Drive mechanism for a drug delivery device and drug delivery device

• US 9,393,368 B2
• Filed: 11/11/2011
• Issued: 07/19/2016
• Est. Priority Date: 11/12/2010
• Status: Active Grant

• Current Assignee: Sanofi-Aventis Deutschland GmbH (Sanofi )
• Original Assignee: Sanofi-Aventis Deutschland GmbH (Sanofi )
• Inventors: Nzike, Philippe, Raab, Steffen, Dasbach, Uwe, Boeser, Uwe, Brggemann, Ulrich
• Primary Examiner(s): Mehta, Bhisma
• Assistant Examiner(s): Zhang, Jenna
• Application Number:
  US13/883,393
• Publication Number:
  US 20130226091A1
• Time in Patent Office: 1,712 Days
• US Class Current: 1/1
• CPC Class Codes: A61M 5/31501 Means for blocking or restricting the movement of the rod or piston A61M5/5013 takes precedence
• CPC Class Codes: A61M 5/31511 Piston or piston-rod constructions, e.g. connection of piston with piston-rod A61M5/5066 takes precedence
• CPC Class Codes: A61M 5/31515 Connection of piston with piston rod
• CPC Class Codes: A61M 5/31525 Dosing burettes, pipettes B01L3/02
• CPC Class Codes: A61M 5/31528 by means of rotational movements, e.g. screw-thread mechanisms
• CPC Class Codes: A61M 5/31533 Dosing mechanisms, i.e. setting a dose administrating mechanisms A61M5/31565
• CPC Class Codes: A61M 5/31565 Administration mechanisms, i.e. constructional features, modes of administering a dose dosing mechanisms for setting a dose A61M5/31533
• CPC Class Codes: A61M 5/31571 Means preventing accidental administration for automatic syringes A61M5/20
• CPC Class Codes: A61M 5/31583 based on rotational translation, i.e. movement of piston rod is caused by relative rotation between the user activated actuator and the piston rod
• CPC Class Codes: A61M 5/31585 performed by axially moving actuator, e.g. an injection button

Abstract

The drive mechanism comprises a piston rod, a dose member with a thread engaging a corresponding thread of the body to allow a helical movement of the dose member with respect to the body, a drive sleeve rotationally coupled to the dose member, and stop means provided to restrict or inhibit a movement of the drive sleeve in the proximal direction and in the distal direction with respect to the body, the drive sleeve and the piston rod being unidirectionally coupled.

Claims

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

a body having a proximal end and a distal end,

a piston rod arranged within the body along an axis of rotation,

a dose member having a thread, the thread engaging a corresponding thread of the body to allow a helical movement of the dose member with respect to the body, the helical movement comprising a rotation around the axis and a simultaneous shift along the axis,

a drive sleeve arranged within the body, rotatable with respect to the body around the axis and rotationally coupled to the dose member,

a proximal stop interface provided to restrict a movement of the drive sleeve in the proximal direction with respect to the body,

a distal stop interface provided to restrict a movement of the drive sleeve in the distal direction with respect to the body,

a stop member arranged within the body and being rotationally locked to the body with respect to the axis and being axially movable with respect to the body along the axis,

a drive member arranged within the body, the drive member being rotationally locked to the piston rod and held in contact with the stop member,

a first gear locking the drive member unidirectionally rotationally to the stop member in a first sense of rotation with respect to the body, and

a second gear locking the drive member rotationally to the drive sleeve when the drive sleeve is rotated in a second sense of rotation, which is opposite to the first sense of rotation, with respect to the body.

2. The drive mechanism according to claim 1, wherein the thread of the dose member is arranged in such a manner that the helical movement of the dose member with respect to the body comprises a rotation having the first sense of rotation when the dose member is moved towards the proximal end and a rotation having the second sense of rotation when the dose member is moved towards the distal end.

3. The drive mechanism according to claim 1, wherein the piston rod has a thread guiding the piston rod in the body in such a manner that the piston rod advances towards the distal end when the piston rod is rotated in the second sense of rotation with respect to the body.

4. The drive mechanism according to claim 1, wherein the drive sleeve is rotationally locked to the dose member.

5. The drive mechanism according to claim 1, further comprising:

a clutch sleeve arranged between the dose member and the drive sleeve,

the clutch sleeve forming a clutch, which couples the clutch sleeve rotationally with the dose member in a releasable manner,

the clutch sleeve being rotationally locked to the drive sleeve.

6. The drive mechanism according to claim 5, wherein the clutch locks the clutch sleeve unidirectionally rotationally to the dose member.

7. The drive mechanism according to claim 6, wherein the unidirectional rotational locking of the clutch sleeve with the dose member generates a rotation of the clutch sleeve during a helical movement of the dose member with respect to the body in the proximal direction.

8. The drive mechanism according to claim 5, further comprising:

a resilient element acting on the clutch sleeve and the dose member so that the clutch sleeve and the dose member are rotationally locked to one another when the clutch is engaged, the resilient element being arranged in such a manner that moving the dose member in the distal direction reduces or removes the engagement of the clutch.

9. The drive mechanism according to claim 5, wherein the dose member can be moved helically in the distal direction without rotating the clutch sleeve.

10. The drive mechanism according to claim 1, wherein a set operation is performed by a helical movement of the dose member with respect to the body in the proximal direction, the helical movement being guided by the thread of the dose member.

11. The drive mechanism according to claim 1, wherein a dispense operation is performed by a helical movement of the dose member with respect to the body in the distal direction, the helical movement being guided by the thread of the dose member, and the drive sleeve rotating simultaneously.

12. The drive mechanism according to claim 1, wherein a correcting set operation is performed by a helical movement of the dose member with respect to the body in the distal direction, the helical movement being guided by the thread of the dose member, and the drive sleeve being stationary with respect to the body.

13. A drug delivery device, comprising of a drive mechanism according to claim 1.

14. The drug delivery device according to claim 13, wherein the body has a shape of an injection pen.