Drafting system and drafting system unit for a spinning machine

Abstract

A drafting system for a spinning machine, which drafting system has a drafting system unit, and to such a drafting system unit, having at least one weighting arm, which can be pivoted between an operating position and an open position by a repositioning device. In order to provide a drafting system and a drafting system unit for a drafting system for a spinning machine, the drafting system unit having a particularly simple design and permitting user-friendly operation, it is provided that the at least one weighting arm is connected to a retaining rod for conjoint rotation, which retaining rod is mounted on a retaining rod holder for rotation about the longitudinal axis of the retaining rod by the repositioning device.

What is claimed is: 
     
         1 . A drafting system unit for a spinning machine, comprising at least one weighting arm, which can be pivoted between an operating position and an open position by a repositioning device,
 characterized in that:   the at least one weighting arm is connected to a retaining rod for conjoint rotation, which retaining rod is mounted on a retaining rod holder for rotation about the longitudinal axis of the retaining rod by the repositioning device.   
     
     
         2 . The drafting system unit according to  claim 1 , characterized in that the repositioning device has a knee lever assembly, which is operatively connected to the retaining rod and which can be repositioned between a closing position associated with the operating position and an opening position associated with the open position. 
     
     
         3 . The drafting system unit according to  claim 2 , characterized in that in the closing position the knee lever assembly is arranged in a position beyond dead center. 
     
     
         4 . The drafting system unit according to  claim 2 , characterized in that the knee lever assembly has a first knee lever and a second knee lever,
 the first knee lever being pivotable about a first joint axis, which is stationary relative to the retaining rod,   the first knee lever and the second knee lever being articulated to each other by a knee lever joint axis, and   the second knee lever having a knee lever portion spaced apart from the knee lever joint axis, which knee lever portion is connected to the retaining rod so as to transmit a rotational motion.   
     
     
         5 . The drafting system unit according to  claim 3 , characterized in that in the closing position the knee lever assembly is arranged in a position beyond dead center. 
     
     
         6 . The drafting system unit according to  claim 4 , characterized in that the second knee lever is articulated, at an end opposite the knee lever joint axis and constituting a knee lever portion, to a link by a second joint axis, which link is connected, at the end thereof opposite the second joint axis, to the retaining rod for conjoint rotation. 
     
     
         7 . The drafting system unit according to  claim 6 , characterized in that the knee lever assembly can be repositioned between the operating position and the closing position by a hand lever. 
     
     
         8 . The drafting system unit according to  claim 7 , characterized in that the hand lever can be pivoted, together with the first knee lever, about the first joint axis. 
     
     
         9 . A drafting system for a spinning machine, comprising a drafting system unit, which has at least one weighting arm, which can be pivoted between an operating position and an open position by a repositioning device,
 characterized in that:   the at least one weighting arm is connected to a retaining rod for conjoint rotation, which retaining rod is mounted on a retaining rod holder for rotation about the longitudinal axis of the retaining rod by the repositioning device.   
     
     
         10 . The drafting system according to  claim 9 , characterized in that the repositioning device has a knee lever assembly, which is operatively connected to the retaining rod and which can be repositioned between a closing position associated with the operating position and an opening position associated with the open position. 
     
     
         11 . The drafting system according to  claim 10 , characterized in that in the closing position the knee lever assembly is arranged in a position beyond dead center. 
     
     
         12 . The drafting system according to  claim 10 , characterized in that the knee lever assembly has a first knee lever and a second knee lever,
 the first knee lever being pivotable about a first joint axis, which is stationary relative to the retaining rod,   the first knee lever and the second knee lever being articulated to each other by a knee lever joint axis, and   the second knee lever having a knee lever portion spaced apart from the knee lever joint axis, which knee lever portion is connected to the retaining rod so as to transmit a rotational motion.   
     
     
         13 . The drafting system according to  claim 12 , characterized in that in the closing position the knee lever assembly is arranged in a position beyond dead center. 
     
     
         14 . The drafting system unit according to  claim 12 , characterized in that the second knee lever is articulated, at an end opposite the knee lever joint axis and constituting a knee lever portion, to a link by a second joint axis, which link is connected, at the end thereof opposite the second joint axis, to the retaining rod for conjoint rotation. 
     
     
         15 . The drafting system unit according to  claim 14 , characterized in that the knee lever assembly can be repositioned between the operating position and the closing position by a hand lever. 
     
     
         16 . The drafting system unit according to  claim 15 , characterized in that the hand lever can be pivoted, together with the first knee lever, about the first joint axis.