| 摘要 |
A magnetic tape reel in which transformation of the tape winding surface owing to the heat shrinkage after molding is suppressed, and also transformation of the hub hole owing to the winding tension of the magnetic tape is suppressed. At least a tape winding drum portion is provided with concentric cylindrical portions including an inner cylindrical portion having a hub hole to be engaged with a rotary driving shaft, an intermediate cylindrical portion provided concentrically with and outside the inner cylindrical portion, and an outer cylindrical portion provided concentrically with and further outside the intermediate cylindrical portion so as to form a tape winding surface. The intermediate cylindrical portion and the outer cylindrical portion are connected to each other through a plurality of reinforcing ribs which extend in the radial directions of the reel but which are not present between the inner cylindrical portion and the intermediate cylindrical portion.
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