Patent ID: 8529520

Claim:
A medicament delivery device, comprising: a generally elongated housing having distal and proximal housing parts having opposite distal and proximal ends; a medicament container coaxially arranged within the proximal housing part; a drive mechanism arranged to act on the medicament container for expelling a dose of medicament; and an electromechanical dose setting mechanism interactively connected to the drive mechanism, wherein the electromechanical dose setting mechanism includes: a manually operable dose setting button; a dose setting member that includes sensors arranged to be linearly displaced a predetermined distance along a linear path when the dose setting button is manually operated; and a printed circuit board that has a code sensing area having a code along the linear path of the sensors, wherein the sensors are arranged adjacent the code sensing area such that a value of an immediate position of the dose setting member is determined and displayed as a dose value by electronic components on the printed circuit board; wherein the drive mechanism includes: a threaded plunger rod having a proximal end abutting a stopper within the medicament container; a rotational locking member interactively connected to the plunger rod; a nut threadedly arranged to the plunger rod, a locking member interactively connected to the rotational locking member, a driver having a shape of an elongated tube, inside which the plunger rod extends; the driver being releasably attached to the nut; and the driver being arranged with threads on its outer surface; and a force mechanism having a first end connected to the driver and a second end connected to a fixed point on the distal housing part; and the dose setting member has a tubular shape, is arranged surrounding the driver and with corresponding threads on its inner surface, and includes guide devices on its outer surface that cooperate with grooves on an inner surface of the distal housing part for preventing rotation of the dose setting member but allowing linear movement of the dose setting member; and the distal end of the driver is fixedly connected to the manually operable dose setting button, capable of turning the driver.