Abstract:
A stress deformable and sealed breathing mask that includes an air permeable rectilinear mask body having at least one layer of air filtering material and a resilient sealing strip at an upper edge of the mask body for sealing engagement with a user&#39;s face. An upper attachment strap is in a laced engagement with the mask body and the resilient sealing strip such that tightening of the upper attachment strap about a user&#39;s head causes the resilient sealing strip to resiliently deform substantially to the contour of the user&#39;s face in the bridge area of the user&#39;s nose. A lower attachment strap secures the bottom of the mask body against a portion of the user&#39;s face below the user&#39;s mouth.

Description:
COPYRIGHT NOTICE 
       [0001]    Portions of the disclosure of this patent application may contain material that is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent application or the patent disclosure, as it appears in the Patent and Trademark Office patent file or records, but otherwise reserves all copyright rights whatsoever. 
       BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The present invention relates to face masks in general and more particularly to a face mask that is stress deformable to seal the mask against a wearer&#39;s face. 
         [0004]    2. Discussion of the Related Art 
         [0005]    Filtering face masks are worn by individuals who desire to filter the air they breathe, either inhaled to filter out particulates in the ambient air or to filter exhaled air, such as required by medical professionals during the treatment of patients. The mask can be of a planar configuration or of a unidirectional folding configuration. Other configurations include those having shaped bodies including cup types or duck-billed types. 
         [0006]    A planar type mask does not employ any measures to seal the mask against the wearer&#39;s face. Therefore, when worn, this type of mask leaves large gaps between the mask and the sides of the bridge of the nose of the wearer. This results in a large quantity of the unfiltered air being inhaled as entering through these gaps, thereby defeating the purpose of wearing the mask. Since the majority of the mask is in direct contact with the wearer&#39;s skin, the mask does not form a breathing space for the wearer and does not effectively filter the air. 
         [0007]    Unidirectional folding masks also have inherent disadvantages. Although the unidirectionally folded mask can be spread out in a longitudinal direction, this configuration has its own disadvantages. A folded portion of the unidirectionally folded mask tends to cling on a sensitive portion of the wearer&#39;s face such as the tip of the wearer&#39;s nose or the wearer&#39;s lips, thus resulting in discomfort for the wearer. 
         [0008]    Some masks, such as unidirectionally folded masks or duck-billed masks, incorporate metal wires or aluminum strips in the design. The wires and strips are adapted to function as a nose clip seal to eliminate or minimize the gap between the wearer&#39;s skin and mask in the bridge area of the wearer&#39;s nose. However, these sealing features are easily deformable and are thus easily pulled straight. Therefore, even minimal pulling forces on the mask tend to undo the seal around the bridge of the wearer&#39;s nose. 
         [0009]    The cup type mask generally employs a hard cup type shell which cannot be folded and is therefore inconvenient to carry and is not widely accepted. Further, the cup type mask employs a wider aluminum strip to act as the nose clip seal. However, the larger aluminum strip utilized for the seal exhibits an increased rigidity such that the strip cannot be completely enjoined against the bridge of the wearer&#39;s nose to create a proper seal. To resolve this problem, the cup type mask generally uses straps having a greater pull force to keep the mask in a sealing interface with the wearer&#39;s nose by increasing the pressure applied by the mask against the wearer&#39;s face. However, prolonged wearing of this mask with increased pressure results in pain to the wearer and a deep skin indentation. 
         [0010]    The cup type mask also has a relatively large interior cavity which, when the wearer breathes, primarily causes an exchange of air within the cavity rather than drawing air through the mask. This results in a low concentration of oxygen and increased moisture inside the mask, thereby causing the wearer to experience suffocation and a moist feeling. In some cases, the wearer can also experience cases of eczema. 
         [0011]    Although a variable plane cavity type mask is relatively easy to use, it does have problems. Manufacturing of this mask requires forming protuberant rings on each end of the mask and at the center of a sealing strip disposed on an upper edge of the mask. While the rings are merely fabricated by a plastic molding process, a fixing strap must then be affixed in an overlapping insertion manner. This results in a relatively complicated manufacturing process for this mask with correspondingly high costs. Additionally, the two ends of the fixing strap on the bottom edge of the mask are respectively fixed in a section of the mask through which the strap passes. The ends of the fixing strap are fixed first and then the strap is packed which results in decreased manufacturing efficiency. Finally, the ends of the upper and lower fixing straps are all fixed on the sealing strip and in the upper and lower sections, so the length of the straps is not adjustable to accommodate the different sizes of heads wearing the masks. 
         [0012]    Therefore, previous masks often offer either ease of manufacturing with a corresponding beneficially low cost, but do not seal about the user&#39;s face, or, the masks provide a desired level of sealing, but are relatively complicated to manufacture with a correspondingly undesirable high cost. 
