Drive assembly for a drug delivery device and related methods

A method of assembling a drive assembly for a drug delivery device, the method comprising:

• providing a casing having a bottom surface, a plurality of sidewalls extending from the bottom surface and defining a cylindrical body portion, and a lid;
• inserting at least a portion of a plunger rod guide through a cavity formed through the bottom surface and the lid of the casing;
• feeding a metal band into the casing through an opening in the plurality of sidewalls;
• winding the metal band around a portion of the plunger rod guide within the casing to form a spring;
• and
• selectively coupling a lock component with the lid of the casing, wherein the lock component is configured to prevent rotational movement of the plunger rod guide relative to the casing and lock the spring in an energized state when the lock component is coupled with the lid.

A method of manufacturing a drive assembly for a drug delivery device, the method comprising:

• stamping, via a stamping tool, a sheet of metal to form a bottom surface, a plurality of sidewalls, and a lid of a casing, the bottom surface, the plurality of sidewalls, and the lid being integrally formed;
• cutting, via a cutting tool, the bottom surface, the plurality of sidewalls, and the lid from the sheet of metal;
• folding the bottom surface, the plurality of sidewalls, and the lid to form the casing;
• inserting at least a portion of a plunger rod guide through a cavity formed through the bottom surface and the lid of the casing;
• feeding a metal band into the casing through an opening in the plurality of sidewalls of the casing;
• winding the metal band around a portion of the plunger rod guide within the casing to form a spring;
• and
• selectively coupling a lock component with the lid of the casing, wherein the lock component is configured to prevent rotational movement of the plunger rod guide relative to the casing and lock the spring in an energized state when the lock component is coupled with the lid.