Magnetic roll for use in xerographic printing, and method of making thereof

Abstract

A magnetic roll, such as for use in a xerographic printing apparatus, is formed from two semicylindrical partial cylinders. The partial cylinders can be molded and attached to each other to form a complete cylinder defining magnetic poles along the circumference thereof.

1 . A method of making a magnetic roll suitable for use in developing an electrostatic latent image, comprising the steps of: 
 providing a first partial cylinder, the first partial cylinder defining a first partial cylindrical surface;    providing a second partial cylinder, the second partial cylinder defining a second partial cylindrical surface;    attaching the first partial cylinder to the second partial cylinder, thereby combining the first partial cylindrical surface with the second partial cylindrical surface; and    imparting at least one magnetic pole to a portion of the combined first partial cylindrical surface and second partial cylindrical surface.    
     
     
         2 . The method of  claim 1 , wherein the combined first partial cylindrical surface and second partial cylindrical surface form a complete cylindrical surface.  
     
     
         3 . The method of  claim 1 , wherein the first partial cylindrical surface and second partial cylindrical surface each define one-half of a cylindrical surface.  
     
     
         4 . The method of  claim 1 , wherein the step of providing a first partial cylinder includes inserting a quantity of magnetically-permeable, curable material into a mold, the mold defining a negative partial cylindrical surface.  
     
     
         5 . The method of  claim 4 , wherein the inserting step includes extruding the magnetically-permeable material.  
     
     
         6 . The method of  claim 4 , wherein the step of imparting at least one magnetic pole includes magnetizing the magnetically-permeable, curable material at a predetermined location of the first cylindrical surface.  
     
     
         7 . The method of  claim 1 , wherein the step of imparting at least one magnetic pole includes the steps of 
 imparting a first magnetic pole of a first polarity at a predetermined location in the first partial cylinder;    imparting a second magnetic pole of a second polarity opposite the first polarity at a predetermined location in the second partial cylinder; and    attaching the first partial cylinder to the second partial cylinder so that the first magnetic pole is immediately adjacent the second magnetic pole.    
     
     
         8 . A magnetic roll suitable for use in developing an electrostatic latent image, comprising: 
 a first partial cylinder, the first partial cylinder defining a first partial cylindrical surface;    a second partial cylinder, the second partial cylinder defining a second partial cylindrical surface;    the first partial cylinder being attached to the second partial cylinder, to yield a combined cylindrical surface; and    at least one magnetic pole defined in a partial cylinder of the combined cylindrical surface.    
     
     
         9 . The roll of  claim 8 , wherein the combined first partial cylindrical surface and second partial cylindrical surface form a complete cylindrical surface.  
     
     
         10 . The roll of  claim 8 , wherein the first partial cylindrical surface and second partial cylindrical surface each define one-half of a cylindrical surface.  
     
     
         11 . The roll of  claim 8 , wherein a first magnetic pole of a first polarity is defined at a predetermined location in the first partial cylinder; 
 a second magnetic pole of a second polarity opposite the first polarity is defined at a predetermined location in the second partial cylinder; and    the first partial cylinder is attached to the second partial cylinder so that the first magnetic pole is adjacent the second magnetic pole.    
     
     
         12 . The roll of  claim 8 , further comprising at least one discrete magnetic member disposed within the combined cylindrical surface.