Patent Publication Number: US-9422038-B2

Title: Submersible personal flotation device

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. Provisional Application No. 62/017,968, filed Jun. 27, 2014. 
    
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     Not Applicable. 
     BACKGROUND 
     1. Field 
     This disclosure pertains to personal flotation devices. 
     More particularly, this disclosure pertains to fully submersible flotation devices that allow for hands-free operation while the user sits upright and mostly submerged in the water. 
     2. Description of the Related Art 
     Personal flotation devices are extremely popular for recreational use in the water. However, these devices can be uncomfortable and difficult to use because they require the user to hold on to the device or otherwise restrict use of the user&#39;s hands, arms, and legs. Most devices also require the user to float on top of the water rather than having the majority of the user&#39;s body under the water. 
     Moreover, personal flotation devices can be difficult to transport because they are either have bulky foam pieces or require inflating. An additional problem is that in order to float, the devices are either made of a light fragile material such as foam that is subject to breaking, or a fragile inflatable casing that is subject to puncturing. Most of these devices also do not accommodate users of different sizes, weights and buoyancies. 
     BRIEF SUMMARY 
     According to one embodiment of the present invention, a personal flotation device is provided. The device is comprised of a hard outer shell that is waterproof and hollow, and includes a seat and a raised leg straddle support centered at the front of the seat. A water ballast valve allows for water to enter or exit the shell thereby changing the buoyancy of the device. Internal support columns protect the device from crushing forces. A cavity on the bottom of the shell that is complementary to the shape of the raised straddle support allows for the devices to be stacked on top of one another. A handle extending from the device allows the device to be carried easily. 
     Is it is an object of the present disclosure to provide a flotation device that is lightweight, durable, relatively small, and easy to carry. 
     Is it is an object of the present disclosure to provide a flotation device that allows a user to sit upright in the water at chest level. 
     Is it is an object of the present disclosure to provide a flotation device that has an adjustable buoyancy and accommodates users of difference sizes and buoyancies. 
     Is it is an object of the present disclosure to provide a flotation device that will not break if sat upon on dry land. 
     Is it is an object of the present disclosure to provide a flotation device that is inexpensive to manufacture. 
     Is it is an object of the present disclosure to provide a flotation device that is stackable. 
     Is it is an object of the present disclosure to provide a flotation device that allow a user to operate the device hands-free. 
     Is it is an object of the present disclosure to provide a flotation device that is easy to clean. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
       The above-mentioned features will become more clearly understood from the following detailed description read together with the drawings in which: 
         FIG. 1A  displays a front view of a user using an embodiment in the water. 
         FIG. 1B  displays a side view of the user and embodiment of  FIG. 1A . 
         FIG. 2  is a front isometric view of a first embodiment. 
         FIG. 3  is a rear isometric view of the embodiment of  FIG. 2 . 
         FIG. 4  is a side view of the embodiment of  FIG. 2 . 
         FIG. 5  is a bottom view of the embodiment of  FIG. 2 . 
         FIG. 6  is a front view of the embodiment of  FIG. 2 . 
         FIG. 7  is a front isometric view of a second embodiment. 
         FIG. 8  is a bottom view of the embodiment of  FIG. 7 . 
         FIG. 9  is a front view of the embodiment of  FIG. 7 . 
         FIG. 10  is a rear view of the embodiment of  FIG. 7 . 
         FIG. 11A  is a front isometric view of an embodiment without a leg straddle support portion. 
         FIG. 11B  is a front view of the embodiment of  FIG. 11A . 
         FIG. 11C  is a side view of the embodiment of  FIG. 11A . 
         FIG. 11D  is a rear isometric view of the embodiment of  FIG. 11A . 
         FIG. 12A  is a rear isometric view of a leg straddle support for the embodiment displayed in  FIGS. 11A through 11D . 
         FIG. 12B  is a bottom isometric view of the embodiment of  FIG. 12A . 
         FIG. 12C  is a top view of the embodiment of  FIG. 12A . 
         FIG. 12D  is a rear view of the embodiment of  FIG. 12A . 
         FIG. 13A  is a rear isometric view of a bottom half of an embodiment. 
         FIG. 13B  is a front isometric view of the embodiment of  FIG. 13A . 
         FIG. 14A  is a bottom isometric view of a top half complementary to the embodiment in  FIG. 13A . 
         FIG. 14B  is a second bottom isometric view of the embodiment of  FIG. 14A . 
         FIG. 15A  is a top isometric view of another embodiment. 
         FIG. 15B  is a side view of the embodiment of  FIG. 15B . 
         FIG. 15C  is a front view of the embodiment of  FIG. 15A . 
         FIG. 15D  is a rear view of the embodiment of  FIG. 15A . 
         FIG. 16  displays the user of  FIG. 1A  using the embodiment of  FIG. 1A . 
         FIG. 17A  displays a second user using the embodiment of  FIG. 1A . 
         FIG. 17B  displays the user of  FIG. 17A  using the embodiment of  FIG. 1A . 
     
