The invention relates to an injection device for injecting a selectable dose of a liquid substance from an ampoule, located in an ampoule holder, comprising a piston and a sleeve-shaped mechanism holder, in the interior of which a longitudinally shiftable shaft is provided, the shaft being surrounded...http://www.google.com/patents/US6086567?utm_source=gb-gplus-sharePatent US6086567 - Injection device
