| 摘要 |
PURPOSE:To improve productivity and reduce cost by forming an auxiliary flange in parallel with a flange at the lower end of a cylindrical part in such a manner that the auxiliary flange is spaced from the flange by a distance equal to or a little larger than the thickness of the edge of an attaching hole and has a diameter a little larger than that of the hole, preventing thereby the need for attaching a film from the rear side. CONSTITUTION:A tapered inclined step 11a is formed approximately in the middle of a cylindrical part 11 to which a cap 2 is attached, while a flange 12 and an auxiliary flange 13 formed below the flange 12 are attached to the lower part of the cylindrical part 11 in such a manner that the flange 13 is spaced from the flange 12 by a distance nearly equal to or a little larger than the thickness of the edge of an attaching hole and the flange 13 has a diameter a little larger than that of the hole. And a circular groove 14 is formed around the lower part of the cylindrical part. |
