Closure plugs

A resiliently deformable plug for closing an end of a tube, the plug comprising:

• a deformable circular disc portion;
• a deformable annular skirt portion of circular cross-section which projects from the periphery of the disc portion to one side thereof and substantially normal to the normal plane of the disc portion, the skirt portion presenting an outwardly directed annular closure member having an outer diameter which is reducible by resilient deflection of the disc portion to either side thereof;
• and a pin member which is integral with said disc portion and projects in the direction of the longitudinal axis of the plug from the center of the disc portion to said one side thereof, the pin member being circular in transverse cross-section throughout its entire length, the outer wall of said pin member being spaced from the inner surface of said annular skirt portion and concentric therewith with the portion of the circular disc portion disposed between the inner surface of the annular skirt portion and the outer surface of the circular base of the pin member comprising a flexible annulus of uniform width, the skirt portion having a terminal edge and said annular closure member comprising an outwardly projecting, annular sealing member of bulbous form as viewed in transverse cross-section disposed intermediate said circular disc portion and said terminal edge, an outwardly directed annular rim member projecting from the periphery of said annular skirt portion between said annular closure member and said terminal edge, said rim member having an annular abutment face extending normal to the axis of the plug and directed toward said disc portion, said annular skirt portion being formed with an annular groove between said annular abutment face and said annular closure member, at least one wall of said groove extending normal to the axis of said plug and being coextensive with said abutment face of the annular rim member, and axial movement of said pin member from its normal position resiliently deflecting said disc portion substantially symetrically about the center thereof and substantially uniformly reducing the outer diameter of said annular skirt portion and the outwardly directed annular closure member.