Abstract:
A breathing apparatus for a diver is configured to include a second stage pressure regulator and a hollow exhaust tube. An input port is located on a side of the pressure regulator and is attached to a supply hose coming from a tank mounted on a scuba diver&#39;s back. Additionally, an exhaust port is located on the same side of the regulator as the input port. The hollow exhaust tube is attached to the exhaust port. The exhaust tube is able to trap gas therein by the placement of one-way valves at each end of the exhaust tube, thus supplying a counteracting buoyant force to the same side of the regulator as the side where the supply hose enters the regulator, while defining an exhaust port arranged so that bubbles leaving the exhaust tube do not obstruct the diver&#39;s vision. The regulator may be fit with a supporting surface designed to rest on a diver&#39;s chin.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    The present invention generally pertains generally to the art of self-contained underwater breathing apparatus (SCUBA). More specifically, the invention concerns a device for reducing the amount of force which must be supplied at a diver&#39;s mouth while a breathing apparatus is in use and, additionally, structure for diverting exhaust bubbles away from the diver&#39;s face while reducing produced vibrations.  
           [0003]    2. Discussion of the Prior Art  
           [0004]    A typical self-contained underwater breathing apparatus or scuba arrangement includes many functional parts which are designed to work together to provide air or other breathable gas to a diver while he is underwater. First air or other suitable gas is typically stored in a high-pressure tank supported by a harness designed to mount on a scuba diver&#39;s back. Typically the tank is made either of aluminum or steel and can handle gas pressures of approximately 3000 psi. The tank or bottle has a single port in which is mounted a high-pressure tank valve. A first stage pressure regulator is mounted to the high pressure tank valve and functions to reduce the supplied gas pressure to about 150 psi. A flexible supply hose is connected at one end to the first stage regulator and carries the reduced pressure gas to a second stage regulator typically mounted in front of the diver&#39;s mouth and supported by a mouthpiece. The mouthpiece has some type of tabs to allow for the diver to bite down upon the mouthpiece and thereby support the second stage regulator in the diver&#39;s mouth. The weight of the supply hose and force supplied through the hose from the tank all work to dislodge the regulator from the diver&#39;s mouth. A diver must spend considerable effort and use a strong bite to maintain the second stage regulator in the proper position. This of course is very uncomfortable and fatiguing to the diver.  
           [0005]    The second stage regulator typically will provide pressurized gas when the diver inhales. This function is accomplished by means of a diaphragm switch which activates a lever to open a valve controlling the flow of gas to the diver. When the diver stops inhaling, or alternatively is exhaling, the diaphragm senses an increase in gas pressure and moves accordingly to close the valve and stop the flow of gas. A separate exhaust valve or port is provided to allow for the escape of exhausted gases. The valve prevents water from entering the second stage regulator when the diver is inhaling. The exhaust gases tend to leave the diver&#39;s regulator as bubbles, most often quite close to the diver&#39;s face thus obstructing the diver&#39;s view. This can be particularly bothersome in underwater photography wherein photographers will frequently have to time their breathing in order to avoid having a photograph filled with bubbles or distorted by vibration.  
           [0006]    In an attempt to overcome these deficiencies, several solutions have been proposed. For example, U.S. Pat. No. 3,721,235 discloses using an extendible flexible extension  15   b  which transfers exhaust bubbles from a mouthpiece exhaust port  10   a  to a relatively remote venting port  15   d  located away from the diver&#39;s face. However, while this arrangement does remove the bubbles from the diver&#39;s face, it does nothing to address the problem of the large forces which act upon the second stage regulator and, more particularly, the diver&#39;s mouthpiece. Indeed with such a relatively long flexible tube as proposed in U.S. Pat. No. 3,721,235 being carried in the water behind the diver, the force on the mouthpiece could increase dramatically due to the resistance of the water acting on the tube while the diver is swimming.  
           [0007]    U.S. Pat. No. 4,467,797 discloses an embodiment of a regulator wherein the amount of exhalation and inhalation effort produced by the diver is reduced. Additionally there is provided an exhaust conduit  40  that permits exhaust venting somewhat remote from the diver&#39;s face. However, no where in this patent is there disclosed either the problem or a solution to counter the various forces that would be placed on the mouthpiece given this arrangement.  
