A needle assembly with a needle shield is disclosed. The shield includes a lumen slidable on the needle, a holder and a needle blocking object which moves at least partially into the lumen in order to block distal movement of the needle. A spring biases the blocking object towards the needle axis. When the needle shield moves from a non-shielding position to a shielding position, the needle blocking object moves at least partially into the lumen. The needle blocking object is radially and axially constrained in the shielding position. The holder also prevents radial, longitudinal and circumferential movement of the blocking object.本發明揭露一種針頭保護裝置。針頭保護裝置包含可於針頭上滑動的內腔、支架以及針頭擋塊,針頭擋塊係部份移動進入內腔,用以堵塞針頭尖銳的末端的移動。彈簧在針頭擋塊上施加偏壓,使其朝向針頭的軸向。當針頭保護裝置從未受保護位置移動到受保護位置,針頭擋塊係部份移動進入內腔。針頭擋塊在受保護位置處,係受到徑向以及軸向的限制。支架亦防止針頭擋塊在徑向、縱向以及周圍方向的移動。2‧‧‧彈簧3‧‧‧球狀體10‧‧‧針頭12‧‧‧表面18‧‧‧孔洞22‧‧‧內腔23‧‧‧轂95‧‧‧第一殼體
