Method for producing roller member, roller-member mold, roller shaft, and roller member

Abstract

A roller shaft is inserted into a mold including molding members respectively having a first mold surface that defines an outer circumference of a roller portion and second and third mold surfaces that respectively define first and second flat portions of the roller portion, and the mold is then closed. A molding material is injected around the roller shaft to integrally mold the roller portion. The roller portion includes the outer circumference and the first and second flat portions rising from the roller shaft to the outer circumference. The roller shaft includes flange portions at portions corresponding to the first and second flat portions. The flange portions prevent the molding material from leaking outside the first and second flat portions when the roller portion is integrally molded around the roller shaft by injection molding.

What is claimed is: 
     
         1 . A roller member including a roller shaft having a first outer diameter and a second outer diameter larger than the first outer diameter, and a roller portion,
 wherein the roller portion includes an outer circumference, a first flat portion rising from the roller shaft to the outer circumference, and a second flat portion rising from the roller shaft to the outer circumference,   wherein the roller shaft includes a first flange portion and a second flange portion each having an outer diameter larger than the second outer diameter, and   wherein a thickness of the roller portion in a diametrical direction is smaller at the first flat portion by a thickness of the first flange portion and smaller at the second flat portion by a thickness of the second flange portion.   
     
     
         2 . The roller member according to  claim 1 , wherein the roller shaft includes a cut portion smaller than the second outer diameter. 
     
     
         3 . The roller member according to  claim 2 , wherein a thickness of the roller portion in a diametrical direction at the cut portion is smaller than a thickness of a part of the roller portion having the second outer diameter in the diametrical direction. 
     
     
         4 . The roller member according to  claim 1 , wherein the first and second flange portions are larger than the second outer diameter by a value in a range from 0.2 mm to 3 mm. 
     
     
         5 . The roller member according to  claim 4 , wherein the first and second flange portions each have a thickness in a range from 0.1 mm to 3 mm. 
     
     
         6 . The roller member according to  claim 1 , wherein the first flange portion or the second flange portion has a step shape. 
     
     
         7 . The roller member according to  claim 1 , wherein the first flange portion or the second flange portion has a tapered shape. 
     
     
         8 . A copying machine including the roller member according to  claim 1 . 
     
     
         9 . A printer including the roller member according to  claim 1 .