Abstract:
An underwater writing and drawing tablet that stretches a length of waterproof (plastic) vellum between two rollers over a flat surface thereby enabling the user to easily draw or write on said vellum and permanently save the drawing and writing.

Description:
This application claims priority, under 35 U.S.C. §119, of U.S. Provisional Application No. 60/471,489, filed May 15, 2003. 

   BACKGROUND OF THE INVENTION 
   The present invention relates to scuba diving and more specifically to a submersible tablet for use in writing and drawing. 
   There are many reasons a scuba diver may need to write or draw underwater. The first is to communicate with other divers. Other uses are to record notes, to aid in gathering reference material, architectural drafting for marine construction and artistic rendering as is done at underwater archeological sites. 
   Presently most underwater communication is accomplished with hand signals or dive slates. Hand signals can be confusing and are limited in what they can communicate. Dive slates are limited in the amount that they can record by the size of the slate. When the slate is full, new writing can only be added by erasing all previous work. In urgent situations this erasing time can be inconvenient. Some communication is performed electronically but this is expensive and vulnerable to the underwater environment. 
   The use of multiple pages of waterproof material on a clipboard underwater is awkward because in the marine environment the pages can stick together and are difficult to manipulate especially if the diver is wearing gloves. Multiple page slates also cannot be reused until all previous work has been erased. 
   SUMMARY OF THE INVENTION 
   It is an object of the invention to provide a novel submersible drawing and writing tablet in which all writing and drawing is of a permanent nature. 
   It is also an object of the invention to provide a novel submersible drawing and writing tablet that will provide an unlimited amount of workable media underwater. 
   It is another object of the invention to provide a novel submersible drawing and writing tablet that can provide workable media quickly and easily in an underwater environment through the use of scrolls rather than pages. 
   It is also an object of the invention to provide a writing and drawing surface that is phosphorescent to accommodate working in low light conditions. 
   It is also an object of the invention to provide a novel submersible drawing and writing tablet that is of simple construction, does not involve the use of electronics and is impervious to the demands of the marine environment. 
   It is another object of the invention to provide a novel submersible drawing and writing tablet that can be economically manufactured and marketed. 
   It is also an object of the invention to provide a novel submersible drawing and writing tablet that is designed to have a buoyancy underwater that renders it nearly weightless and will shed air and water so as not to encumber the diver as he or she enters or leaves the water. 
   It is another object of the invention to provide a novel submersible drawing and writing tablet that can be easily disassembled for travel. 
   These and other objects of the present invention will become apparent to those skilled in the art upon consideration of the following description of the present invention. 
   According to one aspect of the present invention an underwater writing table includes first and second plastic rollers, first and second rotation knobs fitted at respective ends of the first and second plastic rollers, a face plate positioned between the first and second plastic rollers, and a plastic vellum sheet rolled around the first and second plastic rollers and placed over the face plate, wherein the plastic vellum sheet rolls between the first and second plastic rollers when the first or second rotation knob is rotated by the user. 
   According to another aspect of the present invention a wrist-mounted underwater writing tablet includes first and second plastic rollers positioned in a direction parallel to the user&#39;s arm, first and second rotation knobs fitted at respective ends of the first and second plastic rollers, a cover plate including first and second arm belt slots and first and second vellum slots, and a plastic vellum sheet rolled around the first and second plastic rollers and placed over the cover plate and passing through the first and second vellum slots, wherein the plastic vellum sheet rolls between the first and second plastic rollers when the first or the second rotation knob is rotated by the user. 
   The features of the invention believed to be novel are set forth with particularity in the appended claims. The invention itself however, both as to organization and method of operation, together with further objects and advantages thereof, may be best understood by reference to the following description taken in conjunction with the accompanying drawings. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a perspective view of a first embodiment of the underwater drawing tablet according to the present invention; 
       FIG. 2  is a detailed diagram showing the drawing frame, the face plate, and the drawer of the first embodiment shown in  FIG. 1 ; 
       FIG. 3  is a detailed diagram showing the drawer latch assembly and handle of the first embodiment shown in  FIG. 1 ; 
       FIG. 4  is a detailed diagram showing the support rails and roller supports of the first embodiment shown in  FIG. 1 ; 
       FIG. 5  is a detailed diagram showing the rollers and knobs of the first embodiment shown in  FIG. 1 ; 
       FIG. 6  is a perspective view of a second embodiment of the underwater drawing tablet according to the present invention; 
       FIG. 7  is a side view of a second embodiment of the underwater drawing tablet according to the present invention; 
       FIG. 8  is a top view of the second embodiment shown in  FIG. 6 ; 
       FIG. 9  is a side view of the second embodiment shown in  FIG. 6 ; 
       FIG. 10  is a detailed diagram showing the drawing frame of the second embodiment shown in  FIG. 6 ; and 
       FIG. 11  is a top view of the cover plate of the second embodiment shown in  FIG. 6 . 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   While this invention is susceptible of embodiment in many different forms, there is shown in the drawings and will herein be described in detail specific embodiments, with the understanding that the present disclosure is to be considered as an example of the principles of the invention and not intended to limit the invention to the specific embodiments shown and described. In the description below, like reference numerals are used to describe the same, similar or corresponding parts in the several views of the drawing. 
