This refers to an actuating mechanism which is suitable for an injection device (1, 101), especially a device for Administration of medication type of Pencil.The mechanism comprises a housing (4), (5), 104, 105), a member of Dial (6； 106), a torsion Spring (12, 112), Set between the accommodation (4, 5； 104, 105) and the Member of Dial (6； 106) in such a way that energy is stored in the torsion Spring (12, 112) with the rotation of the Member Dial (6； 106) with respect to the housing (4, 5； 104, 105), a Drive Member (8)； 108),Contact with a Screw Guide (9； 109 (18), a First Clutch； 118), coupled to the Rotary Drive Member (8)； 108) and accommodation (4, 5； 104, 105), in an engaged State and allows relative rotation between the Drive Member (8)； 108) and Accommodation (4, 5； 104, 105), in a decoupled State, and a Second Clutch (19； 119)The member that engages a rotation Drive (8； 108) and the Member of Dial (6； 106) in an engaged State and allows relative rotation in clockwise and Counter Clockwise between the Drive Member (8)； 108) and the Member of Dial (6； 106) in a decoupled State.The Second Clutch (19； 119) comprises a toggle Ratchet teeth (19a, 19B； 119a and 119b) with angles of tooth with different slopes in the clockwise and counterclockwise, so allowing the Teeth (19a, 19B； 119a and 119b) exceed a s Others in the State is decoupled from the second Clutch (19； 119)With a different Resistance in the clockwise and Counter Clockwise.La presente se refiere a un mecanismo de accionamiento que es adecuado para un dispositivo de inyección (1； 101), especialmente un dispositivo de administración de medicamento del tipo de lápiz. El mecanismo comprende un alojamiento (4, 5； 104, 105), un miembro de dial (6； 106), un resorte de torsión (12； 112), fijado entre el alojamiento (4, 5； 104, 105) y el miembro de dial (6； 106) de un modo tal, que se acumula energía en el resorte de torsión (12； 112) con la rotación del miembro de dial (6； 106) con respecto al alojamiento (4,
