Patent ID: 6375641
Filing Date: 2002-04-23
Classification: A61M

Abstract:
A medical anesthetic needle comprising an inner needle main body having a pencil-pointed, conically shaped tip and an outer needle having a straight tubular shape, the inner needle being inserted into and through the tubular outer needle from the rear end thereof, wherein said outer needle includes:an outer needle main body with a hollow, cylindrical shape having an inner diameter (D) greater than an outer diameter (d) of said inner needle main body, said outer needle having a fore-end portion, a foremost-end portion and a rear end portion, said fore-end portion having a hollow, truncated, substantially conical shape that extends axially from said outer needle main body towards the fore-end portion of said outer needle; and the foremost-end portion having a hollow, truncated substantially conical shape that further extends axially from said fore-end portion towards the fore-end side of said outer needle; wherein, when the inner diameter of said fore-end portion is constant and equal to the inner diameter of said outer needle main body, the inner diameter of said foremost-end portion is reduced along the axis thereof towards the fore-end thereof with the minimum inner diameter (d1) of said foremost-end portion being smaller than the outer diameter (d) of said main body of said inner needle, said foremost-end portion having a circumferential fore-end edge which is biased against a circumferential surface of said tip of said inner needle when said inner needle is inserted into and through said outer needle to its limit, whereby a smooth transition is created between the circumferential fore-end edge of the tubular outer needle and the circumferential surface of the conically shaped tip of the inner needle.