Patent Publication Number: US-8113200-B2

Title: Respirator mask with corrective lens frame assembly

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims priority on International Application No. PCT/US2006/017072, filed May 4, 2006, which claims the benefit of U.S. Provisional Patent Application No. 60/677,509, filed May 4, 2005, which is incorporated herein in by reference in its entirety. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to respirator masks. In one of its aspects, the invention relates to respirator masks with a removably mounted corrective lens support frame that is adapted to adjustably mount a corrective lens frame. In another of its aspects, the invention relates to respirator masks with an integral resiliently foldable corrective lens frame. In another of its aspects, the invention relates to respirator masks with a releasable lock to retain a corrective lens frame in adjusted position in the mask. In another of its aspects, the invention relates to respirator masks with a corrective lens support frame that is adapted to mount a corrective lens frame and that is securely retained in the mask. 
     2. Description of the Related Art 
     Respirator masks are devices commonly used by military personnel, firefighters, and industrial workers in hazardous environments for protection from inhalation of harmful substances including smoke, chemicals, and biological agents. These respirator masks may employ a filtration system to purify air before it is inhaled by a wearer and thus an air-tight seal between the mask and the wearer&#39;s face is crucial during its utilization in a dangerous environment. 
     Vision correction is necessary for many individuals, including those with an occupation that may require occasional use of a respirator mask, and is a well-known problem in the art. Conventional eye glasses cannot be worn with respirator masks because of lack of space within the mask and the possibility of spectacle side arms jeopardizing the necessarily tight fit of the mask. Contact lenses are an alternate vision correction means, but allergies and other medical conditions may not permit the use of contact lenses for some individuals. Contact lenses are also problematic as these lenses may become polluted with environmental contaminants such as smoke or chemicals, thereby causing problems for the user. 
     Thus, respirator masks with vision correction lens assemblies to be used by an individual wearing a mask have been developed. Any vision correction assembly must be installed within the mask in order to maintain the air-tight seal needed for the mask to function properly. Since these masks are often used in critical situations, it is also essential that the lenses stay in the correct position during operational use. It is also advantageous to allow for adjustment of the lens position within the mask to accommodate different individuals and also for the assembly to be interchangeable for different prescriptions and removable for those not needing vision correction. It is also desirous for a respirator mask, and subsequently any for any mask insert to be foldable to allow easy handling, transport and retention of fit. 
     Many such assemblies have been proposed to provide vision correction within a respirator mask, some of which are discussed herein. U.S. Pat. No. 6,019,468 to Altemare, Jr. discloses a spectacle kit having a protective mask insert clip and detachable means for attaching a spectacle front piece firmly to the protective mask insert, by snapping the receiver onto an insert clip. The front piece includes notch attachments for optionally mounting a head strap to the front piece so that the front piece can be worn separately from the mask. 
     A device for holding spectacles in a mask is disclosed in U.S. Pat. No. 3,563,640 to Wise. The device comprises a spring wire with a wire loop that slidably supports a friction member attached to a spectacles frame. The friction member is vertically adjustable on the wire loop to adjust the vertical position of the spectacles frame. The spring wire is mounted against a window of the mask and is retained in position by spring force thereof. 
     U.S. Pat. No. 3,004,525 to Nielson discloses a gas mask with an optical insert comprising a nose piece and spectacle frames that are flexible so that the optical insert can be folded onto itself. The optical insert is mounted to the gas mask through a strap having a tip integrally molded to the mask and sized so that the optical insert can be snap fit thereto. The strap forms a loop that can be adjusted to change the position of the optical insert in the gas mask. 
     A support structure for a protective mask optical insert comprising a pair of hinged eyewires sized to hold corrective lenses is disclosed in U.S. Pat. No. 4,711,539 to Krusas. The eyewires can fold at the hinge onto one another and are biased apart by a pair of torsion springs. The optical insert is mounted to a front hinge block, which is vertically adjustable relative to a back block. An anchor mounted to a structural element located between the face plates of the mask supports the back block and thereby the optical insert inside the face mask. 
