Patent ID: 7108812

Claim:
A method of adjusting a forming die unit having a spherical section held by a die holding member having a spherical receiving surface and wherein a curvature center of the spherical receiving surface is located on or in the vicinity of a forming surface of the forming die unit, a driven member extending to outside of the spherical receiving surface and moving together with the forming die unit and having a plane surface on an outer circumferential surface thereof, an apply member applying a displacing force to the driven member, and a roller disposed between the driven member and the apply member, the roller being rotatable around a central axis thereof, comprising steps of: discharging a pressure transmitting medium from at least one of the forming die unit and the die holding member to the other one so as to apply a power in a direction that the forming die unit is spaced away from the die holding member; and adjusting the forming die unit relative to the die holding member by applying the displacing force on contact with on a line of the roller to the driven member at an outside of a radius of curvature in relation to the curvature center of the spherical receiving surface by the apply member, wherein when the forming die unit is located on the receiving surface after the forming die unit is displaced relative to the die holding member, a displacement perpendicular to the central axis of the forming die unit per 1° of an angle of rotation of the forming die unit relative to the die holding member is 100 μm or less.