           [0008]    Therefore, there exists a need in the art for an arrangement of a second stage pressure regulator which will direct exhaust bubbles away from a diver&#39;s face and simultaneously increase a diver&#39;s comfort level by reducing the amount of force on the second stage regulator&#39;s mouthpiece. Additionally, there exists a need in the art for such a device to be easily attached to or integrated with currently available scuba regulators so that a diver may obtain these benefits without having to purchase an entirely new regulator.  
         SUMMARY OF THE INVENTION  
         [0009]    In accordance with the present invention, a breathing apparatus is configured to include a second stage regulator and a hollow exhaust tube. The second stage regulator has a housing from which a mouthpiece extends to allow gas or air to be supplied to a diver. An input port is located on the side of the second stage regulator and is attached to a gas supply hose coming from a first stage regulator secured to a tank mounted on the scuba diver&#39;s back. The supply hose is relatively heavy, receives gas from the gas source or tank located on the scuba diver&#39;s back, and directs the gas to the second stage regulator housing. Additionally, an exhaust port is located on the same side of the regulator as the input port. A hollow exhaust tube, which may be of variable length and cross-section, is attached to the exhaust port. The exhaust tube is designed to trap gas therein, thus supplying a controlled amount of buoyant force to the same side of the regulator as the side where the supply hose enters the regulator.  
           [0010]    With this arrangement, the buoyancy force from the gas in the exhaust tube counteracts the weight of the supply hose so less twisting force is supplied through the mouthpiece to the diver. Preferably the exhaust tube has a first end attached to the exhaust port, a long hollow central portion, and a second end located remote from the exhaust port so that bubbles leaving the exhaust tube do not obstruct the diver&#39;s vision. The exhaust tube is attached to the supply hose by one or more hooks that are preferably integrally formed with the exhaust tube. Alternatively, the exhaust tube may be attached to the supply hose by a wire tie.  
           [0011]    In a second embodiment, the breathing apparatus is arranged to be a retrofit unit. In this arrangement, a standard second stage regulator having two housings that are detachable from one another is modified to incorporate the present invention. The first part of the housing in a typical regulator arrangement includes a mouthpiece along with various operating parts such as a diaphragm and lever actuated valve, and also includes an input port to be connected to the supply hose for receiving gas. The exhaust housing is detachably mounted to the main housing and includes ports for exhausting exhaled air. The invention provides for a retrofit exhaust housing having an exhaust tube mounted thereto in a similar manner to the first embodiment. Essentially, once the retrofit housing is attached to the original main housing, a unit is formed similar to the first embodiment. A gasket seals the two housings. The exhaust tube is attached to the supply hose by a hook integrally formed with the exhaust tube. Alternatively, the exhaust tube may be attached to the supply hose by a wire tie. In order to improve gas flow through the exhaust tube, includes a hollow central portion made of a flexible plastic material having a smooth interior. Preferably the exterior of the tube is corrugated to provide additional strength. The exhaust tube preferably has one-way valves, one located at each end in order to aid in trapping gas within the hollow tube, however, the valve closest to the second stage regulator is optional.  
           [0012]    In a variation of both the first and second embodiments, the regulator is fit with a resting or support surface designed to rest on a diver&#39;s chin, thereby stabilizing the second stage regulator by obtaining additional support for the housing from the diver&#39;s chin. This support surface can either be directly mounted on the second stage regulator as in the first embodiment above or, alternatively, may be mounted on the retrofit unit. If the surface is mounted on the retrofit housing, then a standard second stage regulator may be modified by the invention to obtain the invention&#39;s advantages without having a diver purchase an entire new unit. The support surface may be a modular piece, one of many such pieces of differing shapes preferably adhered to the second stage regulator or retrofit unit such as by an adhesive.  