    
    
     REFERENCE NUMERALS 
     
         
           110  First user 
           200  Flotation device first embodiment 
           210  Shell 
           212  Seat 
           214  Raised leg straddle support 
           216  Shell side 
           218  Straddle support distal side 
           220  Straddle support proximal sides 
           222  Straddle support proximal sides 
           224  Internal support columns 
           226  Raised middle ridge 
           228  Handle 
           230  Handle attachment locations 
           232  Shell bottom 
           234  Threaded valve stem 
           236  Threaded cap 
           238  Tether 
           300  Cavity 
           700  Flotation device second embodiment 
           710  Shell 
           712  Seat 
           714  Raised leg straddle support 
           716  Shell side 
           718  Straddle support distal side 
           720  Straddle support proximal sides 
           722  Straddle support proximal sides 
           724  Internal support columns 
           728  Handle 
           730  Handle attachment locations 
           732  Shell bottom 
           734  Threaded valve stem 
           736  Threaded cap 
           738  Tether 
           740  Cavity 
           742  Stem recess 
           1100  Seat and main body 
           1110  Slots 
           1112  Recess 
           1200  Leg straddle support 
           1210  Tabs 
           1212  Proximal sides 
           1214  Proximal sides 
           1300  Bottom 
           1310  Threads 
           1400  Top 
           1410  Complementary threads 
           1500  Foam embodiment 
           1710  Second user 
       
