PROBLEM TO BE SOLVED: To prevent water from infiltrating into the inner cylinder of an extension and contraction bar, and also to facilitate assembly.SOLUTION: The inner cylinder is composed of a metallic receiving member 8 and a synthetic resin lid member 9. The receiving member 8 is such that a recessed part 8b is formed between the end edges of a cross-sectionally C shaped bottom part 8a and that a region surrounded by the bottom part 8a and the recessed part 8b is made a hermetically sealed space. In the boundary of the bottom part 8a and the recessed part 8b, there are projecting inward a pair of overhanging parts 8c, 8d. In the lower part of the connection part 9b of the lid member 9, pegs 9c, 9d are provided having flexibility with a prescribed space apart and, on both sides of the root part, groove parts 9f, 9g are formed facing outer side. With the connection part 9b placed on the receiving member 8 and pushed in from above, the pegs 9c, 9d go through the overhanging parts 8c, 8d to enter the recessed part 8b. After that, the pegs 9c, 9d restore to the original shape, with the overhanging parts 8c, 8d fitted into the groove parts 9f, 9g respectively, and with the receiving member 8 connected to the lid member 9.COPYRIGHT: (C)2015,JPO&INPIT【課題】伸縮棒の内筒内への水の浸入を防止すると共に、組立てを容易とする。【解決手段】 内筒は、金属製の受部材8と、合成樹脂材の蓋部材9とから成る。受部材8では断面C字状の底部8aの端縁間に凹状部8bが形成され、底部8aと凹状部8bに囲まれた領域は密閉空間とされている。底部8aと凹状部8bの境界部に一対の張出部8c、8dが内方に向けて突出されている。蓋部材9の連結部9bの下部には所定間隔で可撓性を持つ爪部9c、9dが設けられており、その根本部の両側には外側に向けて溝部9f、9gが形成されている。受部材8の上に連結部9bを載置し上方から押し込むと、爪部9c、9dは張出部8c、8dを潜ぐり抜けて凹状部8b内に入り込む。その後に、爪部9c、9dは元の形状に復元し、溝部9f、9g内に張出部8c、8dがそれぞれ嵌合し、受部材8と蓋部材9とが連結する。【選択図】図2
