#$%^&*AU2017202877B220180726.pdf#####ABSTRACT A medication injection pen includes a housing and a dose set knob having at least one internal tooth. A brake member has a plurality of axially extending splines. A driver or setback member includes at least one external tooth engaging the at least one internal tooth of the dose set knob and at least one ratchet arm engaging the plurality of axially extending splines. The driver is prevented from rotating with the dose set knob while moving axially with the dose set knob during dose setting and dose correcting, and the driver rotates with the dose set knob during an injection.36/54 01 00 CD.
