Drive mechanism for a drug delivery device

Patent metadata

Field	Value
Publication number	US-10864328-B2
Application number	US-201414915821-A
Country	US
Kind code	B2
Filing date	Sep 3, 2014
Priority date	Sep 3, 2013
Publication date	Dec 15, 2020
Grant date	Dec 15, 2020

Abstract

A drive mechanism (4) for a drug delivery device comprising—a piston rod (14), —a trigger member (9) coupled with the piston rod (14) in such a manner that rotational movement between the piston rod (14) and the trigger member (9) is constrained in a first state, the trigger member (9) being elastically deformable in such a manner that the piston rod (14) is rotationally moveable with respect to the trigger member (9) in a second state, —a trigger button (10) being suitable for activating the deformation of the trigger member (9).

First claim

The invention claimed is:

1. A drive mechanism for a drug delivery device, the drive mechanism comprising:
a piston rod,
a trigger nut that is axially movable with respect to the piston rod,
a trigger member surrounding the piston rod, the trigger member being coupled to the piston rod in such a manner that rotational movement between the piston rod and the trigger member is constrained in a first state, the trigger member being elastically deformable in such a manner that the piston rod is rotationally moveable with respect to the trigger member in a second state, and
a trigger button configured to deform the trigger member, wherein a movement of the trigger button towards the trigger nut causes elastic deformation of the trigger member, and wherein the trigger nut is located in a hole of the trigger member.

2. The drive mechanism according to claim 1 , wherein the trigger nut is coupled to the piston rod in such a manner that rotational movement between the trigger nut and the piston rod is constrained,
wherein the trigger member engages with the trigger nut in such a manner that rotational movement between the trigger nut and the trigger member is constrained in the first state, the trigger member being elastically deformable in such a manner that the trigger member disengages from the trigger nut in the second state, thereby enabling rotational movement of the trigger nut with respect to the trigger member.

3. The drive mechanism according to claim 2 , wherein the trigger member comprises a trigger engagement member engaging with a nut engagement means of the trigger nut, the trigger engagement member movable away from the nut engagement means, thereby disengaging from the nut engagement means, when the trigger member is deformed.

4. The drive mechanism according to claim 3 , wherein the trigger engagement member is located offset to a connection between the trigger button and the trigger member.

5. The drive mechanism according to claim 3 , wherein the trigger nut comprises a multitude of teeth that are located circumferentially, the trigger engagement member comprising a protrusion that is suitable for engaging with a gap between two teeth of the multitude of teeth of the trigger nut.

6. The drive mechanism according to claim 2 , wherein the trigger nut is splined with the piston rod.

7. The drive mechanism according to claim 1 , wherein the trigger button and the trigger member are made in one piece.

8. The drive mechanism according to claim 1 , wherein the trigger member comprises a sleeve.

9. The drive mechanism according to claim 1 , wherein the trigger member comprises at least one fixing member configured to be connected with a housing of the drug delivery device in order to fix a position of the trigger member with respect to the housing.

10. The drive mechanism according to claim 1 , further comprising
a drive sleeve axially movable with respect to the piston rod, the drive sleeve being coupled to the piston rod in such a manner that rotational movement between the drive sleeve and the piston rod is constrained, and
a spring member coupled to the drive sleeve in such a manner that the spring member is compressed when the drive sleeve moves proximally with respect to the piston rod.

11. The drive mechanism according to claim 10 , further comprising a dial sleeve being threadedly coupled to the drive sleeve, the spring member being connected with the dial sleeve in such a manner that the spring member is wound and/or compressed in the first state by a helical movement of the dial sleeve with respect to the drive sleeve, the spring member being configured to at least partly relax when rotational movement of the piston rod is allowed in the second state and to thereby rotate the drive sleeve with respect to the dial sleeve.

12. The drive mechanism according to claim 1 , wherein the piston rod is a lead screw.

13. The drive mechanism according to claim 1 , wherein the trigger member is sleeve-shaped.

14. The drive mechanism according to claim 1 , wherein the trigger member comprises a sleeve-shaped portion defining the hole.

15. The drive mechanism according to claim 14 , further comprising a fixing member protruding radially outwardly from the sleeve-shaped portion, the fixing member connecting the trigger member to the trigger button.

16. The drive mechanism according to claim 15 , wherein the sleeve-shaped portion of the trigger member comprises an inner surface and an outer surface, the inner surface of the sleeve-shaped portion defining the hole, wherein the fixing member protrudes radially outwardly from the outer surface of the sleeve-shaped portion,
wherein the inner surface of the sleeve-shaped portion of the trigger member comprises a longitudinally extending protrusion engaged with the trigger nut to rotationally constrain the trigger nut.

17. A drug delivery device comprising:
a housing; and
a drive mechanism at least partially disposed within the housing, the drive mechanism comprising
a piston rod,
a trigger nut that is axially movable with respect to the piston rod,
a trigger member surrounding the piston rod, the trigger member being coupled to the piston rod in such a manner that rotational movement between the piston rod and the trigger member is constrained in a first state, the trigger member being elastically deformable in such a manner that the piston rod is rotationally moveable with respect to the trigger member in a second state, and
a trigger button being suitable configured to deform the trigger member, wherein a movement of the trigger button towards the trigger nut causes elastic deformation of the trigger member, and wherein the trigger nut is located in a hole of the trigger member.

18. A drug delivery device comprising:
a housing; and
a drive mechanism at least partially disposed within the housing, the drive mechanism comprising
a piston rod,
a trigger nut that is axially movable with respect to the piston rod,
a trigger member coupled to the piston rod in such a manner that rotational movement between the piston rod and the trigger member is constrained in a first state, the trigger member being elastically deformable in such a manner that the piston rod is rotationally moveable with respect to the trigger member in a second state, and
a trigger button configured to deform the trigger member, wherein a movement of the trigger button towards the trigger nut causes elastic deformation of the trigger member, and wherein the trigger member is centered along a longitudinal axis of the drug delivery device.

19. The drug delivery device according to claim 18 , wherein the trigger member surrounds the piston rod.

Assignees

• Sanofi Sa

Inventors

• Marsh William

Classifications

• A61M5/20 Primary

  Automatic syringes, e.g. with automatically actuated piston rod, with automatic needle injection, filling automatically (A61M5/142 {, A61M5/46} take precedence; {hypodermic projectiles F42B12/54}) · CPC title

• A61M5/31535

  Means improving security or handling thereof, e.g. blocking means, means preventing insufficient dosing, means allowing correction of overset dose · CPC title

• A61M5/31583

  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 title

• A61M2205/582

  by tactile feedback · CPC title

• A61M2205/583

  by visual feedback · CPC title