Patent Publication Number: US-2012024634-A1

Title: Spring paddle propulsion device

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     Priority is claimed based on U.S. Provisional Application 61/365,286, filed Jul. 16, 2010. 
    
    
     BACKGROUND OF THE INVENTION 
     This invention relates generally to personal propulsion devices and particularly to a device for propelling a skateboard or a watercraft. 
     SUMMARY OF THE INVENTION 
     A propulsion device according to the present invention for propelling vehicles such as skateboards and watercraft comprises an elongate rod formed of an elastic material. The elongate rod has an upper end and a lower end, the upper end being formed to be suitable for grasping by a human hand with a foot section being connected to the lower end. 
     The foot section may have a non-skid surface for engaging a support surface so that a person can bend the elongate rod to store energy and then release the stored energy to use the propulsion device to propel a wheeled vehicle. 
     The foot section may alternatively have a paddle extending therefrom so that a person can bend the elongate rod to store energy and then release the stored energy to use the propulsion device to propel a watercraft. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  illustrates a propulsion device according to the present invention being used to propel a person on a skateboard; 
         FIG. 2  illustrates a first embodiment of the invention; 
         FIG. 3  illustrates a second embodiment of the invention; 
         FIGS. 4A and 4B  illustrate a third embodiment of the invention having a paddle at one end; 
         FIGS. 5A and 5B  show a sequence of configurations that the propulsion device according to the present invention may have as it is used to propel a skateboard or the like; and 
         FIG. 6  shows a segmented embodiment of the invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     As shown in  FIGS. 1-3 ,  4 A,  4 B,  5 A and  5 B, a propulsion device  10  according to the present invention preferably is formed to include an elongate pole  12 . A first end  14  of the pole  12  is formed to be suitable for grasping by a human hand. The second end  16  may be formed to be suitable for placing on a firm surface for propelling a wheeled vehicle such as a skateboard  18  or the like as shown in  FIG. 1 . As shown in  FIGS. 4A and 4B , the second end  16  may be flared to form a paddle  20  so that the propulsion device  10  may be used to paddle a watercraft (not shown). 
     As shown in  FIG. 2 , the propulsion device  10  may include a single flared portion  17  at the end  16 . Alternatively, the propulsion device  10  may include flared portions  19  and  21  at the opposite ends  14  and  16  as shown in  FIG. 3 . 
     As shown in  FIGS. 5A and 5B , the propulsion device  10  is somewhat elastic so that it may be flexed to form a bow  22  having energy stored therein. The propulsion device  10  then begins to straighten as energy is transferred from the propulsion device  10  into kinetic energy of the device being propelled. 
     The propulsion device  10  according to the present invention may be formed of any material such as carbon fiber, fiberglass or any of several plastic materials that are sufficiently elastic so that they will return to a straight configuration after being flexed. 
     The present invention is a lightweight portable resilient spring-actuated propulsion device having a variable shaft of 4 to 7 feet in length exhibiting properties of good bending recovery, hoop strength, modulus of elasticity, torsional strength, impact strength and tenacity including sufficient flexural fatigue life. The tubular tapered hollow resilient rod  12  may include a rubber molded over-grip handle section  24  as shown in  FIG. 6 , a mid section  26  and a tip section  28  that connects to a plurality of footer combinations of a various blade or paddle sections for spring actuated propulsion for operators of stand-up paddle-boards, kayaks and canoes. The tubular tapered hollow resilient rod tip  28  can attach to an additional non-skid foot section engaging a support surface suitable for variable resistance exercise including spring actuated propelling of skateboards or any similar lightweight wheeled device. The construction of a tubular tapered hollow resilient rod spring propulsion device preferably uses high strength wrapped layers of angular and unidirectional glass and graphite fibers in sheets to fabricate either a single monolithic tubular tapering shaft or a variable set of smaller modular tubular tapering shafts conjoined together as shown in  FIG. 6 . 
     Referring to  FIG. 6  the rod  12  may comprise a pair of segments  30  and  32 . An end  34  of the segment  30  has a recess  35  formed therein for receiving a projection  36  formed at and end  38  of the segment  32 . Forming the propulsion device  10  in two or more sections allows it to be packaged in a manner that is convenient for shipping, storage and display. 
     The multi-function propulsion device  10  according to the present invention interchangeably embodies an exercise apparatus that enables an individual to perform a variety of aerobic, isometric, isotonic and stretching exercises utilizing variable resistance forces provided for in strength and endurance training including physical therapy.