         [0013]    Thus what is desired is a mask that is uncomplicated and inexpensive to manufacture and yet provides sealing between the mask periphery and the user&#39;s face. 
       SUMMARY OF THE INVENTION 
       [0014]    The present invention is directed to a stress deformable and sealed breathing mask. The mask includes an air permeable rectilinear mask body having at least one layer of air filtering material and a resilient sealing strip at an upper edge of the mask body for sealing engagement with a user&#39;s face. An upper attachment strap is in a laced engagement with the mask body and the resilient sealing strip such that tightening of the upper attachment strap about a user&#39;s head causes the resilient sealing strip to resiliently deform substantially to the contour of the user&#39;s face in the bridge area of the user&#39;s nose. A lower attachment strap secures a bottom of the mask body against a portion of the user&#39;s face below the user&#39;s mouth. 
         [0015]    Another aspect of the present invention is a stress deformable and sealed breathing mask that includes an air permeable rectilinear mask body having at least one layer of air filtering material. A resilient sealing strip is located at an upper edge of the mask body for sealing engagement with a user&#39;s face. The resilient sealing strip has a central segment for resting on the bridge of the user&#39;s nose and a downwardly extending protrusion proximate to each side of the central segment for bearing against the side of the user&#39;s nose. The resilient sealing strip also defines two symmetrical curves on a lower edge thereof, each curve gradually inclined toward an upper edge of the resilient sealing strip from a respective end of the strip to an adjacent one of the downwardly extending protrusions. An upper attachment strap is in laced engagement with the mask body and the resilient sealing strip such that tightening of the upper attachment strap about a user&#39;s head causes the sealing strip to resiliently deform substantially to the contour of the user&#39;s face on the bridge area of the user&#39;s nose. A lower attachment strap secures a bottom of the mask body against a portion of the user&#39;s face below the user&#39;s mouth. 
         [0016]    These and other features, aspects, and advantages of the invention will be further understood and appreciated by those skilled in the art by reference to the following written specification, claims and appended drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0017]    For a fuller understanding of the nature of the present invention, reference should be made to the accompanying drawings in which: 
           [0018]      FIG. 1  is a front elevation view of a mask according to one embodiment of the present invention illustrating the mask deformations for conforming to the contours of a wearer; 
           [0019]      FIG. 2  is an elevation view of the resilient sealing strip for sealing the mask across the bridge area of the user&#39;s nose; 
           [0020]      FIG. 3  is an elevation view of the back of the mask showing the surface that contacts the user&#39;s face; 
           [0021]      FIG. 4  is a cross section of a right elevation view of the mask shown in  FIG. 3  illustrating the front fold and taken along the line  4 - 4  of  FIG. 3 ; 
           [0022]      FIG. 5  is a cross section of a plan view of the upper edge of the mask shown in  FIG. 4  illustrating the threading of the upper strap relative to the resilient sealing strip and taken along the line  5 - 5  of  FIG. 4 ; 
           [0023]      FIG. 6  is a front elevation view of a user wearing a breathing mask according to one embodiment of the present invention. 
       
    
    
       [0024]    Like reference numerals refer to like parts throughout the several views of the drawings. 
       DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0025]    For purposes of the description herein, the terms “upper”, “lower”, “left”, “rear”, “right”, “front”, “vertical”, “horizontal”, and derivatives thereof shall relate to the invention as oriented in  FIGS. 1 through 6 . However, one will understand that the invention may assume various alternative orientations and step sequences, except where expressly specified to the contrary. Therefore, the specific devices and processes illustrated in the attached drawings, and described in the following specification, are simply exemplary embodiments of the inventive concepts defined in the appended claims. Hence, specific dimensions and other physical characteristics relating to the embodiments disclosed herein are not to be considered as limiting, unless the claims expressly state otherwise. Any embodiment described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other embodiments. 
         [0026]      FIG. 1  is a front elevation view of a stress deformable and sealed mask  30  according to one embodiment of the present invention illustrating the mask deformations for conforming to the contours of a wearer.  FIG. 1  illustrates various features and components of mask  30 . Mask  30  comprises a mask body  70  having a rectilinear shape with an upper attachment strap  32  proximate to an upper edge of mask body  70  and a lower attachment strap  34  proximate to a lower edge of mask body  70 . Straps  32  and  34  function to extend around a user&#39;s head to secure mask  30  over the user&#39;s nose and mouth. Lower strap  34  is secured along a bottom edge of mask body  70 . In one embodiment, lower strap  34  can be bonded to the bottom edge of mask body  70 . In an alternative embodiment, mask body  70  can include a passageway along the bottom edge of mask body  70  through which strap  34  is inserted and passes through. Straps  32  and  34  are made of a resilient-elastic material, and can be selected from natural rubber, synthetic rubber, rubber wire which can be interwoven with silk thread, or other similar resilient-elastic materials known in the art. 
