Spinning rotor for open-end spinning machines

Abstract

A spinning rotor for use at high speeds in open-end spinning machines has a rotor cup having an annular wall portion defining a rotor opening, a bottom wall portion merging with the annular wall portion, and a mounting hub extending exteriorly from the bottom wall portion. A rotor shaft is affixed to the mounting hub coaxially with the rotor cup. The merger of the bottom and annular wall portions of the rotor cup defines a maximum exterior diameter of the rotor and an interior rotor groove. The annular wall portion, the bottom wall portion and the mounting hub are of different cross-sectional thicknesses with the cross-sectional thickness of the bottom wall portion increasing from the rotor groove to the mounting hub. The wall thickness is less than 1.2 mm in the area of the maximum exterior diameter of the rotor cup ( 2 ) and the rotor cup has an aerodynamic exterior contour free of edges for deterring turbulent boundary layer air flow thereabout and an interior contour for promoting fiber spinning into a yarn.

1. A spinning rotor for open-end spinning machines, comprising:
 (a) a rotor cup having, 
 (i) an annular wall portion defining a rotor opening,  
 (ii) a bottom wall portion merging with the annular wall portion to define at the merger thereof a maximum exterior diameter of the rotor cup and in the interior thereof a rotor groove, the wall thickness at the maximum exterior diameter of the rotor cup at the merger of the bottom and annular wall portions being between about 0.3 mm and less than 1.0 mm, and less than a wall thickness of the annular wall, and  
 (iii) a mounting hub extending exteriorly from the bottom wall portion, the cross-sectional thickness of the bottom wall portion increasing from the rotor groove to the mounting hub; and  
 
 (b) a rotor shaft affixed to the mounting hub coaxially with the rotor cup.  
 
     
     
       2. The spinning rotor according to  claim 1 , characterized in that the wall thickness at the maximum exterior diameter of the rotor cup at the merger of the bottom and annular wall portions of the rotor cup is between about 0.75 mm and about 0.85 mm. 
     
     
       3. The spinning rotor according to  claim 1 , characterized in that an exterior contour of the rotor cup defined by the annular wall position and bottom wall position comprises only convex curvatures. 
     
     
       4. The spinning rotor according to  claim 1 , characterized in that the cross-sectional thickness of the annular wall portion constantly increases from the rotor opening to the merger of the bottom and annular wall portions of the rotor cup. 
     
     
       5. The spinning rotor according to  claim 1 , characterized in that an exterior contour defined by the annular wall portion is a straight line from the rotor opening to the merger of the bottom and annular wall portions of the rotor cup. 
     
     
       6. The spinning rotor according to  claim 1 , characterized in that the wall thickness at the maximum exterior diameter of the rotor cup at the merger of the bottom and annular wall portions of the rotor cup and exterior and interior contours of the rotor cup are designed to distribute the mass of the rotor cup for accommodating tensions at the merger of the bottom and annular wall portions of the rotor cup at high rotational operating speeds of the rotor. 
     
     
       7. The spinning rotor according to  claim 1 , characterized in that the ratio of the diameter of the rotor opening to a rotor depth between the rotor opening and the rotor groove is between about 2:1 and about 5:1. 
     
     
       8. The spinning rotor according to  claim 1 , characterized in that the rotor groove has a radius in a bottom of the groove of at least about 0.15 mm. 
     
     
       9. The spinning rotor according to  claim 1 , characterized in that at least one marking is formed in an exterior contour of the rotor cup by removal of material from the rotor cup. 
     
     
       10. The spinning rotor according to  claim 9 , characterized in that the removal of material for forming the marking is selectively made for balancing the spinning rotor. 
     
     
       11. The spinning rotor of  claim 1 , wherein the cross-sectional thickness of the bottom wall portion continually increases from the merger of the bottom wall portion to the mounting hub. 
     
     
       12. The spinning rotor of  claim 1 , wherein indicia is formed on the exterior contour of the rotor cup by removal of material from the rotor cup forming a cavity therein. 
     
     
       13. A spinning rotor for open- end spinning machines, comprising:    ( a )  a rotor cup having  
 ( i )  an annular wall portion defining a rotor opening,    
 ( ii )  a bottom wall portion merging with the annular wall portion to define at the merger thereof a maximum exterior diameter of the rotor cup and in the interior thereof a rotor groove, the wall thickness at the maximum exterior diameter of the rotor cup at the merger of the bottom and annular wall portions being between about  0 . 3  mm and no greater than  1 . 19  mm and less than a wall thickness of the annular wall,    
 ( iii )  the wall thickness of the annular wall increasing toward the merger, and    
 ( iv )  a mounting hub extending exteriorly from the bottom wall portion, the cross - sectional thickness of the bottom wall portion continually increasing from the rotor groove to the mounting hub; and    
   ( b )  a rotor shaft affixed to the mounting hub coaxially with the rotor cup.     
     
     
       14. The spinning rotor according to  claim 13 , characterized in that the wall thickness at the merger is between about  0 . 75  mm and about  0 . 85  mm. 
     
     
       15. The spinning rotor according to  claim 13 , characterized in that an exterior contour of the rotor cup defined by the annular wall portion and bottom wall portion comprises only convex curvatures. 
     
     
       16. The spinning rotor according to  claim 13 , characterized in that an exterior contour defined by the annular wall portion is a straight line from the rotor opening to the merger of the bottom and annular wall portions of the rotor cup. 
     
     
       17. The spinning rotor according to  claim 13 , characterized in that the wall thickness at the merger and exterior and interior contours of the rotor cup are designed to distribute the mass of the rotor cup for accommodating tensions at the merger at high rotational operating speeds of the rotor. 
     
