| 摘要 |
PROBLEM TO BE SOLVED: To omit processing labor by simplifying a process for producing a sprocket adapted to a chain type power transmission of a motor bicycle or the like and to achieve the wt. reduction of the sprocket and the reduction of noise at a time of the meshing with a chain at the same time. SOLUTION: A fiber reinforced resin sheet wherein polypropylene is reinforced by long glass fibers is delivered by predetermined quantity to be cut and this cut sheet is heated to the m.p. of polypropylene or higher to be charged in the sprocket molding part (c) of a mold 1 and, thereafter, the mold is clamped to mold a sprocket material S0 . Subsequently, the peripheral edge mold 2b of an upper mold 2 is raised and a press is allowed to fall to cut off the burr of the peripheral edge of the tooth part of the sprocket material S0 under pressure to enhance accuracy. |
