Abstract: The device of the invention provides preselected doses of liquid medicine and has a cylinder assembly (1, 2) with a left cylinder (1), a right cylinder (2) and a double piston (4, 5) displaceably mounted in the assembly with a left piston end (4) and a right piston end (5). A coupling links the double piston in a positive and/or frictional manner with a drive unit (15). The device is controlled passively by two automatically closing intake valves (7, 8) and two discharge valves (11, 12). Thereby a continuous flow of liquid medicine 20 out of the medicine container 10 can be generated.

Abstract: A feed mechanism for an injection device having an ampoule casing (13) includes an outer casing (2), an inner casing (3) protruding rearwardly from the outer casing and a toothed rack (4) longitudinally displaceable with the inner casing against the force of a spring (8). The rack has teeth (5) of which the length L corresponds to one full injection dose. The inner casing is longitudinally movable by a length L between two stops (6, 7) in the inner and outer casings. The inner casing has a latch (9, 10) which detachably locks the inner casing at its extreme forward position into an aperture (11) of the ampoule casing. A pawl prevents return movement of the rack.