Patient interface assembly and system using same

A patient interface assembly for use in the delivery of a breathing gas to a patient, comprising:

• a patient interface device;
• a headgear adapted to be worn by a patient;
• a coupling member adapted to couple the patient interface device pivotally to the headgear such that the patient interface device pivots about an axis over a range of angles relative to the headgear, the coupling member including a first portion and a second portion, the second portion being structured to pivot about the axis relative to the first portion;
• and
• a spring member extending from the first portion of the coupling member, the spring member contacting the second portion of the coupling member to bias the patient interface device against such a patient's face responsive to the patient interface assembly being donned by such a patient wherein the spring member is a lever spring extending from the first portion of the coupling member, wherein the first portion of the coupling member comprises a housing member, and wherein the second portion of the coupling member comprises a pivot tube received within and coupled to the housing member in a manner wherein the pivot tube is pivotable about the axis relative to the housing.