Breathing mask and a sealing lip device for a breathing mask

An elastomeric cushion for a breathing mask configured for sealed delivery of a flow of breathable gas at a positive pressure with respect to ambient air pressure to an entrance of a patient's airways including at least an entrance of the patient's nares, the elastomeric cushion comprising:

• a peripherally extending shell engaging portion configured to secure the elastomeric cushion to a shell of the breathing mask;
• a sealing lip configured to contact the patient's face, the sealing lip:
• (a) defining an opening adapted to receive at least a part of the patient's nose, and
• (b) comprising an elastomeric wall divided into a first zone, a second zone opposite the first zone and a pair of intermediate zones spanning between the first and second zones, wherein a thickness of the elastomeric wall in the first and second zones is thinner than a thickness of the elastomeric wall in the intermediate zones so that when the elastomeric cushion engages the patient's face, a thickness of a portion of the elastomeric wall in contact with the patient's face varies from the pair of intermediate zones to the first zone and varies from the pair of intermediate zones to the second zone and so that the pair of intermediate zones has a higher load-bearing capability than the first and second zones, wherein the first zone comprises a portion of the elastomeric cushion adapted to sealingly engage a bridge of a patient's nose and the second zone comprises a portion of the elastomeric cushion adapted to sealingly engage the patient's face at a location opposite the first zone;
• and
• a peripheral wall extending from the shell engaging portion to the sealing lip, the peripheral wall comprising a bellows structure positioned between the shell engaging portion and the first zone of the sealing lip.