Drive mechanism of a drug delivery device

Patent metadata

Field	Value
Publication number	US-10478562-B2
Application number	US-201414782622-A
Country	US
Kind code	B2
Filing date	Apr 8, 2014
Priority date	Apr 10, 2013
Publication date	Nov 19, 2019
Grant date	Nov 19, 2019

Abstract

A drive mechanism of a drug delivery device for setting and dispensing of a dose of a medicament includes a housing, a piston rod, a dose indicating member with a dose size information thereon, and a drive wheel. The piston rod engages with a piston of a cartridge for displacing the piston in a distal direction. The dose indicating member is connected to a spring element and is rotatable in a dose incrementing direction against the action of the spring element for setting a dose. The drive wheel is operably engaged with the piston rod for displacing the piston rod in the distal direction for dose dispensing. The dose indicating member is engageable with the drive wheel during dose dispensing to transfer a force to the drive wheel when driven by the relaxing spring element in a dose decrementing direction.

First claim

The invention claimed is:

1. A drive mechanism of a drug delivery device for setting and dispensing of a dose of a medicament, the drive mechanism comprising:
a housing;
a piston rod to operably engage with a piston of a cartridge for displacing the piston in a distal direction;
a dose indicating member with dose size indicating numbers or symbols thereon, wherein the dose indicating member is connected to a spring element and is rotatable in a dose incrementing direction against an action of the spring element for setting of the dose, and wherein the dose indicating member is rotatable in a dose decrementing direction under an action of the spring element for dispensing of the dose, the dose decrementing direction being opposite to the dose incrementing direction; and
a drive wheel operably engaged with the piston rod for displacing the piston rod in the distal direction for dose dispensing,
wherein the dose indicating member is engageable with the drive wheel during dose dispensing to transfer a driving force to the drive wheel when driven by the relaxing spring element in a dose decrementing direction.

2. The drive mechanism according to claim 1 , wherein the dose indicating member comprises a flat-shaped dose indicating disc.

3. The drive mechanism according to claim 1 , wherein the spring element comprises a spiral spring having a first end section connected to the housing and having a second end section connected to the dose indicating member.

4. The drive mechanism according to claim 1 , further comprising a ring-shaped dose setting member rotatably supported by the housing and being selectively engageable with the dose indicating member for setting of the dose.

5. The drive mechanism according to claim 4 , wherein the ring-shaped dose setting member comprises a circumferential side wall portion extending into the housing.

6. The drive mechanism according to claim 5 , wherein a last dose limiting member radially sandwiched between the side wall portion and the housing is threadedly engaged with the side wall portion and rotatably locked to the housing.

7. The drive mechanism according to claim 1 , further comprising a dose dispensing member rotatably fixed to the housing and being depressible in an axial direction against an action of a dispensing spring element.

8. The drive mechanism according to claim 7 , wherein the dose indicating member axially abuts with the dose dispensing member.

9. The drive mechanism according to claim 7 , wherein the dose dispensing member comprises a through opening serving as a dose indicating window through which a portion of the dose size indicating numbers of symbols of the dose indicating member is visibly displayed.

10. The drive mechanism according to claim 7 , wherein a dose dispensing member is radially enclosed by a dose setting member.

11. The drive mechanism according to claim 1 , wherein the dose indicating member comprises a spiraled groove to engage with a single dose limiting member.

12. The drive mechanism according to claim 11 , wherein the single dose limiting member is radially displaceable relative to a dose dispensing member along the spiraled groove and is rotatably fixed to the dose dispensing member.

13. The drive mechanism according to claim 12 , wherein the dose dispensing member comprises a radially outwardly extending appendix engaged with a notch of the single dose limiting member.

14. The drive mechanism according to claim 1 , wherein the dose indicating member comprises a centrally located toothed through opening engaged with at least one resilient ratchet element in a dose setting configuration.

15. A drug delivery device for setting and dispensing of a dose of a medicament, the drug delivery device comprises:
a drive mechanism comprising:
a housing;
a piston rod to operably engage with a piston of a cartridge for displacing the piston in a distal direction;
a dose indicating member with dose size indicating numbers or symbols thereon, wherein the dose indicating member is connected to a spring element and is rotatable in a dose incrementing direction against an action of the spring element for setting of the dose, and wherein the dose indicating member is rotatable in a dose decrementing direction under an action of the spring element for dispensing of the dose, the dose decrementing direction being opposite to the dose incrementing direction; and
a drive wheel operably engaged with the piston rod for displacing the piston rod in the distal direction for dose dispensing,
wherein the dose indicating member is engageable with the drive wheel during dose dispensing to transfer a driving force to the drive wheel when the dose indicating member is driven by the relaxing spring element in the dose decrementing direction; and
the cartridge containing the medicament and being arranged in the housing of the drive mechanism.

16. The drug delivery device according to claim 15 , wherein the dose indicating member comprises a flat shaped dose indicating disc.

17. The drug delivery device according to claim 15 , wherein the spring element comprises a spiral spring having a first end section connected to the housing and having a second end section connected to the dose indicating member.

18. The drug delivery device according to claim 15 , further comprising a ring-shaped dose setting member rotatably supported by the housing and being selectively engageable with the dose indicating member for setting of the dose.

19. The drug delivery device according to claim 18 , wherein the ring-shaped dose setting member comprises a circumferential side wall portion extending into the housing.

20. The drug delivery device according to claim 19 , wherein a last dose limiting member radially sandwiched between the side wall portion and the housing is threadedly engaged with the side wall portion and rotatably locked to the housing.

Assignees

• Sanofi Sa

Inventors

• Bayer Stefan
• Berning Daniel
• Blank Philippe
• Pelzer Wolfgang
• Wilden Björn

Classifications

• A61M5/24

  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 title

• A61M5/31541

  Means preventing setting of a dose beyond the amount remaining in the cartridge · CPC title

• A61M5/31533

  Dosing mechanisms, i.e. setting a dose (administrating mechanisms A61M5/31565) · CPC title

• A61M5/31553

  without axial movement of dose setting member · CPC title

• A61M5/31593

  Multi-dose, i.e. individually set dose repeatedly administered from the same medicament reservoir · CPC title