| 摘要 |
PURPOSE:To perform the fastening operation smoothly while raising the fastening force of a lid body to a box body, and lowering the operation force required to close the lid at the same time by a method wherein projections are formed on the box body, and at the same time, the guide surfaces on the opening direction sides are formed by tilted surfaces which have a steeper gradient than that of the guide surfaces on the closing direction sides. CONSTITUTION:A case 11, in which a tape cassette A is stored, is equipped with a box body 12 which opens on one side, and a lid body 13 which opens or closes an opening 12a of the box body 12. In this case, a plurality of projections 24, 25 are formed on the lid body 13, and at the same time, a plurality of fastening holes 16, 17 and a plurality of fastening protuberances 20, 21, which are fastened with the projections 24, 25, are formed on the box body 12. Respective projections 24, 25 are formed of two guide surfaces 24 (a, b), 25 (a, b), which are tilted to the opposite directions to each other. Respective guide surfaces 24 on the opening direction side are formed by tilted surfaces which have a steeper gradient than that of respective guide surfaces 25 on the closing direction side. By this method, the fastening force of the lid body 13 to the box body 12 is raised while the force required to close the lid is lowered, and the fastening operation of respective projections 24, 25 is smoothly performed. |
