Drive mechanism of a drug delivery device

• US 10,478,562 B2
• Filed: 04/08/2014
• Issued: 11/19/2019
• Est. Priority Date: 04/10/2013
• Status: Active Grant

• Current Assignee: Sanofi
• Original Assignee: Sanofi
• Inventors: Bayer, Stefan, Berning, Daniel, Blank, Philippe, Pelzer, Wolfgang, Wilden, Bjorn
• Primary Examiner(s): Bouchelle, Laura A
• Assistant Examiner(s): Ulsh, Dung T
• Application Number:
  US14/782,622
• Publication Number:
  US 20160045663A1
• Time in Patent Office: 2,051 Days
• Field of Search: 604 71, 604186, 604207, 604208, 604211, 604224, 604246
• CPC Class Codes: A61M 2005/3126 Specific display means related to dosing
• CPC Class Codes: A61M 5/20 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 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 5/315 Pistons; Piston-rods; Guiding, blocking or restricting the movement of the rod or piston; Appliances on the rod for facilitating dosing ; Dosing mechanisms
• 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 5/31533 Dosing mechanisms, i.e. setting a dose administrating mechanisms A61M5/31565
• CPC Class Codes: A61M 5/31541 Means preventing setting of a dose beyond the amount remaining in the cartridge
• CPC Class Codes: A61M 5/31553 without axial movement of dose setting member
• 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 5/31593 Multi-dose, i.e. individually set dose repeatedly administered from the same medicament reservoir

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.

Claims

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.