Syringe
AssigneeBaxter Travenol Laboratories, Inc.
InventorDouglas L. Tompkins
Life of this patent
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Abstract
A contamination resistant syringe is provided in which two sealing rings are axially spaced from each other. The sealing rings are prevented from sweeping the same area and there is no communication between the chamber defined by the two sealing rings and the discharge area forward of the inner sealing ring. In this manner, contamination which might enter from the rear of the barrel will be prevented from contact with the inner ssealing ring.
Claims7
In a syringe comprising a barrel defining a bore and having a discharge portion, and a plunger extending into said bore and movable therewithin, the improvement comprising, in combination:
- inner sealing means carried by said plunger and movable axially within said bore in an area proximate to said discharge portion for substantially preventing leakage of medicament or other biologic fluid contained in the space forward of said inner sealing means adjacent said discharge portion;
- outer sealing means carried by said plunger, said outer sealing means being spaced axially from said inner sealing means and movable axially within said bore in an area behind the travel area of said inner sealing means;
- said plunger having an axial length within the bore of more than one-half of the functional length of the bore void of sealing rings;
- and means for preventing said outer sealing means from moving in the area in which said inner sealing means travels.
Dependencies are inferred from the claim text.