Abstract:
A mouthpiece for use in underwater Scuba application, exhibiting a variable-position exhaust flow valve, controllable by the user. The user alters the size of the valve opening during exhale, in order to more easily maintain and control the air pressure within the respiratory system. This increased control reduces the need for compensation by the respiratory muscles (ie. diaphragm, intercostals), thus reducing diver fatigue and increasing diver endurance.

Description:
[0001]    REFERENCES CITED 
         [0002]    U.S. Pat. No. 3,101,732 
         [0003]    U.S. Pat. No. 3,938,511 
         [0004]    U.S. Pat. No. 4,031,888 
         [0005]    U.S. Pat. No. 4,140,113 
         [0006]    U.S. Pat. No. 4,267,832 
         [0007]    U.S. Pat. No. 4,699,137 
         [0008]    U.S. Pat. No. 5,031,611 
         [0009]    U.S. Pat. No. 5,259,374 
         [0010]    U.S. Pat. No. 5,305,741 
         [0011]    U.S. Pat. No. 5,379,762 
         [0012]    U.S. Pat. No. 5,881,718 
         [0013]    U.S. Pat. No. 5,970,977 
         [0014]    U.S. Pat. No. 6,253,763 
         [0015]    U.S. Pat. No. 6,283,122 
         [0016]    U.S. Pat. No. 6,354,291 
         [0017]    U.S. Pat. No. 6,354,291 
         [0018]    U.S. Pat. No. 6,786,216 
         [0019]    U.S. Pat. No. 6,966,319 
         [0020]    U.S. Pat. No. 7,013,895 
       FEDERAL SPONSORSHIP  
       [0021]    The invention was made neither by an agency of the United States Government, nor under a contract with an agency of the United States Government. 
       FIELD OF THE INVENTION 
       [0022]    This invention relates to the field of underwater diving, using the system commonly referred to as Self Contained Underwater Breathing Apparatus (SCUBA). The common SCUBA setup includes: a user-transported tank reservoir containing approximately 3000 psi compressed air, a first-stage regulator to provide approximately 150 psi air from the tank to a supply hose, a supply hose to connect the tank to the second-stage regulator, a second stage regulator placed in front of the user&#39;s mouth (to reduce the supply hose pressure to normal atmospheric breathing pressures of approximately 7 psi), and a mouthpiece attached to the second stage regulator to allow the user to hold the regulator in place, as well as to transfer air from the regulator to the user&#39;s respiratory system. 
         [0023]    The second stage regulator most often contains a two-position air intake valve and a two-position exhalation valve; the two positions of the valve being either opened or closed (or activated/deactivated). The valves allow the passage of air when activated. Previous art has provided for valves that allow for some adjustment of the amount of air when activated, based on diver depth or desired internal pressure. But this adjustment most often includes a finite adjustment across a lengthy time period, not a variable adjustment within the span of a single breath. This previous art often requires the user to manipulate a set-screw or lever on an external portion of the second-stage regulator housing in order to vary the amount of air that will pass to or from the user. This type of step input has shown to increase diver respiratory efficiency, decreasing fatigue. However, further significant gains can yet be made through this invention, by altering the passage of air within a single breath, accounting for continually changing environmental and physiological conditions. 
         [0024]    The gains made by this invention center mainly on the exhalation of air by the SCUBA user and the effort required by the user&#39;s respiratory system in order to slowly expel the air. In order to maximize the time below the surface of the water, and thus the enjoyment or utility taken from the dive, divers learn to control their breathing rate and technique. The most common technique includes a relatively short period of time to intake the air from the second-stage regulator, but a relatively long period of time to exhale the same air through the regulator. Divers are often taught to never hold their breath, in order to prevent lung expansion injuries. As such, a relatively long exhalation period necessitates that the diver release only a small amount of air in a continual fashion. But, as previous art has provided, non-variable exhalation ports often provide a much larger opening than would normally be needed to most efficiently exhale this small amount of air. Due to the overly-large exhalation port, a much lower air pressure is available within the user&#39;s respiratory system, requiring the respiratory muscles to compensate, increasing fatigue. As one would normally do without a second-stage regulator placed in the mouth, in order to relax the respiratory muscles, one would purse the lips to reduce the exhalation area, when required to release a small amount of air. Since the removal of the second-stage regulator is impractical for each exhalation cycle while using the SCUBA system, a variable area exhaust valve would offer solution to the problem at hand. 
