Injection Device

An injection device for apportioning set doses of a drug from a reservoir (40, 240, 340), comprising:

• a housing (10, 210, 310, 510, 610) adapted to hold a reservoir (40,240, 340, 540, 640),
• a dose setting member (30, 50;
• 230, 2150;
• 330, 3150;
• 550;
• 630, 660) for setting the size of the dose to be expelled,
• a scale indication sleeve (90, 290, 390, 590, 690) for indicating the size of the set dose,
• a piston rod (120, 2120, 3120, 5120, 6120) for activating the reservoir (40, 240, 340, 540, 640) to expel the set dose,
• a drive sleeve (70, 270, 370, 570, 670) operational associated with the piston rod (120, 2120, 3120, 5120, 6120) for driving the piston rod (120, 2120, 3120, 5120, 6120) forward,
• characterized in that,
• the drive sleeve (70, 270, 370, 570, 670) is associated with a first thread (112, 2120, 3112, 5112, 6105) and releasable connected to the dose setting member (30, 50;
• 230, 2150;
• 330, 3150;
• 550;
• 630, 660), and
• the dose indication sleeve (90, 290, 390, 590, 690) is associated with a second thread (101, 2101, 3101, 5101, 6101), and releasable connected to the dose setting member (30, 50;
• 230, 2150;
• 330, 3150;
• 550;
• 630, 660), wherein
• the first thread (112, 2120, 3112, 5112, 6105) has a pitch different from the pitch of the second thread (101, 2101, 3101, 5101, 6101).