Auto-injector

Patent metadata

Field	Value
Publication number	US-9474859-B2
Application number	US-201113807445-A
Country	US
Kind code	B2
Filing date	Jun 22, 2011
Priority date	Jun 28, 2010
Publication date	Oct 25, 2016
Grant date	Oct 25, 2016

Abstract

The invention refers to a shuttering mechanism for controlling translation of a longitudinally moveable component within an elongate housing, the shuttering mechanism comprising at least one set of castellations on the housing and at least one resilient arm associated with the longitudinally moveable component, the resilient arm having a dog resiliently biased towards the castellations so as to engage between or behind the castellations and block the translation, wherein a respective shutter arm is arranged alongside the set of castellations, the shutter arm having a number of consecutive ramped protrusions spaced from each other, wherein the castellations and the ramped protrusions have the same pitch, wherein a profiled surface is formed by the castellations and the ramped protrusions, wherein the shutter arm is moveable in longitudinal direction with respect to the set of castellations, wherein the shutter arm has at least one locking position with its ramped protrusions essentially in phase with the castellations thus allowing the dog of the resilient arm to catch between or behind the castellations and wherein the shutter arm has at least one unlocking position with its ramped protrusions out of phase with the castellations in such a manner that the ramped protrusions prevent the dog from engaging with the castellations or disengage them thus allowing translation of the longitudinally moveable component.

First claim

The invention claimed is:

1. A shuttering mechanism for controlling translation of a longitudinally moveable component within an elongate housing, the shuttering mechanism comprising:
a plurality of castellations longitudinally disposed on the housing; and
at least one resilient arm associated with the longitudinally moveable component, the resilient arm having a dog resiliently biased towards the castellations, the dog adapted to engage between or behind the castellations and block the translation of the longitudinally moveable component,
wherein a respective shutter arm is arranged alongside the plurality of castellations, the shutter arm having a plurality of consecutive ramped protrusions spaced from each other,
wherein the castellations and the ramped protrusions have the same pitch,
wherein a profiled surface is formed by the castellations and the ramped protrusions,
wherein the shutter arm is moveable in a longitudinal direction with respect to the plurality of castellations, and
wherein the shutter arm has at least one locking position with its ramped protrusions essentially in phase with the castellations thus allowing the dog of the resilient arm to catch between or behind the castellations and wherein the shutter arm has at least one unlocking position with its ramped protrusions out of phase with the castellations in such a manner that the ramped protrusions prevent the dog from engaging with the castellations or disengage them thus allowing translation of the longitudinally moveable component.

2. An auto-injector for administering a dose of a liquid medicament, the auto-injector having a distal end and a proximal end with an orifice intended to be applied against an injection site, the auto-injector comprising:
an elongate housing arranged to contain a syringe with a hollow needle and a stopper for sealing the syringe and displacing the medicament, wherein the syringe is slidably arranged with respect to the housing,
a drive mechanism capable of, upon activation:
pushing the needle from a retracted position into an advanced position through the orifice and past the proximal end, and
operating the syringe to supply the dose of medicament,

a plunger for transmitting power from the drive mechanism to the syringe and/or stopper, and
a shuttering mechanism arranged to lock the drive mechanism in a compressed state prior to manual operation and capable of, upon manual operation, releasing the drive mechanism for injection,
wherein the shuttering mechanism comprises a plurality of castellations longitudinally disposed on the housing, and at least one plunger arm attached to the plunger, the plunger arm having a dog resiliently biased towards the castellations, the dog adapted so as to engage between or behind the castellations and block the translation of the plunger,
wherein a respective shutter arm is arranged alongside the plurality of castellations, the shutter arm having a number plurality of consecutive ramped protrusions spaced from each other, wherein the shutter arm is moveable in a longitudinal direction with respect to the plurality of castellations,
wherein the shutter arm has at least one locking position with its ramped protrusions essentially in phase with the castellations thus allowing the dog of the plunger arm to catch between or behind the castellations and
wherein the shutter arm has at least one unlocking position with its ramped protrusions out of phase with the castellations in such a manner that the ramped protrusions prevent the dog from engaging with the castellations or disengage them thus allowing translation of the plunger.

3. The auto-injector according to claim 2 , wherein the shutter arm of the shuttering mechanism is: (i) connected to a sheath, (ii) telescoped within the proximal end of the housing, and (iii) arranged to protrude proximally from the housing at least in an initial position in an as-delivered state of the auto-injector with the shutter arm in the locking position, wherein translating the sheath in a proximal direction into a triggering position shifts the shutter arm into the unlocking position.

4. The auto-injector according to claim 3 , further including a syringe carrier arranged inside the housing for holding the syringe, the syringe carrier being slidable with respect to the housing, wherein the syringe carrier comprises at least one clip locking the syringe carrier to the housing in a distal position, in order to prevent axial motion of the syringe carrier relative to the housing, wherein the sheath is arranged to disengage the clip upon translation in the proximal direction before the shutter arm reaches its unlocking position thus allowing the syringe carrier to move in the proximal direction.

5. The auto-injector according to claim 3 , wherein the sheath and the shutter arms are connected by at least one resilient beam, a manner to allow the sheath to be moved away from the shutter arms by a defined maximum distance.

6. The auto-injector according to claim 3 , wherein the sheath is biased in a proximal direction by a sheath spring.

7. The auto-injector according to claim 6 , wherein the sheath spring is arranged to bias the sheath against the syringe carrier.

8. The auto-injector according to claim 6 , wherein the sheath is engaged with the syringe carrier in a manner to allow a maximum distance between the sheath and the syringe carrier so that a maximum proximal position of the sheath is restricted by the longitudinal position of the syringe carrier thus allowing the sheath to move proximally beyond its initial position if the syringe carrier is proximal from is distal position.

9. The auto-injector according to claim 3 , wherein at least one snap is provided near the proximal end of the housing, for preventing the sheath from moving in distal direction when the sheath has moved into a locking position proximally from its initial position.

10. The auto-injector according to claim 2 , wherein the drive mechanism is a compression spring grounded distally in the housing and bearing against the plunger.

11. The auto-injector according to claim 10 , wherein a rotating damper is arranged between the compression spring and a thrust plate at a distal end of the plunger, wherein a cam of the rotating damper is arranged in a cam track on an inner surface of the housing, the cam track having at least one helical section for forcing the rotating damper to rotate upon axial translation under load of the compression spring thus generating friction between the rotating damper and the thrust plate.

12. The auto-injector according to claim 11 , wherein the cam track has a straight section for preventing rotation of the rotating damper during needle insertion.

13. The auto-injector according to claim 2 , further including a pause button adapted to actuate the shutter arm.

14. The auto-injector according to claim 3 , further including a latch mechanism adapted to hold the sheath back when in the triggering position, wherein the plunger arms are arranged to disengage the latch mechanism when the stopper has nearly bottomed out in the syringe.

15. The auto-injector according to claim 14 , further including a button arranged for disengaging the latch mechanism.

Assignees

• Ekman Matthew
• Brereton Simon Francis
• Kemp Thomas Mark
• Sanofi Aventis Deutschland

Inventors

• Ekman Matthew
• Brereton Simon Francis
• Kemp Thomas Mark

Classifications

• A61M2005/206

  With automatic needle insertion · 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

• 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

• A61M2205/582

  by tactile feedback · CPC title

• Y10T74/18984

  Inclined ramp · CPC title