of these rolls are driven.
A preferred embodiment of the transfer device provides that the travel path of the guide arrangement is longer than the web travel path. The travel path, therefore, does not only extend from the pick-up area into the transfer area, or in opposite direction, but also further so that the pick-up apparatus may be guided out of the area of the web travel path. This arrangement allows the pick-up apparatus to be moved, during a machine run
Goebel Werner
Hermsen Thomas
Kugler Georg
Kurtz Rüdiger
Madrzak Zygmunt
Mansen Michael R.
Pham Minh-Chau
Taylor & Austin, P.C.
Voith Sulzer Papiermaschinen GmbH
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