Syringe with retractable needle and moveable plunger seal

Patent metadata

Field	Value
Publication number	US-9642970-B2
Application number	US-82754810-A
Country	US
Kind code	B2
Filing date	Jun 30, 2010
Priority date	Jun 30, 2010
Publication date	May 9, 2017
Grant date	May 9, 2017

Abstract

A medical device having a barrel, a retractable needle, a needle retraction assembly and a plunger, the needle retraction assembly including and being held inside the barrel prior to retraction at least in part by a retainer member contacting the barrel, the plunger comprising a plunger seal with an body having at least a portion that is rearwardly moveable relative to the plunger and an elastomeric web that seals a retraction cavity inside the plunger prior to retraction of the needle, the retainer member and the plunger seal each cooperating with an inside wall of the barrel to provide a sealed liquid containment chamber inside the device.

First claim

What is claimed is:

1. A syringe comprising a barrel, a rearwardly biased needle retraction assembly disposed forwardly in the barrel, and a plunger assembly slidably engaging the barrel to define a fluid chamber disposed between the needle retraction assembly and the plunger assembly;
the plunger assembly further comprising a plunger having a tubular body with a front tip defining an opening into a retraction cavity disposed inside the tubular body, and an elastomeric plunger seal disposed over and around the front tip and the opening;
the elastomeric plunger seal further comprising an annular body portion that provides a fluid seal against the barrel and a transverse web portion that covers the opening into the retraction cavity;
the barrel and the plunger assembly being cooperatively configured so that the annular body portion of the elastomeric plunger seal is pushed rearwardly on the tubular body of the plunger as the plunger is moved forwardly relative to the barrel prior to initiating needle retraction, thereby displacing and repositioning the annular body portion relative to the tubular body, and stretching and thinning the transverse web portion so that the transverse web portion is more easily ruptured by a rearwardly extending portion of the needle retraction assembly and contracts following rupture to a position outside the opening that does not block the opening into the retraction cavity.

2. The syringe of claim 1 wherein the annular body portion of the elastomeric plunger seal comprises a plurality of longitudinally spaced apart, outwardly facing annular ridges that slidably engage the barrel.

3. The syringe of claim 1 wherein the annular body portion of the elastomeric plunger seal comprises an inwardly facing annular recess.

4. The syringe of claim 3 wherein the tubular body of the plunger comprises an outwardly facing positioning ring that is received within the inwardly facing annular recess of the annular body portion of the elastomeric plunger seal.

5. The syringe of claim 1 wherein the rearwardly biased needle retraction assembly comprises a spring.

6. The syringe of claim 1 wherein the rearwardly extending portion of the needle retraction assembly comprises at least one rearwardly projecting structure that is configured to rupture the transverse web portion.

7. The syringe of claim 6 wherein the at least one rearwardly projecting structure is positioned to contact the center of the transverse web portion.

8. The syringe of claim 6 wherein the needle retraction assembly comprises at least two spaced-apart rearwardly projecting structures.

9. The syringe of claim 1 wherein the barrel has a front portion comprising a nose and wherein the needle retraction assembly is at least partially seated inside the nose.

10. The syringe of claim 1 wherein the syringe is a single-use syringe.

11. The syringe of claim 1 wherein the front tip of the tubular body of the plunger comprises a stepped front end.

12. The syringe of claim 1 wherein the needle retraction assembly comprises a needle that is releasably attachable to the needle retraction assembly and can be changed prior to rupture of the transverse web portion.

13. The syringe of claim 1 wherein the front tip of the tubular body of the plunger is configured to concentrate a forwardly directed force applied through the plunger against a portion of the needle retraction assembly.

14. The syringe of claim 1 wherein the tubular body of the plunger further comprises a plurality of circumferentially spaced, axially extending ribs disposed a sufficient distance behind the elastomeric plunger seal to permit rearward movement of the elastomeric plunger seal prior to needle retraction.

Assignees

• Shaw Thomas J
• Zhu Ni
• Retractable Technologies Inc

Inventors

• Shaw Thomas J
• Zhu Ni

Classifications

• A61M2005/3239

  triggered by dislodgement of outer part anchoring the needle portion to the inside of the syringe barrel wall, e.g. a ring-shaped portion · CPC title

• A61M5/3234 Primary

  Fully automatic needle retraction, i.e. in which triggering of the needle does not require a deliberate action by the user · CPC title

• A61M5/508

  Means for preventing re-use by disrupting the piston seal, e.g. by puncturing · CPC title

• A61M5/50 Primary

  having means for preventing re-use, or for indicating if defective, used, tampered with or unsterile {(retractable needles or needle protectors with means for preventing re-use A61M5/321)} · CPC title