DRIVE MECHANISM FOR A DRUG DELIVERY DEVICE

摘要

A lead screw (5) with a screw thread (6) is arranged in a body (1) along an axis (4) and coupled to a lead screw nut (7) with a drive feature (8), so that the lead screw is helically rotatable in the lead screw nut. The lead screw and the lead screw nut are provided with stop features (9) interfering with a rotation of the lead screw in the lead screw nut when a force is applied to the lead screw in an axial direction. The lead screw nut has a surface area facing a guide feature (10) of the body. This surface area has a slope (12) varying around the axis. The assembly interacts such that the lead screw nut rotates in one rotational direction when a force is applied to the lead screw in the axial direction.