Medicament Delivery Devices

• US 20120172817A1
• Filed: 02/03/2010
• Published: 07/05/2012
• Est. Priority Date: 02/05/2009
• Status: Active Grant

• Current Assignee: Sanofi-Aventis Deutschland GmbH (Sanofi )
• Original Assignee: Sanofi-Aventis Deutschland GmbH (Sanofi )
• Inventors: Brüggemann, Ulrich, Jones, Christopher
• Granted Patent: US 9,572,927 B2
• Time in Patent Office: Days
• US Class Current: 604/218
• CPC Class Codes: A61M 2005/14268 with a reusable and a disposable component
• 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 5/14566 with a replaceable reservoir for receiving a piston rod of the pump

Abstract

A medicament delivery device (1) comprises a housing (15), a telescopic piston rod assembly (12) for driving a bung (20) of a medicament container (9), and a drive mechanism (17) for the telescopic piston rod assembly. The telescopic piston rod assembly (12) comprises a plunger (35) for driving a bung (20), a key (40) for allowing predominantly axial movement between the plunger and the housing (30) and an input drive (18) telescopically coupled to the plunger and supported for rotational and axial movement relative the housing. The drive mechanism (17) additionally comprises a transfer drive (16) that operates to rotate the input drive (18). As the input drive (18) rotates, it moves axially relative to the housing (15), expanding telescopically relative to the plunger (35).

Claims

1. A medicament delivery device comprising:

a housing;

a telescopic piston rod assembly for driving a bung of a medicament container; and

a drive mechanism for the telescopic piston rod assembly;

characterised in that;

the telescopic piston rod assembly comprises a plunger for driving the bung, a key for allowing predominantly axial movement between the plunger and the housing; and

an input drive telescopically coupled to the plunger and supported for rotational and axial movement relative to the housing; and

the drive mechanism comprises a transfer drive operative for rotating the input drive whereby the input drive moves axially relative to the housing as the input drive moves telescopically relative to the plunger.

2. A medicament delivery device according to claim 1, wherein the key allows a predetermined amount of rotational movement.

3. A medicament delivery device according to claim 1, wherein the input drive is provided with an external screw thread that engages with and passes through a correspondingly screw threaded opening provided in the housing.

4. A medicament delivery device according to claim 1, wherein the plunger is provided with an external screw thread that engages with an internal screw thread of the input drive so that rotation of the input drive telescopically retracts or expands the plunger relative to the input drive.

5. A medicament delivery device according to claim 4, wherein the input drive is provided with a drive gear at its end opposite the internal screw thread for meshing with an axially extending gear of the transfer drive, so that as the input drive is rotated by the transfer drive, the drive gear can slide along the axially extended gear relative to the housing.

6. A medicament delivery device according to claim 5, wherein the key comprises an elongate member that non-rotationally extends into an end of the plunger opposite from the end thereof that drives the medicament cartridge piston.

7. A medicament delivery device according to claim 6, wherein the key extends through the input drive such that the end of the key remote from the plunger extends into the housing to lie substantially adjacent the axially extended gear of the transfer drive.

8. A medicament delivery device according to claim 7, wherein the end of the key is provided with a tab or projection that extends over the drive gear of the input drive and into a corresponding recess or guide provided on or in the housing.

9. A medicament delivery device according to claim 8, wherein the corresponding recess or guide is disposed parallel to the axially extending gear so that as the input drive is rotated and moves through the screw threaded opening, the key moves axially in parallel for at least part of the length of the axially extending gear.

10. A medicament delivery device according to claim 7, wherein the corresponding recess or guide is disposed non-parallel to the axially extending gear so that as the input drive is rotated and moves through the screw threaded opening, the key moves axially and rotationally according to the skew of the recess or guide.

11. A medicament delivery device according to claim 1, wherein the drive mechanism comprises device for reducing noise and/or reducing tolerances within the drive mechanism.

12. A medicament delivery device according to claim 1, wherein the housing includes a receptacle for a user replaceable medicament cartridge.

13. An auto-injector including a medicament delivery device according to claim 1.