Patent ID: 7585357

Claim:
A multiple use injection port for the introduction of fluid materials by needle injection into a system under positive pressure, and of the type which comprises (a) an injection pedestal having a central axis and having an upwardly facing generally flat compression seat disposed on said axis for the support of a sealing septum, (b) said injection pedestal having an injection passage extending axially from said seat to provide communication with said system under positive pressure, (c) said injection passage being of a diameter to accommodate the insertion of an injection needle, (d) a sealing septum, formed of resilient, elastomeric material, supported on said seat, (e) an injection port cap threadedly engaging said pedestal and positioned over the top of said septum, (f) said cap having an axial guide opening aligned with said injection passage and being of a diameter to accommodate the passage of an injection needle, (g) said cap having a generally flat compression surface positioned above the upper surface of said septum and said seat and arranged to axially compress said septum against said seat when said cap is tightened onto said pedestal, characterized by (h) said septum being of flat form and having generally flat upper and lower surfaces defining a thickness, and having a transverse dimension substantially greater than said thickness, (i) said septum being initially formed with an axial through opening extending throughout the thickness of the septum and which, when the septum is supported on said seat, is aligned with the injection passage and guide opening, (j) said compression seat and said compression surface serving to act upon the upper and lower surfaces of said septum to axially compress said septum in the thickness direction such that the septum material surrounding the through passage in said septum is displaced in a radially inward direction sufficiently to fully close the septum's through passage and form a seal against the positive pressure of said system, and (k) the material surrounding said fully closed axial through opening being subject to radially outward displacement while said septum remains under axial compression to accommodate the axial passage of an injection needle through the septum passage and into the injection passage in said pedestal.