Patent ID: 9381306
Filing Date: 2016-07-05
CPC Classification: A61M

Claim Text:
1. A drive mechanism for a drug delivery device, comprising: a housing, a drive member arranged inside the housing, the drive member being rotatable with respect to the housing, a piston rod, which is coupled to the drive member, a rotation member arranged inside the housing, the rotation member being rotatable with respect to the housing, drive fingers of the drive member, the drive fingers being resilient or resiliently mounted, a slider disposed at the drive member, the slider being axially movable between a first position, in which the slider keeps the drive fingers constrained, and a second position, in which the drive fingers are released, a first unidirectional rotational clutch engaging the drive member with the rotation member, the clutch being formed by the drive fingers when the slider is in the first position, the drive member and the rotation member being disengaged when the slider is in the second position, a unit which is attachable to the housing and removable from the housing, the drive fingers acting on the slider in such a manner that the slider is moved from the first position to the second position when the unit is being removed from the housing, a coupling sleeve of the slider, and an insert sleeve of the unit, the insert sleeve acting on the coupling sleeve and keeping the slider in the first position when the unit is attached to the housing wherein part of the slider has a taper that is operatively engaged with the drive fingers such that the drive fingers are splayed apart and disengaged from the rotation member when the slider is moved from the first position to the second position.