Process and apparatus for cutting a running material web

Winding – tensioning – or guiding – Convolute winding of material – With cutting – perforating – or notching

Reexamination Certificate

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

Reexamination Certificate

active

06427938

ABSTRACT:

CROSS-REFERENCE TO RELATED APPLICATIONS
The present application claims priority under 35 U.S.C. § 119 of German Patent Application No. 198 48 810.6, filed on Oct. 22, 1998 and German Patent Application No. 199 44 704.7, filed on Sep. 17, 1999, the disclosures of which are expressly incorporated by reference herein in their entireties.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a process for separating a running material web, e.g., a paper web, in which the material web is wound sequentially onto several winding cores, e.g., reel-spools, and initiating winding onto a new winding core each time a wound roll formed on a previous old winding core has reached a predetermined diameter. The new winding core is guided between a winding roll, e.g., a king roll, and the old winding core, which continues to be fed via the winding roll, and the running material web is cut or separated in a region between the wound roll formed on the old winding core and a nip formed by the winding roll and the new winding core.
The present invention further relates to a device for performing such a process with at least one cutting device.
2. Discussion of Background Information
Cutting (separation) processes and devices, such as those generally described above, are used in paper manufacturing, for example, to wind the finished paper web onto several winding cores, also referred to as reel-spools, one after the other without interrupting the manufacturing process, i.e., without turning off the paper machine.
In such a process, it must be ensured that the new web end, which is formed by cutting or separating the material web, is guided to the new winding core to form a new wound roll.
International Publication No. WO 97/48632, U.S. Pat. No. 5,360,179, and European Publication EP 0 658 504 B1 disclose cutting the paper web before the winding nip, which is formed between the winding roll and the new winding core, and providing either curved cutting lines or cutting lines that run diagonally to the direction of web travel. However, when the paper web is cut before the winding nip, there is a danger that the new web end will recoil and not be able to be guided into the winding nip.
Further, it has been disclosed to strike the paper web with a swinging separating device running along the width of the machine placed between the new and old winding cores, i.e., behind the winding nip. The ensuing cut edge that runs perpendicular to the direction of web travel can lead to problems in winding the new web end onto the new winding core.
Also, European Publication No. EP 0 658 504 B1 discloses separating the material web behind the winding nip, which is formed between the winding roll and the new winding core, but it is not mentioned how this occurs.
German Publication No. DE 44 01 804 A1 discloses moving a separating device, which includes a sectionally traversing knife as a separating mechanism, into the path of a paper web. It is further known from this publication to weaken the paper web only at one point with a knife and subsequently to separate it using pressurized air. However, using only the sectionally traversing knife or a knife that only weakens the paper web carries the danger of uncontrolled tearing of the paper web.
SUMMARY OF THE INVENTION
The present invention provides a process and a device of the type generally discussed above that allows an optimal initial winding of the new web end onto the new winding core.
Therefore, the invention provides for completely cutting (separating) the material web with at least one cutting device that is movable relative to the material web in a plane substantially parallel to the material web.
Moreover, the instant invention provides for cutting the material web in a vicinity of a winding roll, e.g., in a region between the winding roll and the wound roll or in a region upstream, relative to a web travel direction, from the winding roll.
Complete cutting or separation of the material web, according to the present invention, prevents an undefined tearing of the material web so that the leading edge of the new web end always has the same definable form. Moreover, the leading edge can be guided onto the new winding core in a defined manner. Further, the necessity of applying pressurized air to the material web for complete separation of the material web can be dispensed with.
According to an exemplary embodiment of the invention, the cutting device moves at an at least approximately constant speed and across, e.g., at least essentially perpendicular, to the direction of web travel.
In this manner, a cutting line can be produced in the material web that runs diagonally to the travel direction of the material web from one edge of the material web to its opposite edge. The diagonal edge of the new web end produced in this manner can be wound onto the new winding core in a relatively problem-free manner even under very high web speeds, and produces a conically wound initial winding.
According to a further embodiment of the invention, two cutting devices can be moved in opposite directions across, e.g., at least essentially perpendicular to, the direction of web travel and can preferably be moved at an at least approximately constant speed.
In relation to the cross-direction, the two cutting devices can be placed against the material web in the region of its center or its ends in such a way that two intersecting cutting lines ensue, both of which run diagonally to the web travel direction and either from the center to the edges or vice versa. In this manner, the leading edge of the new web end can be cut in a pointed fashion such that the initial winding onto the new winding core is simplified.
The present invention further provides a device for performing the process according to the instant invention, and includes at least one cutting device structured and arranged for completely separating the material web.
Accordingly, the present invention relates to a process for cutting a running material web in which the material web is wound onto several winding cores in succession, such that winding of the material web onto a new winding core begins after a predetermined diameter has been attained in a wound roll formed on an old winding core. The process includes moving the new winding core between a winding roll and the wound roll, such that the material web is fed onto the wound roll from the winding roll. The process further includes forming a nip between the new winding core and the winding roll, positioning at least one cutting device one of in a region between the wound roll and the nip and in a region upstream of the winding roll relative to a web run direction, and moving the at least one cutting device relative to the material web in a plane substantially parallel to the material web. In this manner, the running material web can be completely cut.
In accordance with another feature of the instant invention, the moving of the at least one cutting device may include moving the at least one cutting device across a web travel direction. In this manner, a diagonal cutting line results. The at least one cutting device can be moved substantially perpendicular to the web travel direction.
According to another feature of the invention, the moving of the at least one cutting device can include moving the at least one cutting device diagonally to a web travel direction. The diagonal movement can include a component parallel to and opposite the web travel direction. Alternatively, the diagonal movement can include a component parallel to and in the web travel direction.
In accordance with a further feature of the present invention, the moving of the at least one cutting device can include moving the at least one cutting device continuously across an entire width of the material web.
In accordance with another feature of the invention, the moving of the at least one cutting device may include moving the at least one cutting device at an at least approximately constant speed. The at least approximately constant speed can be between approximat

LandOfFree

Say what you really think

Search LandOfFree.com for the USA inventors and patents. Rate them and share your experience with other people.

Rating

Process and apparatus for cutting a running material web does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Process and apparatus for cutting a running material web, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Process and apparatus for cutting a running material web will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFUS-PAI-O-2929125

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.