Disposal sterile syringe with retractable taper

A disposable sterile syringe with retractable taper includes a plunger, a barrel, a needle lock and a taper;

• wherein, the plunger having at its rear end disposed with a flange, a plunger locking holder comprised of a locking ring holder and a locking nose cone at its front end, and a ring plug provided surrounding the locking ring holder;
• the barrel having at its rear end provided with a flange, a range of scale on the body of the barrel, a locking nipple on the upper edge of a lower needle lock and another locking nipple on the lower needle lock being provided in sequence in the inner edge of the barrel on the distal side from the flange;
• the needle lock comprised of an upper needle lock and the lower needle lock, an injection way penetrating through the upper needle lock;
• a scalene cone externally expanding toward the side of the lower needle lock being disposed on the upper needle lock close to the side of the lower needle lock;
• a groove being provided surrounding the external circumference of the injection way of the upper needle lock and divided into an upper groove and a lower groove by a partitioning plate, the upper groove being disposed with an internal thread while the lower needle lock being comprised of a through hole and a flange, and a retainer edge being provided on one side of the inner wall of the through hole;
• and the taper, having its one end fixed with a needle and another end disposed with a flange with the taper contained in the upper needle lock of the needle lock is characterized by that:
• the lower needle lock being inserted into the injection way by the through hole, the needle lock then placed into the barrel, the needle lock secured in the barrel by having the locking nipple on the upper edge of the lower needle lock and the locking nipple on the lower needle lock respectively engaged to the flange of the lower needle lock and the scalene cone on the upper needle lock, the taper being placed in the upper needle lock by having the flange of the taper screwed into the upper groove, a cap being provided to cover up the needle, and the plunger being inserted into the barrel;
• upon completing the injection the plunger being pushed all way down the barrel, the locking nose cone at the front end of the plunger being pushed into the through hole of the lower needle lock and secured by having the hooking member interlocked with the retainer edge of the through hole, and the plunger being pulled back for both of the needle lock and the taper to retract into the barrel.