Device and method for producing knitted fabric

Abstract

Knitted fabric is produced with a knitting machine and a roving drawing and strengthening unit. A roving supply unit provides a roving and an auxiliary thread supply unit provides an auxiliary thread. A stretching unit receives the roving and the auxiliary thread. A spinning nozzle following the stretching unit in a roving conveying direction forms a fiber strengthening segment by applying compressed air and an end thread gripping roller pair rotatable in opposite directions provided downstream from the spinning nozzle device in the roving conveying direction delimiting the fiber strengthening segment. A soft knitted fabric is formed by guiding an auxiliary thread through an auxiliary thread gripping roller pair with an adjustable rotational speed before the roving and auxiliary thread enter the stretching unit. The gripping roller pair holds the auxiliary thread so that the auxiliary thread is subjected to tension of no more than 2 cN.

1 - 10 . (canceled) 
     
     
         11 . A device for producing knitted fabric with a knitting machine and a roving drawing and strengthening unit, the device comprising:
 a roving supply unit with at least one roving;   an auxiliary thread supply unit with at least one auxiliary thread;   a stretching unit coupled to said roving supply unit for supplying the roving and said auxiliary thread supply unit for supplying the auxiliary thread, said stretching unit including stretching roller pairs arranged one after another in a roving conveying direction;   a spinning nozzle device following said stretching unit in the roving conveying direction and forming a fiber strengthening segment by applying compressed air; and   an end thread gripping roller pair rotatable in opposite directions and disposed following said spinning nozzle device in the roving conveying direction delimiting said fiber strengthening segment;   at least one auxiliary thread gripping roller pair disposed between said auxiliary thread supply unit and said stretching unit, said at least one auxiliary thread gripping roller pair having two auxiliary thread gripping rollers that are rotatable in opposite directions and adjustable with regard to a rotational speed, said auxiliary thread gripping rollers being pressed or capable of being pressed to one another and guiding the auxiliary thread towards said stretching unit, said auxiliary thread gripping roller pair forming a clamping lead-through for the at least one auxiliary thread, and wherein a rotational speed of said auxiliary thread gripping rollers of said auxiliary thread gripping roller pair is adjustable such that a thread tension of the auxiliary thread exiting said auxiliary thread gripping roller pair is smaller than 2 centinewtons.   
     
     
         12 . The device according to  claim 11 , which comprises a device control configured to adjust the rotational speed of at least one of said auxiliary thread gripping rollers and to adjust a rotational speed of said stretching rollers of said stretching unit. 
     
     
         13 . The device according to  claim 11 , wherein said auxiliary thread gripping rollers include a first, profiled auxiliary thread gripping roller and a second, rubberized auxiliary thread gripping roller. 
     
     
         14 . The device according to  claim 11 , further comprising an auxiliary thread oscillation device before said at least one auxiliary thread gripping roller pair in the roving conveying direction of the device. 
     
     
         15 . The device according to  claim 11 , further comprising at least one optical thread sensor following the auxiliary thread gripping roller pair in an auxiliary thread conveying direction. 
     
     
         16 . The device according to  claim 11 , wherein said auxiliary thread supply unit comprises a closed housing formed with at least one opening for exiting the auxiliary thread. 
     
     
         17 . A method for producing knitted fabric, the method comprising:
 supplying at least one roving from a roving supply unit;   supplying at least one auxiliary thread from an auxiliary thread supply unit;   clamping the auxiliary thread between rollers of at least one auxiliary thread gripping roller pair that rotate in opposite directions, the rollers of the auxiliary thread gripping roller pair having two auxiliary thread gripping rollers that are pressed or capable of being pressed to one another;   adjusting the rotational speed of the auxiliary thread gripping rollers such that a thread tension of the auxiliary thread exiting the auxiliary thread gripping roller pair is less than 2 centinewton;   guiding the roving and the auxiliary thread to a stretching unit, the stretching unit having stretching roller pairs arranged one after another in a roving conveying direction;   subjecting a drawn roving with the auxiliary thread exiting the stretching unit to pressurized air by a spinning nozzle device in a fiber strengthening segment, to thereby strengthen the drawn roving, wherein the fiber strengthening segment is delimited by an end thread gripping roller pair rotating in opposite directions through which the drawn and strengthened roving with the auxiliary thread is led in clamped fashion and an end thread exiting the end thread gripping roller pair is supplied to a knitting machine.   
     
     
         18 . The method according  claim 17 , which comprises supplying the auxiliary thread to the auxiliary thread gripping roller pair oscillating in axis direction of the auxiliary thread gripping rollers. 
     
     
         19 . The method according to  claim 17 , which comprises optically recording a thread tension of the auxiliary thread between the auxiliary thread gripping roller pair and the stretching unit.