Sheet feed roller

Abstract

A sheet feed roller capable of achieving highly accurate sheet feed distance has an outer peripheral surface including a feed surface that extends at least locally in an axial direction of the roller over an entire circumference of the roller. The feed surface of the roller is provided with a plurality of projections, including microscopic spikes that can be pierced into the sheet, and stoppers for limiting a piercing depth of the spikes in the sheet.

1 . A sheet feed roller having an outer peripheral surface, said outer peripheral surface including at least one feed surface region that extends at least locally in an axial direction of the roller and over an entire circumference of the roller, said feed surface being provided with a plurality of projections, said plurality of projections being comprised of microscopic spikes that can be pierced into the sheet, and stoppers for limiting a piercing depth of the spikes in the sheet.  
     
     
         2 . The sheet feed roller according to  claim 1 , wherein each of said plurality of projections comprises one of said spike and said stopper.  
     
     
         3 . The sheet feed roller according to  claim 1 , wherein each of said projections comprising said spike further comprises said stopper.  
     
     
         4 . The sheet feed roller according to any one of  claims 1  to  3 , wherein each of said projections is arranged in that region of said feed surface, which is defined by first helices extending in parallel with each other on the outer peripheral surface, and second helices extending in parallel with each other on the outer peripheral surface, said second helices crossing said second helices.  
     
     
         5 . The sheet feed roller according to  claim 4 , wherein at least one projection comprising said spike is arranged alternately with at least one projection comprising said stopper, along said first helices or said second helices.  
     
     
         6 . The sheet feed roller according to any one of  claims 1  to  3 , wherein each of said projections is arranged in that region of said feed surface, which is defined by generatrices extending along the outer peripheral surface in parallel with an axial direction of the roller, and circumferential lines extending in parallel with each other on the outer peripheral surface, said circumferential lines crossing said generatrices.  
     
     
         7 . The sheet feed roller according to  claim 6 , wherein at least one projection comprising said spike is arranged alternately with at least one projection comprising said stopper, along said generatrices or said circumferential lines.  
     
     
         8 . The sheet feeder according to any one of  claims 1  to  7 , wherein said stopper has a flat surface that is substantially at right angles to a radial direction of the roller.