Retractable Syringe with Plunger Disabling System

• US 20080255513A1
• Filed: 01/28/2005
• Published: 10/16/2008
• Est. Priority Date: 01/28/2004
• Status: Active Grant

• Current Assignee: UNL Holdings, LLC
• Original Assignee: Unitract Syringe Pty Limited (Unilife Corp.)
• Inventors: Kaal, Joseph Hermes, Thorley, Craig Stephen, Judd, Damien
• Granted Patent: US 8,002,745 B2
• Time in Patent Office: Days
• US Class Current: 604/110
• CPC Class Codes: A61M 2005/31518 designed to reduce the overall size of an injection device, e.g. using flexible or pivotally connected chain-like rod members
• 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 5/5066 Means for preventing re-use by disconnection of piston and piston-rod
• CPC Class Codes: A61M 5/508 Means for preventing re-use by disrupting the piston seal, e.g. by puncturing

Abstract

A retractable, single use syringe (10) comprises a barrel (20), a collar (60) mounted to the barrel, a retraction spring (70), a needle mount (40) located at a needle end (23) of the barrel and a plunger (30). The plunger comprises a first plunger member (31) and a second plunger member (33) that are releasably coupled to co-operatively maintain the retraction spring in an initial compressed state. The second plunger member (33) further comprises a seal (34) to prevent fluid leakage between plunger (30) and barrel (20). After depression of the plunger to deliver the fluid contents of the syringe, the first plunger member (31) engages the needle mount (40) with needle (12) attached thereto and is rotatably uncoupled from the second plunger member (33) to allow decompression of the retraction spring (70), which forces retraction of the first plunger member (31), needle mount (40) and needle (12) engaged therewith. The first plunger member (31) and the collar (60) comprise elements that co-operatively form a disabling means that prevents or at least minimizes the likelihood of subsequent depression or withdrawal of the plunger (30). Also following retraction of the first plunger member (31), the second plunger member (33) and seal (34) remains at the needle end (23) of the barrel (20) thereby preventing refilling and re-use of the syringe.

Claims

1. A plunger for a retractable syringe having a spring and a needle mount, said plunger comprising a first plunger member and a second plunger member that are releasably engageable to co-operatively maintain said spring in an initial compressed state, arranged so that disengagement of said first plunger member and said second plunger member can facilitate decompression of said spring from the initial compressed state when required to force retraction of said first plunger member and said needle mount when engaged therewith, following depression of said plunger to deliver fluid contents of said syringe.

2. The plunger of claim 1, wherein the first plunger member and the second plunger member are releasably engageable by a bayonet coupling.

3. The plunger of claim 1 wherein said first plunger member and said second plunger member can be disengaged by rotation of the first plunger member relative to the second plunger member.

4. The plunger of claim 1, wherein the first plunger member comprises a needle mount engagement device.

5. The plunger of claim 1, wherein the needle mount engagement device comprises two barbed arms.

6. The plunger of claim 1, wherein the second plunger member comprises a seal mounted thereto.

7. A retractable syringe comprising a plunger, a barrel, a spring and a needle mount, said plunger comprising a first plunger member and a second plunger member that are releasably engaged to co-operatively maintain said spring in an initial compressed state and are disengageable to facilitate decompression of said spring to force retraction of said first plunger member and said needle mount, when engaged therewith, following depression of said plunger to deliver fluid contents of said syringe.

8. The retractable syringe of claim 7, wherein the first plunger member and the second plunger member are engaged by a bayonet coupling.

9. The retractable syringe of claim 7, wherein the first plunger member and the second plunger member can be rotatably disengaged to facilitate decompression of the spring.

10. The retractable syringe of claim 7, wherein the first plunger member comprises a means for engaging said needle mount engagement device.

11. The retractable syringe of claim 8, wherein the means for engaging the needle mount engagement device comprises two barbed arms.

12. The retractable syringe of claim 11, wherein the needle mount comprises recesses that are respectively engageable by the barbed arms.

13. The retractable syringe of claim 7, wherein the second plunger member comprises a seal mounted thereto.

14. The retractable syringe of claim 7, further comprising a collar mounted to the barrel.

15. The retractable syringe of claim 14, wherein said collar comprises one or more projections capable of co-operating with one or more abutments of said first plunger member to form a plunger disabling means device that is capable of preventing subsequent depression and/or withdrawal of said first plunger member following retraction of the needle mount.

