PROBLEM TO BE SOLVED: To provide an indwelling needle which is simply structured, excels in operability, and can fix a needle tip protection device correctly at the apical end of an inner needle.SOLUTION: An indwelling needle C is composed of an outer needle 10 which consists of a cannula 11 and a housing 12, an inner needle 20 which consists of a metal needle 21 and a hub 22, and a needle tip protection device 60. Additionally, the needle tip protection device 60 is attached to the housing 12 with the metal needle 21 inserted inside and is removed from the outer needle 10 with the inner needle 20 when the inner needle 20 is extracted from the outer needle 10. Moreover, the body 61 of the needle tip protection device 60 is formed cylindrically, and window parts 64a, 64b are prepared at the part opposite to the periphery of the body 61, movable engagement parts 62, 63 where outer parts 62b, 63b project toward the outside of the body 61 at the one marginal part of the window parts 64a, 64b and the other end part is formed on engageable engagement pieces 62c, 63c at the other marginal part of the window parts 64a, 64b are provided.COPYRIGHT: (C)2012,JPO&INPIT【課題】 簡単な構造で、操作性に優れかつ、内針の先端部に針先保護具を確実に取り付けることのできる留置針を提供すること。【解決手段】 留置針Cを、カニューレ11とハウジング12からなる外針10と、金属針21とハブ22からなる内針20と、針先保護具60とで構成した。そして、針先保護具60を、内部に金属針21を挿通させた状態でハウジング12に取り付け、内針20を外針10から抜いたときに、内針20とともに外針10から取り外されるようにした。また、針先保護具60の本体61を円筒状に形成し、本体61の周面の対向する部分に窓部64a,64bを設けるとともに、窓部64a,64bの一方の縁部に、外側部62b,63bが本体61の外側に向って突出し、他端部が窓部64a,64bの他方の縁部に係合可能な係合片62c,63cに形成された可動係合部62,63を設けた。【選択図】 図19
