Coupling for an auto-injection device

• US 7,758,548 B2
• Filed: 12/08/2005
• Issued: 07/20/2010
• Est. Priority Date: 12/09/2004
• Status: Active Grant

• Current Assignee: West Pharmaceutical Services of Delaware, Inc. (West Pharmaceutical Services Incorporated)
• Original Assignee: West Pharmaceutical Services of Delaware, Inc. (West Pharmaceutical Services Incorporated)
• Inventors: Gillespie, Richard David, Crow, Doug Owen
• Primary Examiner(s): Lucchesi; Nicholas D
• Assistant Examiner(s): Stigell; Theodore J
• Application Number:
  US11/297,225
• Publication Number:
  US 20060178629A1
• Time in Patent Office: 1,685 Days
• Field of Search: 604/110, 604/131, 604/134, 604/135, 604/136, 604/137, 604/138, 604/156
• US Class Current: 604/134
• CPC Class Codes: A61M 2005/206 With automatic needle insertion
• CPC Class Codes: A61M 2005/2073 preventing premature release, e.g. by making use of a safety lock
• CPC Class Codes: A61M 2005/2403 Ampoule inserted into the ampoule holder
• CPC Class Codes: A61M 2005/3107 for needles
• CPC Class Codes: A61M 2005/31516 reducing dead-space in the syringe barrel after delivery
• CPC Class Codes: A61M 5/001 Apparatus specially adapted for cleaning or sterilising syringes or needles
• CPC Class Codes: A61M 5/1782 Devices aiding filling of syringes in situ combination of a vial and a syringe for transferring or mixing their contents A61J1/2096, filling of medical containers in general B65B3/003
• 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 5/2459 upon internal pressure increase, e.g. pierced or burst A61M5/2429 takes precedence
• CPC Class Codes: A61M 5/286 upon internal pressure increase, e.g. pierced or burst A61M5/283 takes precedence
• CPC Class Codes: A61M 5/3129 Syringe barrels A61M5/3205 and A61M5/50 take precedence
• CPC Class Codes: A61M 5/31596 comprising means for injection of two or more media, e.g. by mixing
• CPC Class Codes: A61M 5/3202 Devices for protection of the needle before use, e.g. caps A61M5/50 takes precedence; for infusion spikes A61M5/1626; protectors for sharps A61B50/3001
• CPC Class Codes: A61M 5/326 Fully automatic sleeve extension, i.e. in which triggering of the sleeve does not require a deliberate action by the user

Abstract

A coupling for selectively securing a spring to a plunger is provided. The coupling has a first end defining a spring rest for receiving the spring and a second end defining a shoulder. The shoulder is moveable to a first position into contact with the plunger and to a second position out of contact with the plunger. The shoulder is normally in the second position and is resiliently moveable to the first position.

Claims

1. A power injection assembly, comprising:

a plunger rod having a rib;

an injection spring;

an inner housing having a first opening and an inner diameter, said injection spring surrounding said inner housing and said plunger rod being disposed in said inner diameter; and

a coupling having a spring rest and a shoulder, said coupling being disposed in said inner diameter such that said spring rest extends through said first opening and receives said injection spring and such that said shoulder is compressed to a first position by said inner diameter, said shoulder being engaged with said rib in said first position.

2. The assembly of claim 1, wherein said inner housing further comprises a second opening defined at a predetermined position along an injection direction.

3. The assembly of claim 2, wherein said second opening allows said shoulder to resiliently bias through said inner housing to a second position, said shoulder being disengaged from said rib in said second position.

4. The assembly of claim 2, wherein said injection spring acts on said coupling to urge said plunger in said injection direction.

5. The assembly of claim 2, further comprising an activation device said activation device maintaining said injection spring in a compressed state, said shoulder being remote from said second opening in said compressed state.

6. The assembly of claim 5, wherein said activation device releases said injection spring from said compressed state upon movement of said activation device in two directions.

7. The assembly of claim 1, wherein said spring rest is radially offset and axially offset relative to said shoulder.

8. The assembly of claim 1, further comprising a housing that houses the plunger rod, the injection spring, the inner housing and the coupling.