BigPatents India

A single-use syringe includes a shield (2), a barrel (1) mounted for axial movement within the shield and being biased to a rearward position by resilient biasing means (10), and a plunger assembly (3) mounted for axial movement within the barrel. A resilient locking member (6) initially prevents the barrel from moving rearwardly. When fluid is expressed from the barrel, the barrel moves forward thereby disabling rearward movement prevention means (15) and enabling forward movement prevention means (14) such that the barrel can move rearwardly and is locked in the rearward position to prevent repeated use.