Abstract:
A buoyancy control apparatus for underwater swimming includes a non-expandable housing having a fixed volume and having each of a predetermined shape and a predetermined size. An air chamber and a water chamber sealed from the air chamber are formed within the housing. A pump, disposed in a fluid communication with the water chamber and with a source of water, is operable for at least one of introducing such water into the water chamber and discharging such water therefrom and a controller is provided for operating the pump.

Description:
FIELD OF INVENTION  
       [0001]     The present invention relates, in general, to underwater swimming equipment and, more particularly, this invention relates to a buoyancy control apparatus for underwater swimming.  
       BACKGROUND TO THE INVENTION  
       [0002]     Buoyancy control devices have been used by scuba divers generally in the form of an inflatable jacket worn by the diver for many years. When the diver reaches a depth at which he or she wishes to remain for a time, the diver manually inflates and deflates this jacket using the compressed gas stored in the breathing tanks until a point of neutral buoyancy is found.  
         [0003]     However, if the diver ascends or descends following setting the inflation of the jacket, the pressure of the water surrounding the diver rises or falls. Accordingly, this change in pressure causes the inflatable jacket to increase or decrease in volume and thus alters the volume of water displaced by the jacket with a consequential change in the buoyancy provided by the jacket.  
         [0004]     By way of further explanation, when the diver descends, the rise in pressure causes the volume of the jacket to decrease. The volume of water displaced by the jacket is thus reduced causing the effect of reducing the buoyancy of the diver to a state of negative buoyancy. This further causes the diver to descend at a steadily increasing rate.  
         [0005]     If the diver ascends, than the drop in pressure causes the volume of the jacket to increase. The volume of water displaced by the jacket is thus increased and this has the effect of raising the buoyancy of the diver to a state of positive buoyancy. This causes the diver to ascend at a steadily increasing rate.  
         [0006]     In order to achieve neutral buoyancy again, the diver has to add or remove air to or from the jacket, by trial and error until neutral buoyancy is again achieved. This process can be repeated numerous times during a dive. The current systems require a great deal of user intervention and consumes a portion of available air supply. This reduces the amount of useful “bottom time” that the diver can spend in a dive.  
         [0007]     Furthermore, it is important that a diver can accurately control their rate of ascent. It is well known that coming up too fast can be very dangerous. Nitrogen accumulated in a diver&#39;s body, if not given enough time to come out of the body&#39;s tissue, can form bubbles. These bubbles can cause discomfort, pain and even death—this condition is commonly referred to as the bends. Without constant user adjustment, the above described inflatable jacket device causes a steadily increasing rate of ascent, which brings with it the risk of experiencing the bends.  
         [0008]     Efforts have been made to improve buoyancy control of the diver. U.S. Pat. No. 3,695,048 to Dimick, et al; U.S. Pat. No. 3,643,449 to Murphy; U.S. Pat. No. 4,437,843 to Birle; U.S. Pat. No. 4,779,664 to Courtney; U.S. Pat. No. 3,695,048 to Greenwood; U.S. Pat. No. 5,221,161 to Toy et al; and U.K. Patent 1 532 411 disclose various arrangements including a rigid tank and control means for varying the amount of air within such rigid tank for regulating buoyancy of the diver. However, the above prior art fails simply and economically to regulate such buoyancy and further fails to enable the diver to control rate of the descend or ascend.  
         [0009]     Therefore, there is a need for an improved buoyancy control apparatus for underwater swimming that enables the diver to regulate desired buoyancy and control a rate of the descend or ascend.  
       SUMMARY OF THE INVENTION  
       [0010]     According to one embodiment of the invention, there is provided a buoyancy control apparatus for underwater swimming. Such buoyancy control apparatus includes a non-expandable housing having a fixed volume and having each of a predetermined shape and a predetermined size. An air chamber and a water chamber sealed from the air chamber are formed within the housing. A pump, disposed in a flow communication with the water chamber and with a source of water, is operable for at least one of introducing such water into the water chamber and discharging such water therefrom. A controller is provided for operating the pump.  
