| 摘要 |
<p>PURPOSE:To prevent generation of a recess due to a sink on the outer surface of a circumference wall of a magnetic tape reel, by providing an outer barrel in a body with an inner barrel to the outer circumference of the inner barrel of a male mold and having a double layer structure of inner and outer barrels for the circumference wall of the reel. CONSTITUTION:An inner barrel 3 is produced for a circumference wall 2, and then an outer barrel 4 is formed in a body with the barrel 3 to the outer circumference of the barrel 3 and with the barrel 3 used as a male mold. Therefore a part of the barrel 4 produced later is filled into a recess 7 which is produced by a sink on the outside center surface 3a of the barrel 3. Thus a reel circumference wall 2 with a prescribed amount of thickness is obtained. In other words, the wall 2 has a double layer structure of inner and outer barrels 3 and 4 by making use of the proper feature by synthetic resin, i.e., the less the thickness change of the wall 2 the less the degree of recess 7 due to a sink. This substantially eliminates the recess 7 due to a sink on the outer surface 4a of the barrel 4 which serves as the outer surface of the wall 2 of a reel 1.</p> |
