| abstract |
Mask assembly comprising: a first upper portion (154) comprising a first wall (182) and a second wall (184) converging at an apex (180), the apex (180) being located in use near the nose of a user; a lower portion (156) connecting to and positioned below the first upper portion (154); a region between the face contacting rim (160) defined at least in part by the first upper portion (154) and the lower portion (156); a hinge axis (H) extending laterally through the mask assembly, the first upper portion (154) being positioned vertically higher than the hinge axis (H); a band (174) extending along at least a portion of the first wall (182) and along at least a portion of the second wall (184), the band (174) comprising a first end (186 ) and a second end (188), both ends being separated away from the hinge axis (H) towards the apex (180), the band (174) forming a first border; a second upper portion (130) located distally of the first upper portion (154) in a direction away from the region between the face-contacting rim (160), the second upper portion (130) comprising an arc length (132 ) defined along an upper extremity of a surface of the second upper portion (130), the arc length (132) forming a second boundary; an offset between a distal portion of the first upper portion (154) and a proximal portion of the second upper portion (130), being proximal and distal relative to the region between the face-contacting rim; and wherein at least a portion of a first outer surface of the first upper portion (154) is configured to wave-fold to cover or underlie at least a portion of a second outer surface (170). ) of the second upper portion (130) when the first border moves towards the second border. |