Retracting needle assembly for a syringe

• US 6,689,106 B2
• Filed: 01/29/2003
• Issued: 02/10/2004
• Est. Priority Date: 07/31/2000
• Status: Expired due to Term

• Current Assignee: Becton, Dickinson & Co
• Original Assignee: Becton, Dickinson & Co
• Inventors: Sharifi-Mehr, Amir A., Bush, Charles L. Jr., Hoeck, Roger
• Primary Examiner(s): Denion, Thomas
• Assistant Examiner(s): Corrigan, Jaime
• Application Number:
  US10/353,392
• Publication Number:
  US 20030163091A1
• Time in Patent Office: 377 Days
• Field of Search: 604/110, 604/192, 604/194, 604/195, 604/198, 604/181
• US Class Current: 604/181
• CPC Class Codes: A61M 5/3234 Fully automatic needle retraction, i.e. in which triggering of the needle does not require a deliberate action by the user
• CPC Class Codes: A61M 5/349 using adhesive bond or glues
• CPC Class Codes: A61M 5/502 for blocking the piston
• CPC Class Codes: A61M 5/508 Means for preventing re-use by disrupting the piston seal, e.g. by puncturing

Abstract

A retracting needle assembly for use with a syringe barrel having a distally-facing annular sealing surface includes an outer hub having a conduit therethrough, a proximally facing annular sealing surface and means for connecting the outer hub to the syringe barrel. An inner hub having a passageway therethrough is provided. The inner hub includes a distally extending stem and a proximal flange for releasably engaging the outer hub. A needle having a sharp distal end and a proximal end is mounted in the passageway of the inner hub so that the sharp distal end projects distally outwardly. An elongate spring is disposed about the stem of the inner hub and is deflected to provide a bias between the inner hub and the outer hub. A hollow sleeve sized to fit within the conduit of the outer hub over the spring is provided. The sleeve has a sharp edge at its distal end for cutting through the flange to activate the retracting needle feature.

Claims

1. An operable retracting needle assembly for use with a syringe barrel assembly including a syringe barrel having an inside surface defining a chamber, an open proximal end, an open distal end including a needle assembly engaging structure and a distally facing annular sealing surface, and a hollow elongate plunger having a proximal end and a closed distal end defining a cavity therein, said distal end of said plunger forming a slidable seal with said inside surface of said barrel, comprising:

an outer hub having a proximal end, a distal end, an inside surface defining a conduit therethrough, a proximally facing annular sealing surface and an inwardly directed shoulder in said conduit, said outer hub including means for connecting said outer hub to said needle assembly engaging structure of said syringe barrel so that said proximally facing annular sealing surface contacts said distally facing annular sealing surface of said syringe barrel;

an inner hub having a passageway therethrough, said inner hub having a distally extending stem, a proximal flange with an engagement for releasably engaging said conduit of said outer hub, said stem being disposed within and sized for slidable movement within said cavity of said outer hub, said flange having a distal surface and a proximal surface;

a needle having a sharp distal end, a proximal end and a passageway therethrough, said proximal end of said needle being mounted in said passageway of said inner hub so that said sharp distal end projects distally outwardly;

an elongate spring disposed about said stem of said inner hub, said spring being deflected to provide a bias between said flange and said inwardly projecting shoulder; and

a hollow sleeve sized to fit within said conduit of said outer hub over said spring, said sleeve having a distal end disposed at said shoulder and a proximal end having a sharp edge facing said distal surface of said flange so that when said needle assembly is installed on said syringe assembly and a distally directed force, greater than the force required to expel fluid from said chamber, is applied to said plunger, said inner hub is moved sufficiently distally in said outer hub for said sharp edge of said sleeve to cut through said flange and said closed distal end of said plunger to expose said cavity therein, thereby allowing said bias of said spring to urge a sufficient proximal movement of a cut portion of said hub having said needle mounted therein and a cut portion of said distal end of said plunger into said cavity in said plunger to a position wherein an inadvertent exposure of said sharp distal point is substantially prevented.

2. The needle assembly of claim 1 further including an elongate hollow needle shield having a distal end and an open proximal end removably engaged to said outer hub so that said needle shield covers said needle.

3. The needle assembly of claim 1 wherein said means for connecting said outer hub to said syringe barrel includes at least one thread on said outer hub.

4. The needle assembly of claim 3 wherein said at least one thread is a right-hand thread.

5. The needle assembly of claim 3 wherein said at least one thread is a multiple lead thread.

6. The needle assembly of claim 1 wherein said means for connecting said outer hub to said syringe barrel includes at least one thread engaging projection on said outer hub.

