Winding – tensioning – or guiding – Helical or random winding of material – Distributing material along the package
Reexamination Certificate
1999-08-03
2001-11-06
Mansen, Michael R. (Department: 3653)
Winding, tensioning, or guiding
Helical or random winding of material
Distributing material along the package
Reexamination Certificate
active
06311920
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to winding lengths of material on a package.
2. Description of the Prior Art
Precision wound packages of lengths of materials, such as textile yarns, are well known in the art and have been used as the industry standard because of their uniform over-end take-off tension during removal of the length of material and due to their attractive high quality appearance which is unique to precision wound packages. Precision wound packages are so named because the length of material is traversed in a precise pattern across the package as the package rotates and winds the length of material thereon. This pattern avoids one wrap of the length of material from being overlaid on an adjacent wrap of the length of material in a given helical band of the package P. Such overlay, which is common in cross-wound (non-precision wound) packages, produces poor material take-off tension uniformity and can also cause “bumps” which result in vibration during rotation of the package.
Lengths of material that need to be wound at a constant or nearly constant speed are precision wound at low material speeds because of the inherently higher helix angle utilized at the beginning of winding the package than at the end. As used herein “helix angle” is the angle between a lengthwise axis of the length of material being supplied to the package and a plane perpendicular to a lengthwise axis of the package. At a constant, or nearly constant yarn speed the higher helix angle at the beginning of winding the package requires the length of material M to be traversed at a higher traverse frequency at the beginning of winding the package than the traverse frequency at the end of winding the package P. At high winding speeds however, the required traverse frequency may be mechanically unattainable at the beginning of winding the package or may result in an unacceptably low helix angle at the end of winding the package.
U.S. Pat. No. 4,049,211 to Spescha discloses a winding apparatus wherein the actual winding ratio step decreases with increasing diameter of the package, e.g., see FIG. 3 of the Spescha patent. The Spescha patent, however, discloses that each step in actual winding ratio is at least two integer steps. Moreover, the Spescha patent discloses that a ratio of actual winding ratio to integer winding ratio closest adjacent the actual winding ratio during winding, hereinafter “integer offset ratio”, varies for the different values of actual winding ratio utilized during winding of the package. It is believed that utilizing different integer offset ratios during winding produces differences in spacing between centers of adjacent wraps of the length of material wound at different actual winding ratios.
It is therefore an object of the present invention to overcome these problems and others by providing a method and apparatus for winding packages with the appearance and take-off performance of precision wound packages while avoiding unacceptably high or low traverse speeds at the beginning and end of the package, respectively. It is an object of the present invention to provide a method and apparatus for winding a package, wherein the actual winding ratio is step decreased during the winding of the package and the integer offset ratio is constant throughout the winding of the package. It is an object of the present invention to provide a method and apparatus for winding a package wherein the actual winding ratio step decreases during the winding of the package between adjacent an integer winding ratio and adjacent a sub-integer winding ratio in a manner whereby a ratio of the actual winding ratio to sub-integer winding ratio closely adjacent the actual winding ratio, hereinafter “sub-integer offset ratio” is constant during winding of the package and the integer winding ratio is constant throughout winding of the package.
SUMMARY OF THE INVENTION
Accordingly, we have invented a method of precision winding a package. The method includes supplying a continuous length of material to a bobbin having a lengthwise axis. The bobbin is rotated around the lengthwise axis and the supplied continuous length of material is wound around the periphery of the bobbin to form a package. The supplied continuous length of material is traversed between ends of the package while winding the same therearound. The rotational velocity of the rotating package and the traverse frequency that the supplied continuous length of material traversed between ends of the package are determined. The length of material is wound on the package at a first actual winding ratio adjacent a first integer winding ratio. The traverse frequency is decreased in response to decreasing rotational velocity of the package so that the first actual winding ratio parallels adjacent the first integer winding ratio. The traverse frequency is step increased so that the first actual winding ratio step decreases to a second actual winding ratio adjacent a second integer winding ratio. Each actual winding ratio corresponds to a ratio of the determined rotational velocity of the package to the determined traverse frequency. A ratio of the first actual winding ratio and the adjacent first integer winding ratio defines an integer offset ratio and a ratio of the second actual winding ratio on the second integer winding ratio corresponds to the integer offset ratio.
The integer offset ratio is constant during winding of the package for each actual winding ratio that parallels adjacent an integer winding ratio with decreasing rotational velocity of the package.
The method can include step increasing the traverse frequency whereby the first actual winding ratio step decreases to an actual winding ratio adjacent a sub-integer winding ratio between the first integer winding ratio and the second integer winding ratio. The traverse frequency is decreased in response to decreasing rotational velocity of the package whereby the actual winding ratio parallels adjacent the subinteger winding ratio. The traverse frequency is step increased whereby the actual winding ratio paralleling adjacent the sub-integer winding ratio step decreases to the second integer winding ratio. A ratio of the actual winding ratio and the sub-integer winding ratio adjacent thereto corresponds to a sub-integer offset ratio. The integer offset ratio and the sub-integer offset ratio are different.
We have also invented a winding apparatus for winding a length of material. The apparatus includes a package drive connected to rotatably drive around a lengthwise axis, a package positioned to receive a length of material therearound. A cam is positioned adjacent the package and a cam drive is connected rotatably to drive the cam. The cam drive and the cam coact to reciprocatingly traverse the length of material between ends of the package when receiving the length of material therearound. A package tachometer and a cam tachometer detect the rotational velocity of the package and the cam, respectively, and provide output signals indicative thereof. A controller is connected to receive the output signals from the package tachometer and the cam tachometer and is connected to the cam drive for controlling the rotational velocity thereof so that the traverse frequency of the length of material between the ends of the package is controlled as a function of the rotational velocity of the package. The length of material is wound on the package at a first actual winding ratio adjacent a first integer winding ratio. In response to decreasing rotational velocity of the package, the traverse frequency is decreased whereby the first actual winding ratio parallels adjacent the first integer winding ratio. The traverse frequency is step increased whereby the first actual winding ratio step decreases to a second actual winding ratio adjacent a second integer winding ratio. Each actual winding ratio corresponds to a ratio of the detected rotational velocity of the package to the detected rotational velocity of the cam. A ratio of the first actual windi
Batten Jesse Alexander
Chastain Michael Stanley
Dean, II Kenneth Marvin
Jennings Uel Duane
Soule Duane Clifford
Mansen Michael R.
TB Wood's Enterprises, Inc.
Webb Ziesenheim & Logsdon Orkin & Hanson, P.C.
LandOfFree
Precision winding method and apparatus does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Precision winding method and apparatus, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Precision winding method and apparatus will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2613552