EP4448052A1 — Sub-assembly of a medicament delivery device

USPTO Abstract

The present disclosure relates to a sub-assembly of a medicament delivery device comprising a plunger rod configured to be moveable inside the medicament delivery device, a spring abutting the plunger rod in one end and abutting an inner wall of the sub-assembly in another end to compress the spring upon the plunger rod being moved towards a distal end of the medicament delivery device, an arm extending axially and being immovable with respect to a housing, the arm having a radially extending end section, an inner surface of which end section pressing radially against the spring-loaded plunger rod to axially fix the spring-loaded plunger rod relative to the arm, a rear wall member axially movable from a lock position where an inner wall of the rear wall member radially encloses an outer surface of the arm to a release position where the rear wall member is radially offset relative to the outer surface of arm, a radially flexible tab having an axially directed surface adjacent to a counter surface of an engagement member to form an axial abutment preventing the rear wall member from moving into the release position, and a release member configured to be axially moved into contact with a radial protrusion of the flexible tab to radially deflect the flexible tab, thereby radially offsetting the axially directed surface from the counter surface of the engagement member.