Method and associated apparatus for reducing the tension of wires during a strand production process

Abstract

Method for reducing the tension of wires during a process for production of a strand using said wires, comprising the steps of unwinding at least one wire ( 1 ) from a supply reel, feeding the unwound wire ( 1 ) to a stranding machine which pulls the wire, winding it onto a take-up reel ( 31 ) at a predetermined winding speed, said at least one wire being subjected to a pulling/pushing action in the same sense as the direction of feeding thereof, along the section of the travel path between the supply reel and the point of entry into the stranding machine.

1 ) Method for reducing the tension of wires during a process for production of a strand using said wires, comprising the steps of: 
 unwinding at least one wire ( 1 ) from a supply reel;    feeding the unwound wire ( 1 ) to a stranding machine which pulls the wire, winding it onto a take-up reel ( 31 ) at a predetermined winding speed;    characterized in that said at least one wire is subjected to a pulling/pushing action in the same sense as the direction of feeding thereof, along the section of the travel path between the supply reel and the point of entry into the stranding machine.    
     
     
         2 ) Method according to  claim 1 , characterized in that said pulling/pushing action is obtained by means of application of a sliding friction to the wire.  
     
     
         3 ) Method according to  claim 2 , characterized in that said sliding friction is determined by the pulling/pushing action of at least one motorized roller on which the wire is wound at a predefined winding angle.  
     
     
         4 ) Method according to  claim 2 , characterized in that said sliding friction is determined by the pulling/pushing action of a pair of motorized rollers on which the wire is wound at a predefined winding angle.  
     
     
         5 ) Method according to  claim 3 , characterized in that said winding angle is between 60° and 300°.  
     
     
         6 ) Method according to  claim 5 , characterized in that said winding angle is preferably between 90° and 240°.  
     
     
         7 ) Method according to  claim 3 , characterized in that the roller which applies the pulling/pushing action to the wire is rotationally actuated so as to have a speed greater than the speed of driving of the wire by the stranding machine.  
     
     
         8 ) Method according to  claim 3 , characterized in that the speed of rotation of the motorized roller is greater than the speed of driving of the wire by an amount ranging between 2% and 10% of the latter.  
     
     
         9 ) Apparatus for reducing the tension of the wires ( 1 ) during a process for forming a strand ( 2 ) wound onto a reel ( 30 ) of a stranding machine using at least one wire ( 1 ) fed from a supply reel ( 10 , 11 ), characterized in that it comprises means ( 111 , 112 ) able to impart to said at least one wire ( 1 ) a pulling/pushing action in the same sense as the direction of feeding of the said wire, along the section of the travel path between the supply reel ( 10 , 11 ) and the winding reel ( 30 ).  
     
     
         10 ) Apparatus according to  claim 9 , characterized in that said pulling/pushing means comprise at least one first roller ( 111 ) which is motorized and able to impart said pushing/pulling action and a second drive roller ( 112 ) which is idle, the wires ( 1 ) being wound around said rollers.  
     
     
         11 ) Apparatus according to  claim 9 , characterized in that said pushing means comprise at least one first motorized roller ( 111 ) able to impart said pushing/pulling action and at least one second motorized roller ( 112 ), around which rollers the wires ( 1 ) are wound.  
     
     
         12 ) Apparatus according to  claim 10  or  11 , characterized in that said first and second rollers are parallel to each other.  
     
     
         13 ) Apparatus according to  claim 10  or  11 , characterized in that said second roller ( 112 ) is movable translationwise relative to the first roller ( 111 ).  
     
     
         14 ) Apparatus according to  claim 10 , characterized in that said first motorized roller ( 111 ) is rotated at a speed of rotation greater than the winding speed of the reel ( 30 ) of the stranding machine.  
     
     
         15 ) Apparatus according to  claim 14 , characterized in that the speed of rotation of the motorized roller ( 111 ) is greater than the speed of driving of the wire ( 1 ) by an amount preferably ranging between 2% and 10% of the latter.  
     
     
         16 ) Apparatus according to  claim 11 , characterized in that said first motorized roller ( 111 ) is rotated at a speed of rotation greater than the winding speed of the stranding machine and said second motorized roller ( 112 ) is rotated at a speed substantially the same as that of the first roller.  
     
     
         17 ) Apparatus according to  claim 10 , characterized in that it comprises a device ( 120 ) for controlling the speed of rotation of the motorized roller(s) on which one of the wires ( 1 ) fed to the stranding machine ( 30 ) is wound.  
     
     
         18 ) Apparatus according to  claim 17 , characterized in that said control device ( 120 ) is able to detect the speed of the roller and send corresponding signals to actuating means able to vary the speed of rotation of the motor ( 111   a , 111   b ) for actuating the motorized roller(s).  
     
     
         19 ) Apparatus according to  claim 1 , characterized in that the angle of winding of the wire ( 1 ) around the motorized roller(s) is between 60° and 300°.  
     
     
         20 ) Plant for forming strands ( 2 ) from wires ( 1 ), in which at least one stranding machine with a winding reel ( 30 ) and at least one reel ( 10 , 11 ) for feeding at least one wire ( 1 ) are envisaged, characterized in that it comprises an apparatus for reducing the tension of said at least one wire ( 1 ), which is provided with means ( 111 , 112 ) able to impart to said at least one wire ( 1 ) a pulling/pushing action in the same sense as the direction of feeding of the said wire, along the section of the travel path of the wire between the supply reel ( 10 , 11 ) and the winding reel ( 30 ).  
     
     
         21 ) Plant according to  claim 20 , characterized in that said pushing/pulling means of the apparatus comprise at least one first roller ( 111 ) which is motorized and able to impart said pushing/pulling action and one second drive roller ( 112 ) which is idle, the wires ( 1 ) being wound around said rollers.  
     
     
         22 ) Plant according to  claim 21 , characterized in that said pushing/pulling means of the apparatus comprise at least one first motorized roller ( 111 ) able to impart said pushing/pulling action and at least one second motorized roller ( 112 ), around which rollers the wires ( 1 ) are wound.  
     
     
         23 ) Plant according to  claim 21 , characterized in that said first motorized roller ( 111 ) is rotated at a speed of rotation greater than the winding speed of the stranding machine.  
     
     
         24 ) Plant according to  claim 23 , characterized in that the speed of rotation of the motorized roller ( 111 ) is greater than the speed of driving of the wire ( 1 ) by an amount ranging between 2% and 10% of the latter.  
     
     
         25 ) Plant according to  claim 22 , characterized in that said first motorized roller ( 111 ) is rotated at a speed of rotation greater than the winding speed of the stranding machine and said second motorized roller ( 112 ) is rotated at a speed substantially the same as that of the first roller.  
     
     
         26 ) Plant according to  claim 21 , characterized in that it comprises a device ( 120 ) for controlling the speed of rotation of the motorized roller(s) on which one of the wires ( 1 ) fed to the stranding machine ( 30 ) is wound.  
     
     
         27 ) Plant according to  claim 26 , characterized in that said control device ( 120 ) is able to detect the speed of the roller(s) and send corresponding signals to actuating means able to vary the speed of rotation of the motor ( 111   a , 112   b ) actuating the motorized roller(s).  
     
     
         28 ) Plant according to  claim 21 , characterized in that the winding angle of the wire ( 1 ) around the motorized roller(s) is between 60° and 300°.