PROBLEM TO BE SOLVED: To provide a three-way cock 10 allowing proper removal of a second liquid medicine remaining inside a second introduction pipe 15 from inside the second introduction pipe 15, after the completion of supply of the second liquid medicine into the second introduction pipe 15 from a syringe.SOLUTION: In this three-way cock 10, a switching path 18 of a valve element 17 has a through-hole 18a and a peripheral groove 18b. The through-hole 18a linearly penetrates the valve element 17. The peripheral groove 18b is formed in a peripheral part of the valve element 17 over a range of 90° in the turn direction of the valve element 17, one end communicates with one end of the through-hole 18a, and the other end is positioned at the central position between both the ends of the through-hole 18a in the turn direction. In a first switching position of the three-way cock 10, a first liquid medicine of a first introduction pipe 13 deeply advances into the second introduction pipe 15 through the through-hole 18a, takes in the second liquid medicine remaining inside the second introduction pipe 15, and thereafter comes off to a lead-out pipe 14 through the peripheral groove 18b.COPYRIGHT: (C)2012,JPO&INPIT【課題】シリンジから第2導入管15への第2薬液の供給終了後、第2導入管15内に残存する第2薬液を第2導入管15内から的確に除去することができる三方活栓10を提供する。【解決手段】弁体17の切換路18は貫通孔18aと周溝18bとを有する。貫通孔18aは弁体17を直線状に貫通する。周溝18bは、弁体17の回動方向へ90°の範囲にわたり弁体17の周部に形成され、一端は貫通孔18aの一端に連通し、他端は回動方向へ貫通孔18aの両端の中心位置になっている。三方活栓10の第1切換位置では、第1導入管13の第1薬液は、貫通孔18aを介して第2導入管15内へ深く進入して、第2導入管15内に残存中の第2薬液を取り込んでから、周溝18bを介して導出管14へ抜ける。【選択図】図4
