Headgear adjustment mechanism

Abstract

A headgear assembly for retaining a respiratory mask on a user's face is provided. The headgear assembly comprising an adjustment mechanism or arrangement that includes a pair of rails configured to allow a first and second strap to be slideably moved relative to each other to adjust the size of the headgear assembly.

1 - 12 . (canceled) 
     
     
         13 . A mask assembly comprising:
 a mask configured to contact a user's face and deliver gases to the user in use; and   a headgear configured to secure the mask to the user's face in use, the headgear comprising a top strap and an adjustment mechanism configured to allow for adjustment of the top strap, the adjustment mechanism comprising first and second strap portions and a friction component, the first and second strap portions configured to telescope relative to each other and the friction component configured to resist telescoping movement between the first and second strap portions.   
     
     
         14 . The mask assembly of  claim 13 , wherein the friction component comprises at least one o-ring. 
     
     
         15 . The mask assembly of  claim 13 , wherein the friction component comprises a plurality of flexible fins. 
     
     
         16 . The mask assembly of  claim 13 , wherein the friction component comprises at least one roller. 
     
     
         17 . The mask assembly of  claim 13 , wherein the friction component comprises a spring loaded arm having a friction surface. 
     
     
         18 . A mask assembly comprising:
 a mask configured to contact a user's face and deliver gases to the user in use; and   a headgear configured to secure the mask to the user's face in use, the headgear comprising a top strap and an adjustment mechanism configured to allow for adjustment of the top strap, the adjustment mechanism comprising outer and inner strap portions configured to telescope relative to each other, wherein the outer strap portion is deformable about the inner strap portion, one of the outer and inner strap portions comprises a lock tooth, and the other of the outer and inner strap portions comprises a lock recess, wherein in a locked position the lock tooth engages the lock recess.   
     
     
         19 . The mask assembly of  claim 18 , wherein the outer strap portion is configured to be squeezed by the user to disengage the lock tooth from the lock recess and allow for adjustment of a length of the top strap. 
     
     
         20 - 24 . (canceled) 
     
     
         25 . The mask assembly of  claim 13 , wherein one of the first and second strap portions comprises an inner tube and another comprises a hollow outer tube. 
     
     
         26 . The mask assembly of  claim 25 , wherein the inner tube includes a groove that extends around a circumference of an outer surface of the inner tube that at least one o-ring is disposed within. 
     
     
         27 . The mask assembly of  claim 13 , wherein one of the first and second strap portions comprises a hollow outer rail and another of the first and second strap portions comprises an inner rail. 
     
     
         28 . The mask assembly of  claim 27 , wherein a portion of the inner rail is disposed within the hollow outer rail. 
     
     
         29 . The mask assembly of  claim 27 , wherein a ring is coupled to an end of the hollow outer rail and disposed about the inner rail. 
     
     
         30 . The mask assembly of  claim 29 , wherein the ring is integrally formed with the end of the hollow outer rail. 
     
     
         31 . The mask assembly of  claim 29 , wherein the ring is removably coupled to the end of the hollow outer rail. 
     
     
         32 . The mask assembly of  claim 29 , wherein the ring is permanently coupled to the end of the hollow outer rail. 
     
     
         33 . The mask assembly of  claim 18 , wherein the lock tooth is integrally formed with one of the outer and inner strap portions. 
     
     
         34 . The mask assembly of  claim 18 , wherein the adjustment mechanism is hidden.