| 摘要 |
PROBLEM TO BE SOLVED: To provide a string for preventing a tool from falling down, which is enhanced in engaging strength between an engaging piece in the body side or the tool side and a twist returning piece while rotation around an axis is allowed and prevents the engaging piece in the body side or tool side from coming off the twist returning piece by drawing force. SOLUTION: Press fitting type twist returning pieces (2, 4) are equipped respectively between an engaging piece 1 in the body side and a connection code 3 and an engaging piece 5 in the tool side and the connection code 3. Projecting engaging parts (13, 53) are equipped on the engaging piece 1 in the body side or the engaging piece 5 in the tool side via ring shape recess parts (13a, 53a). Engaging members (22, 42) are equipped on twist returning pieces (2, 4) so that the engaging piece in the body side or the engaging piece in the tool side are engaged rotatably around the axis. Slit grooves (11a, 42a) are equipped on the engaging members (22, 42) so that the grooves can be opened by press fitting force upon press fitting the projecting engaging parts (13, 53). Ring shape engaging projections (22b, 42b) are equipped on the edge parts to the inner diameter side to block opening of the projecting engaging parts (13, 53) by drawing-out force. |
