DRIVMEKANISME TIL EN INJEKTIONSANORDNING

The present disclosure relates to an injection device for expelling of a number of preset or user-selectable doses of a medicament, the injection device comprising:- an elongated housing (10; 310; 410) extending along a longitudinal axis (I),- an expelling mechanism (2) comprising a trigger (70) and a piston rod (30),- a dose setting mechanism (3) comprising a rotatable member (260; 360; 460; 560) and a counterpart member (240; 340; 440; 540), wherein the counterpart member and the rotatable member comprise a first mechanical code (242; 342; 442; 542) and a second mechanical code (262; 362; 462; 562), respectively,- wherein for setting of a dose the rotatable member (260; 360; 460; 560) is rotatable relative to the housing (10; 310; 410) and relative to the counterpart member (240; 340; 440; 540) within a range of numerous rotational states, and wherein during setting of the dose the rotatable member (260; 360; 460; 560) is constrained along the longitudinal axis (I) relative to the housing (10; 310; 410) or relative to the counterpart member (240; 340; 440; 540),- wherein for expelling of a dose one of the rotatable member (260; 360; 460; 560) and the counterpart member (240; 340; 440; 540) is displaceable along the longitudinal axis (I) into an expelling position (e) relative to the other one of the rotatable member (260; 360; 460; 560) and the counterpart member (240; 340; 440; 540) only when the first mechanical code (242; 342; 442; 542) is aligned with the second mechanical code (262; 362; 462; 562).