Dual-chamber syringe & method

A medical syringe, including

• a 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 one end an ejection port and at the other end an opening, said ejection port and opening being aligned with each other and disposed along the longitudinal axis,
• 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 chamber holding a reservoir of liquid, with the outer tubular element having a fluid passageway therein that allows the liquid to flow from the chamber into the inner tubular element,
• said opening in the barrel having a porous seal which surrounds the plunger, said porous seal allowing air to enter the barrel yet inhibits the flow of liquid from the chamber,
• the inner tubular element having an end nearby the injection port with a seal thereon that has an orifice therein, 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 seal with the orifice therein seals the injection port as the plunger is moved towards said injection port, preventing liquid in the chamber from passing into the inner tubular element and forcing any liquid in the inner tubular element through the orifice and out the injection port, and a second position where said seal with the orifice therein is moved to a retracted position away from the injection port, allowing liquid to flow from the chamber through the passageway and through the orifice into the inner tubular member, the plunger being initially in a forward position that forces the seal with the orifice therein into engagement with the injection port to seal this port, and
• a safety seal on the plunger which is broken by movement of the plunger into a retracted position, pulling the seal with the orifice therein away from the injection port, to thereby initially fill the inner tubular element with liquid from the chamber.

A medical syringe, including

• a barrel with an ejection port at one end, an opening at the other end, and an internal partition member extending lengthwise between the opening and ejection port to provide a channel running between the ejection port and the opening and a chamber holding a reservoir of liquid,
• a moveable tubular element seated within the channel and having an end nearby the injection port with a seal thereon that has an orifice therein,
• a fluid passageway in the partition which allows the liquid to flow from the chamber into the tubular element,
• a plunger seated within the tubular element having one end that extends through the opening and another end in the tubular element to which is attached a resilient seal,
• said resilient seal fitting snug against the tubular element to grip said tubular element and, in response to movement of the plunger, to move the tubular element between a first position where said seal with the orifice therein seals the injection port as the plunger is moved towards said injection port and moves the tubular element into a position which blocks the passageway to prevent liquid in the chamber from passing into the tubular element, said plunger as it is moved towards the ejection port forcing any liquid in the tubular element through the orifice and out the injection port, and a second position where said seal with the orifice therein is moved to a retracted position away from the injection port to move the tubular element into a position which unblocks the passageway to allow liquid in the chamber to flow from the chamber through the passageway and through the orifice into the tubular member.