Winding – tensioning – or guiding – Helical or random winding of material – Distributing material along the package
Reexamination Certificate
2002-04-10
2004-08-17
Nguyen, John Q. (Department: 3654)
Winding, tensioning, or guiding
Helical or random winding of material
Distributing material along the package
C242S476700
Reexamination Certificate
active
06776367
ABSTRACT:
TECHNICAL FIELD AND BACKGROUND OF THE INVENTION
This invention relates to a servo-controlled traverse mechanism for a winder, particularly a textile winder used to wind textile strands onto tubular support packages for further processing. The invention relates generally to textile strands such as yarns, filaments or tapes of natural or synthetic materials (all referred to as “yarns”) and is particularly concerned with the traversing mechanism necessary for laying the yarn onto the package in a precise, regular pattern. The traditional mechanism for producing such traversing motion includes a grooved scroll or drum which either engages the yarn directly or drives a yarn guide, causing it move in a reciprocating, traversing motion. Such mechanisms are, however, limited in their speed of operation, are subject to mechanical wear, and must be replaced when changing the pattern by which the yarn is to be applied to the package.
Winders for which the invention is suitable include back-winders, rewinders and spoolers, among others. While the system is adaptable to new machines, the particular embodiment disclosed herein is explained by way of example with reference to a Leesona 861 rewinder to which the system has been retrofitted. The system is likewise adaptable to wind both straight-sided cylindrical and tapered packages.
Winding systems are as old as the mechanical processing of yarn. There are numerous types of winders for differing purposes. Recently developed methods of yarn production such as continuous filament extrusion and texturizing have further emphasized this demand for winders having higher speeds of operation. One form of traversing mechanism which has been proposed for operation at such high speeds includes slot-like yarn guides mounted on closely spaced driving members moving in opposite directions across the traverse so that the yarn is carried from one end of the traverse to the other by a guide of one member and is then transferred to a guide of the other member so as to be carried back in opposite direction. This avoids the problem arising from the inertia of the yarn guides or other parts being caused to move first in one direction and then the other with a very abrupt reversal at the end of each traverse. The transfer of the yarn from one guide to another presents its own problems and proposals have been made to include a deflector arrangement at each end of the field of traverse for assisting the transfer of the yarn from one guide to the other. Such traversing mechanisms must be used in conjunction with a package support roller on the winder so that the yarn passes from the yarn guide to a nip between the package and the support roller and is thus maintained under control over this part of its travel.
Other mechanical solutions have been proposed, but all contain inherent limitations arising out of the use of fixed design and machined parts specific to a particular wind.
There are several basic parameters which determine the pattern by which the yarn is applied to the package. These are the wind ratio, traverse length and gain. The wind ratio refers to the number of rotations of the spindle on which the yarn package is positioned for each back-and-forth passage of the yarn traverse. For example, a wind ratio of 6 means that approximately six winds are placed on the package during each back-and-forth passage of the yarn traverse along the length of the package, i.e, three in each direction. Traverse length refers to the length along the spindle of the yarn applied to the package. The “gain” refers to the minute amount of incremental progression in the placement of the yarn on the package during each traverse to prevent successive wraps of yarn from being placed directly on top of the previous wraps of yarn.
These parameters are well understood in the art. Moreover, efforts have been made to adapt these concepts to electronic systems. For example, the Vander Groef U.S. Pat. No. 5,499,775 Patent discloses a winder for winding a wire cable with a programmable traverse control. The system takes into account the unique problems of winding wire which is subject to kinking and twisting. A “figure
8
” package is produced which forms a “hole” at a point where no cross-overs occur during the wire winding process. The stroke of the traverse is slightly out phase with the rotation of the wire spool so that the cross-overs progress around the spool. The number of cross-overs never advances a full 360 degrees around the spindle. Thus, the radial “hole” is formed at the point where no cross-overs are made. The machine is operated by conventional motors.
The present system provides an electronic means of winding textile yarns which permits the various parameters to be controlled by software instead of by hardware. Thus, changes in wind ratios and traverse length can be made by changing the inputs into the system. In addition, a very efficient and effective traverse mechanism is provided capable of operating at the high speeds made possible by the electronic control of the winding process.
SUMMARY OF THE INVENTION
Therefore, it is an object of the invention to provide a winder which utilizes a programmable electronic controller to control various input parameters.
It is another object of the invention to provide a winder which uses a servo-motor to reciprocate a mechanical traverse mechanism efficiently and at high speed.
It is another object of the invention to provide a winder which uses a cable with a helical driving surface to move the traverse at high speed.
It is another object of the invention to provide a winder which utilizes a servo system which both runs the traverse motor and also executes the motion control application which defines the traverse parameters.
It is another object of the invention to provide a winder which is suitable for being retrofitted to a wide variety of existing mechanically-operated winders.
It is another object of the invention to provide a winder which improves machine flexibility, speeds machine setup changes, reduces maintenance costs and reduces machine noise and parts wear.
These and other objects of the present invention are achieved in the preferred embodiments disclosed below by providing a winding machine for winding a strand onto a tubular support to form a strand package, and comprising a spindle on which the tubular support is mounted for rotation therewith, a motor for rotating the spindle, and a reciprocating traverse mechanism, including a strand guide, for guiding the strand onto the tubular support at a predetermined traverse stroke and wind ratio. The traverse mechanism comprises a servo-motor for selectively starting and stopping reciprocating movement of the strand guide in accordance with the predetermined traverse stroke and wind ratio; and a programmable servo-controller for accepting data inputs reflecting the desired traverse stroke and wind ratio and for outputting data to the servo-motor reflecting the desired traverse stroke and wind ratio.
According to one preferred embodiment of the invention, the spindle is rotated at a constant strand winding speed. A speed sensor is provided for detecting the surface speed of the strand package. A spindle motor speed controller accepts a signal output from the speed sensor representing the surface speed of the strand package and outputs a signal representing the surface speed of the strand package. The signal is sent to the spindle motor speed controller for slowing the rpm of the spindle as the diameter of the strand package increases to maintain a constant spindle surface winding speed, and to the servo-controller for slowing the traverse servo-motor in synchronization with the slowing of the rpm of the strand package and thus maintaining a constant wind ratio.
According to another preferred embodiment of the invention, the traverse mechanism comprises a drive cable pulley carried by the servo-motor for rotation therewith, a driven cable pulley positioned in spaced-apart relation to the driven pulley, and a drive cable having first and second opposed ends attached to an
Adams Evans P.A.
Nguyen John Q.
R & S Machinery & Design, Inc.
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