To form projections arranged on a conveying flat belt discontinuously in the width direction without increasing unnecessary man-hour.
An unvulcanized rubber sheet 21', and a canvas 22 are successively attached to an outer circumferential surface 47 of a columnar inner mold 40. An outer mold 50 is arranged so as to surround the inner mold 40. The outer mold 50 consists of a plurality of outer mold pieces 51. A plurality of recesses for molding projections are arranged in the axial direction X in an inner circumferential surface 51B of each outer mold piece 51. Each outer mold piece 51 is displaced inwardly in the radial direction, and the unvulcanized rubber sheet 21' and the canvass 22 are pressed by the outer mold 50. The unvulcanized rubber sheet 21' and the canvass 22 are heated together with the pressurization. A part of the unvulcanized rubber sheet 21' is allowed to flow inside each recess, and the unvulcanized rubber sheet 21' is vulcanized to form a belt sleeve with projections formed on its outer circumferential surface. Next, the outer mold 50 is expanded to release the outer mold 50 from the belt sleeve. Then, the belt sleeve is released from the inner mold 40.
Hiroki Ogura
Tsuyoshi Nonaka
Shigeru Torayama
Tsubouchi Shin