   First Embodiment 
   The novel underwater drawing tablet according to the first embodiment of the present invention is a hand held device as shown in  FIG. 1 . The diver can draw or write continuously, accessing various writing instruments such as pencils (not shown) stored in a drawer  80  and advancing a plastic writing material easily with one hand while the other stabilizes the tablet through the use of a handle  45  on one side. 
   The tablet is designed, through the use of buoyant materials such as polystyrene, to have a slightly negative buoyancy at a depth of about fifty feet so that it can be very easy to manipulate underwater and will not sink or ascend rapidly if let go. 
   Underneath the face plate  1  used as a drawing table is a retractable drawer  80  to hold drawing instruments (not shown) through the use of a hook and loop material on its surface and that of the drawing instrument holders. The drawer  80  can be locked in an extended position or in a retracted position. The drawer  80  does not have sides so that it will not retain air or water during entrances or exits of the water&#39;s surface. 
   On each end of the face plate  1  used as a drawing table are rollers  60  and  65  for holding lengths of plastic vellum  2  (not shown for clarity) used as the drawing support. Through the use of grips  50  on the ends of the rollers  60  and  65  the plastic vellum  2  can be wound from one roller to the other as it is used. 
   The submersible drawing tablet parts are constructed of various plastic resin materials that are impervious to salt water such as polycarbonate, acrylic Plexiglas and polystyrene. The acrylic Plexiglas is produced in bright florescent colors so that the pallet can be located easily if it is set aside underwater where visibility can be poor. 
   The submersible drawing tablet is designed so that it can easily be disassembled for travel. 
   The first embodiment of the submersible writing and drawing tablet will now be described by referring to  FIGS. 1-6 . The overall submersible writing and drawing tablet is shown in  FIG. 1 . 
   All writing and illustration is done on rolls of plastic vellum with a writing instrument such as a graphite pencil. The vellum  2  is wound onto the lower vellum roller  60 . The lower roller  60  is made of buoyant polystyrene and has a small diagonal vellum slot  63  on each side of the roller to grasp the vellum as it is being loaded onto the roller. The lower roller  60  is supported by the left and right lower roller supports  35  and  40 . The lower roller  60  extends past the left and right roller supports  35  and  40  and is held in place by the left roller end knob  85  on the left and the rotation knob  50  and the right roller end knob  95  on the right. The vellum  2  is advanced or rewound by turning the rotation knobs  50 . The plastic vellum  2  (not shown for clarity) extends from the lower roller  60 , over the face plate  1  and is attached to the upper vellum roller  65  (not visible in  FIG. 1 ) by means of two other diagonal vellum slots  63  shown in  FIGS. 1 and 5 . The face plate  1  is constructed of phosphorescent polypropylene or Plexiglas to accommodate working in low light conditions. The face plate  1  can also include a grid (not shown) as a drawing aid. The upper vellum roller  65  is held in place by the right and left roller supports  25  and  30 , the right roller end knob  85  on the left and the rotation knob  50  and the right roller end knob  95  on the right. 
   The upper roller supports  25  and  30  are connected to the upper support rail  20  by two ⅜″ flat head nylon screws  75 . The lower roller supports  35  and  40  are connected to the lower support rail  15  by two ⅜″ flat head nylon screws  75  shown in  FIGS. 1 and 6 . The vellum  2  is held tightly against the face plate  1  by use of the roller tension adjusting knobs  70  that apply pressure when turned clockwise to the upper and lower vellum rollers  60  and  65 . The vellum  2  is also held in place on the face plate  1  by use of the drawing frame  10 . The drawing frame  10  and the face plate  1  are attached to the upper and lower roller supports through separators  100  by four nylon screws  75  located in each corner. Vellum  2  travels between drawing frame  10  and face plate  1 . 
   The upper and lower support rails  20  and  15  extend beyond the left side of the face plate  1  and drawing frame  10  to provide support for the handle  45  and the drawer latch assembly  55  and  90 , details shown in  FIG. 3 . Fitted into the drawer grooves  81  shown in  FIG. 4  on the inner sides of the upper and lower support rails  20  and  15  is the drawer  80 . 