           [0013]    Additional objects, features and advantages of the present invention will become more readily apparent from the following detailed description of preferred embodiments when taken in conjunction with the drawings wherein like reference numerals refer to corresponding parts in the several views. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0014]    [0014]FIG. 1 is a side elevation view showing a typical diver in an underwater environment using scuba gear equipped with the present invention;  
         [0015]    [0015]FIG. 2 is a close-up view of a diver using a second stage regulator equipped with a preferred embodiment of the invention;  
         [0016]    [0016]FIG. 3 is a perspective view of a second stage regulator equipped with a second preferred embodiment of the invention;  
         [0017]    [0017]FIG. 4 is a perspective view of the regulator shown in FIG. 2;  
         [0018]    [0018]FIG. 5 is an expanded view of a regulator according to another preferred embodiment of the invention;  
         [0019]    [0019]FIG. 6 is a perspective view of an exhaust tube according to another preferred embodiment of the invention;  
         [0020]    [0020]FIG. 7 is a perspective view of the exhaust tube of FIG. 6 attached to a second stage regulator;  
         [0021]    [0021]FIG. 8 is a perspective view of a regulator found in the prior art;  
         [0022]    [0022]FIG. 9 is a side view of a regulator incorporating a chin support surface according to yet another embodiment of the invention; and  
         [0023]    [0023]FIG. 10 is a side view of a regulator having a retro-fit housing and incorporating a chin support surface according to yet another preferred embodiment of the invention.  
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0024]    With initial reference to FIG. 1, there is shown a diver  10  swimming underwater equipped with a self-contained underwater breathing apparatus according to a first embodiment of the invention. The breathing apparatus or scuba gear includes a tank  12  that stores air or other breathable gas under extremely high pressure. Tank  12  is supported by a harness (not shown) and mounted on the scuba diver&#39;s back. Typically, tank  12 , which includes a tank valve  20 , is made of either aluminum or steel and is designed to contain gas at pressures of approximately 3000 PSI, with the gas being slowly released to provide air to diver  10  during a dive. A first stage pressure regulator  22  is mounted to tank  12  via the high-pressure tank valve  20 . First stage pressure regulator  22  functions to reduce the supply of gas pressure to about 150 psi. First stage pressure regulator  22  is easily removed from tank valve  20  to allow tank  12  to be filled and is securely attached to tank  12  during a dive. A flexible supply hose  28  is connected at one end to first stage regulator  22  and carries reduced pressure gas to a second stage regulator  30  mounted in front of the diver&#39;s mouth. Also mounted to second stage regulator  30  is an exhaust tube  35 , which is designed to direct bubbles away from the diver&#39;s face and attached to supply hose  28 .  
         [0025]    Turning now to FIGS.  2 - 6 , there is shown the second stage regulator  30  of FIG. 1 in further detail. Flexible supply hose  28  is relatively heavy and tends to pull on second stage pressure regulator  30 . A mouthpiece  36  is provided which both allows diver  10  to hold the second stage pressure regulator  30  in place and provides for air from tank  12 . In order to hold second stage pressure regulator  30  in place, mouthpiece  36  is provided with clamping tabs  37  (see FIG. 4) designed to be easily held by the diver&#39;s teeth. Mouthpiece  36  also has an internal conduit  38  to allow for diver  10  to breathe while biting down on mouthpiece  36 . Conduit  38  leads into main housing  39  of second stage regulator  30 . As seen in FIG. 5, main housing  39  includes a breathing port  40  having an oval cross section and a mounting flange  41  designed to allow mouthpiece  36  to be removably attached thereto. Opposite the breathing port  40  is a diaphragm  45  that is secured across a majority of main housing  39 . A securing ring  47  is provided around main housing  39  to seal the edges of diaphragm  45  to main housing  39 .  
         [0026]    As stated above, supply hose  28  provides relatively high pressure air to the second stage regulator  30 . Supply hose  28  is first attached to a swivel connection  50  to enhance the positioning of second pressure regulator  30  in the diver&#39;s mouth. Swivel connection  50  is threaded to a valve  55  located inside main housing  39 . A cover  56  is mounted over diaphragm  45 . Cover  56  has a securing tab  57  that wraps around main housing  39  and is held in place by being trapped between swivel connection  50  and main housing  39 . Valve  55  is physically located in main housing  39  and is actuated by a lever  58  contacting diaphragm  45 . Lever  58  is preferably constituted by a thin metal elongated flexible member which is pivotably attached to valve  55 . Valve  55  includes a stem  59  with a poppet seat insert  60  which is biased by a spring  61 . A lever support  62  pivotably supports lever  58 . Additionally there is a purge button  64  or actuation switch that can manually activate lever  58  and thus valve  55  of second stage regulator  30 . Button  64  may either be a flexible portion of cover  56  or a separately movable actuation member.  
