Printing – Rolling contact machines – Rotary
Reexamination Certificate
2000-04-21
2001-08-28
Yan, Ren (Department: 2854)
Printing
Rolling contact machines
Rotary
C101S227000, C101SDIG029, C226S195000
Reexamination Certificate
active
06279472
ABSTRACT:
BACKGROUND OF THE INVENTION
This invention relates generally to an apparatus handling a continuous web of paper or like material such as, typically, a web-fed rotary printing press. More specifically, the invention deals with how to preclude, in a rotary printing press or the like, the curling of the web from being held under tension against such relatively small-diameter, web-tensioning members as tension rollers and turnbars for an extended period of time when the machine is out of operation.
As a typical application of the instant invention, let us consider the postprinting station in a web-fed rotary printing press where the printed web is slit longitudinally into a pair of halves and where the web halves are subsequently placed one upon the other. The web is held taut between pairs of nip rollers as it travels along the predefined path through the postprinting station. Conventionally, the web has been held tightly against guide rollers, tension rollers, and turnbars regardless of whether the press is in or out of operation. Left tightened against such members, particularly those of relatively small diameters, for an extended period of time, the web easily develop semipermanent curls.
The curling web has caused some serious inconveniences in subsequent processing thereof. For instance, when the superposed web halves are cut transversely into individual sheets, they have tended to warp while or after being cut, jamming the cutter in the worst case. Furthermore the warping sheets have often impeded such additional postprinting operations as folding, pressing, and delivery, again possibly resulting in jamming or in the wrinkling of the products.
A so-called “decurler” has been known and used for removing the curl from a continuous web or strip of paper that has been kept in roll form, by running the web. The web that has curled from being kept in roll form does so in one direction only, but the web curls indefinitely in both directions in a rotary printing press. Some of such web curls might therefore grow even worse should the web be rubbed only in one way.
There are additional objections to curl removal by rubbing. The forcible rubbing of paper can damage its surface and create large volumes of fibrous dust. Such dust not only deteriorates the quality of the printings but pollutes the working atmosphere.
SUMMARY OF THE INVENTION
It is therefore an object of this invention to preclude the development of curls in a web of paper or the like, no matter how long it has been kept threaded through a rotary printing press in particular, rather than to remove the curls after they have been created.
Another object of the invention is to compactly incorporate the means for curl preclusion into a rotary printing press or the like without in any way interfering with the intrinsic operations of the machine.
A further object of the invention is to automate the curl precluding means in relation to the beginning and end of the operation of the machine, demanding no additional labor on the part of the machine operator or supervisor for the functioning of the curl precluding means.
Briefly, the present invention concerns a web-handling machine such as a web-fed rotary printing press wherein a continuous web of paper or like material is guided to travel along a predefined path. More specifically, in such a machine, the invention pertains to the combination of a tension member such as a tension roller or a turnbar, and drive means for moving the tension member between a working position, in which the tension member is disposed contiguous to the predefined path of the web for holding the same under tension, as when the machine is in operation, and a retracted position in which the tension member is held away from the predefined path of the web for relieving the same of tension, as when the machine is out of operation.
Thus, when the machine is out of operation, the web is slackened by the retraction of the tension member and so does not curl from being held still and under tension against the tension member for an extended period of time. Since the web does not develop any semipermanent curls according to the invention, no rubbing of the web is necessary as has been taught heretofore. The means for retraction of the tension member, which may take any of several different forms to be herein disclosed, can be compactly built into a web-fed rotary printing press of standard construction.
Preferably, the tension member is retracted as above while the web is held nipped by rollers on the upstream and downstream sides, respectively, of the tension member. There will consequently be no longitudinal displacement of the web relative to the tension member when the latter is subsequently driven back from the retracted to the working position.
According to a further feature of the invention, the travel of the tension member is automated in relation to the operation and nonoperation of the machine. It is automatically driven to the working position when the machine is set into operation, and retracted when the machine is set out of operation. No additional task is thus imposed on the machine operator in order to prevent the curling of the web.
The above and other objects, features and advantages of this invention and the manner of achieving them will become more apparent, and the invention itself will best be understood, from a study of the following description and attached claims, with reference had to the accompanying drawings showing the preferred embodiments of the invention.
REFERENCES:
patent: 3667664 (1972-06-01), Schroeder
patent: 3912145 (1975-10-01), Meihofer
patent: 4129238 (1978-12-01), Herd
patent: 5003889 (1991-04-01), Glunz et al.
patent: 5024156 (1991-06-01), Hank et al.
Kishine Toshiaki
Wada Kenichiro
Yamazaki Yuichi
Miyakoshi Printing Machinery Co., Ltd.
Wenderoth , Lind & Ponack, L.L.P.
Yan Ren
LandOfFree
Web curling prevention device for a rotary printing press or... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Web curling prevention device for a rotary printing press or..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Web curling prevention device for a rotary printing press or... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2536962