Patent ID: 7600400

Claim:
A tensioning device for circular knitting machines comprising: a supporting frame ( 2 ) to be mounted turnably below a circular knitting machine ( 3 ), a cutter ( 9 ) associated to said supporting frame ( 2 ) and designed to cut on a cutting point ( 9 a ) a knitted fabric in tubular piece ( 5 ) produced by the circular knitting machine ( 3 ), an opener and stretcher ( 11 ) for opening and stretching the cut piece ( 5 ) in a single fabric layer, a collector ( 16 ) for collecting the piece ( 5 ) stretched in a single layer by said opener and stretcher ( 11 ), and a tensioner ( 12 ) for said piece ( 5 ) of knitted fabric, designed to tension the piece ( 5 ) of fabric so as to enable the correct production of the piece ( 5 ) of fabric by the knitting machine ( 3 ), said tensioner ( 12 ) for the piece ( 5 ) of fabric being arranged upstream from said opener and stretcher ( 11 ), characterized in that said tensioner ( 12 ) comprises at least two first tensioning rollers ( 13 a , 13 b ) placed side by side for operatively acting upon at least one portion of a first flap ( 5 a ) of said piece ( 5 ) of fabric and at least two second tensioning rollers ( 14 a , 14 b ) placed side by side for operatively acting upon at least one portion of a second flap ( 5 b ) of said piece ( 5 ) of fabric.