The syringe includes a barrel, a plunger, and an adapter for mounting the needle in the distal end of the barrel. The adapter includes a protrusion projecting away from the needle end and into the barrel defining an annular space between the barrel and the protrusion. The plunger and protrusion have...http://www.google.com/patents/US6033386?utm_source=gb-gplus-sharePatent US6033386 - Safety syringe needle device with interchangeable and retractable needle platform
