Patent ID: 7850587

Claim:
A roller comprising: an outer tubular member; a central shaft penetrating the outer tubular member in an axial direction of the roller; a connecting member disposed between the outer tubular member and the central shaft at a central area of an axis of the roller, connecting the outer tubular member and the central shaft; a bend adjustable mechanism disposed between the outer tubular member and the central shaft at both ends of the axis; a first bearing structure that engages the outer tubular member and the bend adjustable mechanism; a second bearing structure that engages the bend adjustable mechanism and the central shaft, the second bearing structure being aligned with the first bearing structure in a radial direction of the roller; and a rotation preventing mechanism that prevents rotation of the bend adjustable mechanism, where: the bend adjustable mechanism comprises a plurality of spacer structures that individually adjust a distance between the first bearing structure and the second bearing structure in the radial direction of the roller, each spacer structure comprises a cotter block and an adjusting screw to be screw-engaged in the cotter block, and the cotter block moves in the axial direction of the roller depending on an amount of screwing of the adjusting screw to adjust the distance between the first bearing structure and the second bearing structure in the radial direction of the roller.