Auto-injector

Patent metadata

Field	Value
Publication number	US-9724472-B2
Application number	US-201113993528-A
Country	US
Kind code	B2
Filing date	Dec 21, 2011
Priority date	Dec 21, 2010
Publication date	Aug 8, 2017
Grant date	Aug 8, 2017

Abstract

According to the invention, an auto-injector for administering a dose of a liquid medicament (M) comprises of a substantially cylindrical housing arranged to contain a pre-filled syringe filled with the medicament (M), a needle shroud slibably arranged with respect to the housing and adapted to rest on the skin of a patient receiving an injection, a releasable drive means arranged within the housing that is capable of, upon release, translating the needle shroud in a proximal direction (P) towards a safe position (PS) and a rotating collar rotatably arranged within the housing. The needle shroud in the safe position (PS) surrounds the injection needle after the injection has been carried out. The rotating collar engages the needle shroud in a manner that forces the rotating collar to rotate within the housing when the needle shroud is translated in the proximal direction (P).

First claim

The invention claimed is:

1. Auto-injector for administering a dose of a liquid medicament (M), comprising:
a substantially cylindrical housing arranged to contain a pre-filled syringe filled with the medicament (M),
a needle shroud slibably arranged with respect to the housing and adapted to rest on the skin of a patient receiving an injection,
a releasable drive spring arranged within the housing that is capable of, upon release, translating the needle shroud in a proximal direction (P) towards a safe position (PS),
a rotating collar rotatably arranged within the housing,
wherein the needle shroud in the safe position (PS) surrounds the injection needle and wherein the rotating collar directly engages the needle shroud in a manner that forces the rotating collar to rotate within the housing when the needle shroud is translated in the proximal direction (P) towards the safe position (PS),
wherein the rotating collar is arranged to partially absorb excess energy of the drive spring and slow down the proximal movement of the needle shroud.

2. Auto-injector according to claim 1 , wherein the rotating collar comprises a pin that engages a helical recess formed into the needle shroud.

3. Auto-injector according to claim 1 , wherein the needle shroud is slidable from an advanced position (PA) in a distal direction (D) to a retracted position (PR) and from the retracted position (PR) in the proximal direction (P) to the safe position (PS).

4. Auto-injector according to claim 3 , wherein safety member (S) are arranged to cooperate with the needle shroud to prevent a release of the drive spring when the needle shroud is in the advanced position (PA).

5. Auto-injector according to claim 4 , wherein the safety member (S) comprise a blocking element that is slidably arranged relative to the housing, wherein the blocking element is arranged to limit a pivoting movement of the release element hinged to a lateral side of the housing when the needle shroud is in the advanced position (PA) and wherein the blocking element is arranged to allow the release element to pivot about a hinge when the needle shroud is in the retracted position (PR).

6. Auto-injector according to claim 4 , wherein the safety member (S) comprise a bushing that engages a plunger of the pre-filled syringe and/or the bushing engages a coupling shroud slidably arranged within the housing to prevent the release of the drive spring.

7. Auto-injector according to claim 6 ,
wherein the bushing engages the coupling shroud, wherein the drive spring is capable of, upon release, driving the coupling shroud releasably coupled to the plunger from a first position (I) in the proximal direction (P), wherein the proximal translator movement of the coupling shroud with respect to the housing,
translates a syringe retainer receiving the pre-filled syringe in the proximal direction (P) to expose the injection needle of the pre-filled syringe,
depresses the plunger connected to a stopper into the syringe barrel to expel the dose of medicament (M) and
translates the needle shroud in the proximal direction (P).

8. Auto-injector according to claim 7 , wherein the syringe retainer is releasably mounted to the housing, wherein the needle shroud in the retracted position (PR) is arranged to release the syringe retainer to allow for the proximal translation of the syringe retainer with respect to the housing.

9. Auto-injector according to claim 6 , wherein the bushing engages the coupling shroud, wherein the coupling shroud is arranged to be decoupled from the plunger at a pre-determined second position (II) defined by an aperture formed into the housing.

10. Auto-injector according to claim 6 , wherein the bushing engages the coupling shroud, wherein a coupling catch is arranged to abut against a shoulder formed to the plunger to releasably couple the plunger to the coupling shroud.

11. Auto-injector according to claim 10 , wherein the bushing engages the coupling shroud, wherein the aperture allows the coupling catch to deflect radially outwards to decouple the coupling shroud from the plunger at the second position (II).

12. Auto-injector according to claim 1 , wherein the drive spring arranged to be released by manual actuation of a release element that is hinged to the housing or slidably arranged with respect to the housing.

13. Auto-injector according to claim 1 , wherein the drive spring is arranged as a single compression spring.

Assignees

• Hourmand Yannick
• Barrow-Williams Timothy Donald
• Ekman Matthew
• Sanofi Aventis Deutschland

Inventors

• Hourmand Yannick
• Barrow-Williams Timothy Donald
• Ekman Matthew

Classifications

• A61M5/50

  having means for preventing re-use, or for indicating if defective, used, tampered with or unsterile {(retractable needles or needle protectors with means for preventing re-use A61M5/321)} · CPC title

• A61M5/2033 Primary

  Spring-loaded one-shot injectors with or without automatic needle insertion (multishot dosing syringes A61M5/31525, needle insertion only A61M5/3287) · CPC title

• A61M5/326

  Fully automatic sleeve extension, i.e. in which triggering of the sleeve does not require a deliberate action by the user · CPC title

• A61M2005/206

  With automatic needle insertion · CPC title

• A61M2005/208

  Release is possible only when device is pushed against the skin, e.g. using a trigger which is blocked or inactive when the device is not pushed against the skin · CPC title