Drug delivery device for delivering a precise drug dose to an injection site of a patient body

Abstract

The present invention relates to a drug delivery device (100). The drug delivery device (100) comprises: an outer housing (1) designed to have a drug reservoir (4) installed therein; an actuating mechanism (6) designed to generate an actuating force; a dose-setting mechanism (5) installed at least partly in the outer housing (1), wherein the dosesetting mechanism (5) is capable of setting a drug dose and functionally connected to the actuating mechanism (6); an inner housing (11) installed in the outer housing (1) and functionally connected to the dose-setting mechanism (5); a rod (13) movably installed at least partly in the inner housing (11) so as to enable the drug to be discharged from the reservoir (4); a driving part (15) provided with radial teeth, wherein the driving part (15) is intermeshed in the outer housing (1) with the inner housing (11) and threadably engaged with rod (13) such that the actuating force is transferred to the rod (13) in order to move the latter depending on the set drug dose; and a cylindrical part (14) having at least one resilient element (14.1) provided with a pawl (14.2), wherein the cylindrical part (14) is secured in the outer housing (1) so as to enable the pawl (14.2) to jump at least over one of the radial teeth of the driving part (15) when rotating the driving part (15).