| 摘要 |
PROBLEM TO BE SOLVED: To improve airtightness with an adhesive tape or the like by making external surfaces at a joint of a mask case smooth. SOLUTION: Joints between a body and a lid are socket-and-spigot jointed with stages provided on both. A plastic hinge is inserted and fixed between the case body and the lid. The hinge is integrally molded of a rigid plastic material, wherein a center body is divided into two pieces, which are to open/ close with a thin center joint as an axis, while each of the two-divided pieces of the body is integrally formed with an attaching wing. The case body, the lid and the hinge are formed so that the external surfaces of the case body, the lid and the hinge are smooth when the respective wings of the hinge are inserted into mount grooves formed on a rim of the joint between the case body and the lid for joining the case body and the lid. |
