The present invention relates to a device for the drawing and winding of organic or mineral strands, especially glass strands. More particularly, it relates to a keeper for keeping a strand within a winder.
It will be recalled that the manufacture of glass reinforcement strands results from a complex industrial process that consists in obtaining strands from streams of molten glass flowing out through the orifices of bushings. These streams are drawn in the form of continuous filaments, these filaments are then collected into base strands and then these strands are collected in the form of a package.
Within the meaning of the invention, the packages are in the form of wound packages with straight flanges or in the form of cylindrical packages.
The package-forming operation is carried out using winders, which as their name indicates are responsible for winding, at very high speed (about 10 to 50 meters per second), the glass strands that have been presized.
These winders draw and wind these filaments, and the operating parameters of these winders, together with those of the bushing, determine the dimensional characteristics of the strand, especially the linear density expressed in tex (tex being the weight in grams of 1000 meters of fiber or strand).
Thus, to guarantee a constant linear density of the strand throughout the package production phase, despite the increase in its diameter, the speed of the winding member of the winder is slaved so as to ensure a constant linear winding speed of the strand although its angular speed varies, this speed slaving operation being carried out by reducing the rotation speed of the spindle that supports the package according to the increase in its diameter.
Another important parameter upon which the formation of a package of optimum quality is conditional consists of its ability to be easily unwound, with no loops, no parasitic knots and with limited friction.
To do this, it is necessary that the precision in the resulting deposition of an axial distribution of the strands wound directly onto the rotating spindle be optimal. For this purpose, the winder is provided with one or more strand guides which ensure that the strands are distributed axially along one or more packages by a traversing motion synchronized with the rotation of the spindle, this strand guide or guides forming part of a subassembly of the winder, which is generally called a crossover device.
This crossover device is mounted on a moveable support allowing it to be permanently repositioned during winding, parallel to the spindle axis, in order to keep it at a certain distance between the strand guide or guides and the external cylindrical surface of the package or packages, the diameter of which continues to increase over its or their construction.
The known winders essentially consist of a frame generally positioned beneath a bushing, this frame supporting the crossover device and at least one rotating spindle, this spindle being designed, on the one hand, to generate the package and, on the other hand, to support the latter.
Conventionally, a crossover device comprises a member shaped in the form of a cursor that moves linearly within a groove, this moving cursor allowing the strand to be positioned on the rotating spindle and the movement impressed by the cursor essentially consisting of an oscillatory or flapping movement only along one dimension of the package.
To obtain a wound package, the cursor is mounted so as to undergo a traversing motion translationally on a shaft fastened to the frame and parallel to the axis of the spindle, this second translational motion thus making it possible to cover the length of the package.
It will be understood that, to describe the entire length of the package, the strand moves from a substantially fixed point located generally downstream of the bushing, this point being called the gathering point, in a triangle whose opening substantially encompasses the total length of the package.
The entire manufacturing range leads in certain cases to the strands undergoing vibrations which may flap between the two stable points located, on one side, near the gathering point and the point where the strand is deposited on the package, it being possible for this vibration or flapping movement to cause the strand to escape out of the crossover device and therefore result in the package winding phase being stopped before its completion.
The present invention therefore aims to alleviate these drawbacks by proposing a device that prevents any ejection of the strand from the crossover device during the package winding phase and which improves the quality and precision with which the strand is deposited, despite the increase in package thickness (which is primarily important during the drying phase) and increase in speeds (during subsequent unwinding phases).
For this purpose, the winder according to the invention essentially comprising a frame, this frame having at least one spindle designed to support at least one package, said spindle rotating about a first axis approximately perpendicular to the diameter of the package so as to draw and wind at least one strand in the form of a package, and at least one positioning and guiding device designed to position and guide at least said strand on the rotating spindle, it being possible for said device to move closer toward or further away from the package while it is being wound, is characterized in that it further includes a keeper designed to keep said strand in contact with said positioning and guiding device.
Thanks to these arrangements and especially to the presence of the keeper, the strand is kept constantly in contact with the positioning and guiding device, which helps to eliminate any risk of ejection or flapping of the strand during the winding phase.
In preferred embodiments of the invention, one or more of the following arrangements may optionally be furthermore applied:
Other features and advantages of the invention will become apparent over the course of the following description of one of its embodiments, given by way of nonlimiting example and with reference to the drawings appended hereto.
In the drawings:
According to a preferred embodiment of a winder 1 according to the invention, illustrated in
Joined onto this base is a partly covered closed structure that is intended to receive all the components needed to operate the winder 1. In this regard, but nonlimitingly, this closed structure shaped in the form of a cabinet is provided with the control and operating devices needed to control the various members, which will be described later in the present description, and hydraulic, electrical, compressed-air and other fluid systems needed to operate said members.
A drum that projects laterally is fitted onto the closed structure. This drum is mounted so as to rotate about an axis of rotation and is held in place within one of the walls of the closed structure by means of a plurality of guiding members (for example a ball bearing ring or ball bearing slide).
This drum in fact constitutes a spindle-support assembly.
Each of the spindles fastened to the drum constitutes a rotating assembly designed to draw and wind the strand onto a sleeve introduced beforehand onto the spindle 6. This winding operation is carried out about a first axis of rotation substantially parallel to the axis of rotation of the drum relative to the structure of the frame.
Other subassemblies needed to operate the winder are integrated into the frame.
The winder 1 includes at least one keeper 2 which is mounted so as to rotate relative to the frame (the reference 3 is the articulation point) and travels between a rest position, in which the strands are set back from the positioning and guiding device, and a working position, in which the strands are in contact with said positioning and guiding device. These two positions are visible in
This keeper 2, the angular position of which is slaved by an actuator of the motor type, the latter being controlled by a controller in such a way that the angular position of the keeper varies during the package winding phase.
More precisely still, by controlling the keeper it is possible to prevent a strand from flapping or vibrating between two stable points formed, on the one hand, by the gathering point (reference A in
During the winding phase, the keeper introduces an additional contact point along the path (A,B) of the strand, this additional contact point (referenced D in
The keeper controls the geometry of the path of the strands over the entire winding operation, owing to the mobility of the deposition point (reference B) and of the strand engagement point in the strand guide (reference C) relative to the fixed point, represented by the gathering point (reference A). The geometry is controlled in this way by there being a minimum distance between the points B and C for good deposition precision and by an optimum engagement angle of the strand in the strand guide, this angle being illustrated in
In the example shown in
As a variant, illustrated in
The ejection arm 9 is made in the form of a bar but projects laterally from a side wall of the closed structure of the frame. It can occupy two positions, namely a rest position (
As the winding proceeds (and the thickness of strands on the package increases), the crossover device 5 moves further away from the external peripheral surface of the package and the keeper guarantees permanent contact of a strand at the point C of the crossover device.
Number | Date | Country | Kind |
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0407599 | Jul 2004 | FR | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/FR05/50518 | 6/29/2005 | WO | 00 | 2/14/2007 |