controlled retraction syringe and plunger therefor

• US 20090221962A1
• Filed: 05/11/2006
• Published: 09/03/2009
• Est. Priority Date: 05/12/2005
• Status: Active Grant

• Current Assignee: UNL Holdings, LLC
• Original Assignee: Unitract Syringe Pty Limited (Unilife Corp.)
• Inventors: Judd, Damien, Kaal, Joseph Hermes, Thorley, Craig Stephen
• Granted Patent: US 8,114,050 B2
• Time in Patent Office: Days
• US Class Current: 604/110
• CPC Class Codes: A61M 2005/31508 provided on the piston-rod
• CPC Class Codes: A61M 2005/31516 reducing dead-space in the syringe barrel after delivery
• CPC Class Codes: A61M 2005/3241 Needle retraction energy is accumulated inside of a hollow plunger rod
• CPC Class Codes: A61M 5/3232 Semi-automatic needle retraction, i.e. in which triggering of the needle retraction requires a deliberate action by the user, e.g. manual release of spring-biased retraction means
• 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 5/508 Means for preventing re-use by disrupting the piston seal, e.g. by puncturing

Abstract

A retractable syringe (10) and plunger (20) therefore are provided, the syringe having a barrel (20), a retractable needle mount (40) to which is mounted or is mountable a needle (11), and a plunger (80), the plunger comprising an initially compressed spring (60), a means for engaging the retractable needle mount, an integrally formed plunger seal (22) and a removable controlling means (70) for facilitating control of the rate of retraction of needle mount when engaged with plunger. The needle mount is held in the barrel by a holding means which prevents inadvertent retraction of the needle mount when the plunger is withdrawn to fill the syringe. The holding means comprises a plurality of clips (196A, 196B, 196C) that may be integrally formed with the barrel or may be present on a cap mounted to the barrel. An ejector means (52) is also provided, whereby plunger depression can urge the ejector means to release the needle from the holding means and thereby allow retraction of the needle mount following decompression of the spring.

Claims

1. A plunger for a retractable syringe having a barrel and a retractable needle mount to which is mounted or is mountable a needle, said plunger comprising a means for engaging said retractable needle mount, an integrally formed plunger seal and a removable controlling means for facilitating control of the rate of retraction of said retractable needle mount when engaged with said plunger.

2. The plunger of claim 1, said plunger further comprising a biasing means, a plunger housing and a plunger member that co-operate to releasably maintain said biasing means in an initially compressed state.

3. The plunger of claim 2, wherein the plunger seal is integrally formed with said plunger housing.

4. The plunger of claim 3, wherein the plunger seal is insert moulded into said plunger housing.

5. The plunger of claim 2, arranged so that release of said plunger member from said housing allows decompression of said biasing means to facilitate retraction of said retractable needle when said plunger member is engaged to said needle mount.

6. The plunger of claim 5, further comprising a retaining means for releasably coupling said controlling means to said plunger housing prior to retraction of said retractable needle mount

7. The plunger of claim 6, arranged so that decompression of said biasing means facilitates disengagement of said retaining means to thereby allow release of said controlling means from said plunger housing.

8. The plunger of claim 7, wherein said controlling means is a control rod.

9. The plunger of claim 7, wherein said biasing means is a spring.

10. A plunger for a retractable syringe having a barrel and a retractable needle mount to which is mounted or is mountable a needle, said plunger comprising a plunger housing, a plunger member and a spring, said plunger housing and plunger member co-operating to maintain said spring in an initially compressed state, said plunger member comprising means for engaging said retractable needle mount, an integrally formed plunger seal and a removable controlling means for facilitating control of the rate of retraction of said retractable needle mount when engaged with said plunger, said plunger further comprising a retaining means for releasably coupling said controlling means to said plunger housing prior to retraction of said retractable needle mount.

11. A retractable syringe having a barrel;

a retractable needle mount to which is mounted or is mountable a needle; and

a plunger comprising a means for engaging said retractable needle mount, an integrally formed plunger seal and a removable controlling means for facilitating control of the rate of retraction of said retractable needle mount when engaged with said plunger.

12. The retractable syringe of claim 11, said plunger further comprising a biasing means, a plunger housing and a plunger member that co-operate to releasably maintain said biasing means in an initially compressed state.

13. The retractable syringe of claim 12, wherein the plunger seal is integrally formed with said plunger housing.

14. The retractable syringe of claim 13, wherein the plunger seal is insert moulded into said plunger housing.

15. The retractable syringe of claim 12, further comprising a holding means that releasably engages said needle mount to thereby prevent retraction of the retractable needle mount during withdrawal of the plunger.

16. The retractable syringe of claim 15, wherein said holding means comprises holding clips integrally formed in said barrel.

17. The retractable syringe of claim 15, wherein said holding means comprises holding clips in a cap mounted to said barrel.

18. The retractable syringe of claim 15, wherein said syringe further comprises an ejector means operable to release said holding means from engagement with said needle mount to thereby allow retraction of said needle mount.

19. The retractable syringe of claim 18, arranged so that release of said plunger member from said housing allows decompression of said biasing means to facilitate retraction of said retractable needle when said plunger member is engaged to said needle mount.

20. The retractable syringe of claim 12, further comprising a retaining means for releasably coupling said controlling means to said plunger housing prior to retraction of said retractable needle mount.

21. The retractable syringe of claim 20, arranged so that decompression of said biasing means facilitates disengagement of said retaining means to thereby allow release of said controlling means from said plunger housing.

22. A retractable syringe comprising a barrel, a retractable needle mount to which is mounted or is mountable a needle;

a plunger comprising a plunger housing, a plunger member and a spring, said plunger housing and said plunger member co-operating to maintain said spring in an initially compressed state;

a holding means that releasably engages said needle mount to thereby prevent retraction of the retractable needle mount during withdrawal of the plunger; and

ejector means operable to release said holding means from engagement with said needle mount to thereby allow retraction of said needle mount;

said plunger member comprising means for engaging said retractable needle mount, an integrally formed plunger seal and a removable controlling means for facilitating control of the rate of retraction of said retractable needle mount when engaged with said plunger, said plunger further comprising a retaining means for releasably coupling said controlling means to said plunger housing prior to retraction of said retractable needle mount.