The present invention relates to drive mechanisms suitable for use in drug delivery devices, in particular pen-type injectors, wherein a number of pre-set doses of medicinal product can be administered. In particular, the present invention relates to such drug delivery devices where a user may activate the drug delivery device.本發明關於適合用於藥物輸送裝置、特別是筆形注射器的驅動機構,其中多份預設劑量的醫藥產品可由其投送。特定言之,本發明關於此等藥物輸送裝置,且一使用者可作動此藥物輸送裝置。