Abstract:
The invention is a special modified scuba diving apparatus intended for use by an animal, and more specifically the famous diving dog “Shadow.” The invention includes a helmet, a harness for supporting the helmet and a source of breathable gas, a special regulator providing a supply of breathable gas to the interior of the helmet, an exhaust for withdrawing exhaled air and residue water from the helmet without depressurizing the helmet, and a system of weights to compensate for the buoyancy of the user, and to counteract a net moment created about the center of buoyancy. The breathing system includes a muffler. An intercom system for providing voice instructions to Shadow can also be included.

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to a diving apparatus for a user that cannot operate a conventional diving apparatus, including animals. The invention has been employed with an animal, the wellknown diving dog, Shadow. Shadow, being a canine, cannot communicate with her owner and handler, Dwane Folsom, and is unable to operate a scuba apparatus herself. 
     Accordingly, the present invention provides a means for Shadow to dive both in swimming pools and the open ocean. Shadow has accomplished numerous dives in pools and in the Carribean Sea around Grand Cayman, British West Indies. She has appeared on approximately thirty television programs or news reports, many of them broadcast nation-wide, such as CBS&#39;s morning news and ABC&#39;s “Good Morning America,” and is a highly experienced diver. 
     SUMMARY OF THE INVENTION 
     According to the invention, there is provided a helmet that has an opening for the user&#39;s neck. The helmet includes a regulator mounted on, its external surface. The regulator is made from a conventional scuba demand regulator, but is specially modified. A muffler is provided to reduce or eliminate air noise. The helmet can be equipped with an intercom system, and can receive a weight to compensate for the user&#39;s buoyancy and any net moment about the user&#39;s center of buoyancy. The helmet is attached to a harness that supports the helmet and a tank of air or other breathable gas. The harness also receives compensating weights. 
    
    
     DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a drawing of Shadow wearing her scuba apparatus. 
     FIG. 2 is a drawing of the helmet used with the Scuba apparatus. 
     FIG. 3 is a drawing of the modified regulator which provides a supply of air or other breathable gas at no less than ambient pressure to the interior of the helmet. 
     FIG. 4 is a drawing of the harness. 
     FIG. 5 is a drawing of the muffler. 
     FIG. 6 is a block diagram of the intercom system. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     A scuba apparatus  10  is shown being worn by Shadow  12  in FIG.  1 . Referring to FIGS. 1 and 2, the apparatus  10  includes a helmet  14  worn by Shadow. Helmet  14  is spherical and made of any suitable plastic material. Helmet  14  is preferably large enough to hold a reasonable volume of air and avoid contact with the user&#39;s head and nose, but not any larger since increased helmet volume adds to the user&#39;s buoyancy. Also, helmet  14  tends to create a significant moment because the buoyancy of helmet  14  is at one end of Shadow&#39;s body, and well away from its center of buoyancy. Helmet  14  is preferably UV-stabilized so that it will not lose its transparency. In Shadow&#39;s case, helmet  14  is approximately 10{fraction (1/2 )}inches in diameter. 
     Helmet  14  includes an opening  16  the interior of which is lined with a skirt  15  of any non-abrasive, water-resistant material. In Shadow&#39;s case, Naugahyde® material has proved suitable. The skirt  15  seals the helmet  14  to a harness  42 , described below, and therefore assists in creating a slight back pressure in helmet  14 . Skirt  15  also cushions the helmet and prevents abrasion to Shadow&#39;s neck. Helmet  14  also includes a regulator  18 , a compensating weight  20 , and an intercom system  22 . 
     Compensating weight  20  must be adjusted for the particular user, and for changes from salt to fresh water. In Shadow&#39;s case, weight  20  is approximately four to six pounds. Less weight is required in fresh water than in salt water. More weight can be used to insure that all four of Shadow&#39;s feet contact the bottom, or to enable her to lie on the bottom or enable her to perform certain movements or positions she has been trained to use upon signals from her handler, Dwane Folsom. 
     The bottom surface of weight  20  is hemispherical to fit the bottom of helmet  20 . Weight  20  is anchored to helmet  14  by some means  20   a  that allows the weight to be removed if necessary, for example, when Shadow dives in a fresh water pool instead of the ocean. In the present embodiment, Velcro®  20   a  material has proven useful and convenient. 
