Winding – tensioning – or guiding – Convolute winding of material – With particular drive
Reexamination Certificate
1999-05-28
2001-07-17
Rivera, William A. (Department: 3653)
Winding, tensioning, or guiding
Convolute winding of material
With particular drive
C242S530300, C242S541500, C242S541600
Reexamination Certificate
active
06260789
ABSTRACT:
CROSS-REFERENCE TO RELATED APPLICATIONS
The present application claims priority under 35 U.S.C. §119 of German Patent Application No. 198 24 619.6, filed on Jun. 2, 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 is directed to a multi carrying-roll winder having a first driven carrying roll and a second driven carrying roll, that forms a winding bed, and a loading device.
2. Discussion of Background Information
Multi-carrying-roll winders (e.g., a winder with two or more carrying rolls) are often used in connection with a roll cutter to wind up web sections that have been longitudinally cut by the roll cutter from a material web, so as to form reels.
Such multi-carrying-roll winders have a particularly large field of application in the manufacture of paper webs. Paper webs are typically manufactured in widths of up to 10 m. However, users, such as, for example, print shops, normally require paper web widths of approximately 0.8 to 3.8 m.
Multiple rolls can be wound near each other, so that they have a common winding axis. In such a situation, the sum of the axial lengths of the winding rolls corresponds to the width of the original paper web. The same is true for other material webs, such as, for example, plastic films or metal foils.
In contrast to support roll winders, in which individual reels are wound offset, relative to each other, it is normally not possible to support the reels on a core, or to introduce torques at the reels with dual-carrying-roll winders. In particular, when the rolls are very wide, problems arise with controlling roll hardness.
The reels are supposed to be structured such that they have a relatively high hardness in the region of their core. That is, in the core region, the paper (or other material web) is intended to be firmly wound. The hardness in the central region is supposed to be somewhat less and remain constant (or decrease) from the inside of the reel towards the outside of the reel.
With multi-carrying-roll winders, the production of the hard core region presents difficulties. If the core is not hard enough, core sags can occur in wide rolls. An attempt has been made to solve this problem by pressing the roll core into the winding bed. That is, the roll core is pressed against the carrying rolls with a relatively high force at the beginning of the winding process. The carrying rolls are driven with different torques, such that a web tension is “wound into” the reel. However, if the pressure is too great, other problems, such as, for example, a layer shift, may occur.
SUMMARY OF THE INVENTION
It is, therefore, an object of the present invention to provide an additional influencing capability to control roll hardness.
According to the present invention, a dual-carrying-roll winder includes an additional drive device that acts on the circumference of the reel to control a roll hardness.
The additional drive device functions to assist the two carrying rolls to drive the reel. This arrangement permits a greater driving power to be transferred to the reel than is possible in the prior art devices. Driving power refers to the rate (in kilowatts) of transferring energy from, for example, a drive, to, for example, a carrying roll.
Increasing the amount of driving power to the reel has not been possible, prior to the development of the present invention, because, for example, it has not been possible to prevent slippage against the reel when an excessively high drive torque is applied. In particular, when the winding process begins (e.g., the reel comprises a core with perhaps, a few material web layers wound thereon), the winding power that can be transferred from the carrying rolls to the reel is limited.
It is desirable to set different driving powers for the first carrying roll and the second carrying roll, in, for example, a dual-carrying-roll-winder, in order to create a desired web tension in the reel. However, it has not been possible to apply a full driving power (e.g., 100% of the torque generated by an associated driving device) to each carrying roll of a dual-carrying-roll winder. Rather, the sum of the driving power that can be applied to two carry rolls has generally been only slightly more that the driving power that could be applied to a single carrying roll winder. This problem is overcome, in the current embodiment, by the inclusion of an additional drive device. As a result, it is now possible to apply greater drive torques to the reel, increasing the web tension, especially at the beginning of the winding process.
The procedure for designing a loading device as a loading roll and for driving it is known in the art. However, such prior art systems have not been useable for driving a reel. Instead, such systems have traditionally been used only to provide a flywheel effect, in order to prevent the reel from having to also turn the loading roll.
On the other hand, the current invention discloses a driving device that actually acts upon the reel to drive it.
According to a preferred embodiment of the invention, the additional drive device supplies, at least in a winding section at the beginning of a winding operation, at least approximately 15% (and preferably approximately 20%), of the drive power to the reel. This is a significant increase in the amount of drive power (torque) transferred to the reel, as compared to the prior art devices.
In the preferred embodiment, the drive device contacts the reel with a contact pressure distribution that is directed towards the winding bed. The drive device is also used to hold the reel in the winding bed and to press it against the carrying rolls. An improved frictional grip is achieved between the reel and the carrying rolls, so as to increase the amount of driving power (torque) transferred from the carrying rolls to the circumference of the reel.
The present invention is realized using a simple design, in which the drive device is formed by a loading device. Thus, two functions are combined in the loading device. First, a contact pressure is applied to the reel, which is necessary (at least at the beginning of the winding operation) to generate the necessary nip pressures on the carrying rolls for the winding process. Second, the application of additional drive power significantly increases the ability to control a web tension, and thus, control the winding hardness.
Preferably, the drive device applies a greater portion (e.g., percentage) of the total driving power (e.g., torque) to the winding roll than to the first carrying roll in a predetermined winding section of the winding process. As noted above, it is desirable (in many cases) to apply differing driving powers to the first carrying roll and the second carrying roll. In the current invention, more power (torque) is (at least initially) applied to the second carrying roll, as compared to the first carrying roll. In this regard, as discussed above, the inclusion of the additional drive device permits a greater amount of driving power (torque) to be applied to the carrying rolls. Thus, the reel can be rotated with a relatively high torque.
In this regard, it is noted that the torque is not applied in the first nip (e.g., the location between the first carrying roll and the reel). Rather, an increased web tension is generated immediately behind the nip. As a result, the web tension can be “wound into” the reel, producing the desired winding hardness.
In the preferred embodiment, the predefined winding section amounts to at least 40% of the final diameter of the reel. However, this percentage can vary without departing from the scope and/or spirit of the invention. As the diameter of the reel increases, the proportion of driving power (torque) applied to the reel by the first carrying roll increases. As a result, the winding hardness decreases as the reel diameter increases.
In the current invention, a control device operates to distribute the amount of driving power between the two carrying rolls and the addition
Greenblum & Bernstein P.L.C.
Rivera William A.
Voith Sulzer Papiertechnik Patent GmbH
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