Refillable column for chromatography at elevated pressure

Claim 1

A refillable column for chromatography at elevated pressure comprised of: (a) a cylinder having a first and a second end with a length exceeding the diameter by a factor of 2 or more, said cylinder being connected at each end to a coupling having internal threads of an inside diameter greater than the inside diameter of said cylinder at the point of connection between said coupling and said cylinder and an annular shoulder disposed at the internal terminus of said thread; (b) a resilient plug having external threads adapted to mate with said internal threads of said coupling disposed therein, said plug having an inwardly tapered extension depending from said threads adapted to contact and cooperate with the annular shoulder of said coupling forming a seal therewith, said extension also having an inwardly and upwardly tapered bottom, said plug also having an axial bore with internal threads disposed in the end opposite said extension and an axially disposed hole communicating between the bottom of said bore and the bottom of said extension of said plug; and (c) a bushing having external threads adapted to engage the internal threads of said bore and disposed therein, said bushing also having an axial hole communicating between the top thereof and the axial hole in said plug with a tubular extension from the top of said hole adapted to receive a flexible tube connection therewith.