it possible to insert the fabric between them when the machine is operating the fabric is thus inserted between the row of drums 10 and the rows of pressure rollers 20 and 22 the axle 15 turns as a result of the activation of the constant torque motor which acts upon it thus placing each spring 13 under tension these in their turn drawing round the related drum 10 in direction r1 the rotation of axle 15 ceases when the elastic reaction of the fabric 2 imparts an overall torque to the drums 10 that is equal and opposing to the torque to which the axle 15 is subjected considering a section of fabric as wide for example as the distance between two operating units the passing of each operating unit present on the carriage gives rise to the formation of a row of fabric and a consequent decrease in the intensity of the elastic reaction of the fabric below at this point the elastic reaction of the spring 13 acting on the drum corresponding to this section of fabric causes the drum to rotate in direction r1 independently of the remaining drums until the fabric returns to the preset tension restoring the balance between the elastic reaction of the fabric and elastic reaction of the spring 13 to optimise performance of the above and ensure that the required tension value is restored the electromagnet 41 is activated at the moment in which the drum and rollers turn this being effected by means of a series of signals that are sent to it by the electronic control unit not illustrated following the instructions inserted as necessary in the knitting program when the overall torque value imparted in direction r2 to the row of drums 10 by the elastic.