         [0027]    When second stage pressure regulator  30  is dropped by diver  10  and second stage pressure regulator  30  floods with water, diver  10  has two basic options. Diver  10  may replace second stage pressure regulator  30  in the diver&#39;s mouth and exhale thus clearing the second stage regulator  30  as water is forced out exhaust tube  35 . Otherwise diver  10  may press purge button  64  to allow high pressure air tend to second stage regulator  30  from the supply and thus venting second stage regulator  30 . A one way exhaust valve  65  is provided in main housing  39 . One way exhaust valve  65  is mounted over an opening  66  having an open lattice grid  67 . A rubber oval flexible member  70  is mounted over grid  67  and secured in place by pins  75 . As air pushes in one direction flexible member  70  is pulled away from grid  67  and allows for the passage of air. When the air flows in the other direction flexible member  70  is pushed against grid  67  and thus stops the airflow.  
         [0028]    An exhaust housing  76  is mounted over one way valve  65  and exhaust housing  76  is provided with an exhaust port  78 . Exhaust housing  76  may be integrally formed with main housing  39  or detachably mounted thereto by screws  79 . Exhaust tube  35  is attached to supply hose  28  by one or more hooks  100  that are preferably integrally formed with exhaust tube  35 . Alternatively, as shown in FIG. 3, exhaust tube  35  may be attached to supply hose  28  by one ore more wire ties  101 . In order to improve gas flow through exhaust tube  35 , tube  35  is provided with a hollow central portion  108  is preferably made of a flexible plastic material having a smooth interior. Preferably the exterior of tube  35  is corrugated to provide additional strength. The exhaust tube  35  may be designed with different lengths or of different cross section thus changing the amount of gas held therein.  
         [0029]    Since the buoyant force provided by tube  35  is controlled by the tube&#39;s volume, tube  35  should be sized to compensate for the weight of supply hose  28 . Ideally the weight of supply hose  28  will be canceled by the buoyancy of tube  35 . Exhaust tube  35  preferably has two one way valves  109 ,  110 , one located at each end in order to aid in trapping gas within hollow central portion  108 . However, valve  109  is optional. Exhaust tube  35  is placed in fluid communication with exhaust port  78  on exhaust housing  76  and extends away from exhaust housing  76  along the same path as supply hose  28 . As mentioned above, main housing  39  and exhaust housing  76  may be integrally formed as shown in FIG. 4 or may be two separate detachable pieces as shown in FIG. 5. In the case of a detachably mounted arrangement, a seal or gasket  112  is formed between main housing  39  and exhaust housing  76 .  
         [0030]    Turning now to FIG. 6, there can be seen an exhaust tube  35  having two one-way valves  109  and  110 , one located at each end of the hollow central portion  108  in a manner similar to that shown in FIG. 4. However, in the embodiment shown in FIG. 6, there is additionally provided an abutment  114  formed as part of tube  35  which extends along the entire length of tube  35 . Abutment  114  has a concave surface  116 . As seen in FIG. 7, concave surface  116  and hooks  100  cooperate to trap supply hose  28  snugly against tube  35 . With this configuration, when tube  35  is attached to hose  28 , tube  35  and hose  28  are held tightly together in a snug manner and thus reduce the amount of resistance a diver feels when swimming.  
         [0031]    In normal use, diver  10  holds mouthpiece  36  in his mouth so that when he inhales the pressure on one side of diaphragm  45  inside main housing  39  is lowered. This lower pressure actuates lever  58  that opens valve  55  regulating the air supplied to second stage pressure regulator  30  from supply hose  28 . Air then travels through second stage pressure regulator  30  and mouthpiece  36  into the diver&#39;s lungs. When diver  10  exhales, diaphragm  45  is moved in the opposite direction thus shutting off valve  55  at the inlet to second pressure stage regulator  30 . Further exhalation forces air out of exhaust port  78  on second stage regulator  30  and passes first optional one-way valve  109  and into elongated hollow central portion  108 . Air finally exits out of second one-way valve  110 . Typically these one-way valves  109 ,  110  are formed with a flexible flap  120 , 122  made of rubber or other suitable material. Flaps  120 , 122  are held in normally a closed position. Pressure from one end of one of flaps  120 , 122  simply allows flaps  120 , 122  to open and allow air pressure to travel through a respective one way valve  109 ,  110 . However, when the flow of fluid is in the other direction, the one way valves  109 ,  110  will simply close thereby prohibiting any further flow of air.  
