PROBLEM TO BE SOLVED: To provide a needle assembly having a novel structure that can surely regulate movement of a needle hub to the proximal end side relative to a housing without making a projection protruding to the inside relative to the housing.SOLUTION: In a needle assembly 10, an engaging hole 62 is provided which opens to a housing 16 while an engaging projection 36 is provided which elastically protrudes from a needle hub 14. At a retraction position to the housing 16 of a hollow needle 12, the engaging projection 36 is engaged with the engaging hole 62, and re-protrusion of the hollow needle 12 from the housing 16 is prevented. Also, with the retraction of the hollow needle 12 into the housing 16, the inner face on the front side in the axial direction from the engaging hole 62 of the housing 16, with the engaging projection 36 in sliding contact with the engaging hole 62, is situated on the outer peripheral side from the inner face on the rear side in the axial direction of the engaging hole 62 in the housing 16, so that the engaging projection 36 is defined as a guide face 68 for introducing into the engaging hole 62.SELECTED DRAWING: Figure 3COPYRIGHT: (C)2018,JPO&INPIT【課題】ハウジングに対して内側に突出する突部を設けることなく針ハブのハウジングに対する基端側への移動をより確実に規制することができる、新規な構造の針組立体を提供する。【解決手段】針組立体10において、ハウジング16に開口する係止穴62が設けられている一方、針ハブ14から弾性的に突出する係止突部36が設けられており、中空針12のハウジング16への引込位置で係止突部36が係止穴62に係止されて中空針12のハウジング16からの再突出が防止されるようになっていると共に、中空針12のハウジング16への引込みに伴って係止突部36が係止穴62に向かって摺接するハウジング16の係止穴62よりも軸方向前方側の内面が、ハウジング16における係止穴62の軸方向後方側の内面よりも外周側に位置して係止突部36を係止穴62に導き入れる案内面68とされている。【選択図】図3
