Syringe assembly having a telescoping plunger rod

Patent metadata

Field	Value
Publication number	US-10159796-B2
Application number	US-201213622384-A
Country	US
Kind code	B2
Filing date	Sep 19, 2012
Priority date	Sep 30, 2011
Publication date	Dec 25, 2018
Grant date	Dec 25, 2018

Abstract

A syringe assembly including a syringe barrel having a first end, a second end, and a sidewall extending therebetween defining a chamber is disclosed. The syringe assembly includes a stopper disposed within the chamber of the syringe barrel and a plunger rod having an inner member engaged with the stopper and an outer member adapted for telescopic movement with respect to the inner member. The plunger rod is transitionable from a collapsed position, in which a portion of the inner member is nested within the outer member, to an extended position, in which the same portion of the inner member extends outside the outer member. The syringe assembly also includes a stop member configured for cooperation with a portion of the syringe barrel, upon relative movement of the outer member with respect to the inner member, to limit the outward travel of the plunger rod from the syringe barrel.

First claim

The invention claimed is:

1. A syringe assembly comprising:
a syringe barrel having a first end, a second end, and a sidewall extending between the first end and the second end defining a chamber;
a stopper disposed within the chamber of the syringe barrel;
a plunger rod having both an inner member engaged with the stopper and an outer member adapted for telescopic movement with respect to the inner member, wherein the plunger rod is transitionable from a collapsed position in which a portion of the inner member is nested within the outer member, to an extended position in which the same portion of the inner member extends outside the outer member; and
at least one stop member located on the inner member of the plunger rod configured for cooperation with a portion of the syringe barrel upon relative movement of the outer member with respect to the inner member to limit the outward travel of the plunger rod from the syringe barrel,
wherein the outer member comprises at least one detent having at least one flexible finger, the detent configured to cooperate with the syringe barrel to limit movement of the outer member into the syringe barrel upon the application of a distally directed force to the plunger rod prior to the plunger rod transitioning to the extended position.

2. The syringe assembly of claim 1 , wherein the at least one stop member limits pull-out of the plunger rod from the syringe barrel.

3. The syringe assembly of claim 1 , wherein the at least one stop member comprises a laterally extending member positioned at a distal end of the inner member.

4. The syringe assembly of claim 3 , wherein the laterally extending member is configured to cooperate with an internal portion of a syringe barrel flange to limit the outward travel of the plunger rod from the syringe assembly upon extension of the plunger rod to the extended position.

5. The syringe assembly of claim 4 , wherein the inner member comprises a locking member for cooperating with an aperture in the outer member for locking the outer member to the inner member in the extended position.

6. The syringe assembly of claim 5 , wherein the outer member comprises a pair of holding members surrounding the aperture and the locking member comprises a pair of reverse bevels for cooperating with the pair of holding members to maintain the outer member in the extended position upon the application of a distal force and a proximal force applied to the outer member.

7. The syringe assembly of claim 1 , wherein the inner member comprises a substantially X-shaped profile configured for engagement with a corresponding substantially X-shaped opening within the outer member.

8. The syringe assembly of claim 1 , further comprising a molded cover having a tear tab for removal of the cover, wherein the cover is configured to constrain the plunger rod from inadvertent transition to the extended position.

9. The syringe assembly of claim 1 , further comprising a medication or drug disposed within the syringe barrel.

10. The syringe assembly of claim 1 ,
wherein, when the outer member is in the collapsed position, a portion of the inner member contacts at least one flexible finger such that the at least one flexible finger is held in a stressed state wherein, if a distally directed force is applied to the plunger rod, the at least one flexible finger engages an upper portion of the syringe barrel and thereby limits the movement of the outer member in the distal direction, and
wherein, when the outer member is in the extended position, the at least one flexible finger is allowed to enter a relaxed state wherein the at least one flexible finger no longer limits the movement of the outer member in the distal direction.

11. The syringe assembly of claim 10 , wherein the at least one flexible finger comprises a ramped portion which, when the outer member is in the collapsed position, engages a sidewall portion of the inner member and thereby forces the at least one flexible finger to be in the stressed state.

12. A telescopic plunger rod assembly comprising:
a plunger rod for use with a syringe assembly, the plunger rod comprising both:
an inner member having a distal end configured for being secured to a stopper located within a syringe barrel, and
an outer member having an open portion configured for telescopically engaging a portion of the inner member, wherein the outer member is integral with the plunger rod, wherein the plunger rod is transitionable from a collapsed position to an extended position; and

at least one stop member located on the inner member of the plunger rod configured for cooperation with a portion of the syringe barrel to limit the outward travel of the outer member from the syringe barrel upon transition of the plunger rod to the extended position,
wherein the outer member comprises at least one detent having at least one flexible finger, the detent configured to cooperate with the syringe barrel to limit movement of the outer member into the syringe barrel upon the application of a distally directed force to the plunger rod prior to the plunger rod transitioning to the extended position.

13. The telescopic plunger rod assembly of claim 12 , wherein the at least one stop member comprises a laterally extending member positioned at the distal end of the inner member and configured to cooperate with an internal portion of a syringe barrel flange to limit the outward travel of the plunger rod from the syringe assembly upon extension of the plunger rod to the extended position.

14. The telescopic plunger rod assembly of claim 13 , wherein the inner member comprises a locking member configured for cooperating with an aperture in the outer member for locking the outer member to the inner member in the extended position.

15. The telescopic plunger rod assembly of claim 14 , wherein the inner member comprises a substantially X-shaped profile configured for engagement with a corresponding substantially X-shaped opening within the outer member.

16. The telescopic plunger rod assembly of claim 12 ,
wherein, when the outer member is in the collapsed position, a portion of the inner member contacts the at least one flexible finger such that the at least one flexible finger is held in a stressed state wherein, if a distally directed force is applied to the plunger rod, the at least one flexible finger engages an upper portion of the syringe barrel and thereby limits the movement of the outer member in the distal direction, and
wherein, when the outer member is in the extended position, the at least one flexible finger is allowed to enter a relaxed state wherein the at least one flexible finger no longer limits the movement of the outer member in the distal direction.

17. The telescopic plunger rod assembly of claim 16 , wherein the at least one flexible finger comprises a ramped portion which, when the outer member is in the collapsed position, engages a sidewall portion of the inner member and thereby forces the at least one flexible finger to be in the stressed state.

Assignees

• Becton Dickinson France Sas

Inventors

• Schiff David Robert
• Turpault Mathieu Dominic
• Gatta Antonio
• Coleman John Depler

Classifications

• A61M2005/3104

  Caps for syringes without needle · CPC title

• A61M5/31511 Primary

  Piston or piston-rod constructions, e.g. connection of piston with piston-rod (A61M5/5066 takes precedence) · CPC title

• A61M5/002

  Packages specially adapted therefor, e.g. for syringes or needles, kits for diabetics (needle protection, e.g. caps, A61M5/3202; for sharps A61B50/3001) · CPC title

• A61M2005/31518

  designed to reduce the overall size of an injection device, e.g. using flexible or pivotally connected chain-like rod members · CPC title

• A61M5/5086

  for indicating if defective, used, tampered with or unsterile · CPC title