Patent Publication Number: US-6986690-B2

Title: Propulsion structure for a water craft

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
   This is a continuation of U.S. patent application Ser. No. 10/708,627, filed on Mar. 16, 2004, now U.S. Pat. No. 6,848,958, which is a continuation of U.S. patent application Ser. No. 10/604,139, filed on Jun. 27, 2003, and titled “Manually Propelled Personal Notation Device,” now U.S. Pat. No. 6,736,688. 

   BACKGROUND OF INVENTION 
   The present application relates generally to personal floatation devices and, more particularly, to personal floatation devices that are manually propelled in a body of water. 
   It is well known that personal floatation devices, such as air-encapsulating inner tubes and the like, can be propelled by a user with simple hand and/or foot movement. It is also well known that such movement can be maximized and enhanced with the utilization of fin-like structures, typically coupled to a user&#39;s foot, to maximize water resistance to cause the floatation device to travel in the desired direction. However, a limitation of such a design is that hand and leg movement are not synchronized and thus can be counterproductive. Further, when returning the fin-like structure to the origination point to begin another cycle, the fin-like structure generally increases water resistance in the return stroke, consequently degrading and hindering travel in the desired direction. 
   It is also well known that simultaneous and synchronous hand and foot movement can be achieved via a ski-like machine on land, wherein an interconnecting structure, such as an elongated rod, is used to coordinate hand and leg movement. However, such a structure is not readily adaptable for water usage, let alone buoyancy. As such, there exists a need in personal floatation devices to incorporate the benefits of simultaneous and synchronous movement of the hands and legs. 
   SUMMARY OF INVENTION 
   The present application discloses a manually propelled personal floatation apparatus. The apparatus comprises a central body portion capable of being buoyant in a body of water and a depending propulsion structure that is pivotally coupled to the body portion. 
   The propulsion structure includes a fin member pivotally coupled to an elongated rod and is adapted to extend substantially perpendicular from the body portion, thereby acting as a sail, to propel the floatation apparatus forwardly and to lay substantially parallel to the body portion to encourage continued gliding of the floatation apparatus. The elongated rod is pivotal between forward and rearward positions relative to the body portion. As such, when the rod is pivoted from the forward to the rearward position, the fin member extends perpendicular from the body portion, consequently affecting forward movement of the floatation apparatus caused by water resistance acting upon the fin member. When the rod is pivoted from the rearward position to the forward position, the fin member lays parallel to the body portion where water resistance with the fin member is minimized, thus encouraging continued forward movement of the floatation apparatus in a gliding manner. 
   A foot-holding structure, adapted to secure a user&#39;s foot or leg to the elongated rod, may be coupled adjacent to the lowermost terminus of the elongated rod. In such an embodiment, the user&#39;s foot or leg can assist the manual movement of the elongated rod from forward and rearward positions relative to the central body portion, and vice-versa, thereby assisting in forward propulsion. 

   
     BRIEF DESCRIPTION OF DRAWINGS 
     For the purpose of facilitating an understanding of the subject matter sought to be protected, there are illustrated in the accompanying drawings embodiments thereof, from an inspection of which, when considered in connection with the following description, the subject matter sought to be protected, its construction and operation, and many of its advantages, should be readily understood and appreciated. 
       FIG. 1  is a front elevation view of a floatation apparatus in accordance with the present application; 
       FIG. 2  is a reduced side view of the floatation apparatus of  FIG. 1  depicted in use by a user with the foreground fin member disposed in the substantially parallel position; 
       FIG. 3  is a view similar to  FIG. 2  with the foreground fin member disposed in the substantially perpendicular position; 
       FIG. 4  is an enlarged, side elevation view of the floatation apparatus of  FIG. 1  with the fin member disposed in the substantially parallel position; 
       FIG. 5  is a cross-sectional front view taken along line  5 — 5  in  FIG. 1  with a propulsion structure removed for clarity purposes; 
       FIG. 6  is an enlarged, rear view of the pivoting structure of  FIG. 1  with the vertical bore and bottom surface shown with hidden lines; and 
       FIG. 7  is a view similar to  FIG. 6  but with the vertical bore and the top surface shown with hidden lines. 
   

