Syringe with multifunctional needle holder and retainer ring assembly
Inventors
Shaw, Thomas J. • Zhu, Ni • Duesman, Jordan
Assignees
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Publication Number
US-11298467-B2
Publication Date
2022-04-12
Expiration Date
Abstract
A syringe for medical use, the syringe having a selectively retractable needle and a multifunctional needle holder and retainer ring assembly including a needle holder with a head section having an inwardly tapering frustoconical section of the fluid pathway and a rearwardly facing annular surface surrounding the rear opening, and an elastomeric retainer ring with a substantially unexpanded collar extending rearwardly beyond the rearwardly facing annular surface to increase needle pushout force, reduce activation force and improve fluid flow through the syringe. Annular projections inside the retainer ring and on the outer surface of the head section of the needle holder are also disclosed.
Core Innovation
The invention relates to a retractable-needle medical syringe having a cooperatively configured needle holder and retainer ring assembly. The needle holder includes a head section having a rear opening into a coaxially aligned fluid flow path that communicates with a retractable needle, and the rear opening has a frustoconical inwardly facing wall surface located proximally to the rear opening.
The syringe includes an elastomeric retainer ring having a first longitudinally extending portion that is expanded radially and surrounds the head section of the needle holder. The retainer ring also includes a second longitudinally extending collar portion that is substantially unexpanded radially and extends rearwardly behind the head section of the needle holder, and the rearwardly extending collar portion cooperates with the frustoconical inwardly facing wall surface.
By this cooperative configuration, the rearwardly extending collar portion and the frustoconical inwardly facing wall surface reduce a thumb force required to advance the plunger assembly inside the barrel during injection. The cooperative features also reduce turbulence in a fluid entering the rear opening into the fluid flow path and reduce retention of any air bubble in fluid disposed around the opening during use of the syringe.
Claims Coverage
The provided content identifies one independent claim with three main inventive features centered on the needle-holder geometry and elastomeric retainer ring cooperation.
Frustoconical fluid-flow rear opening at the needle-holder head section
A head section of the needle holder has a rear opening into a coaxially aligned fluid flow path communicating with the retractable needle, and a frustoconical inwardly facing wall surface is located proximally to the rear opening.
Expanded radial retainer portion and substantially unexpanded rearward collar portion
An elastomeric retainer ring has a first longitudinally extending portion expanded radially and surrounding the head section of the needle holder, and a second longitudinally extending collar portion substantially unexpanded radially and extending rearwardly behind the head section.
Cooperation of the rearward collar portion with the frustoconical wall
The rearwardly extending collar portion cooperates with the frustoconical inwardly facing wall surface to reduce a thumb force required to advance the plunger assembly inside the barrel, reduce turbulence in a fluid entering the rear opening during injection, and reduce retention of any air bubble in fluid disposed around the opening during use of the syringe.
The independent claim is directed to the frustoconical inwardly facing wall near the coaxially aligned rear opening, combined with an elastomeric retainer ring having an expanded radial portion and a substantially unexpanded rearward collar, with the cooperation of those features used to reduce thumb force, turbulence, and air-bubble retention.
Stated Advantages
Reduce thumb force required to advance the plunger assembly inside the barrel.
Reduce turbulence in a fluid entering the rear opening into the fluid flow path during injection.
Reduce retention of any air bubble in fluid disposed around the opening during use of the syringe.
Documented Applications
Use of the syringe as a selectively retractable needle medical syringe during injection.
Use of the syringe to reduce retention of air bubbles disposed around the opening during use.
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