         [0032]    During normal operation, exhaust tube  35  will become full of air or other breathable gas. As such, it will have a buoyant force. Supply hose  28  going from scuba tank  12  to first stage regulator to second stage regulator  30  will naturally have a certain weight and thus also apply a force to second stage regulator  30 . As can best be seen in FIG. 4, hooks  100  are integrally molded into exhaust tube  35  and are also attached to supply hose  28 . The interaction of these hooks  100 , the buoyant force of exhaust tube  35  and the weight of supply hose  28  all work to counteract one another and thus avoid twisting action on second stage pressure regulator  30 . As such, there is much less of a force applied to diver  10  through mouthpiece  36  as diver  10  tries to hold second stage pressure regulator  30  in place while breathing.  
         [0033]    As mentioned above, the amount of buoyant force provided can be adjusted by changing the size and shape of tube  35 . As mentioned above, in an alternative embodiment, as shown in FIG. 3, exhaust tube  35  may be held together with supply hose  28  by means of wire tie  101  which serve the same function as hook  100 . The details of the airflow throughout this process can probably best be seen in FIG. 4. In addition to the force of supply hose  28  on the diver&#39;s mouth being lessened, there is also an added benefit that bubbles leaving from exhaust tube  35  will be exhausted at a point remote from the diver&#39;s face. Unlike in the prior art device where these bubbles move in front of the diver&#39;s face and thus cause distraction, especially in underwater photography. With the addition of exhaust tube  35  no such problems occur.  
         [0034]    The problem of bubbles leaving a typical prior art second stage regulator  200  can be seen by the air flow diagram shown in FIG. 8. Regulator  200  works in a similar manner to the regulator discussed in regards to the embodiment shown in FIG. 4 and has an input valve that is actuated by a lever moved by a diaphragm (all not shown). Such a regulator  200  is currently made by Sherwood Scuba and sold as model Brut SRB5100. Essentially, a two part housing is provided. A first housing  239  includes the valving arrangement such as a diaphragm and a lever actuated valve and an input port  255  connected to supply hose  28 . Additionally, an opening for a mouthpiece  265  is provided in order to supply gas to diver  10 . A second housing  276 , an exhaust housing  276 , is detachably mounted to the main housing  239 . Exhaust housing  276  has a pair of output ports  280 ,  285  that allow for escaping gas.  
         [0035]    Turning now to FIG. 9, there is shown a second stage regulator  400  which in most respects is identical to that shown in FIG. 4 with the exception that it has an additional custom fit chin supporting surface  410  glued or otherwise secured below mouthpiece  39 . Chin supporting surface  410  is designed to abut against a diver&#39;s chin during use. As such chin supporting surface  410  provides a force provided from the diver&#39;s chin to stabilize second stage regulator  400  reducing vibration and other sorts of discomfort. Ideally, several custom fit supporting surface  410  pieces would be available at a store and customers could try them to see which provides a better fit. The chosen surface would then be glued to the regulator  400 .  
         [0036]    In FIG. 10, a similar configuration is shown wherein a chin supporting surface  510  is mounted on a retrofit housing  500 . This arrangement is similar to the two part regulator shown in FIG. 5 except for of course the addition of chin supporting surface  510 . Once again, chin support surface  510  will rest against the diver&#39;s chin during use and counteract any turbulence or other undesirable motion of the regulator  500 . It is important to note that since chin support surface  510  is on the retrofit unit, such housing may be added to any existing regulator device  200 .  
         [0037]    Although described with reference to preferred embodiments of the invention, it should be readily understood that various changes and/or modifications could be made to the invention without departing from the spirit thereof. In general, the invention is only intended to be limited by the scope of the following claims.