Device and method for anchoring the terminal turns of the yarn to a cop of yarn

Abstract

A device for anchoring the terminal turns of yarn (F) on a cop or reel (R) to prevent accidental unwinding is described. The device comprises at least one cylinder ( 19 ) whose cylindrical surface is equipped with a plurality of needles ( 21 ) projecting from said surface.

What I claim is:  
     
         1 . A device for stopping the last turns of yarn on a cop of yarn to prevent accidental unwinding, which includes at least a cylinder which is equipped, on its cylindrical surface, with a plurality of needles projecting from said surface.  
     
     
         2 . Device according to  claim 1 , wherein said cylinder is idly supported on a respective rotation axis.  
     
     
         3 . Device according to  claim 1 , wherein said needles have a double tip.  
     
     
         4 . Device according to  claim 2 , wherein said needles have a double tip.  
     
     
         5 . Device according to  claim 1 , wherein said needles are entangling needles.  
     
     
         6 . Device according to  claim 2 , wherein said needles are entangling needles  
     
     
         7 . Device according to one or more of the preceding claims, wherein the needles project from the cylinder by a length comprised in the range from 1 to 10 mm, and preferably from 2 to 4 mm.  
     
     
         8 . Device according to one or more of  claims 1  to  6 , wherein said cylinder is equipped with a translation movement which is parallel to its axis.  
     
     
         9 . Device according to one or more of  claims 1  to  6 , including a rotating support for at least one cop and means for approaching the cylinder to the cop.  
     
     
         10 . Device according to one or more of  claims 1  to  6 , wherein said needles project from the surface of the cylinder in a direction which is orthogonal to the axis of the cylinder.  
     
     
         11 . A textile machine comprising means for winding a yarn on a reel or cop, including at least a device according to one or more of the  claims 1  to  6 .  
     
     
         12 . Machine according to  claim 11 , including a pivoting arm which idly support said at least one cylinder, the pivoting arm being capable of alternatively assuming a non-working position, in which the cylinder is held at a distance from said reel or cop, and a working position in which the cylinder is moved against a cop during winding completion.  
     
     
         13 . Machine according to  claim 12 , wherein the pressure with which the cylinder is pressed against the cop is variable.  
     
     
         14 . A method for anchoring the end turns of a cop of yarn and prevent accidental unwinding thereof, wherein a cylinder equipped with needles is moved against the cylindrical surface of the cop in the winding area of the last turns of yarn, and the cop is turned whereby turning the cylinder, the needles penetrating in the turns of yarn causing reciprocal mating of the turns.  
     
     
         15 . Method according to  claim 14 , wherein the turns are anchored to the cop at the end of the yarn winding phase on the cop in a textile machine for the development of cops of yarn.