     Regulator  18  is shown in FIG.  2  and in more detail in FIG. 3. A conventional Scuba second-stage regulator is modified in two ways. A description of a conventional second-stage regulator may be found at pages  61  and  62  of  Diving for Fun , Joe Strykowski, and published by Dacor Corporation, Northfield, Ill. First, exhaust port  24 , normally used by a human diver, is blocked by plate  26 . Second, normal regulators do not provide air unless the user inhales. Regulator  18  has an adjusting screw  28  threadably engaged with a clearing button  30 . Turning screw  28  causes it to bear against second stage air valve  32  causing it to remain open by an amount determined by the position of screw  28 . Since valve  32  remains open, there is a small but constant flow of air from the air tank and its first-stage regulator, neither of which is shown here. Screw  28  is protected from accidental movement by a shroud  34 , made from stainless steel. 
     Air delivered through valve  32  would normally be ported directly to the mouth of a human user. With modified regulator  18 , however, air flows instead through a muffler  37  to port  36 , which is connected to the interior of helmet  14 . Port  36  is specially designed to induce a flow of air near the interior surface of helmet  14  and toward the front of the helmet. Experience has revealed that, without properly directed air flow, helmet  14  fogs, and interferes with good visibility. The shape of port  36  causes the flow of dry air (or any breathable gas) to follow the inner curvature of helmet  14 , thus preventing fogging of helmet  14 . 
     Muffler  37  eliminates or reduces air noise caused by the constant flow of air into helmet  14 . As shown in FIG. 5, muffler  37  receives air from regulator  18  and delivers it to port  36 . Muffler  37  is comprised of two overlapping sections of hose  39  and  41 . Hose  41  is also rubber, and is about one inch in diameter. Hose  39  is smaller than hose  41  and is connected to regulator  18 . The portion of hose  39  that is inside hose  41  has a series of holes  43  that allow air to flow out of hose  39  and into the interior of hose  41 , thus reducing the noise created by the flow of air. Holes  43  are one quarter-inch in diameter. The outlet of hose  41  is connected to port  36 . Hose  39  is centered inside hose  41  by means of a series of plastic rings  45 , which have holes in them to allow flow of air in the annular space between hoses  39  and  41  while still supporting and centering hose  39  inside hose  41 . A stainless steel mesh screen  47  is located inside hose  41  and just prior to the outlet to port  36 ; screen  47  baffles the air and provides additional quieting. 
     Shadow inhales and exhales as necessary; slight excess pressure, typically about a few ounces per square inch, prevents water from leaking past skirt  15  into helmet  14 . Shadow&#39;s exhalations flow out of the helmet through two exhaust ports  38 , one on each side of the lower portion of helmet  14 . Ports  38  are spaced about four and one-half inches apart to allow space for weight  20 , and are located slightly above the bottom of skirt  15 . Each of ports  38  is connected to a hose  40 , described in more detail below. 
     As mentioned above, helmet  14  is attached to a harness  42 . The harness must of course be adapted to the particular user. Nevertheless, several features are essential. Harness  42  can be constructed of the same strap material that is used for divers&#39; weight belts. Harness  42  includes straps  44  with quick-release buckles for securing the harness around Shadow. Harness  42  has a pocket  46  on each side to receive and hold a weight to counteract Shadow&#39;s normal buoyancy. Pockets  46  are constructed with quick-release fastenings made of Velcro® or other suitable material, and can be made of strapping of a different color so that the weights can be removed quickly. The weights are coated with plastic and curved to fit Shadow&#39;s side comfortably. 
     The top of harness  42  has a central member  48  that is made of three layers of strapping material sewed together. The triple thickness protects Shadow&#39;s back and spine from the weight of an air tank, not shown, that can be attached to a a stainless steel saddle connector  50  on the central member  48 . The triple thickness of central member  48  also provides additional rigidity to the combined assembly of helmet  14  and harness  42 , thus preventing any buoyancy in helmet  14  from bending and placing stress on Shadow&#39;s neck. A handle  52  can be located on the member  48 , preferably near the center of gravity of the apparatus. If desired, a flat stainless steel plate can be placed inside the sewed spine section to provide additional strength and stiffening. Harness  42  can also have a short line attached to the front of the harness; the line can be used as a guide or leash. In the present embodiment, a loop about three or four inches in size is used. A stainless steel saddle, not shown, can also be installed on the top spine section of harness  42  to support a separate air tank. 
