Drug reservoir loading and unloading mechanism for a drug delivery device using a unidirectional rotated shaft

A drug delivery device comprising:

• a shaft;
• a drive system operably connected to the shaft and configured to only rotate the shaft in a first direction;
• a disposable drug reservoir having a first engagement feature and a plunger used to adjust a volume of the drug reservoir;
• a piston rod operably connected at a first end to the plunger and providing threads, the piston rod being operably connected to the shaft, wherein said drug delivery device provides a secured position which permits the rotation of the shaft to drive the piston rod and move the plunger to adjust the volume of the drug reservoir, and an unsecured position which permits the drug reservoir to be removed unobstructed from the drug deliver device and replaced without having to rotate the shaft in a direction opposite to the first direction;
• a base which defines a compartment to hold the drug reservoir;
• and
• a lid having a second engagement feature which engages with the first engagement feature of the drug reservoir, said lid being mounted pivotably to the base and providing open and closed positions wherein when in the closed position the drug reservoir is enclosed by the lid within the compartment of the base to place the drug deliver device in the secured position, and when in the open position the engagement between the first and second engagement features holds the drug reservoir to the lid such that the drug reservoir is held out from the compartment to place the drug deliver device in the unsecured position.