       BACKGROUND OF THE INVENTION  
       [0025]    Previous art relating to this invention make use of three distinct developments: 
         [0026]    1. Variable inlet (inhalation-only, not for exhalation) valves for use in Scuba application; 
         [0027]    2. Customizable mouthpieces promoting utility, safety, and comfort, for multiple application; 
         [0028]    3. One-way exhaust exhalation valves for use in medical application. 
         [0029]    Each of these three developments add utility to previous art, but do not account for the exhalation effort required at the varying environmental and physiological conditions encountered during scuba activity. The variable inlet art has dramatically reduced the effort required for inhalation, including at varying conditions, but makes no effort to account for the exhale portion of the user&#39;s respiration cycle (see U.S. Pat. Nos. 4,796,618, 5,259,374, 5,379,762, 5,549,107, 5,660,502, 5,678,541, 5,881,718, 5,970,977). The variable inlet art may easily be incorporated into a design using the variable exhaust functions mentioned herein. 
         [0030]    The customizable mouthpieces increase physiological comfort and effectiveness while engaged in scuba activity, but makes no attempt to address the aforementioned exhalation effort (see U.S. Pat. Nos. 3,107,667, 3,844,281, 3,929,548, 4,136,689, 4,031,888, 5,031,611, 5,048,519, 5,305,741, 6,079,411, 6,536,424, 6,966,319). As well, the customizable mouthpieces may also be incorporated into a design using the variable exhaust functions mentioned herein. 
         [0031]    The one-way exhalation valves (currently adapted for use in medical application) do offer a decrease in the effort required for user exhalation, however, previous art only allows for a two-stage embodiment of the exhaust valve of either fully open or fully closed (see U.S. Pat. Nos. 6,283,122, 6,786,216, 7,013,895). This embodiment does not allow for user-controlled adjustment based on variations of environmental or physiological conditions within a single breath. 
       SUMMARY OF THE INVENTION  
       [0032]    One presently preferred embodiment and one alternative embodiment exist for a variable exhaust scuba mouthpiece for use in underwater application. Both embodiments include a variable exhaust flow valve, controllable by the user. The user alters the size of the valve opening during exhale in order to increase back pressure within the respiratory system, thus reducing fatigue and increasing diver endurance. The preferred embodiment includes a linear spring that holds the opening of the mouthpiece fully open until depressed by the user&#39;s teeth or lips. The alternative embodiment includes an iris valve that reduces the opening of the mouthpiece concentrically as depressed by the user&#39;s teeth or lips. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS  
         [0033]      FIG. 1  is a top view of a presently preferred embodiment and alternate embodiment. 
           [0034]      FIG. 2  is a side view of  FIG. 1 . 
           [0035]      FIG. 3  is a front view of  FIG. 1  during the open (or deactivated) valve state of a presently preferred embodiment. 
           [0036]      FIG. 4  is a front view of  FIG. 1  during the closed (or activated) valve state of a presently preferred embodiment. 
           [0037]      FIG. 5  is a front view of  FIG. 1  during the open (or deactivated) valve state of an alternate embodiment. 
           [0038]      FIG. 6  is a front view of  FIG. 1  during the closed (or activated) valve state of an alternate embodiment. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0039]    The detailed description set forth below in connection with the appended drawings is intended as a description of exemplary embodiments, and is not intended to represent the only forms in which embodiments may be constructed and/or utilized. The description sets forth the functions and the sequence of steps for constructing and operating embodiments. However, it is to be understood that the same or equivalent functions and sequences may be accomplished by different embodiments that are also intended to be encompassed within the spirit and scope of the embodiments disclosed herein. 
