US Patent 11931552 Cartridge insertion for drug delivery device

A drug delivery device includes a compartment sized to receive a cartridge. The compartment includes a cartridge bay that opens so that a cartridge may be inserted into the cartridge bay and that closes when the cartridge is received by the compartment. The drug delivery device also includes a housing including an expanding assembly. The expanding assembly includes a driver supported from a distal end by a linear stabilizer that includes a bearing configured to push against the housing. The driver is rotated by a motor. The expanding assembly also includes two mid screws threadedly connected to the driver, a plunger driver threadedly connected to the two mid screws, and an anti-rotational guide that prevents rotation of the plunger driver.