Patent Publication Number: US-7581735-B2

Title: Skateboard ski with spring suspension

Description:
PRIOR APPLICATION 
   Not Applicable. 
   FIELD OF THE INVENTION 
   This invention relates to the field of skateboards and snow skis/snowboards, in particular, the instant invention involves a traditional skateboard that has been transformed into a skiing device that can perform skateboard maneuvers on snow. 
   BACKGROUND OF THE INVENTION 
   In the area of skateboarding, skateboarders have traditionally had to turn to snowboards to have similar recreation in the snowy weather. Snowboarding, however, varies in many significant ways from skateboarding. The most obvious difference is the fact that a snowboarder&#39;s feet are bound and attached through boots to the snowboard, whereas, on a skateboard, the rider&#39;s feet are merely placed on top of the deck of the skateboard and are easily freed from the board to perform tricks and to discontinue the use of the board. Another significant difference is the feel and handling of the snowboard compared to a skateboard due to the fact that the skateboard has wheels and a truck between the deck and the ground that allows for steering and control while a snowboard&#39;s deck comes in direct contact with the ground. The locked-in feet and lack of suspension/steering ability make snowboarding a related, but different skill than skateboarding. Another feature of snowboarding and skiing is that both are edging devices. The instant invention, on the other hand, provides a turning/steering ability rather than an edging ability. 
   There have been devices known in the prior art that purport to combine skateboarding and snow recreation. However, none of the previous inventions have been able to offer the same suspension/steering or truck turning ability found on skateboards that are required to perform skateboard tricks. Chou in U.S. Pat. No. 6,481,725 teaches of a skateboard that attaches to one traditional ski. This invention does not have any spring suspension/steering ability, however. Differing from the instant invention, this device involves a single ski with no independent truck-turning ability. Similarly, Dotson in U.S. Pat. No. 4,116,455 involves a skateboard platform combined with removable ski shoes. No spring suspension/steering ability is included in this invention and therefore, most, if not all, skateboard tricks are not achievable on this device. This invention defines a board with only two skis, therefore there is no independent suspension and the define ski does not have the rocker provided in the instant invention. 
   Hirbod in U.S. Pat. No. 4,181,319 discloses a self-propelled skateboard with improved suspension capabilities. However, this invention is very complex, contains footpads and mechanisms for use with the hands. Therefore, a need exists for a simple skateboard/ski combination, without foot bindings, that can be used on snow and that has the same suspension/steering abilities that a skateboard does on pavement. 
   SUMMARY OF THE INVENTION 
   In the preferred embodiment of the invention, a skateboard/ski combination is described. A traditional skateboard deck has its wheels removed. The skateboard trucks remain in place, however. The four wheels on the traditional skateboard truck are replaced with four skis. The apparatus contains a spring suspension/steering system providing a neutral location of the skis at rest that rebounds to a neutral location when the skis are excited by external force. 
   The spring suspension/steering system includes two anchoring plates that are mounted between the underside of the skateboard deck and the trucks. The anchoring plates are hooked to a plurality of extension springs either through holes or prongs. Each ski has two extension springs connected between the ski and the anchor plate. The anchor plate helps create a tool-less ability to pre-load the skis for desired ride and functionality. The skis can be pre-loaded in either direction by disconnecting one spring per ski, be it the inboard or outboard springs, to achieve the desired performance enhancements. 
   The skis are composed of a base made of either plastic or metal that has a traditional ski shape, i.e., providing a ski shovel at both the front and rear ends of said base. The ski base, which has a flat or concave surface perpendicular to the length of the ski, contains a radius positioned longitudinally to the ski length (rocker) that then transitions to a small radius at the front and rear of the skis. This provides a traditional ski shovel in the front and rear of the ski base. Metal or plastic rails are mounted to the ski base on opposing sides of the base in a vertical fashion, extending below the surface of the base. The rails have a radius positioned longitudinally to the ski length (rocker) that transitions to a small radius at both the front and rear ends of the base. These rails are interchangeable to achieve different types of performance characteristics and to quickly and easily repair or replace worn or damaged rails. 
   In an alternative embodiment of the invention, the spring suspension/steering system is comprised of a torsion spring mounted inside of the vertical portion of the skateboard/ski combination in the vicinity of the hole of the axle. The torsion springs act against the axle and the ski base to provide a neutral suspended location and spring tension when he ski is rotated about the axle in either a clockwise or counterclockwise direction. 
   Another alternative embodiment of the invention involves the addition of a multi-purpose leash  24  and cuff assembly  23  that attaches the board to the rider that is added for safety and utility. 
   OBJECT OF THE INVENTION 
   The principal object of the invention is to replace the wheels on a traditional skateboard with skis. This allows the skateboard rider to ride on snow with the same agility as the traditional wheeled skateboard on pavement. The rider will be able to perform all the same tricks and maneuvers as on a non-snowy surface. Skateboarders, snowboarders and anyone interesting in trying new sports will find this invention useful. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  illustrates a top view of the skateboard/ski combination of the present invention; 
       FIG. 2  illustrates a side view of the skateboard/ski combination of the present invention; 
       FIG. 3  illustrates a perspective view of the skateboard/ski combination of the present invention; 
       FIG. 4  illustrates an end view of the skateboard/ski combination of the present invention; 
       FIG. 5  is a side view of a ski of the skateboard/ski combination of the present invention; 
       FIG. 6  is a perspective view of the anchor plate of the component of the skateboard/ski combination of the present invention; 
       FIG. 7  is a perspective view of the rail of the skateboard/ski combination of the present invention; 
       FIG. 8  is a cross-sectional view of a ski having a flat base of the skateboard/ski combination of the present invention; 
       FIG. 9  is a cross-sectional view of a ski having a concave base of the skateboard/ski combination of the present invention; 
       FIG. 10  is a perspective view of a ski with rails detached of the skateboard/ski combination of the present invention; 
       FIG. 11  is an exploded perspective view of a ski and rail assembly of the skateboard/ski combination of the present invention 
       FIG. 12  is a top view of a cuff attachable to a rider of the skateboard/ski combination of the present invention; 
       FIG. 12A  is a side view of the cuff of  FIG. 12  of the skateboard/ski combination of the present invention; 
       FIG. 12B  is a front view of the cuff of  FIG. 12  of the skateboard/ski combination of the present invention; and 
       FIG. 13  is a view of the leash. 
   

