DRIVE ASSEMBLY SUITABLE FOR USE IN A MEDICATION DELIVERY DEVICE AN MEDICATION DELIVERY DEVICE

• US 20100137791A1
• Filed: 12/02/2008
• Published: 06/03/2010
• Est. Priority Date: 12/02/2008
• Status: Active Grant

• Current Assignee: Sanofi-Aventis Deutschland GmbH (Sanofi )
• Original Assignee: Sanofi-Aventis Deutschland GmbH (Sanofi )
• Inventors: PLUMPTRE, David
• Granted Patent: US 9,545,483 B2
• Time in Patent Office: Days
• US Class Current: 604/68
• CPC Class Codes: A61M 2005/3104 Caps for syringes without needle
• CPC Class Codes: A61M 2005/31518 designed to reduce the overall size of an injection device, e.g. using flexible or pivotally connected chain-like rod members
• CPC Class Codes: A61M 2005/3152 including gearings to multiply or attenuate the piston displacing force
• CPC Class Codes: A61M 2205/581 by audible feedback
• CPC Class Codes: A61M 2205/582 by tactile feedback
• CPC Class Codes: A61M 2205/583 by visual feedback
• 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 5/3146 Priming, e.g. purging, reducing backlash or clearance
• CPC Class Codes: A61M 5/31541 Means preventing setting of a dose beyond the amount remaining in the cartridge
• 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 5/31575 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: A61M 5/50 having means for preventing re-use, or for indicating if defective, used, tampered with or unsterile retractable needles or needle protectors with means for preventing re-use A61M5/321

Abstract

A drive assembly for use in a medication delivery device is provided for, which comprises a housing having a proximal end and a distal end, a drive member moveable in the proximal direction with respect to the housing for setting a dose of the medication to be delivered and in the distal direction with respect to the housing for delivering the dose, a piston rod adapted to be driven by the drive member in the distal direction with respect to the housing during movement of the drive member in the distal direction for delivering the dose and a restriction member for restricting proximal movement of the piston rod with respect to the housing during proximal movement of the drive member by mechanical interaction of the restriction member with a stop feature of the piston rod, wherein the restriction member and the stop feature are arranged for the piston rod to be moved proximally a first distance during a first proximal movement of the drive member before the restriction member and the stop feature interact mechanically, wherein the first distance which the piston rod moves proximally during the first proximal movement of the drive member is larger than a subsequent distance which the piston rod moves proximally during a subsequent proximal movement of the drive member.

Claims

1. A drive assembly for use in a medication delivery device, comprising:

a housing having a proximal end and a distal end,

a drive member moveable in the proximal direction with respect to the housing for setting a dose of the medication to be delivered and in the distal direction with respect to the housing for delivering the dose,

a piston rod adapted to be driven by the drive member in the distal direction with respect to the housing during movement of the drive member in the distal direction for delivering the dose, and

a restriction member for restricting proximal movement of the piston rod with respect to the housing during proximal movement of the drive member by mechanical interaction of the restriction member with a stop feature of the piston rod,

characterized in that

the restriction member and the stop feature are arranged for the piston rod to be moved proximally a first distance during a first proximal movement of the drive member before the restriction member and the stop feature interact mechanically, wherein the first distance which the piston rod moves proximally during the first proximal movement of the drive member is larger than a subsequent distance which the piston rod moves proximally during a subsequent proximal movement of the drive member.

2. The drive assembly according to claim 1,

wherein a priming movement of the drive member comprises the first proximal movement of the drive member.

3. The drive assembly according to claim 1,

wherein the drive member and the piston rod are releasably engaged.

4. The drive assembly according to claim 1,

wherein the restriction member engages the piston rod.

5. The drive assembly according to claim 1,

wherein the restriction member is secured against at least one of or both of rotational movement with respect to the housing and axial movement with respect to the housing.

6. The drive assembly according to claim 1,

wherein the stop feature is provided on an outer surface of the piston rod.

7. The drive assembly according to claim 1,

wherein the piston rod comprises a plurality of stop features, the drive assembly being configured for the restriction member to mechanically interact with a different stop feature after distal movement of the drive member for dose delivery.

8. The drive assembly according to claim 7,

wherein the stop features are arranged equidistantly along the piston rod.

9. The drive assembly according to claim 7,

wherein the piston rod and the restriction member are arranged for a proximal movement of the piston rod to be prevented during a second and any subsequent proximal movement of the drive member for setting a dose by the restriction member already mechanically interacting with one of the stop features before the second and any subsequent proximal movement of the drive member for setting a dose.

10. The drive assembly according to claim 8,

wherein the piston rod and the restriction member are arranged for a proximal movement of the piston rod to be prevented during a second and any subsequent proximal movement of the drive member for setting a dose by the restriction member already mechanically interacting with one of the stop features before the second and any subsequent proximal movement of the drive member for setting a dose.

11. The drive assembly according to claim 1,

wherein the drive assembly is configured for rotational movement of the piston rod with respect to the housing to be restricted.

12. The drive assembly according to claim 1,

wherein the drive assembly is configured for the piston rod to be rotatable with respect to the housing.

13. The drive assembly according to claim 1,

wherein the piston rod comprises a thread and the restriction member engages the thread of the piston rod.

14. The drive assembly according to claim 13,

wherein the restriction member is a thread or a part of a thread.

15. The drive assembly according to claim 13,

wherein the thread of the piston rod comprises the stop feature with the stop feature being a region of the thread that has a different thread angle as compared to an adjacent region of the thread.

16. The drive assembly according to claim 14,

wherein the thread of the piston rod comprises the stop feature with the stop feature being a region of the thread that has a different thread angle as compared to an adjacent region of the thread.

17. The drive assembly according to claim 1, wherein the first distance is greater than a distance which the piston rod moves proximally subsequent to a distal movement of the piston rod for delivering a dose.