Narrow diameter needle having reduced inner diameter tip
OwnerMark Batich, Andrew T. Hunt +1inventors
InventorsMark Batich, Andrew T. Hunt, Miodrag Oljaca
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Abstract
Tubular needles have a reduced inner diameter tip portion that increases back pressure behind the tip portion. This constricted tip portion promotes improved atomization, particularly when the liquid passes through the needle at near-supercritical conditions. A preferred method for constricting the inner diameter of a needle tip is to dip the dip of the needle in an electroless plating solution, such as an electroless nickel solution.
Claims27
A needle having a cylindrical portion of a first inner diameter of less than 500 microns in diameter extending to a tip portion having a constriction of a second inner diameter reduced relative to said first inner diameter by at least about 25%, wherein said constriction is provided by material deposited on said tip portion, said material extending at least about 1 mm along the interior surface of said tip portion and wherein at least a longitudinal portion of said needle is in thermal contact with a heat transfer means formed of thermally conducting material, whereby said longitudinal portion may be heated through said heat transfer means.
An electrically conducting needle having a cylindrical portion of a first inner diameter of less than 500 microns in diameter extending to a tip portion having a constriction of a second inner diameter reduced relative to said first inner diameter by at least about 25% , wherein said constriction is provided by material deposited on said tip portion, said material extending at least about 1 mm along the interior surface of said tip portion, and a pair of electrical leads are attached at longitudinally spaced-apart locations on said needle whereby current may be passed through the needle to resistively heat said needle.
Dependencies are inferred from the claim text.