Expanding Plunger Rods for Syringes

• US 20170182254A1
• Filed: 02/03/2015
• Published: 06/29/2017
• Est. Priority Date: 02/03/2014
• Status: Active Grant

• Current Assignee: UNL Holdings, LLC
• Original Assignee: Unitract Syringe Pty Limited (Unilife Corp.)
• Inventors: Heinsbergen, Daniel A., Bell, JR., Bryan Frederick, Russo, Robert Scott, Panneerselvam, Dinesh, McKee, Brandon J.
• Granted Patent: US 10,420,891 B2
• Time in Patent Office: Days
• 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 5/28 Syringe ampoules or carpules, i.e. ampoules or carpules provided with a needle
• CPC Class Codes: A61M 5/3134 characterised by constructional features of the distal end, i.e. end closest to the tip of the needle cannula
• CPC Class Codes: A61M 5/3135 characterised by constructional features of the proximal end
• CPC Class Codes: A61M 5/31501 Means for blocking or restricting the movement of the rod or piston A61M5/5013 takes precedence
• CPC Class Codes: A61M 5/31511 Piston or piston-rod constructions, e.g. connection of piston with piston-rod A61M5/5066 takes precedence
• CPC Class Codes: A61M 5/31515 Connection of piston with piston rod

Abstract

An expanding plunger rod for a syringe is configured to transition from a packaged configuration to an expanded configuration for operation. The rod includes a substantially cylindrical outer sleeve having a closed-off bottom end and an open upper end, and an inner rod having a lower end and an upper end. The inner rod is slidably disposed coaxially within the outer sleeve. In the packaged configuration, the inner rod is nested within the outer sleeve. In the expanded configuration, the inner rod is disposed substantially axially above the outer sleeve, and the inner rod locks axially in place to prevent transition from the expanded to the packaged configuration.

Claims

1. An expanding plunger rod for a syringe, the expanding plunger rod configured to transition from a packaged configuration for packaging to an expanded configuration for operation, the expanding plunger rod comprising:

a substantially cylindrical outer sleeve having a closed-off bottom end and an open upper end; and

an inner rod having a lower end and an upper end, the inner rod being slidably disposed coaxially within the outer sleeve;

wherein, in the packaged configuration, the inner rod is nested within the outer sleeve; and

wherein, in the expanded configuration, the inner rod is disposed substantially axially above the outer sleeve, and the inner rod is configured to lock axially in place so as to prevent transition from the expanded configuration to the packaged configuration.

2. The expanding plunger rod of claim 1, wherein the outer sleeve includes a first locking mechanism and the inner rod includes a second locking mechanism, and wherein, in the expanded configuration, the first locking mechanism is engaged with the second locking mechanism so as to prevent transition from the expanded configuration to the packaged configuration.

3. The expanding plunger rod of claim 1, wherein the closed bottom end of the outer sleeve is configured to connect to a plunger, the outer sleeve and the plunger seal being slidable within a fluid compartment of the syringe.

4. The expanding plunger rod of claim 1, further comprising an inner sleeve having a lower end and an upper end, the inner sleeve being slidably disposed coaxially within the outer sleeve and the inner rod being slidably disposed within the inner sleeve, wherein, in the expanded configuration, the upper end of the inner sleeve and the lower end of the inner rod are disposed axially above the open upper end of the outer sleeve.

5. The expanding plunger of claim 4, wherein the outer sleeve includes a first stop mechanism, the inner sleeve includes a second stop mechanism and a third stop mechanism, and the inner rod includes a fourth stop mechanism, wherein, in the expanded configuration, the first stop mechanism is engaged with the second stop mechanism and the third stop mechanism is engaged with the fourth stop mechanism so as to prevent further axial travel of the inner sleeve and the inner rod away from the outer sleeve.

6. The expanding plunger rod of claim 4, wherein the outer sleeve includes a first locking mechanism, the inner sleeve includes a second locking mechanism and a third locking mechanism, and the inner rod includes a fourth locking mechanism, and wherein, in the expanded configuration, the first locking mechanism is engaged with the second locking mechanism and the third locking mechanism is engaged with the fourth locking mechanism so as to prevent transition from the expanded configuration to the packaged configuration.

7. The expanding plunger rod of claim 1, wherein the outer sleeve further comprises a pull-back lockout tab that is configured to prevent removal of the outer sleeve from a barrel of the syringe.

