Details for Patent: 7,935,088

Title:	Drive mechanisms suitable for use in drug delivery devices
Abstract:	A drive mechanism suitable for use in drug delivery devices is disclosed. The drive mechanism may be used with injector-type drug delivery devices, such as those permitting a user to set the delivery dose. The drive mechanism may include a housing, a dose dial sleeve, and a drive sleeve. A clutch is configured to permit rotation of the drive sleeve and the dose dial sleeve with respect to the housing when the dose dial sleeve and drive sleeve are coupled through the clutch. Conversely, when the dose dial sleeve and drive sleeve are in a de-coupled state, rotation of the dose dial sleeve with respect to the housing is permitted and rotation of the drive sleeve with respect to the housing is prevented. In the de-coupled state, axial movement of the drive sleeve transfers force in a longitudinal direction for actuation of a drug delivery device.
Inventor(s):	Veasey; Robert Frederick (Leamington Spa, GB), Perkins; Robert (Leamington Spa, GB), Plumptre; David Aubrey (Droitwich, GB)
Assignee:	Sanofi-Aventis Deutschland GmbH (DE)
Filing Date:	Sep 14, 2006
Application Number:	11/520,598
Claims:	1. A drive mechanism for a drug delivery device comprising: an internal housing having a helical thread surrounded by a main housing; a dose dial sleeve having a helical thread engaged with the helical thread of the internal housing, the dose dial sleeve positioned between the internal housing and the main housing; a piston rod, a drive sleeve releasably connected to the dose dial sleeve via a clutch mechanism that is located between the dose dial sleeve and the drive sleeve, wherein: when the dose dial sleeve and the drive sleeve are coupled via the clutch mechanism, both are allowed to rotate with respect to the internal housing and with respect to the piston rod, and when the dose dial sleeve and the drive sleeve are decoupled, rotation of the dose dial sleeve with respect to the internal housing is allowed, rotation of the drive sleeve with respect to the internal housing is not allowed, and axial movement of the drive sleeve with respect to the internal housing is allowed so that a force is transferred in a longitudinal direction to drive the piston rod of the drug delivery device. 2. The drive mechanism according to claim 1, wherein when the dose dial sleeve and the drive sleeve are decoupled, the drive sleeve is secured to the internal housing, whereby rotation of the drive sleeve with respect to the internal housing is prevented while axial movement of the drive sleeve is allowed. 3. An arrangement for a drug delivery device comprising the drive mechanism according to claim 1. 4. A drug delivery device comprising the drive mechanism according to claim 1. 5. A drug delivery device comprising the drive mechanism according to claim 2. 6. The drug delivery device according to claim 4, wherein the drug delivery device comprises a pen-type device. 7. The drug delivery device according to claim 4, wherein the drug delivery device comprises an injector-type device. 8. The drug delivery device according to claim 4, further comprising a needle. 9. The drug delivery device according to claim 6, further comprising a needle. 10. The drug delivery device according to claim 7, further comprising a needle. 11. The drug delivery device according to claim 1, wherein the piston rod comprises a first thread and a second thread, wherein at least one of the first or second threads of the piston rod engages an internal thread of the drive sleeve.