16. The retractable syringe of claim 15, wherein the one or more projections comprise two pawls that are engageable with respective steps on said first plunger member to co-operably prevent subsequent depression said first plunger member following retraction of the needle mount and thereby prevent syringe re-use.

17. The retractable syringe of claim 15, wherein the one or more projections comprise two ribs that are engageable with respective ledges on said first plunger member to co-operably prevent subsequent withdrawal of said first plunger member following retraction of the needle mount and thereby prevent syringe re-use.

18. A retractable syringe comprising:

a barrel;

a collar mounted to the barrel and comprising two ribs and two pawls;

a retraction spring;

a needle mount located at a needle end of the barrel; and

a plunger operably located in said barrel and engageable with said needle mount, said plunger comprising;

a first plunger member having two steps and two ledges; and

a second plunger member and a seal mounted thereto;

wherein the first plunger member and the second plunger member are releasably coupled to co-operatively maintain said spring in an initial compressed state and can subsequently be rotatably uncoupled to facilitate decompression of said spring to force retraction of said first plunger member and said needle mount when engaged therewith following depression of said plunger to deliver fluid contents of said syringe and wherein said two pawls are engageable with respective steps on said first plunger member to co-operably prevent subsequent depression said first plunger member and said two ribs are engageable with respective ledges on said first plunger member to co-operably prevent subsequent withdrawal of said first plunger member following retraction of the needle mount and needle.

19. The syringe of claim 18, arranged so that following retraction of the first plunger member, the needle mount and needle, said second plunger member and said seal remain at a needle end the barrel thereby preventing refilling and re-use of the syringe.

20. A method of making a plunger for a syringe, the method comprising:

releasably engaging a first plunger member and a second plunger member to co-operatively maintain a spring in an initial compressed state;

arranging so that disengagement of the first plunger member and the second plunger member decompresses the spring from the initial compressed state to force retraction of the first plunger member and a needle mount when engaged therewith, following depression of the plunger to deliver fluid contents of the syringe.

21. The method of claim 20, wherein the releasably engaging the first plunger member and the second plunger member further comprises releasably engageable the first plunger member and the second plunger member by a bayonet coupling.

22. The method of claim 20 wherein the arranging further comprises arranging the first plunger member to be disengaged from the second plunger member by rotation of the first plunger member relative to the second plunger member.

23. The method of claim 20, wherein the first plunger member further comprises a needle mount engagement device.

24. The method of claim 20, wherein the needle mount engagement device comprises two barbed arms.

25. The method of claim 20, wherein the second plunger member comprises a seal mounted thereto.

26. A method of making a retractable syringe, the method comprising:

providing a plunger, a barrel, a spring and a needle mount;

releasably engaging a first plunger member and a second plunger member to co-operatively maintain the spring in an initial compressed state; and

arranging so that disengagement of the first plunger member and the second plunger member decompresses the spring to force retraction of the first plunger member and the needle mount, when engaged therewith, following depression of the plunger to deliver fluid contents of the syringe.

27. The method of claim 26, wherein the releasably engaging the first plunger member and the second plunger member further comprises releasably engageable the first plunger member and the second plunger member by a bayonet coupling.

28. The method of claim 26, wherein the arranging further comprises arranging the first plunger member to be disengaged from the second plunger member by rotation of the first plunger member relative to the second plunger member.

29. The method of claim 26, wherein the first plunger member further comprises a needle mount engagement device.

30. The method of claim 29, wherein the needle mount engagement device comprises two barbed arms.

31. The method of claim 30, wherein the needle mount further comprises recesses that are respectively engageable by the barbed arms.

32. The method of claim 26, wherein the second plunger member further comprises a seal mounted thereto.

33. The method of claim 26, further comprising mounting a collar to the barrel.

34. The method of claim 33, wherein the collar comprises one or more projections capable of co-operating with one or more abutments of the first plunger member to form a plunger disabling device that is capable of preventing subsequent depression and/or withdrawal of the first plunger member following retraction of the needle mount.

35. The method of claim 34, wherein the one or more projections comprise two pawls that are engageable with respective steps on the first plunger member to co-operably prevent subsequent depression the first plunger member following retraction of the needle mount and prevent syringe re-use.

36. The method of claim 34, wherein the one or more projections comprise two ribs that are engageable with respective ledges on the first plunger member to co-operably prevent subsequent withdrawal of the first plunger member following retraction of the needle mount and prevent syringe re-use.