         [0040]    Within the appended drawings, both the presently preferred embodiment and an alternate embodiment share the Top and Side Views found in  FIGS. 1 and 2 . The presently preferred embodiment uses the linear spring valve system depicted in  FIGS. 3 and 4  (for both open and closed states), and the alternate embodiment uses the iris valve system depicted in  FIGS. 5 and 6  (for both open and closed states). 
         [0041]    Referring to  FIG. 1 , a flexible housing  10  inserts into the user&#39;s mouth, with the user&#39;s lips wrapping around the housing prior to ring  13 . The housing  10  attaches to the tube directly provided from the second stage scuba regulator. An exterior radial channel  11  at the end of the housing is bounded by raised rings  12  and  13  to allow for compression attached by use of a quick-tie or similar radial fastener. The housing  10  fits over the hollow tube from the regulator with hollow interior linear channel  14 . The air to and from the second stage regulator pass through channel  14  to the user. The housing is retained in the mouth of the user by retaining wings  16  and  17 , and molar pads  18  and  19 . The retaining wings  16  and  17  fit along the inner side of the user&#39;s cheeks, and allow the housing to be held in place by the user&#39;s lips and mouth. The user compresses the molar pads  18  and  19  with the rear teeth, as well to hold the housing in place. The user alters the amount of air exhaled by varying the position of lever  15 . This lever is attached to the valve controlling the area available for the passage of air through channel  14 . Upon exhale, the user compresses lever  15 , reducing the area available for exhaust, and then releases the valve upon inhale, allowing maximum intake area. 
         [0042]    Referring to  FIG. 2 , the retaining wings  16  and  17  flare out slightly at the end of the mouthpiece, to aid in retaining of the housing by the lips and mouth. The figure further shows that exterior radial channel  11 , rings  12  and  13 , and hollow interior linear channel  14  are circular/cylindrical in nature. 
         [0043]    Referring to  FIG. 3 , it depicts a front view of the linear spring system included in the presently preferred embodiment. Upper lever  15  and lower lever  20  are shown in the open (or deactivated) position, with the largest opening possible to channel  14  within housing  10 . To activate the valve upon exhaust, the user compresses lever  15  with the upper set of teeth, and lever  20  with the lower set of teeth. The conjoinment of these levers closes the valve to channel  14  by compressing a linear spring attaching the levers, existing at either side of the channel  14 . Retaining wings  16  and  17 , and molar pads  18  and  19  are also shown from the front view.  FIG. 4  shows the levers and springs compressed, reducing the exit area for exhaust to channel  14  to the smallest possible. Levers  15  and  20  are conjoined far closer than in the open state depicted in  FIG. 3 , but not to close off channel  14  completely. This closed (or activated) state allows the air pressure within the respiratory system of the user to increase, thus reducing respiratory muscle fatigue and increasing user endurance. Should an event occur such that the user inadvertently clamps down on levers  15  and  20  in a moment of stress, the valve springs will release, allowing full area for inhale and exhale. 
         [0044]    Referring to  FIG. 5 , it depicts the front view of the iris valve system included in the presently preferred alternate embodiment. As with the linear spring system, the user controls the amount of exhaust passing into channel  14  by adjusting the position of levers  15  and  20  with the teeth. These levers are attached to the iris valve  21 . The figure shows the iris valve in the full open (or deactivated) position, allowing the maximum possible area for exhaust to enter channel  14 . The retaining wings  16  and  17  and molar pads  18  and  19  are also shown in the front perspective.  FIG. 6  shows the iris valve in the closed position, as the user closes (or activates) the valve by conjoining levers  15  and  20 . The iris valve  21  is shown in the fully closed position, allowing a much smaller amount of exhaust to reach channel  14 , but not closing off the channel completely. Should an event occur such that the user inadvertently clamps down on levers  15  and  20  in a moment of stress, the iris valve will release, allowing full area for inhale and exhale.