Flexible tube for intra-venous feeding

Claim 1

A flexible intra-venous feeding tube including an inner body having proximal and distal ends and formed from stainless wire as a continuously wound lumen-defining helical spring with a majority of the helices thereof in contact with each other; an uninterrupted externally smooth transparent outer sheath having proximal and distal ends and formed from an inert plastic material so applied around said spring that its inner surface is firmly bonded thereto except at the proximal end portion thereof, the proximal end portion of said outer sheath being radially spaced from the adjacent of said spring whereby to define an annular void therebetween, the distal end of said outer sheath extending beyond the distal end of said spring and shaped to define a distally tapered hollow tip having an open distal end, a plurality of the helices of said spring being separated intermediate the proximal and distal ends thereof to provide a sight zone for visual observation of liquid flow; and a connected hub sealingly secured to the proximal ends of said spring and its said outer sheath, said hub having a proximal end portion provided with an axial socket for the initial retention of the handle of a puncture needle and for subsequent connection to a source of feeding liquid and terminating inwardly in a transverse web provided with a central aperture, said hub having a distal end bell housing provided with two serially arranged cylindrical cavities coaxial with said central aperture, the distal one of said cavities having a diameter greater than that of the other thereof, a rigid sleeve affixed within the smaller diameter of said cavities and having a length to extend distally beyond the distal end of said bell housing, said sleeve having an inside diameter to receive and retain the unsheathed proximal end portion of said spring, means for securing the said proximal end portion of said spring within said sleeve, the proximal end of said outer sheath being fitted over the distal end portion of said sleeve and extending proximally into the annular void defined by the outer surface of said sleeve and the inner surface of said larger diameter cylindrical cavity, at least a portion of the wall of said larger diameter cavity being radially displaced inwardly whereby to secure the said proximal end portion of said outer sheath against the adjacent portion of said sleeve within said larger diameter cavity.