Abstract:
An unwinding device for wire or materials containing several wires, having a rotating support for a reel, a coil or the like and a folding roller allocated to a processing device. According to this invention, a dancer is positioned between the support and the folding roller. A constant direction for unwinding and winding is maintained in such as way that the unwound or wound material is directed along the same plane of curvature as the curvature of the reel devoid of torque.

Description:
This application is a 371 of PCT/EP98/03357, filed Jun. 5, 1998. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to a pay-off reel apparatus for wire or multiple-strand wire material having a pivotal receiver for a reel, a coil or the like, and a bending roller assigned to a processing apparatus. 
     2. Description of Prior Art 
     A pay-off reel apparatus is known, from European Patent Reference EP 0 340 322 A1, which feeds coiled material, for example wire from a reel, a coil or a winder to a processing apparatus, and reeling off is frequently performed by drive means. 
     In a conventional pay-off reel apparatus the feeding force varies constantly, subject to the weight of the reel or coil, simultaneously also impairing entry conditions of the material into the processing apparatus, which then affects the processing quality. With broad reels or coils, the feeding direction towards the feeding roller changes continuously and causes further straining, twisting and deforming, likewise negatively influencing the quality of the subsequent processing operation. 
     SUMMARY OF THE INVENTION 
     It is one object of this invention to provide an apparatus and method for reeling off from a spool, coil or the like wherein the prevailing material can be fed to a processing apparatus without its properties fluctuating, such as to develop a pay-off reel straightening apparatus. 
     This object is attained by a pay-off reel straightening apparatus having the characteristics set forth below in this specification and in the claims. 
     This invention attains a uniform change of direction while maintaining the original reel curvature of the wire or multiple-strand wire material, a defined elastic change of direction or deflection by the corresponding deflection rollers, and a calculable and constant one-dimensional bending of the wire or multiple-stand wire material after the elastic-plastic deflection or bending at the bending roller. This invention provides optional generation of reverse tension by the bending roller, embraced by the loop of the of the wire or multiple-strand wire material by more than 180° and/or the use of a destressing straightening device, which reliably prevents deformations, helicities, twists or tangling of the wire or multiple-strand wire material. Moments of torsion, causing these effects, are minimized due to an ideally determined spacing between the rollers, as well as a very simple structure of the pay-off reel straightening apparatus. The apparatus of this invention adapts rapidly to the prevailing diameter of the respective material and the corresponding working material of the wire or multiple-strand wire material as well as to existing entry and discharge conditions. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     This invention is explained in detail in what follows by way or a working example with reference to the drawings, wherein: 
     FIG. 1 is a schematic side view of a pay-off reel straightening apparatus; 
     FIG. 2 is a schematic front view of the pay-off reel straightening apparatus according to FIG. 1; and 
     FIG. 3 is a schematic view of a destressing straightening device according to this invention. 
    
    
     DESCRIPTION OF PREFERRED EMBODIMENTS 
     A pay-off reel straightening apparatus of this invention comprises a support frame  1 , in one embodiment having a base plate  2 , a cover plate  3  and columns  4  provided therebetween. The columns  4  are designed as three column pairs  5 ,  6  and  7 , arranged one behind the other. The columns  4  are connected to the plates  2 ,  3  in any known way. For reasons of stability, it is also possible to provide a different number of columns  4 . A receiving means  8  is fitted to the support frame  1 , to accommodate a horizontally arranged reel  9 , a coil or a winder. The receiving means  8  may be fitted to the pair of columns  5  or to one column  4  and each of the column pairs  5  and  6  or, if necessary, even to a plurality of columns  4 . In the embodiment the receiving means  8  has a drive means  10 , which rotates the reel  9 . Preferably, the receiving means  8  is mounted on the columns  4  in a level adjustable manner, capable of being locked in any position. Between the columns  4  of the central pair of columns  6  at least one freely pivotal deflection roller  11  is mounted in the region of the cover plate  3 . In the embodiment exemplified three deflection rollers  11  are arranged and mounted freely pivotal about a common axis  12 . A dancer  13  is provided between the columns  4  of the pair of columns  6  in a manner enabling the dancer  13  to move up and down. The dancer  13  comprises a frame  14  with freely rotatably wheels  15  that are able to roll off along the columns  4  of the pair of columns  6  and are guided, in which it is also possible to have either no guide means, or differently designed guide means. Within the frame  14  an axis  16  is provided, preferably in a center, about which at least one deflection roller  11 , the embodiment illustrates three deflection rollers  11 , is provided in an adjacent position and in each case freely pivotal. The number of deflection rollers  11  in the region of the cover plate  3  is adapted to the number in the dancer  13 . The dancer  13  is adapted to receive weights, not shown, symmetrically along a vertical axis. 
     On the last pair of columns  7  there is a holding means  17 , adapted to be shifted and stopped, in which a pivotal bending roller  18  is mounted. A processing device  19  is also preferably provided on the holding means  17 , forming a straightening apparatus. 
