Patent ID: 8631793

Claim:
A nasal respiratory mask system comprising: a nasal mask configured to be attachable to a face of a user and serves as means for supplying positive-pressure breathing gas to a nose of the user; a frame to keep the nasal mask at a predetermined position; and a headgear configured to be mountable on a head of the user in order for the nasal mask to be attachable to the face of the user, wherein the headgear comprises a headgear strap configured to adjust the length of the headgear, the headgear strap comprises a headgear fastener that serves as means for connection/disconnection with the frame, the frame comprises a fastener catch that engages with the headgear fastener, the fastener catch comprises an axisymmetric guide whose axis is an insertion direction of the headgear fastener, the shape of the guide is an indentation having a spindle shape or a cone shape, and the headgear fastener has an approximately V-shaped protruding portion adapted to the indentation, wherein, at an open end of the guide, the indentation has a smooth circular inner wall along an entire periphery thereof and extending a predetermined axial length of the indentation such that the headgear fastener can be inserted into the fastener catch in any rotational direction, wherein the headgear fastener is rotatable about the axis of the direction of insertion even when engaged at the engagement site with the fastener catch and wherein the headgear fastener is rotatable by at least 30 degrees with respect to the fastener catch at the engagement site with the fastener catch.