the present invention provides a system for stiffening , as described in more detail herein , a portion of the perimeter of a mask that has a formable element disposed about its perimeter . referring to fig4 , one preferred embodiment of a full face mask 41 has a shell 42 constructed of a compliant and resilient material . a formable element 44 is disposed along the perimeter , and only the perimeter , of the shell 42 . the formable element 44 can be affixed to the surface of the shell 42 but is molded within the shell 42 here . a portion 45 of the formable element 44 running along the wearer &# 39 ; s chin from 46 to 47 is stiffened . it is stiffened in this preferred embodiment by molding a polycarbonate sleeve 48 over the portion 45 of the formable element 44 before the formable element 44 , and polycarbonate sleeve 48 , are molded in the shell 42 . this causes the portion 45 of the formable element 44 to become more difficult to bend but not to be rigid , i . e ., to be stiffened , compared to the remainder of the formable element 44 . the shell 42 of the mask 41 will not crease along the mid - line d running from point 50 at which the mask contacts the bridge of the patient &# 39 ; s nose to point 52 at which the mask contacts the patient &# 39 ; s face in the middle of the patient &# 39 ; s chin as prior art masks might . in other preferred embodiments , one or more other portions of the formable element 44 may be stiffened to eliminate creasing or bending in such other portions . it should be noted that there are a number of means known to those skilled in the art to stiffen a portion of the formable element 42 . a polycarbonate overmold is one of the least costly and most esthetically attractive . it should also be noted that the portion 45 of the formable element 44 that is stiffened should have some “ give ” in it . if it is made rigid , the formable element 44 tends to fail at points 46 and 47 . the formable element 44 can be constructed from any suitable material that is malleable and is capable of retaining the shape into which it is formed against the force of , for example , the compliant shell 42 trying to regain its memory shape . the combination of the compliant shell 42 , malleable element 44 and stiffener ( e . g ., 48 ) produces sufficient rigidity to hold the shell 42 in a selected “ custom - fit ” configuration , formed by a particular user or wearer . because the shell 42 is compliant , the perimeter and overall configuration of an opening of the shell can be reformed repeatedly , as necessary , by the user or wearer of mask 41 . while the principles of the invention have been described herein , it is to be understood by those skilled in the art that this description is made only by way of example and not as a limitation as to the scope of the invention . other embodiments are contemplated within the scope of the present invention in addition to the exemplary embodiments shown and described herein . modifications and substitutions by one of ordinary skill in the art are considered to be within the scope of the present invention .
the present invention is a system for stiffening a portion of the perimeter of a respiratory mask that has a formable element disposed about its perimeter , thereby making the respiratory mask more comfortable to wear .