8. A syringe assembly configured to transition from a packaged configuration for packaging to an expanded configuration for operation, the syringe comprising:

a substantially cylindrical barrel having a plunger end and a connection end;

a plunger seal disposed within the plunger end of the barrel;

a needle seal disposed within the connection end of the barrel;

a fluid compartment defined within the barrel between the plunger seal and the needle seal; and

an expanding plunger rod comprising;

a substantially cylindrical outer sleeve having a closed-off bottom end connected to the plunger, and an open upper end,

an inner sleeve having a lower end and an upper end, the inner sleeve being slidably disposed coaxially within the outer sleeve, and an inner rod having a lower end and an upper end, the inner rod being slidably disposed coaxially within the inner sleeve;

wherein, in the packaged configuration, the inner sleeve and the inner rod are both nested within the outer sleeve; and

wherein, in the expanded configuration, the upper end of the inner sleeve and the lower end of the inner rod are both disposed axially above the open upper end of the outer sleeve, and the inner sleeve and inner rod are configured to lock axially in place so as to prevent transition from the expanded configuration to the packaged configuration.

9. The syringe assembly of claim 8, wherein the outer sleeve includes a first locking mechanism, the inner sleeve includes a second locking mechanism and a third locking mechanism, and the inner rod includes a fourth locking mechanism, and wherein, in the expanded configuration, the first locking mechanism is engaged with the second locking mechanism and the third locking mechanism is engaged with the fourth locking mechanism so as to prevent transition from the expanded configuration to the packaged configuration.

10. The syringe assembly of claim 8, wherein the outer sleeve and the plunger seal are slidable within the fluid compartment of the syringe to expel fluid out of the fluid compartment.

11. The syringe assembly of claim 8, wherein the outer sleeve further comprises a stop mechanism configured to engage with the barrel so as to prevent the expanding plunger rod from being removed from the barrel.

12. The syringe assembly of claim 11, wherein the barrel further comprises a collar disposed at the plunger end of the barrel, the stop mechanism of the outer sleeve being configured to engage with the collar to so as to prevent the expanding plunger rod from being removed from the barrel.

13. The syringe assembly of claim 9, wherein the first locking mechanism is an outer lock orifice formed into a side of the outer sleeve and the second locking mechanism is an inner sleeve lock disposed on a side of the inner sleeve, wherein, in the expanded configuration, the inner sleeve lock extends radially outward into the outer lock orifice.

14. The syringe assembly of claim 13, wherein the third locking mechanism is an inner lock orifice formed into a side of the inner sleeve, and the fourth locking mechanism is an inner rod lock disposed on a side of the inner rod, wherein, in the expanded configuration, the inner rod lock extends radially outward into the inner lock orifice.

15. The syringe assembly of claim 8, wherein the outer sleeve includes a first stop mechanism, the inner sleeve includes a second stop mechanism and a third stop mechanism, and the inner rod includes a fourth stop mechanism, wherein, in the expanded configuration, the first stop mechanism is engaged with the second stop mechanism and the third stop mechanism is engaged with the fourth stop mechanism so as to prevent transition further axial travel of the inner sleeve and the inner rod away from the outer sleeve.

16. An expanding plunger rod for a syringe, the expanding plunger rod configured to transition from a packaged configuration for packaging to an expanded configuration for operation, the expanding plunger rod comprising:

a substantially cylindrical outer sleeve having a closed-off bottom end and an open upper end;

an inner rod having a lower end and an upper end, the inner rod being slidably disposed coaxially within the outer sleeve and including a top piece extending axially above the open upper end of the over sleeve; and

a biasing member disposed between the top piece of the inner rod and the closed-off bottom end of the outer sleeve, the biasing member biasing the top piece and the bottom end axially away from one another;

wherein, in the packaged configuration, the inner rod is nested within the outer sleeve, and in the expanded configuration, the inner rod is disposed substantially axially above the outer sleeve, and the inner rod is configured to lock axially in place so as to prevent transition from the expanded configuration to the packaged configuration; and

wherein the biasing member is configured to automatically transition the expanding plunger rod from the packaged configuration to the expanded configuration.

17. The expanding plunger rod of claim 16, wherein the closed bottom end of the outer sleeve is configured to connect to a plunger, the outer sleeve and the plunger seal being slidable within a fluid compartment of the syringe.

18. The expanding plunger rod of claim 16, further comprising an inner sleeve having a lower end and an upper end, the inner sleeve being slidably disposed coaxially within the outer sleeve, and the inner rod being slidably disposed coaxially within the inner sleeve, wherein, in the expanded configuration, the upper end of the inner sleeve and the lower end of the inner rod are both disposed axially above the open upper end of the outer sleeve.

19. The expanding plunger rod of claim 16, wherein the biasing member is configured to automatically transition the expanding plunger rod from the packaged configuration to the expanded configuration upon being triggered.

20. The expanding plunger rod of claim 18, wherein the outer sleeve includes a first locking mechanism, the inner sleeve includes a second locking mechanism and a third locking mechanism, and the inner rod includes a fourth locking mechanism, and wherein, in the expanded configuration, the first locking mechanism is engaged with the second locking mechanism and the third locking mechanism is engaged with the fourth locking mechanism so as to prevent transition from the expanded configuration to the packaged configuration.