Forehead supports for facial mask

Abstract

A forehead support for a mask assembly includes a frame connector provided to a mask frame, a forehead cushion support movably mounted to the frame connector for generally linear movement between retracted and extended positions with respect to the frame connector, and an adjustment knob movably mounted to the frame connector and threadably engaged with the forehead cushion support such that turning movement of the adjustment knob causes the forehead cushion support to be moved between the retracted and extended positions. The adjustment knob includes a resilient prong having a ratchet bump. The ratchet bump is adapted to selectively engage a series of ridges provided to the frame connector to provide indexed incremental adjustment.

What is claimed is: 
     
         1 . A forehead support for a mask assembly, comprising:
 a frame connector provided to a mask frame;   a forehead cushion support movably mounted to the frame connector for generally linear movement between retracted and extended positions with respect to the frame connector; and   an adjustment knob movably mounted to the frame connector and threadably engaged with the forehead cushion support such that turning movement of the adjustment knob causes the forehead cushion support to be moved between the retracted and extended positions,   wherein the adjustment knob includes a resilient prong having a ratchet bump, the ratchet bump adapted to selectively engage a series of ridges provided to the frame connector to provide indexed incremental adjustment.   
     
     
         2 . A forehead support according to  claim 1 , wherein the adjustment knob includes a threaded shaft that is meshed with an internally threaded tube provided to the forehead cushion support. 
     
     
         3 . A forehead support according to  claim 2 , wherein the tube is joined to forehead cushion support plates that are adapted to carry forehead cushions. 
     
     
         4 . A forehead support according to  claim 3 , wherein the support plates include vertical reinforcing ribs. 
     
     
         5 . A forehead support according to  claim 3 , wherein the support plates include horizontal reinforcing ribs. 
     
     
         6 . A forehead support according to  claim 2 , wherein the support plates are angled with respect to the tube. 
     
     
         7 . A forehead support according to  claim 6 , wherein the support plates are angled about 15-25° with respect to the tube. 
     
     
         8 . A forehead support according to  claim 2 , wherein each support plates include slots for attaching headgear straps. 
     
     
         9 . A forehead support according to  claim 8 , wherein each slot has a width of 6-8 mm. 
     
     
         10 . A forehead support according to  claim 8 , wherein a gap is provided in each support plate to allow the headgear strap to be fitted into the slot. 
     
     
         11 . A forehead support according to  claim 2 , wherein the tube includes two splits that divide the tube into two resilient arms which can deflect to allow insertion of the tube into the frame connector. 
     
     
         12 . A forehead support according to  claim 11 , wherein the splits extend generally parallel to support plates of the forehead cushion support. 
     
     
         13 . A forehead support according to  claim 11 , wherein the splits extend generally perpendicular to support plates of the forehead cushion support. 
     
     
         14 . A forehead support according to  claim 2 , wherein the tube includes key ways that receive respective protrusions provided on the frame connector to prevent rotation of the forehead cushion support. 
     
     
         15 . A forehead support according to  claim 14 , wherein the tube includes 3 key ways and the frame connector includes 3 protrusions. 
     
     
         16 . A forehead support according to  claim 14 , wherein the protrusions protrude outwardly from the frame connector, and the protrusions are adapted to extend into respective holes provided in the forehead cushion support when the forehead cushion support is retracted. 
     
     
         17 . A forehead support according to  claim 14 , wherein a ridge is provided at the end of each key way. 
     
     
         18 . A forehead support according to  claim 17 , wherein each ridge is spaced inwardly from the end of the tube. 
     
     
         19 . A forehead support according to  claim 17 , wherein each ridge is provided at the end of the tube. 
     
     
         20 . A forehead support according to  claim 14 , wherein an L-shaped or bayonet style slot is provided as a lead-in to each key way.