   DETAILED DESCRIPTION OF AN ENABLING AND PREFERRED EMBODIMENT 
   For a better understanding of the invention, we turn now to the drawings.  FIG. 1  offers a top view of the skateboard deck  10  with the skis  11  somewhat obscured underneath. The skis  11  are more readily seen in  FIGS. 2-4 . The skateboard deck  10  has its wheels removed, while the trucks  12  remain in place. The invention includes a spring suspension/steering system  14  providing a neutral location of the skis at rest that rebounds to a neutral location when the skis are excited by external force. 
   The spring suspension/steering system  14  includes two anchoring plates  15  that are mounted between the underside of the skateboard deck  10  and the trucks  12 . The anchoring plates  15  are hooked to a plurality of extension springs  16  either through holes or prongs  19 . Each ski  11  has two extension springs  16  connected between the ski  11  and the anchoring plate  15 . 
   The skis  11  are composed of a base  17  made of either plastic or metal that has a traditional ski shape, i.e., providing a ski shovel at both the front and rear ends of the base  17 . The ski base  17 , which has a flat surface  21  or concave surface  22  perpendicular to the length of the ski  11 , contains a radius positioned longitudinally to the ski length (rocker  20 ) that then transitions to a small radius at the front and rear of the skis  11 . This provides a traditional ski shovel in the front and rear of the ski base  17 . Metal or plastic rails  18  are mounted to the ski base  17  on opposing sides of the base in a vertical fashion, extending below the surface of the base  17 . The rails  18  have a radius positioned longitudinally to the ski length (rocker) that transitions to a small radius at both the front and rear ends of base  17 . These rails are interchangeable to achieve different types of performance characteristics and to quickly and easily repair or replace worn or damaged rails. 
   In an alternative embodiment of the invention, the spring suspension/steering system is comprised of a torsion spring (not shown) mounted inside of the vertical portion  13  of the skateboard/ski combination in the vicinity of the hole of the axle  13 . The torsion springs act against the axle  13  and the ski base  17  to provide a neutral suspended location of the skis and spring tension when the ski  11  is rotated about the axle  13  in either a clockwise or counterclockwise direction. 
   The illustrations and examples provided herein explanatory purposes and are not intended to limit the scope of the appended claims, as those skilled in the art will make modifications to the invention for particular uses.