Patent ID: 7597685

Claim:
An injection device, comprising: a tubular elongated main body, a needle shield unit slidably arranged in the main body, a cartridge containing medicament arranged in the main body, a plunger operatively arranged to the cartridge for ejecting the medicament through a needle attached to the cartridge and arranged on its upper part with first and second sets of outwardly extending stop members, spring means arranged to the plunger for operating the plunger, a dose activating means arranged with inwardly extending stop members that co-operate with the plunger's second set of outwardly extending stop members to hold the plunger and the spring means in a tensioned locked position, a needle shield spring arranged to act on the needle shield unit, a first tubular member rotationally and slidably arranged inside the needle shield unit, wherein the first tubular member comprises a number or ridges and protrusions on both its outer and inner surfaces, the ridges and protrusions on the outer surface of the first tubular member co-operate with guide members arranged on the inner surface of the needle shield unit, and the ridges and protrusions on the inner surface of the first tubular member co-operate with the first set of outwardly extending stop members of the plunger, and a second tubular member rotationally locked to the dose activating means, wherein the second tubular member is arranged with a set of descending ledges on its inner surface that co-operate with the plunger's second set of outwardly extending stop members for setting and delivering a certain preset dose.