DRIVE MECHANISM FOR A DRUG DELIVERY DEVICE AND USE OF A RESET MEMBER FOR A DRIVE MECHANISM

• US 20120283649A1
• Filed: 09/29/2010
• Published: 11/08/2012
• Est. Priority Date: 09/30/2009
• Status: Active Grant

• Current Assignee: Sanofi-Aventis Deutschland GmbH (Sanofi )
• Original Assignee: Sanofi-Aventis Deutschland GmbH (Sanofi )
• Inventors: Veasey, Robert, Bilton, Simon Lewis, Jones, Christopher, Kouyoumjian, Garen, Macdonald, Catherine Anne
• Granted Patent: US 9,402,960 B2
• Time in Patent Office: Days
• US Class Current: 604/208
• CPC Class Codes: A61M 2005/2407 from the rear
• CPC Class Codes: A61M 5/24 Ampoule syringes, i.e. syringes with needle for use in combination with replaceable ampoules or carpules, e.g. automatic ampoules or carpules A61J1/06
• CPC Class Codes: A61M 5/31535 Means improving security or handling thereof, e.g. blocking means, means preventing insufficient dosing, means allowing correction of overset dose
• CPC Class Codes: A61M 5/31543 piston rod reset means, i.e. means for causing or facilitating retraction of piston rod to its starting position during cartridge change
• CPC Class Codes: A61M 5/31555 by purely axial movement of dose setting member, e.g. during setting or filling of a syringe
• CPC Class Codes: A61M 5/3156 using volume steps only adjustable in discrete intervals, i.e. individually distinct intervals
• CPC Class Codes: A61M 5/3158 performed by axially moving actuator operated by user, e.g. an injection button
• CPC Class Codes: A61M 5/31593 Multi-dose, i.e. individually set dose repeatedly administered from the same medicament reservoir

Abstract

A plunger and a lever are arranged in a body and provided with engaging elements engaging the lever with the plunger. The lever is disengageable from the plunger by a shift of the lever, thus enabling a movement of the plunger relatively to the body in the proximal direction.

Claims

1-13. -13. (canceled)

14. 1. Drive mechanism for a drug delivery device, comprising:

a body having a distal end and a proximal end, which are spaced apart in the direction of an axis,

a plunger arranged within the body along the axis, and

a lever arranged within the body,

the lever and the plunger being provided with engaging elements engaging the lever with the plunger,

the lever being disengageable from the plunger by a shift of the lever, thus enabling a movement of the plunger relatively to the body in the proximal direction, and

a release block arranged at a provided location within the body, where the release block prevents the shift of the lever, the release block being removable from the provided location to enable the lever to be reversibly disengaged from the plunger by the shift,

characterized in that

the lever is engaged with the plunger during a delivery of a drug and shifts the plunger in the distal direction while the lever is being turned around a pivot,

the lever is disengaged from the plunger during a setting of a dose of a drug, and

the lever is reversibly disengaged from the plunger during a resetting of the plunger.

15. The drive mechanism according to claim 14, further comprising:

engaging means of the plunger arranged along the axis and forming the engaging element of the plunger, the engaging element of the lever engaging the engaging means, and

the lever being disengageable from the plunger by a shift with respect to the body in a direction transverse to the direction of the axis.

16. The drive mechanism according to claim 14, further comprising:

a removable and attachable part removable from and attachable to the body at the distal end, and

a resilient element acting on the release block,

the release block being kept removed from the provided location by means of the resilient element when the removable and attachable part is not attached to the body.

17. The drive mechanism according to claim 16, wherein

the removable and attachable part is a cartridge holder, and

the release block is held in the provided location when the removable and attachable part is attached to the body with a cartridge inserted.

18. The drive mechanism according to claim 14, further comprising a resilient element exerting a force on the plunger relatively to the body in the proximal direction, the resilient element resetting the plunger to a start position when the lever is disengaged from the plunger by the shift.

19. The drive mechanism according to claim 18, further comprising:

a removable and attachable part removable from and attachable to the body at the distal end, and

a resilient element acting on the release block,

the release block being kept removed from the provided location by means of the resilient element when the removable and attachable part is not attached to the body, and being held in the provided location when the removable and attachable part is attached to the body.

20. The drive mechanism according to claim 19, wherein the removable and attachable part (10) is a cartridge holder.

21. The drive mechanism according to one of claim 14, wherein the drug is delivered by fixed doses.

22. A use of a reset member for a drive mechanism of a drug delivery device, the reset member comprising a resilient element which, in use, acts on a plunger of the drive mechanism and tending to reset the plunger to a start position with respect to the drive mechanism.

23. The use of the reset member according to claim 22, wherein the resilient element is a helical spring introducing a tensile force between the plunger and a location of the drive mechanism that is relatively fixed to the start position.

24. The use of the reset member according to claim 22, wherein the plunger is provided for delivering a drug from a cartridge, and the resilient element automatically resets the plunger to the start position after a removal of the cartridge.

25. The use of the reset member according to claim 24, further comprising a further resilient element provided to release the plunger when the cartridge is removed, thus enabling the plunger to be reset.