| 摘要 |
PROBLEM TO BE SOLVED: To insert in an either direction easily by forming two truncated cone shape screws whose diameter is shrunk while heading for a center on the inside surface including a cylindrical expansion element in which two slits are formed on its end part or one slit is formed across its entire length. SOLUTION: Two slits are installed on the end part or one slit F is installed across its entire length on a cylindrical main body so as to expand by dividing it and truncated cone shape screws A1, A2 whose diameter is shrunk while heading for a center are formed on the inside surface. A projection B for holding the head of a divided element S is installed on the central line of a cylindrical expansion element so as to prevent the drop out of an inner pipe Di from an outer pipe De. A projection C is formed on the outer surface so that the expansion element is easily stuck to the inner wall of the outer pipe De. Therefore, when the expansion element is arranged inside the outer pipe De, after fixing the divided element S on the head of the inner pipe Di, it is not required to confirm the direction and it can be inserted by a hand. |
