Patent attributes
A barrel adapter for a syringe having a barrel and plunger. The adapter comprises a barrel tip and a needle retraction mechanism having a needle subassembly with a needle and a lumen, actuator subassembly, and biasing member. The needle subassembly moves from an injection to a retracted position within the barrel tip. The actuator subassembly includes a retainer connected to the barrel tip, a stylet held in a stylet disc, and a prong passing into the retainer. The stylet slides within the needle lumen and is spaced from the needle tip in the injection position. The biasing member biases the NOM from the retainer. A locking arrangement compresses the biasing member when locked and releases the biasing member when actuated by depression of the plunger, which moves the prong against the retainer. The biasing member moves the needle and stylet from the injection position to the retracted position when released.