NEEDLE HOLDER ASSEMBLY

Cross-Reference to Related Application

[0001] This application claims the benefit of U.S. Provisional Application No. 61/601610, filed February 22, 2013.

Background

Field of the Invention

[0002] This invention relates to an improved needle holder assembly for use in medical devices and, more particularly, in medical devices embodying user-activated needle retraction mechanisms.

Description of Related Art

[0003] Syringes as disclosed for example in U.S. 5,385,551 utilize needle retraction mechanisms comprising a needle holder having a centrally disposed, longitudinal bore with a substantially constant inside diameter. The needle is attached to the walls of the longitudinal bore using glue or other similarly effective means. Because of the small clearances along the sides of the needle, glue sometimes wicks rearwardly and occludes or partially occludes the opening at the blunt, rearwardly facing end of the needle, or is unevenly distributed around the needles so that the needles sometimes detach from the needle holders during use or prior to withdrawal from a patient.

[0004] More recently, syringes as disclosed for example in U.S. 5,632,733 utilize needle retraction mechanisms comprising a needle holder having a centrally aligned longitudinal bore with a varying inside diameter. A series of annular recesses is provided in the front portion of the longitudinal bore of the needle holder to provide glue pockets that hold the needle more securely and reduce the likelihood that glue will wick rearwardly around the needle far enough to occlude the rearwardly facing open end of the needle before the glue hardens or is fully cured. Although the use of annular giue pockets near the front of the needle holder is an effective means for securing the needle to the needle holder and for preventing unintentional blockage of the needle, excess or misapplied glue can interfere with needle retraction, and core pins used to mold the needle holders can wear prematurely when withdrawn from the annular recesses, resulting in undesirably higher labor and equipment costs to manufacture the subject needle holders.

SUMMARY OF THE INVENTION

[0005] A needle holder assembly is disclosed that comprises a needle holder with a longitudinal bore, a needle, and a controlled quantity of a glue or other adhesive composition. The needle has a first end insertable rearwardly into the bore and a second end projecting forwardly from the bore. The glue or adhesive desirably has a viscosity that allows it to be deposited around the needle shaft at a predetermined axial location along the needle shaft in such manner that the glue or adhesive can be inserted past a rearwardly facing, transverse annular shoulder disposed inside the bore of the needle holder to provide abutting engagement against the shoulder when the glue or adhesive is cured or hardened. The needle holder is desirably made of a polymeric or glass material, has a substantially cylindrical head and an elongate body projecting forwardly from the head and having an outer diameter smaller than that of the head. The rearwardly facing annular shoulder of the needle holder is desirably disposed between a front section of the bore having a first inside diameter slightly larger than the outside diameter of the needle, and a rear section of the bore having a second inside diameter that is larger than the first inside diameter.

BRIEF DESCRIPTION OF THE DRAWINGS

[0006] The needle holder assembly of the invention is further described and explained in relation to the following figures of the drawings, in which:

FIG. 1 is an exploded, cross-sectional front elevation view of the needle holder and needle of one embodiment of the invention, with a quantity of glue or adhesive deposited on the needle shaft;

FIG. 2 is a cross-sectional front elevation view of the needle holder of the invention as assembled for use in a medical device having a retractable needle assembly;

FIG. 3 is an enlarged, detail view of the needle of FIG. 1 ; and

FIG. 4 is an enlarged, detail view of the upper portion of the needle holder of FIG. 2.

Like reference numerals are used to describe like parts in all figures of the drawings.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0007] Referring to FIGS. 1-4, needle holder assembly 10 of the invention desirably comprises needle holder 12, needle 14, and a controlled quantity of adhesive 10 that desirably has a viscosity that is low enough to render it sufficiently pliable to be inserted through the smaller diameter section of bore 24 of front part 28 of elongate body portion 26 but high enough that it will not flow rearwardly to occlude rear opening 18 of needle 14.

[0008] Needle holder 12 is preferably made of a moldable polymeric material and further comprises head 22, and elongate body portion 26 with an outer diameter less than that of head 22. The end of needle 14 with rear opening 18 is desirably insertabie into needle holder 30 at front end 30 after a quantity of adhesive 20 is deposited at a predetermined location on needle 14 that corresponds to the position of rearwardly facing, transverse annular shoulder 32 of needle holder 12. After the quantity of adhesive 20 is in place and cured or hardened by conventional means, it desirably abuts against the rearwardly facing annular shoulder 32 to provide additional holding force to needle 14 relative to needle holder 12 to prevent needle 14 from being separated from needle holder 12 during use, and particularly, prior to needle retraction, when beveled front tip 16 of needle 14 is still disposed inside a patient.

[0009] Other alterations and modifications of the invention will likewise become apparent to those of ordinary skill in the art upon reading this specification in view of the accompanying drawings, and it is intended that the scope of the invention disclosed herein be limited only by the broadest interpretation of the appended claims to which the inventors are legally entitled.