     SUMMARY OF THE INVENTION 
     A respirator mask according to the invention comprises a face piece adapted to fit on the face of a user and having an opening at a front portion thereof, a visor mounted in the opening for viewing by a mask user, a corrective lens support frame removably mounted to the face piece behind the visor, and a corrective lens frame adjustably mounted on the corrective lens support frame. 
     According to one embodiment of the invention, the corrective lens frame has an insert molded bridge having a biasing member embedded therein for resiliently flexing the sides of the frame about a central portion thereof. 
     According to another embodiment of the invention, the corrective lens support frame has a shape that conforms to the shape of the visor. 
     According to yet another embodiment of the invention, the support frame has a generally vertical central bridge connecting upper and lower portions of the support frame and has a plurality of generally horizontal detents on the rear of the bridge that mate with a projection on the corrective lens frame for adjustably securing the corrective lens frame in a desired vertical position on the support frame. 
     According to still another embodiment of the invention, the support frame further includes mounting lugs formed on either side of the frame, wherein each of the mounting lugs has spaced projections that are received in pockets on the inner side of the face piece. 
     In another embodiment of the invention, the support frame further has a hole in the central bridge, the inner side of the face piece has a protuberance positioned above the visor, and the protuberance is received within the hole in the bridge for partially mounting the support frame on the face piece. 
     In a further embodiment of the invention, the projection is formed on a pivotally mounted locking tab that is movable between locking and unlocking engagement with the central bridge of the support frame. 
     In yet another embodiment of the invention, the corrective lens frame has a central piece that includes a pair of opposed arms that wrap around a central bridge of the support frame to slidably mount the corrective lens frame to the support frame. 
     In still another embodiment of the invention, the corrective lens frame has a pivotally mounted locking tab that is movable between locking and unlocking engagement with a central bridge of the support frame for adjustably securing the corrective lens frame in a desired vertical position on the support frame. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In the drawings: 
         FIG. 1  is a perspective view of the respirator mask equipped with a removable corrective lens insert according to the invention. 
         FIG. 2  is an enlarged perspective view of a portion of the respirator mask of  FIG. 1  without the corrective lens insert, and showing an insertion pocket. 
         FIG. 3  is a front view of the corrective lens insert shown in  FIG. 1  and comprising a support frame and a corrective lens frame. 
         FIG. 4  is a rear view of the corrective lens insert shown in  FIG. 3 , with a tab in an open position. 
         FIG. 5  is a rear exploded view of the corrective lens frame, showing the insertion of the tab in the corrective lens frame. 
         FIG. 6  is a rear view similar to  FIG. 4  showing the vertical adjustment mechanism of the corrective lens frame with respect to the insert, and with the tab in the closed position. 
         FIG. 7  is a partial rear perspective view of the respirator mask and removable corrective lens insert shown in  FIG. 1  with part of the respirator mask removed to show the insertion pocket. 
         FIG. 8  is a sectional view taken along line  7 - 7  of  FIG. 7  showing a portion of the respirator mask and removable corrective lens insert. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring now to the drawings and specifically to  FIG. 1 , a respirator mask assembly  10  according to the invention comprises a mask  12 , having a facepiece  14  that fits over the face of a user, a transparent visor  16 , a pair of circular or elliptical canister filters  18 , and a front module  20  for speech transmission and exhalation functions. The mask is held to the face of the user by a plurality of harness strap attachments  22  on the periphery of the mask  12 . A corrective lens insert  24  is mounted behind the visor  16  and comprises a support frame  26 , the shape of which conforms to the shape of the visor  16  and a lens frame  28  mounted to the support frame  26 . 
     Referring to  FIG. 2 , a pocket  30  is integrally molded on the inner side of the mask  12  and projects forwardly toward the visor  16  from the facepiece  14 . The pocket  30  has a relatively horizontal partition  32  that creates two separate slots  34  for receiving the support frame  26 . 