7. The needle assembly of claim 1 wherein said proximally facing annular sealing surface is a frusto-conically shaped surface having a total included angle of 3°

to 178°

.

8. The needle assembly of claim 7 wherein said frusto-conically shaped surface has a total included angle of 3°

to 9°

.

9. The needle assembly of claim 7 wherein said frusto-conically shaped surface has a total included angle of 6°

.

10. The needle assembly of claim 1 wherein said inside surface of said conduit of said outer hub has one of a depression therein and a protuberance thereon, and wherein said flange on said inner hub has a conjugate to one of said depression and said protuberance, so that when said stem is disposed in said conduit with said spring compressed between said flange and said shoulder, said conjugates are engaged thereby retaining said inner hub in said outer hub.

11. The needle assembly of claim 1 wherein said sleeve further comprises an outward step adjacent said proximal end, said step serving to accept said cut portion of said flange to allow advancement of said cutter into said distal end of said plunger thereby facilitating cutting through said distal end of said plunger to expose said cavity.

12. The needle assembly of claim 1 wherein said sleeve is formed from a metallic material.

13. The needle assembly of claim 12 wherein said metallic material is stainless steel.

14. The needle assembly of claim 12 wherein said proximal end of said sleeve is subjected to a secondary process to help produce said sharp edge.

15. The needle assembly of claim 14 wherein said process to help produce said sharp edge is selected from the group consisting of grinding, electrochemical processing, honing and combinations thereof.

16. The needle assembly of claim 1 wherein said inner hub and said needle are integrally formed of thermoplastic material.

17. The needle assembly of claim 1 wherein said spring is formed from a metallic material.

18. The needle assembly of claim 1 further comprising being sealed in a package formed from material substantially resistance to the passage of microorganisms and exposed to conditions that render any microorganisms therein substantially non-viable.

19. The needle assembly of claim 1 further including a syringe barrel having an inside surface defining a chamber, an open proximal end, an open distal end including a needle assembly engaging structure and a distally facing annular sealing surface, said hub being threadably engaged to said collar so that said annular sealing surface of said hub contacts said annular sealing surface of said barrel.

20. An operable retracting needle assembly for use with a syringe barrel assembly including a syringe barrel having an inside surface defining a chamber, an open proximal end, an open distal end including a thread and a distally facing frusto-conically shaped annular sealing surface, and a hollow elongate plunger having a proximal end and a closed distal end defining a cavity therein, said distal end of said plunger forming a slidable seal with said inside surface of said barrel, comprising:

an outer hub having a proximal end, a distal end and an inside surface defining a conduit therethrough, a proximally facing frusto-conically shaped annular sealing surface having a total included angle of 3°

to 9° and

an inwardly directed shoulder in said conduit, said outer hub including a thread engaging structure for connecting said outer hub to said thread on said syringe barrel so that said proximally facing annular sealing surface contacts said distally facing annular sealing surface of said syringe barrel;

an inner hub having a passageway therethrough, said inner hub having a distally extending stem, a proximal flange with an engagement for releasably engaging said conduit of said outer hub, said stem being disposed within and sized for slidable movement within said cavity of said outer hub, said flange having a distal surface and a proximal surface;

a needle having a sharp distal end, a proximal end and a passageway therethough, said proximal end of said needle being mounted in said passageway of said inner hub so that said sharp distal end projects distally outwardly;

an elongate spring disposed about said stem of said inner hub, said spring being deflected to provide a bias between said flange and said inwardly projecting shoulder; and

a hollow sleeve sized to fit within said conduit of said outer hub over said spring, said sleeve having a distal end disposed at said shoulder and a proximal end having a sharp edge facing said distal surface of said flange so that when said needle assembly is installed on said syringe assembly and a distally directed force, greater than the force required to expel fluid from said chamber is applied to said plunger, said inner hub is moved sufficiently distally in said outer hub for said sharp edge of said sleeve to cut through said flange and said closed distal end of said plunger to expose said cavity therein, thereby allowing said bias of said spring to urge a sufficient proximal movement of a cut portion of said hub having said needle mounted therein and a cut portion of said distal end of said plunger into said cavity in said plunger to a position wherein an inadvertent exposure of said sharp distal point is substantially prevented.

21. The needle assembly of claim 20 further including an elongate hollow needle shield having a distal end and an open proximal end removably engaged to said outer hub so that said needle shield covers said needle.

22. The needle assembly of claim 20 wherein said thread engaging structure for connecting said outer hub to said syringe barrel includes at least one thread.

23. The needle assembly of claim 22 wherein said at least one thread is a multiple lead thread.