Hypodermic needle, catheter and method

Claim 1

An improved hypodermic needle assembly for intravenous use in positioning a catheter within a vein, said needle assembly comprising, in combination, a principal needle portion and a proximal tip assembly portion, said principal needle portion comprising a cannula and means at the distal end of said cannula for attachment to a needle hub portion, said cannula having a proximal end opposite said distal end; a cylindrical exterior shank or gauge portion of a given diameter, a central bore or lumen portion of a given diameter and an annular end face at said proximal end of the cannula, said cannula at its proximal end receiving and positioning said proximal tip assembly portion, said tip assembly portion comprising a tip body having a first tip body gauge portion of substantially the same diameter as said gauge portion of said cannula, and a tip body rear extension, said rear extension having a gauge portion of a reduced diameter in relation to the diameter of said first body portion and a radial shoulder extending between said tip body rear extension and said first tip body gauge portion, said tip body shoulder engaging said proximal annular end face of said cannula, said tip assembly further including a major diameter passage or lumen extending through said rear extension gauge portion and at least a part of said tip body, with said tip assembly further including a generally frustoconical tip body bevel extending from said first tip body gauge portion, a proximal or exposed tip gauge portion of reduced diameter relative to the diameter of said cannula gauge portion extending from said body bevel, said tip assembly further including a pointed tip portion at the proximal end of said exposed tip gauge portion said pointed tip portion comprising a tip heel portion, a tip bevel and a pointed end said tip bevel extending between said pointed end and said tip heel portion, the proximal end of said tip body having a reduced diameter passage or lumen extending axially therethrough and communicating at its remote end with the interior of said major diameter lumen, the remote end of said reduced diameter lumen lying within said tip body, wherein a catheter is slidably receivable over said needle assembly such that a proximal end of the catheter is in substantially close proximity with said generally frustoconical tip body bevel, and whereby the proximal end of the catheter is adapted to be positioned within a vein when said tip body bevel is inserted into the same vein such that the catheter will remain in the vein when the needle assembly is removed from the vein.