Injection device with dose setting mechanism having maximum dose stop

A dose setting mechanism for a drug delivery device, the mechanism comprising:

• a housing comprising an internal helical thread,
• a dose setting member comprising an external surface that engages the internal helical thread of the housing such that the dose setting member is movable relative to the housing to set a dose,
• a drive sleeve which is at least partially located within the housing and which is moved along a helical path having a rotatory component and a translational component in a first axial direction relative to the housing during dose setting,
• a threaded piston rod in threaded engagement with the drive sleeve,
• wherein an inner side of the housing and a proximal flange of the drive sleeve define corresponding stops,
• wherein the corresponding stops are arranged to abut one another so as to limit the movement of the drive sleeve in the first axial direction during dose setting thereby defining a maximum settable dose, and wherein
• the dose setting member and the drive sleeve are decoupled during dose dispensing such that the dose setting member is free to rotate relative to the drive sleeve and
• the piston rod is free to rotate relative to the drive sleeve.