Details for Patent: 8,556,864
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| 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 (Warwickshire, GB), Perkins; Robert (Warwickshire, GB), Plumptre; David Aubrey (Worcestershire, GB) |
| Assignee: | Sanofi-Aventis Deutschland GmbH (Frankfurt am Main, DE) |
| Filing Date: | Mar 30, 2011 |
| Application Number: | 13/075,212 |
| Claims: | 1. A drive mechanism for use in a drug delivery device comprising: a housing having a helical thread; a dose dial sleeve having a helical thread engaged with the helical thread of the housing; a drive sleeve having two radially extending flanges spaced a distance apart and having an outer helical thread there between, where the drive sleeve is releasably connected to the dose dial sleeve; a piston rod threadedly engaged with the drive sleeve; and a clutch mechanism located between the dose dial sleeve and the drive sleeve. 2. A drive mechanism for use in a drug delivery device is provided comprising: a housing having a helical thread along an inner surface, a dose dial sleeve having a helical thread on an outer surface engaged with the helical thread of the housing; a drive sleeve releasably connected to the dose dial sleeve; and a clutch mechanism located between the dose dial sleeve and the drive sleeve; wherein the clutch mechanism is configured such that, a) when the dose dial sleeve and the drive sleeve are coupled, both are allowed to rotate with respect to the housing; and b) when the dose dial sleeve and the drive sleeve are de-coupled, rotation of the dose dial sleeve with respect to the housing is allowed, while rotation of the drive sleeve with respect to the housing is prevented, whereby axial movement of the drive sleeve is allowed so that a force is transferred in a longitudinal direction to a proximal end of the drug delivery device. 3. The drive mechanism of claim 2 further comprising a piston rod having a first external thread and a second external thread, where the first external thread is threadedly engaged with an insert, and where the second external thread is threadedly engaged with an internal thread on the drive sleeve. 4. The drive mechanism of claim 2 where the drive sleeve has two radially extending flanges spaced a distance apart and having an outer helical thread there between and where the drive sleeve is releasably connected to the dose dial sleeve. 5. The drive mechanism of claim 4 further comprising a dose limiting mechanism. 6. The drive mechanism of claim 5 wherein said dose limiting mechanism is disposed between said first radially extending flange and said second radially extending flange. 7. The drive mechanism of claim 6 wherein said dose limiting mechanism comprises a nut threadedly engaged with the outer helical thread of the drive sleeve and is splined to an internal surface of the housing to prevent the nut from rotating while allowing relative longitudinal movement between the two radially extending flanges, whereby the longitudinal movement is proportional to dispensed doses. 8. A drive mechanism for use in a drug delivery device comprising: a) a main housing having a first end and a second end, a helical thread having a first lead, an insert rotationally fixed to the housing having a thread with a second lead; b) a dose dial sleeve having a helical thread engaged with the helical thread of the main housing configured so that during dose selection the dose dial sleeve rotates and extends axially from the second end of the main housing and during dose delivery rotates and moves axially back into the main housing; c) a tubular drive sleeve having an internal surface and an outer surface having disposed thereon an intermediate thread, where the tubular drive sleeve is releasably connected to the dose dial sleeve through a clutch located between the dose dial sleeve and the tubular drive sleeve and where the tubular drive sleeve has an internal helical thread having a lead equal to the first lead; d) a piston rod having a first external thread and a second external thread, where the first external thread has a lead equal to the second lead that is different and of opposite disposition than the first lead and is threadedly engaged with the insert, and where the second external thread is threadedly engaged with the internal thread of the tubular drive sleeve; wherein, when the dose dial sleeve and the tubular drive sleeve are coupled during dose section, both are allowed to rotate with respect to both the main housing and the piston rod; and when the dose dial sleeve and the tubular drive sleeve are de-coupled during dose delivery, rotation of the dose dial sleeve with respect to the main housing is allowed, while rotation of the tubular drive sleeve with respect to the main housing is prevented, whereby axial movement of the tubular drive sleeve is allowed causing the piston rod to rotate through the tread of the insert and moving axially through the insert so that a force is transferred from the piston rod to a cartridge piston. 9. The drive mechanism of claim 8 wherein the intermediate thread is disposed between two radially extending flanges on the outer surface of the tubular drive sleeve. 10. The drive mechanism of claim 8 wherein the opposite disposition of the second lead of the first external thread compared to the first lead prevents the piston rod from moving during dose selection. |
