| 摘要 |
<p>PURPOSE:To shorten the time required to form a protrusion and to make workability efficient by forming the protrusion conforming to the mold formed on the die side on a magnetic tape traveling surface of a fixed drum by plastic working. CONSTITUTION:A fixed drum 3 is surely clamped by a die 12 and a stripper 14, and a protrusion 10 is formed by a punch 13. Since an external force is exerted directly on the region to form the protrusion while fixing the drum 3, the deformation of the drum 3 resulting from the formation of the protrusion is prevented without influencing the working accuracy of the tape traveling surface 11 of the drum 3, and a desired protrusion is formed at an optional position.</p> |