         [0011]     According to another embodiment, the present invention provides a buoyancy control apparatus for underwater swimming which includes a non-expandable housing having a fixed volume and having each of a predetermined shape and a predetermined size. An air chamber and a water chamber sealed from the air chamber are formed within the housing by one of a piston slideably and sealably disposed within the housing providing for the air chamber being axially opposed to and axially aligned with the water chamber and a flexible bag disposed within the housing and forming the water chamber. A first passageway communicates an interior of the air chamber with a source of ambient air. A second passageway communicates an interior of the water chamber with a source of water.  
         [0012]     According to yet another embodiment of the invention, there is provided a buoyancy regulating apparatus for a buoyancy device used in underwater swimming. Such buoyancy device includes a fixed volume, non-expandable housing having an air chamber and a water chamber formed therein. The water chamber is sealed from such air chamber. The buoyancy regulating apparatus includes a housing having a predetermined shape. A water transfer means disposed within the housing and in a fluid communication with the water chamber and with a source of water and operable for at least one of introducing such water into the water chamber and discharging such water therefrom. A controller is provided for operating the water transfer means.  
         [0013]     According to a further embodiment, the instant invention provides a novel means, engageable with a predetermined portion of an apparatus employed for underwater swimming, for equalizing of air in an air chamber of a buoyancy control device with a surrounding water.  
       OBJECTS OF THE INVENTION  
       [0014]     It is, therefore, one of the primary objects of the present invention to provide a buoyancy control apparatus for underwater swimming.  
         [0015]     Another object of the present invention is to provide a buoyancy control apparatus for underwater swimming that enables simple and economical control of desired buoyancy.  
         [0016]     Yet, another object of the present invention is to provide a buoyancy control apparatus for underwater swimming that enables control of the descend or ascend rate.  
         [0017]     A further object of the present invention is to provide a buoyancy control apparatus for underwater swimming which visually indicates the rate of such ascend or descend.  
         [0018]     An additional object of the present invention is to provide a buoyancy control apparatus for underwater swimming which incorporates pressure equalization features.  
         [0019]     In addition to the several objects and advantages of the present invention which have been described with some degree of specificity above, various other objects and advantages of the invention will become more readily apparent to those persons who are skilled in the relevant art, particularly, when such description is taken in conjunction with the attached drawing Figures and with the appended claims. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0020]      FIG. 1  is a perspective exploded view of a buoyancy control apparatus of the present invention illustrating a housing assembly according to one embodiment of the invention;  
         [0021]      FIG. 2  is a cross sectional side view of the housing assembly taken along the lines  2 - 2  of  FIG. 1 ;  
         [0022]      FIG. 3  is a perspective view of the buoyancy control apparatus of the present invention illustrating a control unit used with the housing assembly of  FIG. 1 ;  
         [0023]      FIG. 4  is a perspective exploded view of the control unit of  FIG. 3 ;  
         [0024]      FIG. 5  is a perspective exploded view of the buoyancy control apparatus of the present invention illustrating a mouthpiece arrangement according to one embodiment of the invention for use with the housing assembly of  FIG. 1 ;  
         [0025]      FIG. 6  is a plan view of the mouthpiece assembly of  FIG. 5 ;  
         [0026]      FIG. 7  is an elevation view of the mouthpiece assembly of  FIG. 5 ;  
         [0027]      FIG. 8  is a cross sectional view of the mouthpiece assembly taken along the line  8 - 8  of  FIG. 7 ;  
         [0028]      FIG. 9  is a perspective exploded view of the buoyancy control apparatus of the present invention illustrating a mouthpiece arrangement according to another embodiment of the invention for use with the housing assembly of  FIG. 1 ;  
         [0029]      FIG. 10  is a plan view of the mouthpiece assembly of  FIG. 9 ;  
         [0030]      FIG. 11  is an elevation view of the mouthpiece assembly of  FIG. 9 ;  
         [0031]      FIG. 12  is a cross sectional view of the mouthpiece assembly taken along the line  12 - 12  of  FIG. 11 ;  
         [0032]      FIG. 13  is a perspective exploded view of a buoyancy control apparatus of the present invention illustrating a housing assembly according to another embodiment of the invention;  
         [0033]      FIG. 14  is a cross sectional view of the housing assembly of  FIG. 13 ; and  
         [0034]      FIG. 15  is a schematic diagram of the buoyancy control apparatus of the present invention. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0035]     Prior to proceeding to the more detailed description of the present invention, it should be noted that, for the sake of clarity and understanding, identical components which have identical functions have been identified with identical reference numerals throughout the several views illustrated in the drawing figures.  
