| abstract |
A drive train for a wind-up injection device, comprises a torsional energy storage adapted to be loaded or unloaded by a rotatable element, a rotatable user handle coupled with a button, a rotationally drivable expelling mechanism, and a clutch element coupled with the torsional energy storage via the rotatable element and comprising a ratchet for maintaining the rotatable element at one of a number of discrete angular positions, wherein via the rotatable element, the clutch element is adapted to transmit a torque from the user handle to the torsional energy storage or from the torsional energy storage to the expelling mechanism, and wherein the ratchet is switchable from one position to an adjacent position by a torque transmitted from the user handle to the torsional energy storage, and wherein the drive train is adapted to dampen torque peaks by a flexible impact portion in the area of the clutch element. |