   As shown in  FIG. 2 , along the back edge of the drawer  80  is the ¼″ high drawer clasp  83  that is grasped by the drawer release trigger  55  (shown in  FIG. 1 ). The drawer release trigger  55  applies pressure to the drawer clasp  83  by use of a common rubber band (not shown) wound through a notch in the trigger  55  and attached to a nylon screw  75  in the upper support rail  20 . This is used to keep the drawer  80  retracted when not in use. The surface of the drawer  80  is covered with hook and loop material so that various writing and drawing instruments (not shown) that utilize the same material can be attached to it. 
   All the components of the submersible drawing and writing tablet are connected to each other through the use of the nylon screws  75 . The width of the slot in these screws is designed to be used with a large coin such as a fifty-cent piece or a Peso rather than a screwdriver. In this way tools are not needed to assemble or disassemble the submersible tablet and the screws will resist stripping due to the lack of edges of the coins. 
   Second Embodiment 
   The second embodiment of the present invention is shown in  FIG. 6  and is a smaller version of the submersible writing tablet designed to be worn on the arm of the diver and used primarily for communication between scuba divers and for note taking. This second version also uses plastic vellum  2  stretched between two rollers  60  and  65  running parallel to the diver&#39;s arm. Writing on the vellum  2  is accomplished with a graphite pencil  170  held in a holder  140  under the drawing surface between the rollers. This smaller version does not have the utility drawer  80  of the larger version and is not designed to be collapsible. This wrist model also is constructed primarily of polycarbonate, acrylic and polypropylene. The device is worn on the diver&#39;s arm through the use of a length of hook and loop material  160  that is attached to the underside of the tablet and can be adjusted to accommodate the circumference of the diver&#39;s arm by the use of the hook and loop material. 
   The Second Embodiment of the submersible writing and drawing tablet will now be described by referring to  FIGS. 6-11 . The overall submersible writing and drawing tablet is shown in  FIG. 6 . 
   All writing and illustration is accomplished on rolls of plastic vellum  2 . The vellum  2  is wound onto the lower vellum roller  60 . As in the first embodiment, the roller also has a small diagonal vellum slot  63  on each side of the roller  60  to grasp the vellum as it is being loaded onto the roller  60 . 
   The lower vellum roller  60  and the upper vellum roller  65  are held in place by the right and left cover plate supports  145  and  150  shown in  FIGS. 6 and 8 . Both vellum rollers  60  and  65  fit into openings in the left cover plate support  150 , shown in  FIG. 8 , and extend through and beyond openings in the right cover plate support  145 . One of roller knobs  50  is attached by pressure fitting to the right ends of each of the vellum rollers  60  and  65 , shown in  FIGS. 6 and 7 . 
   The second embodiment of the submersible writing tablet is not designed to be dismantled since its small size makes this unnecessary. The vellum is advanced or rewound by turning the rotation knobs  50 . The plastic vellum  2  extends from the lower roller  60 , through the lower vellum slot  155  over the cover plate  125  to the upper vellum roller  65 . The cover plate  125  is constructed of phosphorescent polypropylene or plexiglas to aid with visibility under low light conditions and may also include a grid as a drawing aid (not shown). The vellum  2  then passes through the upper vellum slot  155  to the upper vellum roller  65  and, as in the first embodiment, is attached by means of two diagonal vellum slots  63 . 
   The vellum  2  is held in place by the drawing frame  10  that is attached to the cover plate  125  by means of four nylon screws  75  that pass through the cover plate  125  and thread into the left and right cover plate supports  145  and  150 . Vellum  2  travels between cover plate  125  and drawing frame  10 . Pencil holder  140  is positioned between the upper and lower vellum rollers  60  and  65  and attached to openings in the left and right cover plate supports  145  and  150 , shown in  FIGS. 7 and 8 . Next to the pencil holder  140  is a small opening  135  into which one end of rubberized pencil holding tube  165  is held therein. The other end of pencil holding tube  165  is stretched over one end of the graphite drawing pencil  170 . 
   The second embodiment of the submersible writing tablet is attachable to the diver&#39;s arm by means of a length of hook and loop material forming an arm belt  160  that passes through respective arm belt slots  130  on each side of the cover plate  125  as shown in  FIGS. 6 ,  7 , and  9 . One end of the arm belt  160  passes through a plastic loop  161  sewn into the opposite end of the belt  160 . The belt  160  is then folded back on itself and attached by means of the hook and loop material. 
   Thus, it is apparent that in accordance with the present invention an apparatus that fully satisfies the objectives, aims, and advantages is set forth above. While the invention has been described in conjunction with specific embodiments, it is evident that many alternatives, modifications, permutations, and variations will become apparent to those skilled in the art in light of the foregoing description. Accordingly, it is intended that the present invention embrace all such alternatives, modifications and variations as fall within the scope of the appended claims.