| 摘要 |
PURPOSE:To provide efficiently a homogeneous economical grip part by extruding a cylindrical tube to envelope the outside of the grip part of a ball driving implement, compressively tightening a split metal mold provided with a peripherally bevelled edge to shape the grip part and then removing a surplus jutted portion. CONSTITUTION:For example, when a cylindrical tube 4 is extruded from above a grip 2' of a bat A' for base ball by an extruding mechanism to envelope the outside of the grip 2' part and a predetermined length of enveloping the grip 2; part is reached, two split metal molds 5, 5' provided with peripherally bevelled edges b, b' are compressively fastened around the grip 2' part. Surplus burrs 6 jutted to the periphery are cut off by a proper means to form a completed grip part 2'a. Thus, the homogeneous grip portion can effectively be shaped to reduce substantially material cost and labor cost. |