         [0036]     Reference is now made, to  FIGS. 1-15 , wherein there is shown a buoyancy control apparatus, generally designated  10 , for underwater swimming.  
         [0037]     In particular reference to  FIGS. 1-2 , there is shown a first essential element which is a housing assembly  11  constructed according to one embodiment of the present invention. Such housing assembly  11  includes a housing member  14  which is shown in a form of a hollow cylinder  14  preferably having a cross-section in the shape of a kidney bean. A piston  12  is slideably movable inside the cylinder  14  and is sealed against the inside walls of the cylinder  14  by way of at least one O-ring type seal  16 . Preferably, a pair of seals  16  are employed within the cylinder  14 . Each end of cylinder  14  is sealed with an end cap  18  and a seal  20 .  
         [0038]     In a further reference to  FIG. 2 , such piston  12  forms a first chamber  26  and a second chamber  28 . By way of example, air is held in the first chamber  26 , and water is held in the second chamber  28 . It will be understood that as piston  12  moves, the volume of air in the first chamber  26  changes at the same time as the volume of water in the second chamber  28 . By changing the volume of air in the first chamber  26 , the buoyancy of the housing assembly  11  may he adjusted. Piston  12 , cylinder  14  and ends  18  are formed from a non-expandable material, such as PVC, in a thickness rigid enough to substantially resist changes in volume of the chambers at depths normally experienced in underwater swimming. The seals  16  and  18  are made from a suitable rubber material.  
         [0039]     One end cap  18  is provided with a first passageway  22  in communication with the first chamber  26 . The other end cap  18  is provided with a second passageway  24  in communication with the second chamber  28 . Each passageway  22  and  24  has a predetermined shape and a predetermined size. The presently preferred shape is round and the presently preferred size is about 1 cm in diameter.  
         [0040]     Another essential element of the present invention is a controller, generally designated  30 , and best shown in  FIGS. 3 and 4 . Such controller  30  has two main functions. It operates to add or remove water from the second chamber  28  of housing  11 , and it provides an indication of how much water is in the second chamber  28 .  
         [0041]     The controller  30  includes a water transfer means, such as a pump  32  for at least one of adding such water into the second chamber  18  and removing such water therefrom. Accordingly, the pump  32  is connected to the second passageway  24  of the second chamber  28  via a tube  34 . In the presently preferred embodiment of the invention, the pump  32  is powered by a compressed gas drawn from a scuba divers air tank  2  and operates to move the piston  12  by adding or removing water from the second chamber  28  as will now be described.  
         [0042]     To add water to the second chamber  28  quickly, a first switch  36  is used. When actuated, preferably by a pressing action, the first switch  36  activates a first air valve  38  which allows pressurized air to flow from the diver&#39;s main tank  2  through piping  40  towards a first turbine  42 . The pressurized air drives the turbine  42  in a clockwise direction, as shown in  FIG. 4 .  
