Patent ID: 8911411
Filing Date: 2014-12-16
Classification: A61M

Abstract:
1. A drug delivery device comprising: a housing, a piston rod having a first thread and a second thread, a nut member disposed within the housing, and which has an inner thread mating the first or second thread of the piston rod such that the piston rod is screwed in a distal direction when rotated relatively to the nut member, a drive sleeve which has an inner thread mating the first or second thread of the piston rod such that the piston rod is rotated when the drive sleeve is axially moved relatively to the piston rod, wherein a releasable coupling is movable between a first position and a second position to secure the piston rod, against rotation during dose setting in the first position but during dose administration allows the piston rod to rotate and thus axially translate to expel a drug from the device in the second position, wherein the releasable coupling is provided between the piston rod and the drive sleeve.