DRUG DELIVERY DEVICE

• US 20120325865A1
• Filed: 10/14/2010
• Published: 12/27/2012
• Est. Priority Date: 10/16/2009
• Status: Active Grant

• Current Assignee: Sanofi-Aventis Deutschland GmbH (Sanofi )
• Original Assignee: Sanofi-Aventis Deutschland GmbH (Sanofi )
• Inventors: Forstreuter, Axel, Teucher, Axel
• Granted Patent: US 9,108,003 B2
• Time in Patent Office: Days
• US Class Current: 222/390
• CPC Class Codes: A61M 2005/3152 including gearings to multiply or attenuate the piston displacing force
• CPC Class Codes: A61M 5/31536 Blocking means to immobilize a selected dose, e.g. to administer equal doses
• CPC Class Codes: A61M 5/31553 without axial movement of dose setting member
• CPC Class Codes: A61M 5/31558 using scaling up or down transmissions, e.g. gearbox
• CPC Class Codes: A61M 5/31585 performed by axially moving actuator, e.g. an injection button
• CPC Class Codes: Y10T 74/18576 including screw and nut

Abstract

The present invention relates to a drive mechanism for a drug delivery device, comprising: a housing, an axially displaceable piston rod to act on a piston of a cartridge containing a medicinal product to be dispensed, a drive member threadedly engaged with the piston rod and being slidably disposed relative to the housing between a distal stop position and a proximal stop position, wherein for setting of a dose, the drive member is rotatable with respect to the housing (14), a dose dial member operably engaged with the drive member by means of a reduction gear, wherein the drive member at its proximal end section comprises a radially extending receptacle adapted to receive the reduction gear.

Claims

1. A drive mechanism for a drug delivery device, comprising:

a housing,

an axially displaceable piston rod to act on a piston of a cartridge containing a medicinal product to be dispensed,

a drive member threadedly engaged with the piston rod and being slidably disposed relative to the housing between a distal stop position and a proximal stop position, and comprising at its proximal end section a radially extending receptacle adapted to receive a reduction gear,

a dose dial member operably engaged with the drive member by means of the reduction gear, for transferring a dose setting rotative movement of the dose dial member at a lower rate of rotation to the drive member being rotatable with respect to the housing for setting of a dose.

2. The drive mechanism according to claim 1, wherein for dispensing of a dose, the drive member is slidably disposed relative to the housing from the proximal stop position to the distal stop position, and wherein the drive member is adapted to slave the piston rod in distal direction.

3. The drive mechanism according to claim 1, wherein the housing comprises a through opening for guiding of a distal portion of the piston rod.

4. The drive mechanism according to claim 3, wherein the through opening of the housing and the distal portion of the piston rod are correspondingly threaded.

5. The drive mechanism according to claim 1, wherein the drive member comprises a drive sleeve adapted to receive the piston rod at least partially and wherein the piston rod comprises a proximal portion with an outer proximal thread corresponding to an inner thread of the drive sleeve.

6. The drive mechanism according to claim 4, wherein the piston rod'"'"'s distal thread and the piston rod'"'"'s proximal thread are oppositely handed and comprise different leads.

7. The drive mechanism according to claim 1, wherein the threaded engagement of piston rod and drive member is of non-self-locking type.

8. The drive mechanism according to claim 1, wherein the drive member is spring biased with respect to the housing in axial direction.

9. The drive mechanism according to claim 1, wherein the drive member is locked in the distal stop position with respect to the housing by means of a latch mechanism.

10. The drive mechanism according to claim 1, wherein a proximally directed axial displacement of the drive member is delimited by a radially extending flange of the dose dial member adapted to abut with a radially inwardly directed flange of the housing.

11. The drive mechanism according to claim 1, wherein the receptacle that houses the reduction gear is closed in proximal direction by the dose dial member.

12. The drive mechanism according to claim 1, wherein the reduction gear comprises an epicyclic gear or a harmonic drive.

13. The drive mechanism according to claim 11, wherein the reduction gear comprises planetary gears meshing with a sun gear and with a surrounding ring gear, wherein the sun gear is rotatably locked with the dose dial member and the ring gear is rotatably locked with the drive member.

14. The drive mechanism according to claim 1, wherein upon the drive member reaching the proximal stop position, the dose dial member extends in proximal direction from a proximal end face of the housing.

15. The drive mechanism according to claim 1, wherein the dose dial member, the reduction gear and/or the drive member are rigidly connected with each other in axial direction.

16. The drive mechanism according to claim 1, wherein the dose dial member is axially connected with the drive member to displace the drive member in distal direction in response to receive a distally directed injection force.

19. A dose dispensing device comprising a drive dispensing mechanism according to claim 1 and further comprising a cartridge filled with the medicinal fluid to be dispensed.

17. A drive mechanism for a drug delivery device, comprising:

a housing,

an axially displaceable piston rod to act on a piston of a cartridge containing a medicinal product to be dispensed,

a drive member threadedly engaged with the piston rod,

a dose dial member operably engaged with the drive member by means of a reduction gear, wherein said reduction gear being exclusively operable to reduce a drive member'"'"'s displacement during setting of a dose, and

wherein the piston rod, the drive member, the dose dial member and/or the reduction gear are rotatably supported about a common or several axes of rotation being substantially co-aligned.

18. The drive mechanism according to claim 17, wherein the reduction gear is inoperable or deactivated during dispensing of a dose.