Sanofi
Drive mechanism for an injection device

Abstract:

A drive mechanism for an injection device includes an inner body fixable inside a housing. An elongated shaft of the inner body extends in an axial direction. The shaft includes an outer thread and a blocking structure on an outer circumference. A tubular-shaped display member has an inner thread engaged with the outer thread of the inner body (20). A dose member is axially displaceable between a dose setting position and a dose dispensing position relative to the display member. The dose member includes at least one blocking element displaceable, pivotable or bendable in radial direction between a blocking position and a release position and engageable with the blocking structure for inducing a radial displacement of the blocking element. In the blocking position, the blocking element axially abuts with the blocking structure and with the display member to block an axial displacement of the dose member from the dose setting position towards the dose dispensing position.