Winding – tensioning – or guiding – Convolute winding of material – With particular drive
Reexamination Certificate
1999-11-10
2002-06-11
Nguyen, John Q. (Department: 3653)
Winding, tensioning, or guiding
Convolute winding of material
With particular drive
C242S541500
Reexamination Certificate
active
06402082
ABSTRACT:
CROSS-REFERENCE TO RELATED APPLICATIONS
The present application claims priority under 35 U.S.C. §119 of German Patent Application No. 198 52 257.6, filed on Nov. 12, 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 winding machine and process for winding a material web onto a winding core, e.g., a reel spool, so that a wound roll is formed on the winding core. The winding machine includes a press roll (carrier drum) that rests in two moveable bearings so as to be pressed against the wound roll via a pressing device, thereby forming a winding nip. The material web can be guided to partially surround the press roll and to run through the winding nip, which can be set with a desired line load by the pressing device. The winding core, as well as the wound roll, can be arranged within moveable bearings that displace the winding core as the diameter of the wound roll increases so as either to maintain the winding nip at least approximately the same position or to displace the winding nip by only a relatively small amount, e.g., about 10 to 200 mm, during winding. Each of the bearings of the winding core can be displaced by an associated driving device, and a control device is adapted to control the driving device as a function of displacement of the pressing roll from a desired or preferred position.
2. Discussion of Background Information
Such a winding machine is known, e.g., from German Publication No. DE 2 214 350 and its U.S. family member U.S. Pat. No. 3,834,642. Winding machines of the type generally disclosed in these documents are, for example, located at the end of a machine for producing, refining, or otherwise processing a paper web. In the known winding machine, the press roll rests in bearings that are attached to a pivoted lever. The bearings of the winding core can be moved horizontally by a threaded spindle which is provided with a drive that is controlled as a function of displacement of the pivoted levers carrying the press roll. Such a control process is initiated by the opening or closing of a contact.
As with the instant invention, the winding core and wound roll are displaced in accordance with the increase in diameter of the wound roll so that the position of the winding nip remains at least approximately the same during the winding process. However, the known arrangements do not meet the demands placed upon winding machines that serve as a part of a modem high-performance machine for producing or processing a material web. Such high-performance machines normally have a working width of up to approximately 10 m, where work speeds are achieved of around 1500 to 2500 m/min.
The demands placed on such winding machines include, e.g., that:
A. control of winding core displacement (in accordance with the increase in diameter of the wound roll) must occur in as jerk-free a manner as possible and with extreme precision.
B. movements of a press roll bed (when setting the desired line load in the winding nip) must be as small as possible and occur as slowly as possible.
C. the above requirements A and B must contribute to lessening the danger of vibrations and to minimizing the danger of the web ripping because a rip can cause enormous amounts of waste paper to result within seconds.
SUMMARY OF THE INVENTION
The present invention provides a winding machine similar in general to that discussed above that includes a position measurement device coupled to at least one of the two bearings of the press roll to produce an instantaneous position value that is dependent upon an instantaneous (current) position of the pressing roll, a regulator that compares the instantaneous position value with a desired position value and that provides an actuating variable that corresponds to the deviation of the instantaneous value from the desired value, and a wire transmitting the actuating variable from the regulator to the control device of the driving devices so that the above-mentioned requirements are fulfilled to the greatest extent possible.
Therefore, according to the invention, the position regulator is provided for the press roll to ensure that the moveable press roll can supply the material web to the wound roll while maintaining a line load which can be set as desired in the winding nip and to ensure that, in spite of the rapid increase in diameter of the wound roll, the press roll departs from a desired center position only briefly and by very short distances. During a winding process, the displacement movements of the press roll are relatively slow and never jerky, thus, the danger of vibrations and paper rips is eliminated. Moreover, it is possible to intentionally displace the position of the press roll by a relatively short distance, e.g., between approximately 10 and 200 mm, with the aid of the regulator. However, when doing so, the regulator again provides a calm and slow displacement of the press roll.
According to the invention, it has been found that an additional problem that arises in winding especially wide material webs, i.e., the material web can temporarily have very small differences in thickness across its width. Thus, the web can, e.g., be thicker by a very small amount in the region of one edge than at the other edge. This leads to the danger that a wound roll will result that is not exactly cylindrical, but rather is slightly conical. This problem may appear even more markedly in the case in which the wound rolls are produced with a particularly large diameter, e.g., between approximately 3 to 4 m. It has been recognized that such difficult conditions can be better overcome by providing the regulator with a mean instantaneous position value that is derived from measured position values collected at both bearings of the press roll.
The apparatus of present invention permits axial traversal of the material web to be created in the wound roll being produced, which solves a further problem that is discussed below.
Irregularities can occur in the thickness profile of the material web. These irregularities usually only occur briefly, especially in paper machines, because irregularities can be eliminated, e.g., by adjusting the headbox. However, small differences in thickness can adversely influence the winding structure. Thus, for example, it can happen that the winding diameter can be larger than the desired diameter at some point in the web width. This often leads to undesired local overstretching of the material web, which can have a significant effect on the flatness of printing papers, for example. Thus, the present invention provides a winding machine which, despite possible irregularities in the material web, guarantees a consistently trouble-free winding structure in as constant and reliable a manner as possible. For this purpose, the press roll (carrier drum) can be cyclically tilted relative to the travel direction of the supplied web, thereby creating an axial traversal of the material web. Thus, the press roll can be displaced or pivoted alternatingly in one direction and then in the other, so that the carrier drum and the wound roll being created on the reel spool are kept in contact with one another during the winding process, i.e., the winding nip is maintained. As a result of the cyclic tilting according to the invention, any irregularities that occur, such as an irregularly changing thickness cross-direction profile, can be distributed across a large region of the web width, so that flaws in the desired winding structure are practically eliminated and an at least approximately cylindrical winding diameter can be achieved despite any irregularities. Further, local overstretching of the material web can be prevented.
Accordingly, the present invention is directed to an apparatus for winding a material web into a wound roll on a winding core. The apparatus includes a press roll, movable press roll bearings coupled to the press roll, and a pressing device positioned to press the press roll against the wound roll. In t
Ihle Georg
Madrzak Zygmunt
Möller Roland
Greenblum & Bernstein P.L.C.
Nguyen John Q.
Voith Sulzer Papiertecknik Patent GmbH
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