     A spacing A, shown in FIG. 1, between the receiving means  8  for a reel  9  and the first deflection roller  11 , between the deflection roller  11  and each of the following deflection rollers  11 , between the last deflection roller  11  and the bending roller  18 , and between the bending roller  18  and the processing apparatus  19  corresponds to the condition A is equal to or less than π·D, wherein D is the prevailing diameter of the reel  9  or a preceding deflector roller  11  or the bending roller  18 . The diameter of each deflection roller  11  for a defined elastic deflection of the wire or multiple-strand wire material is        D   ≥       d                 E       R     p0      .2                                
     wherein d represents the diameter, E represents the modulus of elasticity, and R p0.2  represents the technical yield point of the wire or multiple-strand wire material. In order to bring about constant bending of the wire or multiple-strand wire material in the plane of curvature, the diameter of the bending roller  18  is        D   ≥       d                 E       R     p0      .2                                
     By adapting the diameter of the roller  11  to the diameter and the material properties of the wire or multiple-strand wire material, a deflection is attained, which is only elastic. 
     The bending roller  18  may have a device, not shown, for applying additional torque. The torque may either be provided as a drive moment or as a braking moment. A reversing motor may be used as a means for providing driving power, but also braking power, preferably transmitting different and adjustable torques. Should only braking moments have to be transmitted, it is also possible to provide a mechanical braking device, in which case preferably dynamometers and control means for monitoring and automatically adhering to a pre-determined applied force may be provided in each case. For this purpose any prior art devices may be used, which are not described in detail. 
     By using the bending roller  18  as a combined bending and braking roller, the technology of stretcher-and-roller levelling can be applied. In this process, in addition to the bends applied in the straightening apparatus, a tensile stress is superimposed, in which context forward tension is brought about by the necessary transport of the material, while reverse tension is brought about by the braking action of the bending roller  18 . 
     Alternatively, a destressing straightening device  20 , as shown in FIG. 3, may be used to reverse tension. The destressing straightening device  20  is fitted between the bending roller  18 , directly ahead of the processing device  19  and comprises three pivotally mounted rollers  21 ,  22 ,  23 , of which two rollers  22 ,  23  have the same diameter and are mounted on a support element  24 . The support element  24  is circular and pivotal about its central axis  25 , the rollers  22 ,  23  are arranged symmetrically in relation to one another and about the central axis  25 . The support element  24  is mounted about its central axis  25  by any desired adjusting means  26 , pivotally in both directions to a defined extent. If the support element  24  is rotated about its central axis  25 , the angle of contact on the two rollers  22 ,  23  fitted thereon changes, and, consequently, the reverse tension action. 
     For rotation, symmetrical cross-sections, as are generally straightened on such apparatus, the generation and use of forward and reverse tension allows an occurrence of a asymmetrical tension distribution in the material to be straightened which is counter-acted. By setting a balanced ratio of the rates of bending and traction in the overall deformation, it is possible to substantially improve the quality, in particular the straighteness or curvature of wire or multiple-strand wire material. 
     The apparatus operates in such a manner that material coiled around the reel  9 , for example a wire  27 , is reeled off the reel  9  by switching on the drive means  10 , is guided along the cover plate  3  via the first deflection roller  11 , is deflected there and is fed to the deflection roller  11  inside the frame  13 . If required, further contacting of further deflection rollers  11  is performed in each case in pairs, guided correspondingly along the cover plate  3  and in the dancer  13 . Finally, the end of the wire  27  coiled around the last deflection roller  11  in the dancer  13  is fed to the feeder roller  18  and to the processing apparatus  19 . 
     The drive means, controlled by the dancer  13 , ensures feeding with constant force in the downstream processing apparatus  19 , regardless of the reel weight. In doing so, the weight of the dancer not only builds up a constant tensile force on the material to be reeled off in the direction of discharge, but also in the reeling off direction. The factors of straightening, constant bending via the bending roller  18 , the deflections and the variable weight of the dancer all have an effect on the discharge force. All these factors result in the material, which already has constant properties, entering the processing device  19 , resulting ultimately in attaining a higher quality with the processing operation. Due to the deflection by deflection rollers  11 , feeding towards the bending roller  18  is also performed uniformly, in which context its coating, where applicable, even its overall design of a material, for example caoutchouc or synthetic material, enhancing the friction coefficient, impairs or prevents twisting about the longitudinal axis of the material. 
     As already mentioned above, any number of deflections, even any number of pairs of deflection rollers  11  may be provided, the number depending on the prevailing discharge lengths and the desired storing function of the dancer  13 . 
     Apart from bringing about a constant entry curvature, at which the respective material enters a processing apparatus, even in the event of a single or multiple loop passage of the material, the bending roller  18  may serve for stretch straightening and/or even for stretcher-and-bender straightening, provided additional torque is transmitted to the latter. 
     The level adjustable arrangement of the receiving means  8  as well as of the holding means  17  always allows adaptation to different entry levels of downstream processing devices  19  or to various sizes of reels  9 , as well as adaptation to spacing in relation to the first deflector roller  11 .