Snowboards today are normally designed with a flat base surface between the tips at the two ends. For steering the board is edged and the weight is distributed between the feet in the two bindings.
From Norwegian patent application no. 981056 a snowboard is known which has a base completely or partly divided into three running surfaces. The object of this patent, however, is to give optimum dynamic when riding the boards on snow. A minimum width is therefore indicated on the sloping lateral surfaces.
The present invention is based on testing of snowboards with bases according to the described patent, when the surprising discovery was made that the first base surface of the regulation bases was too narrow to be optimal for rails. It was found that there was a substantial potential for improvement for use on rails if the flat middle base surface is made much wider, with the result that the secondary running surfaces become correspondingly narrow. The advantage is that the wide central portion is wide enough to form a stable base both for sideways and parallel sliding on rails. At the same time the upwardly sloping secondary base surfaces will prevent the steel edges from catching in small irregularities on the rail that cause the rider to land on his head on the ground.
For use on rails the flat central portion of the base should be as wide as possible, in order to achieve maximum stability, while the secondary base surfaces must be wide enough for the steel edge to be raised slightly over the rail, thereby preventing it from becoming caught.
A good deal of testing has shown that the optimal width for the secondary base surfaces is 2-3 cm, but very good results are also obtained within the interval 1-4 cm, and right at the ends at the transition to the tips where the board is widest, some shorter portions wider than 4 cm may even be contemplated. By means of this design a board is obtained which is both ideal for rails, while at the same time retaining most of the dynamic characteristics of tripartite bases for riding on snow.
However, no snowboard is used only on rails, since after all most of the running takes place on snow. This board therefore has secondary running surfaces which twist up from the middle towards the tip/the rear tip. Over its entire length, or over substantial parts of its length, the board has running surfaces called secondary lateral areas (2) on both sides of the central flat running surface (1) called the first base surface.
On this basis, therefore, it is the object of the invention to provide an improved snowboard specially adapted to achieve increased safety on rails. This is achieved by a snowboard which is characterised by the features which will become apparent from the patent claims.
The invention solves this special problem for snowboards by means of the special design of a raised lateral area from the following criteria:                1. The secondary lateral area (2) must have a certain minimum width which is large enough for the steel edge to be raised far enough above the rail to avoid becoming caught in irregularities.        2. The first base surface (1) must be as wide as possible when sliding with the board along the rail in order to avoid skidding due to running on a sloping lateral area, and when sliding sideways a wider central portion will give greater stability.        3. The cross section shows the base as three substantially straight lines in those parts of the board where there are secondary lateral areas, and the angle formed by the secondary lateral areas with the first base surface is substantially increasing from the middle towards the front and rear tips.        
USPTO Backgrounds
USPTO Backgrounds