     Breathable gas can be supplied to Shadow in two ways. One is by means of an air tank, not shown, attached to connector  50 , with the first-stage regulator and an air guage nearer Shadow&#39;s tail, to keep them away from Shadow&#39;s other equipment. A conventional first-stage regulator, not shown here, is used to connect the high-pressure air in the bottle to the inlet of regulator  18 . Shadow has used an aluminum tank having a capacity of ten or fifteen cubic feet; a tank will typically last for ten to twelve minutes in either a pool or the open ocean. Alternatively, air can be supplied from an air tank and first-stage regulator worn by a human diver, such as Dwane Folsom, Shadow&#39;s owner and trainer. 
     A means of removing Shadow&#39;s exhaled air is necessary. Helmet  14  includes two exhaust ports  38  as mentioned above. Locating the ports  38  low in the helmet assists in the removal of any residue water that might enter helmet  14  and otherwise collect there. As shown in FIGS. 1 and 2, each is connected to a hose  40 . Spacing between the ports helps insure that they will function properly even if helmet  14  is tilted to one side due to Shadow&#39;s movement. The hoses  40  connect to a tee fitting  56  located above helmet  14 , allowing the release of exhaled air. The length and diameter of hoses  40  is critical; improper selection of these parameters can lead to a “chimney” effect, where the hoses  14  draw air out of the helmet  14 , thus interfering with the user&#39;s breathing by reducing the pressure in helmet  14 . This problem may occur because the regulator  18  is above the helmet  14 , the exhaust ports  38  are low, and the tee  56  is at roughly the same height as the regulator  18 . The pressure in helmet  14  must be at least equal to or slightly higher than the pressure faced by air flowing out of tee  56 ; otherwise, there would not be any flow of air. A “chimney” or venturi effect in hoses  40  could reduce the pressure inside helmet  14  while still allowing enough of a pressure difference for flow to continue. Under those circumstances, helmet pressure could conceivably be reduced below the water pressure around Shadow&#39;s neck, which is normally below tee  56 . Thus, water could leak into helmet  14  through opening  16 . 
     Whatever the cause, experimentation has determined that a hose length of about fourteen and one-half inches with an internal diameter of three-quarters of an inch is effective. Tee  56  has two connections having a three-quarter-inch internal diameter to fit hoses  40 . The third opening in tee  56  has a diameter of one inch. This configuration prevents any “chimney” effect. 
     The scuba apparatus can also include an intercom system, shown in a block diagram in FIG.  6 . The intercom includes a power supply and amplifier  54  mounted inside helmet  14 , a water-resistant speaker  57  mounted inside the helmet  14 , and the necessary electrical connections. Power supply  54  is a water-resistant box  58  which contains a rechargeable nine-volt battery, an amplifier, and a magnetically-operated switch of any conventional type, all not shown. The switch can be actuated merely by placing a magnet in the proper place on the outside of box  58 , thereby eliminating any need for the switch to penetrate the wall of box  58 . Two terminals  62  project through the wall of box  58  and allow recharging of the battery. Terminals  62  are protected by plastic, non-conductive caps  64  and o-rings (not shown) when not in use. The caps insure that no electrically conductive path can exist between terminals  62 ; were a conductive path to exist, due perhaps to the presence of sea water, Shadow would be vulnerable to electrical shock. Both power supply  54  and speaker  57  can be attached to the interior of helmet  14  by any convenient means. In this embodiment, Velcro® fastening material is used since it allows easy removal and does not require the use of screws or other fasteners that might penetrate the wall of helmet  14 . Speaker  57  is connected via a lead  66  which leaves helmet  14  through opening  16  and terminates in a watertight quick-disconnect fitting, not shown, secured to harness  42 . A microphone lead for Shadow&#39;s handler, Dwane Folsom, is not shown here, but can be connected at the quick-disconnect fitting and terminates in a microphone mounted inside the regulator used by Dwane. He can use the microphone to give oral commands to Shadow at any time through speaker  57 .