Winding – tensioning – or guiding – Convolute winding of material – With cutting – perforating – or notching
Reexamination Certificate
1999-10-15
2002-10-15
Rivera, William A. (Department: 3654)
Winding, tensioning, or guiding
Convolute winding of material
With cutting, perforating, or notching
Reexamination Certificate
active
06464161
ABSTRACT:
CROSS-REFERENCE TO RELATED APPLICATIONS
The present application claims priority under 35 U.S.C. § 119 of German Patent Application No. 198 48 808.4, filed on Oct. 22, 1998, the disclosure of which is expressly incorporated by reference herein in its entirety.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a process for severing a traveling material web, particularly a paper web in a winding device during reel spool changeover, in which a severing device is moved into the web travel path between a winding roll and an empty reel spool on the one side and the nearly full reel spool on the other side. The invention also relates to a device for performing such a process.
2. Discussion of Background Information
Winding devices of the type related to this invention are used at the end of a machine for manufacturing a material web where they facilitate continuous winding of the material web onto a reel spool. After a reel is finished, which is to say after a desired reel diameter has been reached, the material web must be severed and the full reel spool must be replaced by an empty reel spool, onto which the next reel is wound. On rare occasions, reel spool changeover can even take place when the reel has not yet reached the normally desired diameter.
A process and a device for performing such a reel spool changeover are known from WO 96/11868. To sever the paper web, this device uses a knife blade that traverses the entire width of the web and is moved from a neutral position to the web travel path of the paper web.
SUMMARY OF THE INVENTION
The present invention resides in a process of the type generally discussed above that provides a device for performing such a process.
This process provides a severing device that sequentially severs the material web across the width of the material web at several places so that, relative to the material web, the separation points lie along a line that runs at an angle to the web travel direction.
According to the invention, severing of the material web is performed in such a way that a cut edge results which is angled to the web travel direction. This cut edge can run at the same angle consistently across the entire width of the web. However, the cut edge can also take the form of a V-shape or a zigzag.
Severing the material web sequentially at several places along a line running at an angle to the web travel direction results in an especially advantageous, high-precision cut edge.
Preferably, the new web tail created in this manner is moved toward the empty reel spool by pressurized air. This ensures that the web tail is guided reliably to the empty reel spool.
To perform the process according to the invention, a device is used in one embodiment with a rotationally driven severing roll which moves from a neutral position to a cutting position and back, and which has on its roll sleeve several severing elements arranged along at least one spiral line.
When the severing roll is rotated, the severing elements arranged in a spiral on it engage with the material web one after the other. The circumferential velocity of the severing roll can equal the web travel velocity, but it can also be slower or faster than this velocity.
In addition, it is especially advantageous for the severing roll to be arranged on the side of the material web facing away from the empty reel spool. Thus, the movement of the severing roll between the neutral position and the severing position can take place without interfering with the empty reel spool.
In a further embodiment of the invention, air blast nozzles are provided on the roll. These are designed to aid in guiding the material web onto the empty reel spool. This reduces the risk of faulty guidance of the material web, increasing the reliability of the device correspondingly.
In one embodiment of the invention, the air blast nozzles can each be located directly adjacent to a severing element on the severing roll, and be supplied with pressurized air from the interior of the severing roll. In another embodiment of the invention, however, one or more air blast pipes with air blast nozzles can be provided on the outer surface of the roll sleeve of the severing roll. In this manner, the air volume is kept small, which results in a rapid pressure buildup and has the additional advantage that the air lost to leakage is reduced. The air blast pipes are preferably arranged parallel to the severing elements along a spiral line. Consequently, the pressurized air acts directly on the relevant cut edge.
According to one embodiment of the invention, the spiral line along which the severing elements are arranged on the severing roll can extend continuously across the entire width of the roll. This produces a straight cut edge diagonal to the web travel direction. According to another embodiment of the invention, however, the severing elements can also extend along two spiral lines running outward in opposite directions from a common point in the center of the severing roll. Because of the rotation of the severing roll this design generates a V-shaped cut edge, the peak of which points either in the web travel direction or in the opposite direction, depending on the arrangement of the spiral lines.
According to another embodiment of the invention, the severing elements are arranged along several spiral lines running alternately in opposite directions and connecting with one another across the width of the roll. This design produces a zigzag cut edge, the peaks of which again point either in the web travel direction or in the opposite direction, depending on the arrangement of the spiral lines.
In all cases, the spiral lines can encircle the circumference of the severing roll one or more times. However, it is also possible to arrange the spiral lines such that they encircle only part of the circumference of the severing roll. This arrangement has the advantage that the severing roll can initially be placed against the material web at its region that is free of severing elements. The synchronization of this placement and the rotation of the severing roll is thus simplified.
According to another embodiment of the invention, control structure is provided through which, in sequence, the severing roll can be set to rotate, the air blast nozzles can be supplied with pressurized air, and the severing roll can be moved to its severing position, such that the delivery of pressurized air to the air blast nozzles preferably occurs immediately before the severing roll penetrates the material web. In a corresponding fashion, the process is reversed; the severing roll is moved back to its starting position, the rotation of the severing roll is stopped, and the air supply is shut off. In this way, the severing process can advantageously be automated.
According to another embodiment of the invention, control structure is provided which ensures that the forwardmost severing element when viewed in the rotational direction of the severing roll, is the first to act upon the material web. Thus, the control structure is used to ensure that complete and clean severing takes place across the entire width of the material web.
The process according to the invention can also be performed with a device which has a supporting beam extending essentially across the width of the material web and carrying the severing elements. The severing elements are moveable from a neutral position to a severing position and back, wherein the severing elements are arranged such that they engage the material web one after another when the supporting beam is moved into the severing position. The severing elements are arranged on the supporting beam to produce the desired shape of the cut edge. Thus, the severing elements can be arranged on the supporting beam along a line running continuously across the entire web width at an angle to the web travel direction.
According to another embodiment of the invention, the severing elements on the supporting beam can extend along two lines running outward in opposite directions from a common point in
Greenblum & Bernstein P.L.C.
Rivera William A.
Voith Sulzer Papiertechnik Patent GmbH
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