         [0027]    In one embodiment, a set of six lace apertures  82   a,    82   b,    84   a,    84   b,    86   a,  and  86   b  are disposed along the upper edge of mask body  70 . Lace apertures  86   a  and  86   b  are each disposed at a lateral edge  78  (shown in  FIG. 3 ) of mask body  70 , and a set of central lace apertures  82   a  and  82   b  are positioned at the center of mask body  70 . In one embodiment, lace apertures  84   a  and  84   b  are longitudinally positioned inwardly from an edge of mask body  70  to a distance approximately equal to one-sixth to one-fourth of the width of mask body  70 . Aperture  84   a  is located on the left side of mask body  70  and aperture  84   b  is located on the right side of mask body  70 , at the prescribed distance of one-sixth to one-fourth of the length of mask body  70 . 
         [0028]    An overlapped layer  40  is formed in the middle part of the outer surface of mask  30 . Overlapped layer  40  is formed by bi-directionally folding an upper portion of mask body  70  in the horizontal direction at a bi-directional fold  46  (shown in  FIG. 4 ) and by also bi-directionally folding a lower portion of mask body  70  in the horizontal direction at a bi-directional fold  48  (shown in  FIG. 4 ). 
         [0029]    A supporting sheet  42  is provided within overlapped layer  40 . The middle of supporting sheet  42  defines an elongated aperture  44  therethrough to further define a breathing area  49 , which is unobstructed other than for the layered filter material of mask body  70 . In one embodiment, overlapped layer  40  has a height approximately one-third to one-half the formed height of mask body  70 . 
         [0030]      FIG. 2  is an elevation view of a resilient elongated sealing strip  50  for sealing the mask across the bridge area of the user&#39;s nose. Sealing strip  50  is formed from a resilient, flexible material. Sealing strip  50  has a center section  56  for bearing on the bridge of the user&#39;s nose. Downwardly extending protrusions  58   a  and  58   b  are positioned on both sides of and proximate to center section  56 . Protrusions  58   a  and  58   b  function to bear against the sides of the bridge of the user&#39;s nose during wearing of mask  30 . Two symmetrical curves  60   a  and  60   b  are formed on the lower edge of sealing strip  50 . Each curve  60   a  and  60   b  gradually inclines from a respective end of sealing strip  50  toward an adjacent protrusion  58   a  and  58   b,  respectively, and also toward the upper edge of sealing strip  50 . A central set of lacing apertures  54   a  and  54   b  are defined within center section  56  and a set of end lacing apertures  52   a  and  52   b  are defined at each respective end of sealing strip  50 . End lacing apertures  52   a  and  52   b  correspond to apertures  86   a  and  86   b  (shown in  FIG. 1 ), respectively, in mask body  70  (shown in  FIG. 1 ). Similarly, center apertures  54   a  and  54   b  correspond to apertures  82   a  and  82   b  (shown in  FIGS. 1 and 5 ) in mask body  70 . 
         [0031]      FIG. 3  is an elevation view of the back of mask  30  showing the surface that contacts the user&#39;s face. A horizontal opening  47  (shown in  FIG. 4 ) is formed along the horizontal direction at a mid-portion of an inner surface of mask body  70  by folds  46  and  48 , which also form overlapped layer  40  (shown in  FIG. 1 ). Both ends of overlapped layer  40  are fixedly connected to lateral edges  78  of mask body  70  at bond areas  79 . Each of straps  32  and  34  have ends  33  and  35 , respectively, that are threaded through and engaged with unidirectional adjustment clips  36  and  38 . 
         [0032]    In one embodiment, the bottom edge of mask body  70  defines a passageway along the bottom edge which is slightly wider than lower strap  34 , which allows the bottom edge to naturally shrink and form many folds under friction by pulling on ends  35 . 
         [0033]      FIG. 4  is a cross section of a right elevation view of mask  30  (reference Line  4 - 4  shown in  FIG. 3 ) illustrating the front fold. As shown in  FIG. 4 , mask body  70  is constructed of an inner protective layer  72 , a filter layer  74  and an outer protective layer  76 . Filter layer  74  is one of a number of materials known in the art to filter out undesirable particulates including airborne germs and viruses while allowing the passage therethrough of air for the user to breathe. Protective layers  72  and  76  protect filter layer  74  from being damaged and thus compromising its filtering function. 