     
       18. The spinning rotor according to  claim 13 , characterized in that the ratio of the diameter of the rotor opening to a rotor depth between the rotor opening and the rotor groove is between about  2 : 1  and about  5 : 1 . 
     
     
       19. The spinning rotor according to  claim 13 , characterized in that the rotor groove has a radius in a bottom of the groove of at least about  0 . 15  mm. 
     
     
       20. The spinning rotor according to  claim 13 , characterized in that at least one marking is formed in an exterior contour of the rotor cup by removal of material from the rotor cup. 
     
     
       21. The spinning rotor according to  claim 20 , characterized in that the removal of material for forming the marking is selectively made for balancing the spinning rotor. 
     
     
       22. The spinning rotor of  claim 13 , wherein indicia is formed on the exterior contour of the rotor cup by removal of material from the rotor cup forming a cavity therein. 
     
     
       23. A spinning rotor for open- end spinning machines, comprising:    ( a )  a rotor cup having  
 ( i )  an annular wall portion defining a rotor opening,    
 ( ii )  a bottom wall portion merging with the annular wall portion to define at the merger thereof a maximum exterior diameter of the rotor cup and in the interior thereof a rotor groove, the wall thickness at the maximum exterior diameter of the rotor cup at the merger of the bottom and annular wall portions being between about  0 . 3  mm and no greater than  1 . 19  mm and less than a wall thickness of the annular wall, and    
 ( iii )  a mounting hub extending exteriorly from the bottom wall portion; and    
   ( b )  a rotor shaft affixed to the mounting hub coaxially with the rotor cup.     
     
     
       24. The spinning rotor according to  claim 23 , characterized in that an exterior contour of the rotor cup defined by the annular wall portion and bottom wall portion comprises only convex curvatures. 
     
     
       25. The spinning rotor according to  claim 23 , characterized in that an exterior contour defined by the annular wall portion is a straight line from the rotor opening to the merger of the bottom and annular wall portions of the rotor cup. 
     
     
       26. The spinning rotor according to  claim 23 , characterized in that the wall thickness at the maximum exterior diameter of the rotor cup at the merger of the bottom and annular wall portions of the rotor cup and exterior and interior contours of the rotor cup are designed to distribute the mass of the rotor cup for accommodating tensions at the merger of the bottom and annular wall portions of the rotor cup at high rotational operating speeds of the rotor. 
     
     
       27. The spinning rotor according to  claim 23 , characterized in that the ratio of the diameter of the rotor opening to a rotor depth between the rotor opening and the rotor groove is between about  2 : 1  and about  5 : 1 . 
     
     
       28. The spinning rotor according to  claim 23 , characterized in that the rotor groove has a radius in a bottom of the groove of at least about  0 . 15  mm. 
     
     
       29. The spinning rotor according to  claim 23 , characterized in that at least one marking is formed in an exterior contour of the rotor cup by removal of material from the rotor cup. 
     
     
       30. The spinning rotor according to  claim 29 , characterized in that the removal of material for forming the marking is selectively made for balancing the spinning rotor. 
     
     
       31. The spinning rotor of  claim 23 , wherein indicia is formed on the exterior contour of the rotor cup by removal of material from the rotor cup forming a cavity therein. 
     
     
       32. A spinning rotor for open- end spinning machines, comprising:    ( a )  a rotor cup having  
 ( i )  an annular wall portion defining a rotor opening,    
 ( ii )  a bottom wall portion merging with the annular wall portion to define at the merger thereof a maximum exterior diameter of the rotor cup and in the interior thereof a rotor groove,    
 ( iii )  a wall thickness of the annular wall portion increasing toward the merger,    
 ( iv )  a mounting hub extending exteriorly from the bottom wall portion, and    
 ( v )  the rotor groove producing a wall thickness at the merger less than the narrowest thickness of the bottom wall; and    
   ( b )  a rotor shaft affixed to the mounting hub coaxially with the rotor cup.     
     
     
       33. The spinning rotor according to  claim 32 , characterized in that the wall thickness at the merger is between about  0 . 75  mm and about  0 . 85  mm. 
     
     
       34. The spinning rotor according to  claim 32 , characterized in that an exterior contour of the rotor cup defined by the annular wall portion and bottom wall portion comprises only convex curvatures. 
     
     
       35. The spinning rotor according to  claim 32 , characterized in that the cross- sectional thickness of the annular wall portion constantly increases from the rotor opening to the merger.   
     
     
       36. The spinning rotor according to  claim 32 , characterized in that an exterior contour defined by the annular wall portion is a straight line from the rotor opening to the merger of the bottom and annular wall portions of the rotor cup. 
     
     
       37. The spinning rotor according to  claim 32 , characterized in that the wall thickness at the merger and exterior and interior contours of the rotor cup are designed to distribute the mass of the rotor cup for accommodating tensions at the merger at high rotational operating speeds of the rotor. 
     
     
       38. The spinning rotor according to  claim 32 , characterized in that the ratio of the diameter of the rotor opening to a rotor depth between the rotor opening and the rotor groove is between about  2 : 1  and about  5 : 1 . 
     
     
       39. The spinning rotor according to  claim 32 , characterized in that the rotor groove has a radius in a bottom of the groove of at least about  0 . 15  mm. 
     
     
       40. The spinning rotor according to  claim 32 , characterized in that at least one marking is formed in an exterior contour of the rotor cup by removal of material from the rotor cup. 
     
     
       41. The spinning rotor according to  claim 40 , characterized in that the removal of material for forming the marking is selectively made for balancing the spinning rotor. 
     
     
       42. The spinning rotor of  claim 32 , wherein indicia is formed on the exterior contour of the rotor cup by removal of material from the rotor cup forming a cavity therein.