     Referring now to  FIGS. 3 and 4 , the support frame  26  comprises a generally vertical central bridge  36  connecting upper and lower portions of the frame  26  having a key hole-shaped slot  38  disposed at the upper joint of the bridge, a plurality of horizontal detents  40  on the rear side thereof, and mounting lugs  42  projecting from the generally vertical sides on the frame  26 . The support frame  26  is preferably made of a flexible material so that it may be folded in half and is slightly convex so that the lugs  42  point generally rearward. The mounting lugs  42  comprise U-shaped spaced projections  44  having ramp-like spines  46  that protrude horizontally and laterally from the outer side of the support frame  26 . 
     The lens frame  28  comprises a pair of relatively rigid lens holders  48  joined by a generally horizontal bridge portion  50 . The bridge portion  50  is formed by a relatively rigid central piece  52  connected between the lens holders  48  by an insert molded hinge  54  that spans both sides of the central piece  52 . The hinge  54  is flexible so that the lens holders  48  can be folded onto one another. A biasing member in the form of a metal spring  80  ( FIG. 5 ) embedded in the hinge  54  biases the lens holders  48  to the position illustrated in the drawings. The central piece  52  includes a pair of opposed arms  56  that wrap around the central bridge  36  of the support frame  26 . The central piece  26  further has a pair of channels  64  that have an angled portion  66  and a catch portion  68  molded on the central piece  52  of the lens frame  28 . A pivotal tab  58  has multiple horizontal braces  60  projecting from one side, which are sized to mate with the detents  40  on the central bridge  36 . The tab  58  has a dowel  62  mounted at one end and a narrowed end  78 . 
     Referring now to  FIG. 5 , the metal spring  80  and the tab  58  are shown exploded from the lens frame  28 . The spring  80  is formed from a single piece of thin metal wire that has a central arc  82  with coils  84  on either end of arc  82  and leaving straight ends  86  that extend relatively horizontally to the lens holders  48 . The ends of the dowell  62  are adapted and shaped to fit into the channels  64 . 
     To assemble the corrective lens insert  24 , the central bridge  36  of the support frame  26  is pressed against the central piece  52  of the lens frame  28  so that arms  56  wrap around the central bridge  36 . The dowel  62  of the pivotal tab  58  is then fit into the angled portion  66  of the channels  64  and pushed downwardly and inwardly until it is secured behind the catch  68 . The tab  58  is pivotally retained by the catch portion  68  and can pivot around the central axis of the dowel  62 . The tab  58  narrowed end  78  is shaped to fit tightly between anus  56  when the tab  58  is pivoted upward. 
     Referring now to  FIG. 6 , the lens frame  28  is vertically adjustable relative to the support frame  26 . The central piece  52  is slid along the central bridge  36  with the pivotal tab  58  in an open position illustrated in  FIG. 4 . When the lens frame  28  is in a desired position, the tab  58  is pivoted upwards and towards the central piece  52  about the dowel  62  and snapped thereto so that the braces  60  engage the detents  40  and the narrowed end  78  is press-fitted between the arms  56 , thereby securing the lens frame  28  at the desired vertical position. 
     Referring now to  FIG. 7 , the corrective lens insert  24  is shown attached within the mask  12 , wherein the key hole slot  38  in the support frame  26  is fitted to a protuberance  70  projecting from the mask  12  above the visor  16 . The protuberance  70  has a circular head  72  and a cylindrical stem  74  wherein the head  72  is of slightly greater diameter than the stem  74 . The head  72  is inserted through the larger portion of the key hole slot  38  and the support frame  26  is pushed downward so that the stem  74  engages the smaller portion of the key hole slot  38 , thereby locking the support frame  26  in place in the mask. The mounting lugs  42  ( FIG. 4 ) are inserted into pockets  30  located on both sides of the visor  16 . 
     Referring to  FIG. 8 , the spaced projections  44  of the support frame  26  are received in the slots  34  of the pocket  30  for further attachment of the corrective lens insert  24  to the respirator mask  12 . The spines  46  on the projections  44  of the mounting lugs  42  bear against a wall  76  of the pocket  30  and releasably retain the corrective lens insert  24  behind the visor  16  of the respirator mask  12 . 
     While the invention has been specifically described in connection with certain specific embodiments thereof, it is to be understood that this is by way of illustration and not of limitation, and the scope of the appended claims should be construed as broadly as the prior art will permit.