    
     DETAILED DESCRIPTION 
       FIGS. 1, 2, 3, 4, 5, and 6  illustrate a flotation device first embodiment  200 , which is comprised of a hard outer shell  210 . The shell  210  and all parts of the embodiment  200  are comprised of a plastic such as high density polyethylene, although other materials known to those skilled in the art may be used as well. This embodiment  200  and shell  210  made through blow molding, although other methods such as injection molding and rotational molding are possible. 
     The top surface of the shell  210  includes a substantially concave seat  212  with a raised middle ridge  226 , which is contiguous with a raised leg straddle support  214  whose proximal sides  220 ,  222  extend up from the front of seat  212 . Two internal support columns  224  are hollow and open-ended and extend from seat  212  vertically down to shell bottom  232 . 
     Extending from straddle support distal side  218  is a water ballast valve, displayed here as a threaded valve stem  234  which is coupled with a tether  238  to a threaded cap  236 . Other variations of the valve arrangement, e.g., a spigot, or a plug, or where the cap needs minimal unthreading to allow water and air flow, may be used and are well-known to those with ordinary skill in the art. 
     Handle  228  extends from locations  230  on shell side surface  216 , leaving a gap at handle  228  middle between handle and shell side surface  216 . 
     Shell bottom surface  232  is curved and convex in a dome substantially hemispheric shape and includes the bottom ends of internal support columns  224 . Cavity  300  on bottom surface  732  has a shape complementary to straddle support proximal sides  220 ,  222  such that multiple flotation devices  200  are operable to stack upright vertically, in alternating opposite directions. The cavity  300  shape also acts as a third support column, increasing the structural strength of the device  200 . 
       FIGS. 7, 8, 9 and 10  illustrate a flotation device second embodiment  700 , which includes certain structural differences from first embodiment  200 . By way of example, seat  712  is concave and smooth and does not include raised middle ridge  226 . Three internal support columns  724  extend from seat  712  to shell bottom surface  732 . Water ballast valve  734  is threaded and located in stem recess  742  on shell side  716 , which allows for the user&#39;s leg to avoid being pressed against the valve. Threaded cap  736  is coupled to water ballast valve  734  with tether  738 . 
     Cavity  740  on shell bottom  732  is located directly below raised leg straddle support  714 . The shape of cavity  740  is complementary to the straddle support proximal sides  720  such that multiple devices  700  can be stacked up on one another, each facing the same direction. 
     Referring to  FIG. 15A ,  FIG. 15B ,  FIG. 15C , and  FIG. 15D , another embodiment  1500  displays the device comprised out of hard foam. The primary difference between the embodiment  1500  and the ones previously disclosed is that a water ballast valve  234  is unnecessary, as the device  1500  is generally solid. Buoyancy will be predetermined and nonadjustable and a user must choose in advance a device  1500  of appropriate size and buoyancy. In other embodiments without a water ballast valve, the device may be made of material other than foam, as long as the embodiment has the appropriate positive buoyancy overall. 
     Referring now to  FIGS. 1A, 1B, 16, 17A, and 17B , a method for using the embodiment  200  at the appropriate equilibrium level will now be disclosed. A user first places the device  200  in the water and pushes it down in order to sit on the device. Once the device is in the correct position between the user&#39;s thighs and the device is centered underneath the user similar to sitting on a bar stool, the user can determine if he or she feels stable enough to maintain that position while floating.  FIG. 16  displays a user  110  sitting on personal flotation device  200 , with thighs pressed against two proximal sides  220  of raised leg straddle support  214 . In  FIG. 16 , the user is floating too high in the water, because the buoyancy of the device  200  is too great; unless the user stays alert and exerts great effort the user is likely to be capsized as if attempting to sit on an underwater basketball. 
     In order to reduce buoyancy, the user  110  slightly unfastens threaded cap  236  from valve stem  234 , thereby allowing air to exit the device  200  and water to enter, thereby increasing the ballast and reducing the buoyancy of device  200 . The user, still sitting on device  200 , sinks in the water up to chest level, as displayed in  FIGS. 1A and 1B . The user  110  then retightens the cap  236 , thereby setting the new buoyancy level of the device  200 . When the user is at the water level displayed in  FIGS. 1A and 1B  and a buoyancy equilibrium has been reached, the user will be able sit upright and sit on the device seat  212  with minimal effort, while having free use of his or her hands. The user can use his arms and legs to propel through the water, or perform other activities while floating because his hands are free to do so. 
       FIG. 17A  displays a second user  1710  who is smaller than user  110  and has just been given the device  200  at the buoyancy level from  FIGS. 1A and 1B . When second user  1710  attempts to use the device  200 , the buoyancy of the device that was ideal for the first user is too great for the second user; the second user  1710  floats too high in the water. Like the first user, the second user  1710  opens the water valve  234 , thereby reducing the buoyancy of the device  200  even further until the user  1610  is at optimal buoyancy level as displayed in  FIG. 17B . 
       FIGS. 11A, 11B, 11C, 11D, 12A, 12B, 12C, and 12D  display a manufacturing option for embodiments, including  200  and  700 , where for example laminar flow during the molding process makes it difficult to manufacture an embodiment as a single strong piece. Seat and main body  1100  are manufactured separately from leg straddle support  1200 . Recess  1112  is complementary in shape to the lowest section of straddle support proximal sides  1212 ,  1214 . Tabs  1210  are designed in a shape to permanently lock into slots  1110  thereby affixing straddle support  1200  permanently to main body  1110 . 
       FIGS. 13A, 13B, 14A and 14B  display a second manufacturing option for embodiments, including  200  and  700 . Here, top  1400  includes an outer perimeter of female threads  1410 , and bottom  1300  includes an outer perimeter of male threads  1310  that are complementary to female threads, such that when top  1400  and bottom  1300  are screwed together they create a waterproof embodiment, for example  200  or  700 . 
     Several modifications are available to the presented embodiments. By way of example only, straddle support  214  could be cylindrical with indents for the thighs, or T-shaped, or other shapes that allow a user to hold onto the device with the user&#39;s legs. As another example, the water valve stem  234  could have a stopper instead of a cap with complementary threads, or some other type of water valve, e.g., a spigot, could be used. More internal support columns  224  can be added if necessary to increase the structural strength of the device and protect it from crushing forces. 
     While several illustrative embodiments have been described in considerable detail, it is not the intention of the applicant to restrict or in any way limit the scope of the appended claims to such detail. Additional advantages and modifications will readily appear to those skilled in the art. The inventions in their broader aspects are therefore not limited to the specific details, representative apparatus and methods, and illustrative examples shown and described. Accordingly, departures may be made from such details without departing from the spirit or scope of applicant&#39;s general inventive concepts.