Patent ID: 6132400
Filing Date: 2000-10-17
Classification: A61M

Abstract:
A medical syringe, includinga plunger having at one end a resilient seal,a barrel having a central longitudinal axis and a pair of opposed ends,said barrel having at a distal end an ejection port and at a proximal end an opening,a back flow seal disposed in said ejection port preventing fluid from entering or leaving said barrel through said ejection port, said back flow seal forming a distal boundary of a refill chamber within said barrel,outer and inner telescopic tubular elements seated inside the barrel to be coaxial with said longitudinal axis,the outer tubular element being mounted in a stationary position while disposed in the barrel and the inner tubular element being movable axially within the outer tubular element,said outer tubular element and barrel forming a reservoir chamber, with the outer tubular element having a fluid passageway therein that allows the liquid to flow from the reservoir chamber into said refill chamber,the inner tubular element having a distal end with a needle having a distal tip, said inner tubular element receiving the end of the plunger with the resilient seal thereon,said resilient seal fitting snug within the inner tubular element to grip said inner tubular element and, in response to axial movement of the plunger, to move the inner tubular element between a first position where said distal tip is located within said refill chamber allowing fluid to be drawn through the distal tip into the inner tubular element by proximal movement of the plunger relative to the inner tubular element, and a second position where said distal tip extends through said back flow seal into the ejection port allowing fluid to be expelled through said ejection port upon distal movement of the plunger relative to the inner tubular element.