Drug delivery device with dose counting mechanism

A drug delivery device for executing a predetermined number of dose expelling actions, the drug delivery device comprising:

• a housing extending along an axis and accommodating a dose expelling mechanism,
• a reciprocating element operatively coupled with the dose expelling mechanism and configured to undergo a predefined motion relative to the housing during each dose expelling action to allow a dose to be expelled, the predefined motion comprising displacement in a first axial direction from a first position to a second position followed by displacement in a second axial direction from the second position to the first position,
• a counter element being movable in the first axial direction relative to the housing, a first unidirectional ratchet mechanism configured to prevent motion in the first axial direction and allow motion in the second axial direction of the reciprocating element relative to the counter element, and
• a second unidirectional ratchet mechanism configured to allow motion in the first axial direction and prevent motion in the second axial direction of the counter element relative to the housing.