Abstract:
Though the sport of snowboarding is not new, it has taken many years to understand the specific characteristics which are required for making snowboards. There is better understanding of the dynamic bending properties needed for current riders, especially for the competition driven rider whose demands require boards with different tip, tail and middle characteristics. Early snowboard designers understood the use of snowboards as articles for gliding down a snow covered slope making long curving turns, where tips and tails would be as stiff as the middle core. But now, the boards are jumped into the air, launching from half pipes edges and sliding down steel rails, requiring different flex contours. Snowboards are now required to be very flexible yet elastic being required to bend convexly and concavely, yet springing back to their shape immediately, with some riders wanting stiff tips or soft tails or a combination of both.

Description:
BACKGROUND OF INVENTION 
   This invention relates to the field of devices that are used to enable the user to slide or glide across surfaces such as snow and ice. The device that is particularly suited for this invention is a snowboard. As one skilled in the art will recognize, an application of this invention can extend further than just to the field of snowboarding, and as such would be covered by the concept and spirit of this invention. 
   DESCRIPTION OF THE ART 
   This invention accomplishes some of the attributes desirable for a user to have a device that contains both damping characteristics and a cantilever stiffening aspect in one device. It is desirable for those who participate in the activity of snowboarding to have a board that is soft or damping around the edges, which will keep the snowboard conforming to the terrain, while at the same time being able to have the snowboard “spring” back to its natural state after being bent in both directions around half-pipes, contours or steel pipe rails. Snowboarding is different from skiing as there is more demand for freestyle jumping and riding on the edge of the snowboard. Skiing demands more bending of the ski in a concave direction with extreme flexural characteristics, as skiers tend to ride moguls, contours and uneven terrain, seeking the ski to smoothly transition between valleys and peaks. Snowboarding on the other extreme has more jumps and skateboarding types of terrain where the snowboard needs to “grab” the surface, damping, but also need to provide “spring” or lift when jumping from the edge of half-pipes and rails. Also a snowboard is more likely to be subjected to flexural and compressive forces at the same time and then the opposite forces will be subjected on the board in the next immediate moments. Snowboards need to adapt to bending moments in both the vertical and horizontal planes which are constantly and rapidly changing. 
   The prior art for those devices which can be used for gliding across snow can generally be described as layering materials of various properties longitudinally along the vertical axis of the device. U.S. Pat. No. 4,412,687 issued to Andre on Nov. 1, 1983 discloses a ski that is laminated with high tensile strength materials, rods and filament bundles. The goal is to increase the rigidity and bending strength of the ski. U.S. Pat. No. 4,706,985 issued to Meatto on Nov. 17, 1987 also discloses the basic concept of layering materials to obtain the desired characteristic of the device. Meatto combines both circular rods and sheets of various components to increase flexural response and compressive structural strength of the ski. Snowboards though need to be soft and flexible not stiff as skis. The early snowboards were built as having the same internal material composition of skis. But as snowboarding developed into a different style of sport from skiing, the design of snowboards have started to develop to adapt to this change in use. The prior art of snowboard design has followed the designs of both skis and skateboards. 
