PROBLEM TO BE SOLVED: To provide a needle assembly which enables easy puncture without application of rotary torque when a protection cover moves from a state before use to a state of use.SOLUTION: A needle assembly 1 includes: a protection cover 4 which advances and retreats with respect to a hub 3 that holds a cannula 2 a tubular section 5 which is provided on the hub and houses the protection cover so as to be able to protrude and retract from the tip a spring section 6 as a biasing means which is mounted elastically between the hub and the protection cover an engagement protrusion 14 which is provided on one of either the tubular section or the protection cover and a guide means 21 which is provided on the another of either the tubular section or the protection cover and regulates movements of the engagement protrusion. When the protection cover retreats from a state before use to a state of use, the guide means causes the engagement protrusion to move in an axial direction, and the protection cover retreats without rotating. Rotary torque is not generated during the use, and puncturing can be easily performed.COPYRIGHT: (C)2014,JPO&INPIT【解決手段】 針組立体1は、カヌラ2を保持するハブ3に対して進退動する保護カバー4と、上記ハブに設けられるとともに上記保護カバーを先端より出没可能に収納する筒状部5と、上記ハブと保護カバーとの間に弾装された付勢手段としてのばね部6と、上記筒状部または保護カバーのいずれか一方に設けられた係合突起14と、いずれか他方に設けられて上記係合突起の移動を規制するガイド手段21とを備えている。上記保護カバーが上記使用前状態から使用状態へと後退する際には、上記ガイド手段は係合突起を軸方向に移動させて、上記保護カバーが回転せずに後退するようにした。【効果】 使用時に回転トルクが生じず、容易に穿刺が可能である。【選択図】 図2
