Winding – tensioning – or guiding – Convolute winding of material – Simultaneous winding
Reexamination Certificate
2001-02-27
2003-03-25
Jillions, John M. (Department: 3654)
Winding, tensioning, or guiding
Convolute winding of material
Simultaneous winding
C242S545100, C242S908000
Reexamination Certificate
active
06536703
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to an apparatus for winding parallel strips of material, such as metal strips, onto a drum.
BACKGROUND OF THE INVENTION
Thin strips of material, such as steel, may be formed by slitting a wide web of material into a number of thin strips. For purposes of storage and shipping convenience, these thin strips of material may be wound onto a drum immediately following the slitting process.
FIG. 1
shows three thin strips
20
of material, which have been slit downstream from a continuous web of material (not shown), being wound onto a drum
100
to form separate reels of thin strip material.
Because all thin strips
20
of material wound onto the drum
100
originate from the same wide web of material, it is desirable for all of the strips to be wound onto the drum at the same rate. If the strips
20
are not wound at the same rate, one of two conditions may occur. Winding a strip
20
at a rate that is slower than that of another reel on the drum may produce slack in the more slowly wound strip. Such slack may cause the strip
20
to be wound more loosely than is desired, and result in a drum with nonuniform reels of wound material. In extreme cases, such slack may accumulate to the point that it drags on the floor, or requires the creation of a large pit for accommodation of the slack. Alternatively, winding a strip
20
at a higher rate than other reels may produce excess tension in the more quickly wound strip. This tension may cause the strip to be wound too tightly, or in extreme situations cause damage to the strip or the apparatus used for the winding operation.
One hypothetical method of ensuring that all the strips are wound on a drum with uniform tension and at a uniform speed would be to make sure that all of the reels have the same thickness “d” throughout the winding process. Reels with the same thickness inherently take up thin strip material at the same speed. As shown in
FIG. 1
, however, it is not uncommon for the neighboring reels of thin strip material to have different thickness “d.” The production of reels with different thicknesses on the same drum may occur as a result of any of the following in isolation or combination: uneven wide web thickness, uneven coating thickness on the wide web, excessive/uneven burr on the wound strips, a loose leading strip edge, uneven applications of slitting lubricant, etc. Thus, it is not uncommon for the “natural” rate of strip take up to be different for the various reels on a drum.
It has been determined, however, that the “natural” rate of strip take up for each individual reel of strip material may be modified by providing for slip between the reel and the drum on which it is wound. In other words, the rate of take up of each individual strip may be controlled.
One known method of controlling the take up speed of each strip on a drum is described in, Lofstrom, Roger J.,
The Benefits and Limitations of Coreslip Rewinding
, The Fabricator, October 1995, which is incorporated by reference herein. The afore noted article describes a Coreslip rewinding system in which the winding drum includes a number of outer drive rings on its outer surface. Each thin strip of material may be wound onto a separate drive ring. The drive rings may be made of plastic material, which provides them with the ability to slip relative to each other and the drum that drives them. The amount of “slip” of the drive rings is adjusted by adjusting the lateral pressure applied to the rings. The tighter the drive rings are squeezed together, the greater the friction between them, and the less they slip. By selectively adjusting the lateral pressure applied to the rings, the relative slip may be set so that each thin strip of material is wound under a relatively uniform tension.
While the foregoing Coreslip device provides the needed slip between adjacent reels, it does so at a cost. The plastic drive rings are susceptible to wear and heat, and may need to be changed frequently, raising cost and maintenance concerns. Furthermore, because each strip of material is subjected to the same amount of tension force, the strips must be of comparable width to avoid excessive loading of narrower strips.
Another known method of controlling strip take up speed is described in Lofstrom, U.S. Pat. No. 5,292,084 (Mar. 8, 1994). The Lofstrom patent discloses a core slip rewinding system in which each individual strip is wound over a series of roller bearings. The roller bearings underlying each reel are free to rotate independent of the neighboring roller bearings of other reels. As such this system may be capable of reducing the friction between the reels and the drum to near zero levels. Although this system may be very effective, it suffers from being relatively expensive to manufacture compared to alternatives. Furthermore, such a system can only accommodate one size of drum.
Upon study of the foregoing Lofstrom devices, it became apparent to the present Applicant that a preferable winding apparatus would provide near zero friction between the wound material and the core on which it is wound. Any friction that is needed to control the amount of slip between the wound material and the core may be provided by laterally squeezing the strips of wound material together. By limiting the friction providing component to one parameter, precise control may be exercised over the amount of relative slip between the strips of wound material. While the later Lofstrom device provides the low friction required, it does so at the cost of monetary expense and limited versatility.
Therefore, there is a need for a method and apparatus for winding strip material that is more economical to produce and maintain than previously known systems. There is also a need for a method and apparatus for winding that is easier to operate, able to accommodate a wider selection of drum sizes, and does not require a slack pit. There is also a need for such a system that provides improved control over the relative slip between strips of wound material using lateral pressure.
In response to these needs, the present applicant has developed a method and apparatus for winding strip material on a drum which differs from the systems described above. In a first embodiment of the applicant's invention, a cushion of fluid, preferably air, may be selectively provided between the winding drum and the strip material wound thereon to reduce the friction there between.
OBJECT OF THE INVENTION
It is therefore an object of the present invention to provide a method and apparatus for reducing friction and/or controlling the amount of friction between a winding drum and the material wound thereon or therearound.
It is another object of the present invention to provide a method and apparatus for selectively adjusting the amount of slip between a winding drum and a reel of wound material.
It is still another object of the present invention to provide a method and apparatus for reducing friction and/or controlling the amount of friction between individual strips of material wound on a winding drum.
It is yet another object of the present invention to provide a method and apparatus for winding strip material that is more economical than previous methods and apparatuses.
It is still yet another object of the present invention to provide a method and apparatus for winding strip material that requires less maintenance than previous methods and apparatuses.
It is still another object of the present invention to provide a method and apparatus for winding strip material that can accommodate different sized winding drums.
It is still another object of the present invention to provide a method and apparatus for supplying a bed of pressurized fluid between the outer surface of a winding drum and material wound thereon.
It is still yet another object of the present invention to provide a method and apparatus for controlling the pressure of a fluid provided between the outer surface of a winding drum and material wound thereon.
Additional objects and advantages of the invention
Coil Pro Machinery, Inc.
Collier Shannon Scott PLLC
Jillions John M.
Rygiel Mark W.
Yohannan David R.
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