A syringe includes a hollow barrel, a hollow plunger movable within the barrel and a needle assembly secured within and at a distal end of the barrel. The needle assembly includes a needle holder, a resilient member that biases the needle holder toward the proximal end opening of the barrel, and a retaining member releasably secured to the needle holder via a reduced material section. The retaining member maintains the needle holder at the distal end of the barrel against the bias of the resilient member. When the plunger is fully depressed within the barrel, the plunger engages the needle holder such that the retaining member is forced to break away and separate from the needle holder along the reduced material section to facilitate retraction of the needle holder and a needle secured to the needle holder into the retraction cavity disposed within the plunger.一注射器包含一中空圓筒;一中空柱塞,其可於該圓筒內移動;及一針總成,其鎖固在該圓筒之遠側端內及在該圓筒之遠側端。該針總成包含一針夾具;一彈性構件,其使該針夾具偏向該圓筒之近側端開口;及一止動構件,其經由一縮減材料部分可鬆開地鎖固至該針夾具。該止動構件抵抗該彈性構件之偏壓而將該針夾具維持在該圓筒之遠側端。當該柱塞被完全壓入該圓筒內時,該柱塞嚙合該針夾具,使得該止動構件被迫由該針夾具沿著該縮減材料部分脫離及分開,以有利於該針夾具、及鎖固至該針夾具之針的縮回進入設置在該柱塞內之縮回凹腔。120...注射器122...圓筒123...開口124...主體部份126...遠側端延伸部分127...延伸圓筒部份128...徑向延伸凸緣129...環狀溝槽130...中空柱塞132...彈性密封件138...拇指墊139...徑向延伸凸緣144...栓塞148...縮回孔腔156...針總成160...針168...保護套184...彈性構件210...切口部份212...背脊