         [0043]     The first turbine  42  is keyed to a driveshaft  44 , which in turn drives a first impeller  46 , mounted for rotation within a housing  33 , in a clockwise direction. A second impeller  48 , also mounted within the housing  33  and engages the first impeller  46  and moves therewith causing water to flow from outside, through a filter  50 , piping  52 , then through piping  54  and out through the tube  34  and then to the second chamber  28 , thus causing movement of the piston  12 . The first turbine  42  also drives a knob  56  which is also keyed to the driveshaft  44 .  
         [0044]     Similarly, to remove water from second chamber  28  quickly, a second switch  37  is used. When this is pressed, it activates a second valve  39  which allows pressurized air to flow from the diver&#39;s main tank  2  through piping  41  towards a second turbine  43  which is also keyed to the driveshaft  44 . The pressurized air drives the second turbine  43  in a counter-clockwise direction, as shown in  FIG. 4 , which drives the first impeller  46  in the counter-clockwise direction. This causes water to be drawn from the second chamber  28  via the tube  34 , piping  54 , piping  52 , and out through filter  50  to the outside and thus causes movement of piston  12 . The second turbine  43  also drives knob  56  in an anti-clockwise direction.  
         [0045]     To add or remove water from the second chamber  28  slowly, impeller  46  can be turned in either a clockwise or counter-clockwise direction by way of manually turning knob  56 . This provides for finer control of the buoyancy of the housing assembly  11 .  
         [0046]     Piping  40  and  41  are connected to a y-split connection (not shown) which is then connected to the main air tank  2 . Each turbine  42  and  43  is provided with shrouds  58  and  59 , respectively, to assist with driving of the turbines by compressed air. The components of the controller are housed between a front case  62  and a rear case  64 .  
         [0047]     Whichever method is used to add or remove water from the second chamber  28 , the knob  56  moves in a clockwise or counter-clockwise direction. Furthermore, it does so relative to motion of both turbines  42  and  43  and impellers  46  and  48 . This relativity is preferably on a 1 to 1 basis, with knob  56  rotating once for every revolution of turbines  42  and  43  and impellers  46  and  48 . Alternatively, gears (not shown) could be employed to provide for alternative relativities.  
         [0048]     The rotation of the knob  56  can be quantified by use of a scale  60 . Scale  60  is provided with a plurality of graduated scale markings  61 , spaced from each other at a predetermined angle, and can be set in any desired position. Scale  60  does not rotate along with knob  56 . This allows the user to judge just how much of a revolution knob  56  makes relative to the scale  60 . Since the motion of the knob  56  reflects inward or outward flow of water to the second chamber  28 , being able to quantify movement of the knob  56  allows a relative quantification of the amount of water moving in or out of the second chamber  28  and thus an indication of how much water is in the second chamber  28  at any given time.  
         [0049]     Furthermore, a display  57 , such as a counter, is coupled to the knob  56 , by way of meshing gears  63  and  65 , to record clockwise or anticlockwise rotations as a positive or negative number value respectively. This provides another way in which the rotation of the knob  56  can be quantified. Again, this quantification has a relevance to the amount of water in the second chamber  28 . A simple button  80  maybe provided to reset the counter  57  in order to establish a starting point of reference.  
         [0050]     Referring now to  FIGS. 5-8 , the pressure equalization feature will now be described. This feature allows for balancing the pressure of air in the first chamber  26  with the surrounding water pressure. A standard mouthpiece  66  is connected to a standard regulator  68  by way of a connector  70 . Connector  70  is provided with an aperture  72 . In use, a tube  73  connects the first passageway  22  of the housing assembly  11  to the aperture  72  of the connector  70 .  
         [0051]     At any depth, air at the pressure of the surrounding sea water is provided to the diver&#39;s mouth by a second stage of the regulator  68 . By connecting the first chamber  26  to the connector  70 , the pressure of air in the first chamber  26  is maintained equal to the air provided by the regulator  68 . If the diver descends, then the pressure of air provided by the regulator  68  will increase and air will flow into the first chamber  26 . Similarly, if the diver ascends, then the pressure of air provided by the regulator  68  will decrease and air will flow out of the first chamber  26 .  
