Patent ID: 9377723
Filing Date: 2016-06-28
CPC Classification: B21D,C21D,G03G

Claim Text:
1. A method of manufacturing a stainless-steel seamless belt, comprising: the steps of: (1) obtaining a cup-shaped member by subjecting a stainless-steel plate to a drawing process; (2) obtaining a thin-walled sleeve by subjecting the cup-shaped member to a plastic forming process to be thin-walled and cutting a base portion of the thin-walled cup-shaped member; (3) inserting the thin-walled sleeve into a cylindrical outer die having an internal diameter larger than an external diameter of the thin-walled sleeve so as to be coaxial with the cylindrical outer die, pressurizing the thin-walled sleeve from an inside thereof so as to cause the thin-walled sleeve to closely contact an inner wall of the outer die, and thereby expanding a diameter of the thin-walled sleeve; and (4) subjecting the thin-walled sleeve whose diameter is expanded in (3) to low temperature annealing at 200 to 400 degree C., wherein the step (3) includes expanding the diameter of the thin-walled sleeve without changing the length in a direction perpendicular to the peripheral direction of the thin-walled sleeve.