   DETAILED DESCRIPTION 
   Referring to the figures, the present application discloses a manually propelled personal floatation apparatus  10 . The apparatus comprises a central body portion  11  capable of being buoyant in a body of water W that has a front  12 , a back  13  and two transversely opposing sides  14 ,  15 . 
   A propulsion structure  20  is pivotally coupled to at least one side  14  of the central body portion  11  with a pivoting structure  16  and depends downwardly therefrom into the water W. In an embodiment, a depending propulsion structure  20  may be pivotally coupled to each respective side  14 ,  15 . In such an embodiment, the respective propulsion structures  20  will be substantially similar in design and configuration but will be inverse relative to each other. 
   The back  13  of the central body portion  11  may have an ergonomic shape to support a user&#39;s torso and position during use. The back  13  may include a flattened portion adapted to abut the user&#39;s torso. The front  12  of the central body portion  11  may be substantially similar to a boat hull configuration, thereby angling to an intersection point. 
   The propulsion structure  20  includes an oar-like member having an elongated rod  21  with respective upper and lower portions  22 ,  23  and is pivotally coupled to the central body portion  11  in such a manner so as to facilitate movement of the upper and lower portions  22 ,  23  between forward and rearward positions relative to the central body portion  11  and inversely relative to each other. In other words, when the upper portion  22  is disposed in the forward position, the lower portion  23  is disposed in the rearward position, and vice-versa. The elongated rod  21  is disposed relative to the central body portion  11  such that the upper portion  22  extends substantially upwardly from the central body portion  11  and the lower portion  23  extends substantially downwardly from the central body portion  11 . 
   A fin member  30  is pivotally coupled to the elongated rod  21  intermediate the upper and lower portions  22 ,  23  and is adapted to extend substantially perpendicular from the central body portion  11 , thereby replicating a sail, when the lower portion  23  is moved from the forward position to the rearward position and lay substantially parallel to the central body portion  11  when the lower portion  23  is moved from the rearward position to the forward position. 
   Forward movement of the floatation apparatus  10  is caused by manually moving the upper portion  22  from the rearward position to the forward position, consequently moving the lower portion  23  from the forward position to the rearward position and causing the fin member  30  to extend substantially perpendicular from the central body portion  11  to replicate a sail (as depicted in  FIG. 3 ), thereby increasing water resistance acting upon the fin member  30  to cause the floatation apparatus  10  to travel along a substantially forwardly directed vector. When the lower portion  23  is returned to the forward position by manually moving the upper portion  22  from the forward position to the rearward position, consequently moving the lower portion  23  from the rearward position to the forward position and causing the fin member  30  to lay substantially parallel to the central body portion (as depicted in  FIG. 2 ), water resistance between the fin member  30  and the surrounding water is minimized, thus encouraging forward movement of the floatation apparatus  10  in a gliding manner. 
   Controlled braking or steering of the floating apparatus  10  may be accomplished by selectively causing the fin member  30  to extend substantially perpendicular from the central body portion  11  and maintaining such a position. In such an extended position, again replicating a sail, water resistance acts upon the fin member  30  causing the floating apparatus  10  to slow down and/or turn in the desired direction. 
   A foot-holding structure  40 , adapted to secure a user&#39;s foot or leg  41  to the lower portion  23  of the elongated rod  21 , may be coupled adjacent to the terminus of the lower portion  23 . In such an embodiment, the user&#39;s foot or leg  41  can assist the manual movement of the lower portion  23  from the forward position to the rearward position and vice-versa. In an embodiment, the foot-holding structure  40  may include a strap having both respective strap termini coupled to the terminus of the lower portion  23 , thereby defining a loop. It will be appreciated that while a looped strap is depicted in the figures, other foot-holding structures  40  can be utilized while not departing from the true scope and spirit of the present application. 
   The pivoting structure  16  may include an outwardly extending wing structure  50  disposed adjacent to the waterline on a side  14  of the central body portion  11 . The wing structure  50  has respective top and bottom surfaces  51 ,  52  connected by a vertically aligned bore  53  terminating with apertures  54 ,  55  disposed on each respective surface  51 ,  52 . The aperture  54  on the top surface  51  may be substantially circular and the aperture  55  on the bottom surface  52  may be substantially L-shaped, with a first leg  56  extending parallel to the central body portion  11  and a second leg  57  extending perpendicular from the central body portion  11 . The first and second legs  56 ,  57  intersect each other at an intersection point. In such an embodiment, the bore  53  interconnecting the respective apertures  54 ,  55  is proportionally shaped and tapered to provide a smooth transition therebetween. The elongated rod  21  is disposed through the bore  53  wherein the upper portion  22  is disposed above the top surface  51  and the fin member  30  and the lower portion  23  is disposed substantially below the bottom surface  52 . In this embodiment, the fin member  30  is encouraged to extend perpendicular from the central body portion  11  (as depicted in  FIG. 3 ), when the lower portion  23  is moved from the forward position to the rearward position, by the second-leg  57  of the L-shaped aperture  55  and tapered bore  53 . Conversely, the fin member  30  is encouraged to lay parallel to the central body portion  11  (as depicted in  FIG. 2 ), when the lower portion  23  is moved from the rearward position to the forward position, by the first leg  56  of the L-shaped aperture  55  and tapered bore  53 . 
   A keel  60  may be disposed on the bottommost portion of central body portion  11  to assist the user in stabilizing the floatation apparatus  10  during use. This can be accomplished by manipulating the center of gravity of the flotation apparatus  10 . 
   It will be appreciated that while only one side of the central body portion  11  has been described having a propulsion structure and pivoting structure, the transversely opposing side of the central body portion  11  may have a propulsion structure and pivoting structure with substantially the same configuration as disclosed above. 
   The matter set forth in the foregoing description and accompanying drawings is offered by way of illustration only and not as a limitation. While particular embodiments have been shown and described, it will be apparent to those skilled in the art that changes and modifications may be made without departing from the broader aspects of applicants&#39; contribution. The actual scope of the protection sought is intended to be defined in the following claims when viewed in their proper perspective based on the prior art.