         [0034]      FIG. 5  is a cross section of a plan view of the upper edge of mask  30  (reference Line  5 - 5  shown in  FIG. 4 ) illustrating the threading of upper strap  32  relative to resilient sealing strip  50 . As illustrated in  FIG. 5 , a cross-sectional plan view of the upper portion of mask  30  shows upper strap  32  passing through the six lace apertures  82   a,    82   b,    84   a,    84   b,    86   a  and  86   b  located in mask body  70  and apertures  52   a,    52   b,    54   a  and  54   b  of sealing strip  50 . When passing through end lace apertures  86   a  and  86   b,  and center lace apertures  82   a  and  82   b,  upper strap  32  also passes through end lace apertures  52   a  and  52   b,  and center lace apertures  54   a  and  54   b  of sealing strip  50 , respectively. However, at lace apertures  84   a  and  84   b,  upper strap  32  passes through mask body  70  only. There are no apertures in sealing strip  50  corresponding to apertures  84   a  and  84   b  in mask body  70 . 
         [0035]      FIG. 6  illustrates mask  30  in position on a user  20  and also refers to specific features more fully illustrated and previously discussed in  FIGS. 1-5 . Ends  33  and  35  (shown in  FIG. 1 ) of upper and lower straps  32  and  34  are inserted into adjustment clips  36  and  38  (shown in  FIG. 1 ) respectively. When mask  30  is not worn, mask  30  keeps its original shape. Mask  30  is placed over the face of user  20  such that the upper edge of mask  30  with sealing strip  50  (shown in  FIG. 2 ) is centered over a bridge  22  of the nose of user  20  with straps  32  and  34  encircling the head of user  20 . Ends  33  and  35  of straps  32  and  34  are pulled until mask  30  is comfortably seated against the face of user  20 . Further, adjusting the length of straps  32  and  34  by pulling them through unidirectional clips  36  and  38  permits mask  30  to be worn by users  20  having differently sized heads. This adjustability maintains the functionality and effectiveness of mask  30  regardless of the size or shape of the head of user  20 . 
         [0036]    As ends  33  of strap  32  are pulled through unidirectional adjustment clip  36 , sealing strip  50  resiliently deforms to bear on the face of user  20 . Center section  56  (shown in  FIG. 2 ) and the corresponding area of mask body  70  (shown in  FIG. 1 ) rests directly on bridge  22  of the nose of user  20  and protrusions  58   a  and  58   b  (shown in  FIG. 2 ) bear against the sides of the user&#39;s nose. The remainder of sealing strip  50  along curved areas  60  (shown in  FIG. 2 ) deforms to match the contour of the upper cheek area of user  20 , thus providing a sealed upper edge of mask  30 . 
         [0037]    Sealing strip  50  closely bears on the face of user  20  as a function of its resilience. The tension and compaction of the resilience of upper strap  32  upon and in combination with the resilience of sealing strip  50  causes strip  50  to elastically press against the face of user  20 . The natural deformation and resilience of sealing strip  50  can change according to the movement of facial muscles while maintaining the desired sealing of mask  30  against the face of user  20 . Such facial movements include free breathing, deep breathing, talking, head shaking, looking up, looking down, bowing, and other similar bodily movements. 
         [0038]    Bi-directional folds  46  and  48  (shown in  FIG. 4 ) permit outward expansion of overlapped layer  40  (shown in  FIG. 1 ) to cause a protuberance that approximately conforms to the various contours of the nose and mouth area of user  20 . As ends  35  of lower adjusting strap  34  are pulled through adjusting clip  38 , the lower edge of mask body  70  is naturally shrunk and forms many folds as a result of the friction generated by user  20  pulling on ends  35 . The shrinking of the lower edge of mask body  70  facilitates the protuberance of overlapped layer  40  thereby forming a breathing cavity which does not contact the nose or mouth of user  20 . Aperture  44  (shown in  FIG. 1 ) of supporting sheet  42  (shown in  FIG. 4 ) is positioned proximate to the nostrils and mouth of user  20 , allowing user  20  to easily breathe through filtered area  49  (shown in  FIG. 1 ). Such a protuberance of overlapped layer  40  also increases the effective filtering area by eliminating the contact to the nose and mouth and further enhances the comfort of wearing mask  30  for user  20 . 
         [0039]    While the present invention has been described in detail with regards to embodiments, it should be appreciated that various modifications and variations may be made in the present invention without departing from the scope or spirit of the invention. In particular, the terms “comprises” and “comprising” should be interpreted as referring to elements, components, or steps in a non-exclusive manner, indicating that the referenced elements, components, or steps may be present, or utilized, or combined with other elements, components, or steps that are not expressly referenced. 
         [0040]    The above description is considered that of one embodiment only. Modifications of the invention will occur to those skilled in the art and to those who make or use the invention. Features illustrated or described as part of one embodiment can be used in another embodiment to provide yet another embodiment such that the features are not limited to the specific embodiments described above. Therefore, it is understood that the embodiments shown in the drawings and described above are merely for illustrative purposes and are not intended to limit the scope of the invention, which is defined by the following claims as interpreted according to the principles of patent law, including the doctrine of equivalents.