| 摘要 |
PROBLEM TO BE SOLVED: To easily incorporate a freely deformable spacer into a prescribed location within a hollow lip part. SOLUTION: A spacer is constituted of a spiral linear member 18. After the tip part of the linear member 18 is inserted into an air bleeding hole 17 of a hollow lip part 13, this linear member 18 is revolved so that the spiral may advance and the whole of the linear member 18 is inserted into the hollow lip part 13. At the rear end part of the linear member 18, a restraining projection 19 projecting to a radial outside is formed. The restraining projection 19 is bitten into an inner wall of the hollow lip part 13. The spiral radius at the tip of the linear member 18 is reduced and the insertion into the hollow lip part 13 is made easy. |
