DETACHABLE PLUNGER ROD SYRINGE

• US 20080082055A1
• Filed: 09/27/2007
• Published: 04/03/2008
• Est. Priority Date: 09/29/2006
• Status: Active Grant

• Current Assignee: Kpr U.S., LLC (Cardinal Health, Inc.)
• Original Assignee: Tyco Healthcare Group LP (Medtronic Plc)
• Inventors: Sampson, Eric, Lloyd, Ronald, Morefield, Ellen
• Granted Patent: US 8,038,656 B2
• Time in Patent Office: Days
• US Class Current: 604/218
• CPC Class Codes: A61M 5/31515 Connection of piston with piston rod

Abstract

A plunger rod assembly for use with a syringe barrel is provided and includes a plunger rod slidably disposable within the syringe barrel, wherein the plunger rod includes a hub extending distally from a distal end thereof and at least two tabs extending outwardly therefrom. The syringe further includes a plug configured for slidable disposition in the syringe barrel and configured for selective connection to the plunger rod via a bayonet-type engagement. The plug includes a base wall having at least two resilient fingers supported on a first side thereof, wherein each resilient finger is configured to snap-fit engage a respective tab of the plunger rod during connection of the plug to the plunger rod; and a plunger tip supported on a second side of the base wall, opposite the first side, and being configured to form a substantially fluid tight seal with an inner surface of the syringe barrel.

Claims

1. A syringe, comprising:

a syringe barrel having a distal end, a proximal end and defining a cavity therebetween;

a plunger rod slidably disposed within the cavity of the syringe barrel, the plunger rod including a plunger shaft having a hub extending distally from a distal end thereof, the hub includes at least two tabs extending outwardly therefrom; and

a plug configured for slidable disposition in the cavity of the syringe barrel and configured for selective connection to the hub of the plunger rod, the plug including;

a base wall having at least two spaced apart uprights extending from a first side thereof, wherein each upright includes a resilient finger formed therein, each resilient finger is configured to snap-fit engage a respective tab of the plunger rod during connection of the plug to the plunger rod; and

a plunger tip supported on a second side of the base wall, opposite the first side, and being configured to form a substantially fluid tight seal with an inner surface of the cavity of the syringe barrel.

2. The syringe according to claim 1, wherein each resilient finger includes a shoulder extending inwardly therefrom.

3. The syringe according to claim 2, wherein each shoulder includes a sloping distal surface.

4. The syringe according to claim 2, wherein each shoulder includes a substantially orthogonal surface formed therein for inhibiting a respective tab of the plunger rod from moving therebeyond, whereby disconnection of the plug from the plunger rod is prevented.

5. The syringe according to claim 4, wherein each resilient finger defines a recess formed in an inner surface thereof and defining the substantially orthogonal surface.

6. The syringe according to claim 4, wherein at least one tab includes a stop member configured to engage the substantially orthogonal surface of a respective resilient finger.

7. The syringe according to claim 1, wherein the tabs of the plunger rod are diametrically opposed from one another.

8. The syringe according to claim 1, wherein tabs of the plunger rod extend substantially radially outward from the hub.

9. The syringe according to claim 1, wherein the tabs and the hub of the plunger rod define a substantially planar distal surface.

10. The syringe according to claim 1, wherein at least one upright includes a stop extending from an inner surface thereof for preventing movement of the tabs of the plunger rod as the plunger rod is rotated with respect to the plug.

11. The syringe according to claim 1, wherein the plunger tip is formed of an elastomeric material.

12. The syringe according to claim 1, wherein the base wall and the uprights of the plug are formed from polypropylene.

13. The syringe according to claim 1, wherein the plug is connected to the distal end of the plunger rod in a bayonet-type connection.

14. A plunger rod assembly for use with a syringe barrel, comprising:

a plunger rod slidably disposable within the syringe barrel, the plunger rod including a hub extending distally from a distal end thereof and at least two tabs extending outwardly therefrom; and

a plug configured for slidable disposition in the syringe barrel and configured for selective connection to the plunger rod via a bayonet-type engagement, the plug including;

a base wall having at least two resilient fingers supported on a first side thereof, wherein each resilient finger is configured to snap-fit engage a respective tab of the plunger rod during connection of the plug to the plunger rod; and

a plunger tip supported on a second side of the base wall, opposite the first side, and being configured to form a substantially fluid tight seal with an inner surface of the syringe barrel.

15. The plunger rod assembly according to claim 14, wherein each resilient finger includes a shoulder extending inwardly therefrom.

16. The plunger rod assembly according to claim 15, wherein each shoulder includes a substantially orthogonal surface formed therein for inhibiting a respective tab of the plunger rod from moving therebeyond, whereby disconnection of the plug from the plunger rod is prevented.

17. The plunger rod assembly according to claim 16, wherein each resilient finger defines a recess formed in an inner surface thereof and defining the substantially orthogonal surface.

18. The plunger rod assembly according to claim 16, wherein at least one tab includes a stop member configured to engage the substantially orthogonal surface of a respective resilient finger.

19. The plunger rod assembly according to claim 14, wherein at least one upright includes a stop extending from an inner surface thereof for preventing movement of the tabs of the plunger rod as the plunger rod is rotated with respect to the plug.

20. A syringe, comprising:

a syringe barrel having a distal end, a proximal end and defining a cavity therebetween;

a plunger rod slidably disposable within the cavity of the syringe barrel, the plunger rod including a plunger shaft having a hub extending distally from a distal end thereof, the hub includes a pair of tabs extending outwardly therefrom; and

a plug configured for slidable disposition in the cavity of the syringe barrel and configured for selective connection to the distal end the plunger rod via a bayonet-type engagement, the plug including;

a base wall having a pair of spaced apart uprights extending from a first side thereof, wherein each upright includes a resilient finger formed therein, each resilient finger is configured to snap-fit engage a respective tab of the plunger rod as the plunger rod is rotated with respect to the plug when the pair of tabs are in registration with the respective resilient fingers; and

a plunger tip supported on a second side of the base wall, opposite the first side, and being configured to form at least a substantially fluid tight seal with an inner surface of the cavity of the syringe barrel.