Drive mechanism for a drug delivery device and use of a reset member for a drive mechanism

• US 9,402,960 B2
• Filed: 09/29/2010
• Issued: 08/02/2016
• 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
• Primary Examiner(s): Bosworth, Kami A
• Assistant Examiner(s): Engel, Matthew A
• Application Number:
  US13/395,898
• Publication Number:
  US 20120283649A1
• Time in Patent Office: 2,134 Days
• US Class Current: 1/1
• 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. A drive mechanism for a drug delivery device, comprising:

a body having a distal end and a proximal end, which are spaced apart in a 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 relative to the body in a 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,

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

a resilient element exerting a force on the plunger relative 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, and the resilient element acting on the release block, the release block being kept spaced apart from the provided location by means of the resilient element when the removable and attachable part is not attached to the body, and the release block being held in the provided location when the removable and attachable part is attached to the body,

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

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

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

2. The drive mechanism according to claim 1, 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.

3. The drive mechanism according to claim 1, 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.

4. The drive mechanism according to claim 1, wherein the removable and attachable part is a cartridge holder.

5. The drive mechanism according to claim 1, wherein the drug is delivered by fixed doses.