Drive mechanism for a drug delivery device

Patent metadata

Field	Value
Publication number	US-10076610-B2
Application number	US-201414782655-A
Country	US
Kind code	B2
Filing date	Apr 8, 2014
Priority date	Apr 10, 2013
Publication date	Sep 18, 2018
Grant date	Sep 18, 2018

Abstract

A drive mechanism for a drug delivery device includes an elongated housing extending in an axial direction and a piston rod to operably engage with a piston of a cartridge to displace the piston in an axial distal direction. A drive sleeve is rotatably supported in the housing, operably releasable from the piston rod for setting of a dose, and operably engageable with the piston rod for dispensing of the dose. A dose limiting member is engaged with the drive sleeve and engaged with the piston rod in such a way that it is displaced in axial direction relative to the drive sleeve when the drive sleeve rotates relative to the piston rod during a dose setting procedure. At least one stop is configured to engage with the dose limiting member for limiting the axial displacement of the dose limiting member during the dose setting procedure and to impede further displacement of the drive sleeve relative to the piston rod.

First claim

The invention claimed is:

1. A drug delivery device for dispensing of a dose of a medicament, comprising:
an elongate housing;
a cartridge arranged in the housing and comprising a piston, the cartridge being at least partially filled with the medicament;
a piston rod configured to engage the piston of the cartridge to displace the piston in a distal direction along a longitudinal axis of the housing;
a drive sleeve rotatably supported in the housing and being releasable from the piston rod for setting a dose during dose setting, the drive sleeve being engageable with the piston rod for dispensing the dose during dose dispensing;
a dose limiting member directly engaged with the drive sleeve and directly engaged with the piston rod, the dose limiting member being configured to move along the longitudinal axis relative to the drive sleeve when the drive sleeve is rotated relative to the piston rod during the dose setting; and
a stop configured to abut the dose limiting member and limit displacement of the dose limiting member during the dose setting and to inhibit rotation of the drive sleeve relative to the piston rod during the dose setting.

2. The drug delivery device of claim 1 , wherein the stop is part of a clutch configured to engage with the drive sleeve, and the stop is arranged on and axially protruding from a distal end of the clutch.

3. The drug delivery device of claim 1 , further comprising a helical spring extending around the drive sleeve, the spring being configured to rotatably bias the drive sleeve relative to the housing.

4. The drug delivery device of claim 1 , further comprising a drive nut axially fixed to the housing and rotatably supported in the housing, the drive nut being threadedly engaged with the piston rod, wherein the drive sleeve is axially displaceable relative to the housing to rotatably engage with the drive nut during the dose dispensing and to rotatably disengage the drive sleeve from the drive nut during the dose setting.

5. The drug delivery device of claim 1 , wherein the stop extends radially relative to the longitudinal axis and extends along the longitudinal axis, the stop being configured to engage with a stop portion of the dose limiting member, the stop portion extending radially relative to the longitudinal axis and extending along the longitudinal axis.

6. The drug delivery device of claim 5 , wherein the dose limiting member comprises a clicking member having a resilient arm extending in a circumferential direction from the dose limiting member, the resilient arm comprising a latch portion at a free end of the resilient arm, the latch portion being configured to engage with the stop before or when the stop portion engages with the stop to generate an audible feedback.

7. A drive mechanism of a drug delivery device for dispensing of a dose of a medicament, the mechanism comprising:
an elongated housing extending in an axial direction,
a piston rod to operably engage with a piston of a cartridge to displace the piston in an axial distal direction,
a drive sleeve rotatably supported in the housing and being releasable from the piston rod for setting of a dose during dose setting and being engageable with the piston rod for dispensing of the dose during dose dispensing,
a dose limiting member directly engaged with the drive sleeve and directly engaged with the piston rod, and being configured to move along a longitudinal axis of the housing relative to the drive sleeve when the drive sleeve is rotated relative to the piston rod during the dose setting, and
at least one stop to engage with the dose limiting member for limiting longitudinal displacement of the dose limiting member during the dose setting and to inhibit rotation of the drive sleeve relative to the piston rod during the dose setting.

8. The drive mechanism of claim 7 , wherein:
the drive sleeve encloses a circumference of the piston rod at least in an axial section, and
the dose limiting member is arranged radially between the drive sleeve and the piston rod.

9. The drive mechanism of claim 7 , wherein the dose limiting member is threadedly engaged with the drive sleeve.

10. The drive mechanism of claim 7 , wherein the dose limiting member is rotatably fixed to the piston rod and axially slidably engaged with the piston rod.

11. The drive mechanism of claim 7 , wherein a radially inwardly extending gliding portion of the dose limiting member is configured to be received by an elongated groove of the piston rod.

12. The drive mechanism of claim 7 , wherein the dose limiting member is shaped to extend only partially around a circumference of the piston rod.

13. The drive mechanism of claim 7 , wherein the stop extends radially relative to the longitudinal axis and extends along the longitudinal axis, the stop being configured to engage with a stop portion of the dose limiting member, the stop portion extending radially relative to the longitudinal axis and extending along the longitudinal axis.

14. The drive mechanism of claim 13 , wherein the dose limiting member comprises a clicking member having a resilient arm extending in a circumferential direction from the dose limiting member, the resilient arm comprising a latch portion at a free end of the resilient arm, the latch portion being configured to engage with the stop before or when the stop portion engages with the stop to generate an audible feedback.

15. The drive mechanism of claim 7 , wherein the dose limiting member comprises:
a distal stop portion extending from a distal end section of the dose limiting member and
a proximal stop portion extending from a proximal end section of the dose limiting member, the proximal end section being opposite the distal end section.

16. The drive mechanism of claim 7 , wherein the stop is positioned on an inner wall of the drive sleeve.

17. The drive mechanism of claim 7 , wherein the stop is arranged on and axially protrudes from a proximal end of a clutch configured to be engaged with the drive sleeve.

18. The drive mechanism of claim 7 , wherein the stop extends radially in or on the piston rod, the stop being configured to engage with the dose limiting member in a last dose configuration to inhibit setting of an excess dose exceeding an amount of liquid remaining in a cartridge loaded in the housing.

19. The drive mechanism of claim 7 , wherein the drive sleeve is rotatably biased by a helical spring extending around the drive sleeve.

20. The drive mechanism of claim 7 , further comprising a drive nut axially fixed to the housing and rotatably supported in the housing, the drive nut being threadedly engaged with the piston rod,
wherein the drive sleeve is axially displaceable relative to the housing to rotatably engage with the drive nut during the dose dispensing and to rotatably disengage the drive sleeve from the drive nut during the dose setting.

21. A drive mechanism of a drug delivery device for dispensing of a dose of a medicament, the mechanism comprising:
an elongated housing extending in an axial direction,
a piston rod to operably engage with a piston of a cartridge to displace the piston in an axial distal direction,
a drive sleeve rotatably supported in the housing and being releasable from the piston rod for setting of a dose during dose setting and being engageable with the piston rod for dispensing of the dose during dose dispensing,
a dose limiting member engaged with the drive sleeve and engaged with the piston rod, and being configured to move along a longitudi

Assignees

• Sanofi Sa

Inventors

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

Classifications

• A61M5/3157

  Means providing feedback signals when administration is completed (A61M5/20 takes precedence) · CPC title

• A61M2205/581

  by audible feedback · CPC title

• A61M2005/3154

  limiting maximum permissible dose · CPC title

• A61M2205/582

  by tactile feedback · 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