Injection devices

• US 20040215151A1
• Filed: 06/07/2004
• Published: 10/28/2004
• Est. Priority Date: 07/28/2001
• Status: Active Grant

• Current Assignee: Owen Mumford
• Original Assignee: Owen Mumford
• Inventors: Marshall, Jeremy, Hansen, Nick
• Granted Patent: US 7,695,453 B2
• Time in Patent Office: Days
• US Class Current: 604/198
• CPC Class Codes: A61M 2005/206 With automatic needle insertion
• CPC Class Codes: A61M 2005/3247 Means to impede repositioning of protection sleeve from needle covering to needle uncovering position
• 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• CPC Class Codes: A61M 5/322 Retractable needles, i.e. disconnected from and withdrawn into the syringe barrel by the piston devices for protecting guide needles in combination with catheters A61M25/0612
• CPC Class Codes: A61M 5/3257 Semi-automatic sleeve extension, i.e. in which triggering of the sleeve extension requires a deliberate action by the user, e.g. manual release of spring-biased extension means
• CPC Class Codes: A61M 5/3271 with guiding tracks for controlled sliding of needle protective sleeve from needle exposing to needle covering position

Abstract

An injection device for a syringe incorporates a housing (1) for a syringe (29). A needle shroud (15) is captive to the leading end of the housing and is movable before use between extended and retracted positions. A drive member (17) is releasable from a rearward position within the housing to urge the syringe forwards to project its needle (30) beyond the retracted needle shroud (15) and then to express a dose through the needle. Locating members (12) on the housing capture the drive member (17) at its forward position (attained after expressing the dose). The captured drive member (17) is also arranged to block retraction of the needle shroud (15) from its extended position.

Claims

1-13. -13. (cancelled)

14. An injection device for a syringe, the device comprising a housing for the syringe, a needle shroud captive to the leading end of the housing and movable before use between extended and retracted positions, a drive member releasable from a rearward position within the housing to urge the syringe forwards to project its needle beyond the retracted needle shroud and then to express a dose through the needle, and locating members on the housing for capturing the drive member at its forward position attained after expressing the dose, and wherein the captured drive member is arranged to block retraction of the needle shroud from its extended position.

15. An injection device according to claim 14, wherein the needle shroud is biased forwardly so that, in use, as the device is pressed against the skin, the shroud is pushed back into the housing.

16. An injection device according to claim 14, wherein the drive member is spring-actuated.

17. An injection device according to claim 16, wherein the drive member has a plunger that enters the rear end of the syringe to engage the piston within the syringe, thereby supporting the syringe at its rear end.

18. An injection device according to claim 14, wherein the needle of the syringe has a collapsible rubber sheath which acts as a support for the forward end of the syringe.

19. An injection device according to claim 18, wherein the tip of the sheath is located in a small cup-like formation of the housing provided with a central aperture through which the needle, but not the sheath, can penetrate.

20. An injection device according to claim 14, wherein the drive member has arms that extend forwardly to co-operate with the interior of the housing and the needle shroud.

21. An injection device according to claim 20, wherein locating formations on the housing are provided to cause the leading ends of the arms to be flexed inwards and to enter the retracted needle shroud.

22. An injection device according to claim 21, wherein abutments on the outsides of the arms are provided to be in registry with said locating formations on the inside of the housing so that, after completion of the injection operation, the drive member cannot be pushed back.

23. An injection device according to claim 22, wherein said abutments are hooked for positive interengagement.

24. An injection device according to claim 20, wherein the ends of the arms are aligned with the needle shroud, after completion of the injection operation, and provide abutments to prevent the shroud being pushed back