   Snowboards have three distinct sections, the main body, the front tip or nose, and the rear tail. Each is shaped differently and in snowboards the tip and tail are significantly larger in width than is the body than in skis. Snowboards are ridden with the center of gravity of the user generally over the center of gravity of the snowboard, where on skis the center of gravity is shifted toward the tail of the ski. The skier faces the along the axis of motion, where the snowboarder is transverse to the axis of motion, needing a wider plane in order to attach themselves to the snowboard and creating the need for torsional movement rather than axial movement. Generally, this torsional movement is generated on the edge of the snowboard and thus snowboards are now built with this recognition of movement in mind. Prior art shows snowboards developing softer edge material so that the snowboard is easier to carve in long turns. Patent Publication 2002/0105165 for DeRocco published Aug. 8, 2002 details this concept of varying edge properties by using ABS or other relatively rigid materials in different shapes and thicknesses in the core of the board disclosing that some riders like a stiffer board. U.S. Pat. No. 6,499,758 issued to Fournier on Dec. 31, 2002, discloses a complex series of angles and grooves designed to reduce the compression forces necessary to bend the board. U.S. Pat. No. 6,382,658 issued to Stubblefield on May 7, 2002 discloses a plurality of cross-sections and thicknesses of the core to create an improved turning performance. These are both very complex to design and difficult to manufacture and thus they become very expensive and custom to a particular need of a rider in a particular situation, long smooth turns of Fournier to the sharp tight turns of Stubblefield. It would be desirable for a snowboard to be able to adapt to a multitude of different situations as they present themselves while snowboarding down a mountain slope. U.S. Pat. Nos. 6,520,530 and 6,105,991 issued to Dodge et al on Feb. 18, 2003 and Aug. 22, 2000 respectively, addresses the issue of having various directions of the strength of materials so that the material&#39;s direction of strength is located along the areas of greatest stress on the snowboard. This is very complex and arduous task of aligning materials for a particular style of riding. These patents claim vertically laminated members which are non-parallel to the core axis and anisotropic structures oriented so that the principal axis is not in alignment with any of the core axis. It would be desirable to produce a snowboard that is can be readily manufactured that would contain the positive attributes of the prior art such as varying degrees of flexibility and response but are more easily adaptable and manufacturable. It would be advantageous to be able to have a snowboard that combines the rider&#39;s desires as well as the demands of the conditions available for him to ride. It would be desirable to have a snowboard that is customizable in a short amount of time and can be mass produced for varying levels of ability and that uses the same concepts and materials. 
   This invention derives it&#39;s uniqueness from a combination of responsive materials and a cantilever inspired spring return system. The main uniqueness of this invention is that it treats the core, the tail and the tip as three separate entities which enable the invention to focus on the different materials necessary for each part of the board and yet function as a unit and have the different characteristics in the unique areas of the snowboard. The choice of materials is developed about the nature of the conditions during use and construction of the snowboard. Materials must have consistent properties through-out the manufacturing process including the cooler temperature when the snowboard is made and used, yet do not have their properties depreciated during the pressure, bending and heating processes during construction. Where flex is required in the tail and tip, a softer material is used, and while the core of the body is stiff for responsiveness, the edges are softer. The use of carbon fiber stiffening members “spring” the snowboard back to it&#39;s natural state quickly, so that the snowboard is ready to absorb the next grueling round of stresses around the next corner or half-pipe jump. This invention can be customizable by adjusting the stiffness of the snowboard by adding or subtracting stiffening members or by adjusting the thickness of the stiffening member. 

   
     DESCRIPTION OF FIGURES 
     The following figures are included to graphically detail the invention. 
     In  FIG. 1 , the interior core, tail and tip of the snowboard is shown. 
     In  FIG. 2 , a profile of the snowboard is taken directly down the vertical centerline or section B-B as shown in  FIG. 1 . The entire snowboard is shown with the top and bottom layers along with the core. 
     In  FIG. 3 , the snowboard is shown on a horizontal profile, cut along section A-A. In this figure, the snowboard is shown with only 1 stiffening member on each side of the core. 
     In  FIG. 4 , the snowboard is shown on a horizontal profile, cut along section A-A. In this figure, the snowboard is shown with 2 stiffening members on each side of the core, located equidistant from the vertical center of the board. 
     In  FIG. 5 , the detail of the stiffening member and associated channel is shown in profile view. 
