Intravenous injection apparatus and needle adapter with filter and method of making same

Claim 1

A needle adapter and filter therefor, comprising: a tubular housing having opposite ends and having a stepped axial bore therethrough defining an axially facing annular shoulder between the ends thereof; a tubular insert having opposite ends and having an axial bore therethrough and fitted coaxially within the bore through the housing, with the bore in the insert in axial alignment and registry with the bore in the housing, and one of said insert ends defining a flat, annular, surface normal to the axis of the insert, and substantially commensurate in size and shape with the shoulder; and a mesh filter having a generally dome-shaped central surface surrounded by a flat annular marginal section sealed and secured to said one end of the insert prior to positioning of the insert in the bore of the housing for assembly of the insert and filter as a unit within the housing, the flat annular section of said filter coinciding with said flat annular surface of the insert, said annular section of said filter sealed to said flat annular surface of said insert, and said annular section of said filter further clamped between the insert end surface and the shoulder, thereby defining a relatively large annular seal area to effect a leakproof structure, whereby the filter filters contaminants or particulate matter from materials or solutions flowing through said adapter.