         [0052]     As a further mechanism for allowing air to escape from the first chamber  26 , a one-way release valve  76 , either manually or pressure operated, may be provided on the tube  73 , or may be connected directly to the first chamber  26 . This release valve  76  may be provided as a precaution if the regulator  68  is not able to expel escaping air from the first chamber  26  quickly enough. All tubing mentioned needs to be wide enough to allow smooth flow of air in and out of the first chamber  26 .  
         [0053]     Referring to  FIGS. 9-12 , therein illustrated is a mouthpiece  166  according to another embodiment of the invention. Such mouthpiece  166  is provided with aperture  172  and fits directly onto the standard regulator  68 .  
         [0054]     By use of the above described device, the diver can set their desired level of buoyancy at any depth in the water by using controller  30  as described above. The buoyancy of the housing assembly  11  is regulated by adjusting the position of the piston  12  by pumping water into, or out of, the second chamber  28 . This in turn alters the volume of air held in the first chamber  26 . If the diver then moves to a different depth, the volume of air in the first chamber  26  remains constant.  
         [0055]     The pressure of the air may change, but the changes in the mass of the air in the first chamber  26  due to changes in pressure are negligible. So, the buoyancy of the device remains substantially unchanged despite the diver ascending or descending during their dive. This obviates the need for the diver to adjust buoyancy in order to allow for changes in depth.  
         [0056]     Referring to  FIGS. 13 and 14 , there is illustrated a housing assembly, generally designated  210 , according to another embodiment of the invention. Such housing assembly  210  includes a hollow housing  214 , an expandable means  212 , such as a flexible bag or bellows, end caps  218 , and end seals  220 . The flexible bag  212  is made from a flexible waterproof and airtight material such as polyethylene, PVC, silicone rubber or the like.  
         [0057]     Air may enter and leave a first chamber  226  via a first passageway  222 . Water may enter and leave a second chamber  228  via a second passageway  224 . The second chamber  228  is the space inside flexible bag  212 . In this embodiment, the piston has been replaced by the flexible bag  212 . The volume of air in the first chamber  226  is regulated by adjusting the volume of water inside the flexible bag  212 . In all other respects, operation of the device is the same as for the embodiment described above. The controller  30  shown in  FIGS. 3 and 4  may be used to adjust the volume of water in the second chamber  228 .  
         [0058]     The bellows  212  could increase or decrease in internal volume by expansion or contraction and could be formed from dip coated vinyl, rubber coated polyester fabric or urethane coated polyester fabric and various combinations thereof.  
         [0059]     The chamber defined by the internal space of flexible bag or bellows  212  could contain air instead of water, and the space outside the flexible bag or bellows  212  could contain water instead of air.  
         [0060]     Although the present invention has been shown in terms of the piston  12  being actuated by a pump  32 , it will be apparent to those skilled in the art, that the present invention may be applied to other forms of actuators such as mechanical or electrical actuators. For instance, piston  12  could be mounted on a screw thread which can actuate the piston by rotation. The screw thread could be rotated manually by turning a handle.  
         [0061]     Furthermore, the pump  32  operated by compressed air from the diver&#39;s air tank  2  may be replaced with another type of pump, such as an electric pump.  
         [0062]     Additionally, references to “air” in this specification includes air that might be encountered in scuba diving conditions including air in a diver&#39;s air tank  2 , and air that is inhaled or exhaled by a diver.  
         [0063]     Thus, the present invention has been described in such full, clear, concise and exact terms as to enable any person skilled in the art to which it pertains to make and use the same. It will be understood that variations, modifications, equivalents and substitutions for components of the specifically described embodiments of the invention may be made by those skilled in the art without departing from the spirit and scope of the invention as set forth in the appended claims.