Shaft drive for a power loom

Abstract

The heddle shaft ( 1 ) according to the invention combines a traditional heddle machine ( 2 ) with an eccentric toothed gearing to purposely allow the heddle shaft ( 1 ) to dwell for longer periods of time in the upper and lower reversing region and to reduce any accelerations that occur. This permits an increase in the weaving speed and/or the weaving widths. For a particularly advantageous embodiment, a coupling device is additionally provided, which gives the heddle shaft ( 1 ) a pendulum movement with a stroke ranging from a few millimeters to centimeters during the idle phases, meaning when no sheds are formed. As a result of the pendulum movement of the heddle shaft ( 1 ) in the upper or lower reversing region, the acceleration loads on the heddle shaft ( 1 ) can be further reduced.

1 . A shaft drive ( 2 ) for a weaving loom, 
 with a drive shaft ( 15 ) that is connected to a drive source ( 16 ) and is driven by this source,    with a power take-off ( 6 ) for driving a heddle shaft ( 1 ) and    with a gear ( 17 ), which is installed between the drive shaft ( 15 ) and the power take-off ( 6 ) and comprises an eccentric toothed gearing ( 14 ).    
   
   
       2 . The shaft drive according to  claim 1 , characterized in that the drive shaft ( 15 ) is connected to a balancing weight ( 25 ) for evening out its rotation and for balancing the load fluctuations.  
   
   
       3 . The shaft drive according to  claim 1 , characterized in that the power take-off ( 6 ) is a lever driven so as to swing.  
   
   
       4 . The shaft drive according to  claim 3 , characterized in that the lever is driven by an eccentric cam plate ( 19 ).  
   
   
       5 . The shaft drive according to  claim 4 , characterized in that the eccentric cam plate ( 19 ) is driven exclusively in one predetermined rotational direction.  
   
   
       6 . The shaft drive according to  claim 4 , characterized in that the eccentric cam plate ( 19 ) is driven primarily in one predetermined rotational direction.  
   
   
       7 . The shaft drive according to  claim 1 , characterized in that the gear ( 17 ) is embodied in such a way that two operational modes can be selected, such that the eccentric cam plate ( 19 ) in a first operating mode executes a rotation in a predetermined rotational direction and in a second operating mode executes a rotational movement with alternating rotational direction.  
   
   
       8 . The shaft drive according to  claim 1 , characterized in that the gear ( 17 ) comprises a coupling device ( 12 ).  
   
   
       9 . The shaft drive according to  claim 8 , characterized in that the coupling device ( 12 ) has a first operating position, which is characterized by the unimpeded transmission of a driving movement.  
   
   
       10 . The shaft drive according to  claim 8 , characterized in that the coupling device ( 12 ) has a second operating position, which is characterized by an interruption of the transmission of the drive movement.  
   
   
       11 . The shaft drive according to  claim 10 , characterized in that the coupling device ( 12 ) is embodied in such a way that during the interruption in the drive movement, it transmits a pendulum movement in alternating direction.  
   
   
       12 . The shaft drive according to  claim 1 , characterized in that the eccentric toothed gearing ( 14 ) has at least two toothed gears ( 23 ,  24 ), which constantly mesh with each other.  
   
   
       13 . The shaft drive according to  claim 12 , characterized in that the toothed gears ( 23 ,  24 ) are spur wheels.  
   
   
       14 . The shaft drive according to  claim 1 , characterized in that the number of teeth on the toothed gears ( 23 ,  24 ) are at a whole number ratio to each other.  
   
   
       15 . The shaft drive according to  claim 12 , characterized in that the toothed gears ( 23 ,  24 ) have an identical number of teeth.  
   
   
       16 . The shaft drive according to  claim 1 , characterized in that the toothed gears ( 23 ,  24 ) respectively have a substantially elliptical shape.  
   
   
       17 . The shaft drive according to  claim 1 , characterized in that the eccentric toothed gear ( 14 ) converts the uniform movement of the drive shaft ( 15 ) to a non-uniform movement of an input shaft ( 21 ,  22 ).