JPS638008B

A cylindrical conveyor belt comprises in transverse section a central conveyor portion (1) and a pair of lug portions (2) formed integrally at both sides of the conveyor portion, the paired lug portions being joined in contact with each other to render the conveyor portion cylindrical, the conveyor portion comprising in transverse section a centrally position bottom portion which constitutes a bottom of the cylindrical shape, a pair of side portions positioned on both sides of the bottom portion and constituting side walls of the cylindrical shape, a pair of slant portions positioned outside the paired side portions and constituting slant upper walls of the cylindrical shape, and neck portions (3) positioned between the paired slant portions and the lug portions and constituting an opening in the cylindrical shape, the rigidity of the neck portions in the transverse direction being lower than that of the bottom, side, slant and lug portions in the transverse direction. The selection of suitable reinforcing layers (4, 5, 6) to obtain required variations in rigidity is described.