Automatic injection devices

• US 8,668,670 B2
• Filed: 04/10/2012
• Issued: 03/11/2014
• Est. Priority Date: 06/23/2004
• Status: Active Grant

• Current Assignee: AbbVie Biotechnology Ltd. (Puerto Rico) (Abbvie Incorporated)
• Original Assignee: AbbVie Biotechnology Ltd. (Puerto Rico) (Abbvie Incorporated)
• Inventors: Bicknell, Stephen, Julian, Joseph F., Rudzena, William L.
• Primary Examiner(s): Lucchesi, Nicholas
• Assistant Examiner(s): CHANDER, DIVA KAKAR
• Application Number:
  US13/443,384
• Publication Number:
  US 20120197209A1
• Time in Patent Office: 700 Days
• Field of Search: 604/136, 604/157, 604/164.12, 604/135
• US Class Current: 604/135
• CPC Class Codes: A61M 2005/206 With automatic needle insertion
• CPC Class Codes: A61M 2005/31508 provided on the piston-rod
• CPC Class Codes: A61M 5/2033 Spring-loaded one-shot injectors with or without automatic needle insertion multishot dosing syringes A61M5/31525, needle insertion only A61M5/3287
• 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 5/3287 Accessories for bringing the needle into the body; Automatic needle insertion A61M5/20, A61M5/31525 take precedence

Abstract

An injection device comprises a syringe extendible against a spring bias from a retracted position in a housing to a projecting injecting position. A spring biased plunger has collapsible elbows which, when the plunger is released, initially engage the end of the syringe to drive it to the projecting position, whereupon arresting of the syringe movement causes the elbows to collapse inside the syringe to allow the plunger to engage and drive the bung.

Claims

1. An injection device, comprising:

a housing;

a syringe slideably mounted within the housing for movement between a shrouded retracted position relative to the housing and an extended injecting position relative to the housing;

a movable bung slideably mounted in the syringe and moveable to expel a liquid dose through a needle couplable at a distal end of the syringe;

a plunger having a distal end operable to move the bung and to transmit an expulsion force thereto, the plunger being in the form of a rod including;

an upper solid portion having a circular cross-sectional profile,

a lower solid portion having a distal end operable to move the bung and to transmit an expulsion force thereto, the lower solid portion having a first circular circumference, and

a projecting portion comprising two flexible elbows on either side of a central void extending along a central axis of the plunger between the upper and lower solid portions, wherein the flexible elbows project outwardly from the central void when the projecting portion is in a first projecting position, wherein the flexible elbows are inwardly collapsible toward the central void when the projecting portion is in a second collapsed position; and

an actuating bias spring operable to drive the plunger to move the syringe from the shrouded retracted position relative to the housing to the extended injecting position relative to the housing, and to move the plunger forwardly within the syringe to act upon the bung to transmit the expulsion force thereto in order to expel the liquid dose from the syringe through the needle.

2. The injection device of claim 1, wherein the flexible elbows are formed by bifurcation of opposite ends of the upper and lower solid portions.

3. The injection device of claim 1, wherein the central void is a longitudinal slit in the rod.

4. The injection device of claim 1, wherein the central void has an elongated oval cross-sectional profile extending along the central axis of the plunger, and wherein the central void has a first larger width when the projecting portion is in the first projecting position and a second smaller width when the projecting portion is in the second collapsed position.

5. The injection device of claim 1, further comprising:

a return bias member acting between the housing and a proximal end of the syringe to hold the syringe retracted within the housing until the actuating bias member is released.

6. The injection device of claim 5, wherein one or more of the bias members provided within the housing is in the form of a coil spring.

7. The injection device of claim 1, wherein the housing is held fixed at an injection site and wherein the syringe moves within and relative to the housing during an injection.

8. The injection device of claim 1, wherein the plunger is integrally molded.

9. A syringe assembly, comprising:

a syringe couplable to a needle at a distal end;

a bung slideably mounted in the syringe; and

a plunger comprising;

an upper solid portion having a circular cross-sectional profile,

a lower solid portion having a distal end operable to move the bung and to transmit an expulsion force thereto, the lower solid portion having a first circular circumference, and

a projecting portion comprising two flexible elbows on either side of a central void extending along a central axis of the plunger between the upper and lower solid portions, wherein the flexible elbows project outwardly from the central void when the projecting portion is in a first projecting position, wherein the flexible elbows are inwardly collapsible toward the central void when the projecting portion is in a second collapsed position, and wherein the central void is a longitudinally extending slit.

10. The syringe assembly of claim 9, wherein the syringe is slideably mountable within a housing for movement between a first position relative to the housing in which the needle is shrouded by the housing and a second position relative to the housing in which the needle projects from the housing.

11. The syringe assembly of claim 10, wherein the projecting portion of the plunger is configured to drive the syringe from the first position relative to the housing to the second position relative to the housing such that the needle projects from the housing.

12. The syringe assembly of claim 10, wherein movement of the plunger, upon release of an actuating bias member in an automatic injection device, causes the projecting portion to bear against an enlarged head of the syringe in the automatic injection device to drive the syringe from the first position relative to the housing to the second position relative to the housing.

13. The syringe assembly of claim 12, wherein, when in the second collapsed position, the projecting portion collapses inwardly so that it enters the syringe, wherein the collapse of the projecting portion enables the plunger to move within the syringe to compress a liquid dose within the syringe.

14. The syringe assembly of claim 9, wherein the flexible elbows are formed by bifurcation of opposite ends of the upper and lower solid portions.

15. The syringe assembly of claim 9, wherein the projecting portion of the plunger is in the first projecting position prior to entering the syringe and wherein the projecting portion is in the second collapsed position inside the syringe for applying the expulsion force to the bung.

16. The syringe assembly of claim 9, wherein a housing of an injection device is held fixed at an injection site and wherein the syringe moves within and relative to the housing during an injection.

17. The syringe assembly of claim 9, wherein the plunger is integrally molded.