Winding – tensioning – or guiding – Unwinding – With attachment to preceding material
Reexamination Certificate
2002-09-19
2004-05-04
Rivera, William A. (Department: 3654)
Winding, tensioning, or guiding
Unwinding
With attachment to preceding material
Reexamination Certificate
active
06729573
ABSTRACT:
FIELD OF THE INVENTION
The present invention pertains to a roll changer for a web-treating or -processing machine, which is set up for a roll change during the stoppage of the roll changer. The present invention also pertains to an automatic roll change in such a machine, in which a web to be replaced is pulled into the machine, but is not in production.
BACKGROUND OF THE INVENTION
Web-fed printing presses, which are preferred examples of web-treating machines in the sense of the present invention, usually have roll changers which are able to perform a so-called flying roll change. During a flying roll change, a reserve web is joined fully automatically with a working web being wound off from a working roll in the roll changer during running production and is connected to the working web. The reserve web is wound off in the roll changer from a reserve roll. The working web is cut off, and the old working roll is removed from the roll changer either likewise fully automatically or manually and replaced with a new reserve roll. The reserve web attached to the working web is the new working web.
Even though roll changers that are set up for flying roll change are the standard at least in large newspaper rotary printing presses, such a roll change causes problems during the stoppage of the roll changer. In particular, no roll changers are known which are set up for both flying roll change and for fully automatic roll change during the stoppage of the roll changer.
SUMMARY OF THE INVENTION
Therefore, the object of the present invention is to make possible automatic roll change during the stoppage of the roll changer, preferably in a roll changer with which flying roll change can be performed.
The present invention is based on a roll changer for a web-treating or -processing machine, which is set up for unwinding a working web to be treated from a working roll, for joining a reserve web to the working web and for connecting the two webs to one another. A preferred example of a web-treating machine is a web-fed rotary printing press, preferably an offset printing press for newspaper printing, especially for printing large editions of newspapers. However, the machine may also be a web-treating or -processing machine for plastics or metals and, in principle, for any web-shaped material, e.g., a plastic film, a metal foil, but especially preferably paper. The web that has already been pulled into the machine and is to be replaced with the reserve web, e.g., after it had been used up, is called the working web in the sense of the present invention.
The roll changer has a first mount for the working roll and a second mount for the reserve roll. The mounts are movable in the roll changer preferably such that they can be moved alternatingly into a working position and into a changing position. The working position advantageously also forms a joining position, which is a bonding position in the case of joining by bonding. The mounts are preferably formed by roll arms, which can be alternatingly pivoted into the working position and into the changing position. The roll changer comprises, furthermore, a connecting means for connecting the reserve web to the working web. The connecting means is preferably designed as a bonding means in order to establish a bonded connection between the working web and the reserve web. This is the currently common connection technique for paper webs in web-fed rotary printing. However, the connecting means may also be formed by a welding means in the case of machines for treating or processing plastic films as well as in machines for treating or processing metal webs. However, other suitable connection techniques shall not be excluded, either, not even for paper webs.
The roll changer comprises, furthermore, a holding means, which is arranged behind the connecting means in the direction of feed of the working web, i.e., downstream of the connecting means along the web. The holding means is designed such that it can fix, preferably completely block the working web in relation to the direction of feed. The fixation preferably takes place exclusively by frictional engagement, especially preferably by clamping the working web.
Finally, the roll changer comprises a pulling means for the working web. The pulling means is arranged in the path of the web between the connecting means and the holding means and is set up or designed such that it can pull the working web from the working roll. The pulling off from the working roll takes place either entirely without support by a motor or with support by a motor or even against a braking force, which may be generated by a drive motor or an additional brake. In any case, an advantageous web tension is generated and maintained during the pulling off by means of the pulling means, optionally in cooperation with a rotating drive of the working roll or a brake for the working roll. Even though the pulling means may be a pulling means with which the web is also fed during running production, the web is preferably fed by means of the pulling means only during the stoppage of the roll changer by an amount that must, of course, be large enough to be able to establish the connection of the reserve web to the working web and to perform the automatic roll change with the working web fixed. If the pulling means also feeds the web during running production, this preferably takes place only temporarily.
An especially elegant solution is the use of a tensioning means as the pulling means, which is used to compensate variations in the web tension during the running production of the machine. Prior-art web tensioning means, e.g., pivotably or linearly movably mounted dancing rollers and equivalent roll means, around which the web is wrapped and which regulate the web tension due to their own movement at right angles to their longitudinal axis by changing the length of the path of the web, are suitable for this. The tensioning element wrapped around by the web, a cylindrical body in the case of a roller or optionally also only a simple rod or the plurality of cylindrical bodies in the case of a roll means, is mounted movably at right angles to its longitudinal axis against the force of elasticity of a restoring element. In the variant of a pulling means according to the present invention, the tensioning element is, furthermore, coupled with a drive bringing about this transverse movement. The drive may be, e.g., an electric motor or a fluid drive, especially a piston-and-cylinder unit. Such a pulling means known from tensioning means may also be used only as a pulling means and does not have to be used as a tensioning means. It is consequently not absolutely necessary for a restoring element for generating a restoring force of elasticity to be present.
The holding means may be formed, in principle, by one or more treating or processing means of the machine, which follows/follow the roll changer in the path of the working web and which is/are considered to belong to the roll changer in such a design of the holding means for the purposes of the present invention. However, the holding means is preferably formed on the path of the working web in front of the first treating or processing means, which follows the pulling means according to the present invention in order to obtain a short web path between the pulling means and the holding means. It shall be ensured by the holding means that the stopped working web can indeed be pulled off from the working roll by means of the pulling means by a sufficient amount. The working web must be pulled out by at least such a length that the connection to the working web can be established. The beginning of the web of the reserve roll should preferably also be separated from the reserve roll by the pulling out. The holding means must therefore fix the web at least in the sense that the working web is not pulled out of the machine in the direction of the roll changer by means of the pulling means, while pulling off or pulling out of the working web from the working roll does not take place to a sufficient exte
Burri Daniel
Moser Hans
Maschinenfabrik Wifag
McGlew and Tuttle , P.C.
Rivera William A.
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