     In  FIG. 6 , is a layered view of the snowboard, where each layer is shown by hatch pattern along with the stiffening member. Detail of the dovetail joint is also seen with this figure. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   In  FIG. 1 , the body  2  of the snowboard  1  is shown. Body  2  comprises tip  3 , tail  4 , core  5 , at least 2 stiffening members  6 , with an equal number of channel  7  corresponding to stiffening members  6 , and perimeter edge  8 . Core  5  is defined by right vertical plane wall  13  and left vertical plane wall  14  and upper horizontal plane wall  11  and lower horizontal plane wall  12 . Core  5  is also defined by a front side of core  17  and a rear side of core  18  which extends in the horizontal plane between right vertical plane wall  13  and left vertical plane wall  14 . Central riding surface  40  is defined as that area between the riders feet as they are attached via mountings holes  19  to the board  1 , surface  40  extending from right vertical plane walls  13  through the vertical axis B-B to left vertical plane wall  14 . Riding surface  40  is characterized as having an equal distance or thickness between front side  17  and rear side  18  at corresponding points through out core  5 . Right edge  13  and left edge  14  are concavely circumscribed about an arc of a circle whose radii depends upon personal users preferences. Generally, a radius of approximately 1000 cm is used. Core  5  has a vertical axis of core B-B which is described as being the longitudinal line which is equidistant from corresponding points in the horizontal plane along said right edge  13  and said left edge  14 . Vertical axis of core B-B is along the vertical axis of rotation. Core  5  has a horizontal axis of core A-A which a latitudinal line described as intersecting said vertical axis of core B-B at a right angle and is equidistant from corresponding points on upper horizontal plane wall  11  and lower horizontal plane wall  12 . Midpoint  31  is defined as the intersection of vertical core axis B-B and horizontal core axis A-A. Front side of core  17  is has a reduction in thickness contour  32  tapered commencing at the distal end of mounting holes  39 , tapering toward horizontal plane walls  11  and  12 . The reduction of thickness along contour  32  extends at a constant rate creating an equal thickness of the core extending from right edge  13  and said left edge  14 . Core  5  has a thickness at midpoint  31  of between 4-10 mm, preferable 6-8 mm. Core  5  has a thickness of between 1-6 mm at horizontal plane walls  11  and  12 , preferably 2-4 mm. In this invention, core  5  follows contour  32  from 6 mm to 3 mm in thickness with a slight radius. Contour  32  can have a slope that contains a radius or has a straight slope toward its termination point at the horizontal walls. Tip  3  and tail  4  are joined with equal thickness to horizontal plane wall  11  and  12 . Upper horizontal plane wall  11  and lower horizontal plane wall  12  are adapted for maximum bonding adhesion by increasing the surface area of the bond between core  5  and tip  3  and core  5  and tail  4 . In this invention, a dovetail design  20  is used to accomplish this goal of maximum adhesion. This invention is not limited to a particular design to maximize the surface area for greater adhesion. The goal is to create the maximum necessary bond between said core  5  and tip  3  and core  5  and tail  4 . Bonding means are used to enhance dovetail  20  adhesion to tip  3  and tail  4 . The distance between said front side of core  17  and rear side of core  18  at any one point of core  5  is predetermined by the style of use of said board  1 . This invention is not limited to specific contour angle or lack thereof. Binding mounting holes  19  are located along vertical axis of core B-B, corresponding to a predetermined pattern of inserts that are necessary for the attachment of bindings to said board  1  after completion of bonding of the layers. The pattern of inserts matches the configuration of mounting holes of the bindings, which usually conforms to the industry standards as for location and degree of angle of the mounting to the vertical axis of the snowboard. Binding mounting holes  19  are threaded inserts whose exterior is adapted for maximum adhesion during the bonding process in this invention. Core  5  can be made from wood, such as birch, aspen, balsa or other lightweight woods. 
   Right edge  13  and left edge  14  has circumscribed thereabout a perimeter edge  8 . Perimeter  8  is equivalent in height as is the height of edge  13  and  14  and is bonded to edge  13  and  14  using bonding means. Perimeter edge  8  follows the radius of right edge  13  and left edge  14 . Perimeter edge  8  extends in the horizontal plane a pre-determined distance based on desired board characteristics. Perimeter edge  8  is made of an isotropic material which is invariant with respect to any direction. This material must have stability of the characteristics throughout the range of temperatures for where board  1  is to be subjected thereto and also does not have any degradation of material characteristics when subjected to bonding means. In this invention, Celluarized or Expanded polyvinylchloride is used with of density of between 0.35 and 1 g/cm 3 , preferably 0.55 to 0.75 g/cm 3 . Perimeter  8  edge extends beyond upper horizontal plane wall  11  following tip cutin radius  41 , terminating at the transition between the radii of right edge  13  and left edge  14  and the tip radius  43 . Perimeter  8  edge extends beyond lower horizontal plane wall  12  following tail cutin radius  42 , terminating at the transition between the radii of right edge  13  and left edge  14  and the tail radius  44  as seen in  FIG. 1 . 
   Tail  4  is defined by a distance from the lower horizontal plane wall  12  to the apex of tail radius  38 . Tail  4  constructed of material similar in physical and thermal characteristics to the material used in perimeter edge  8  and is connected to tail cutin radius  42  using bonding means. Tail radius  44  is defined as the curvature needed to connect the termination of right edge  13  and left edge  14  to apex  38 . Distance from lower horizontal plane wall  12  to apex  38  is determined by the bending characteristics desired of board  1  by the riders. In this invention, the distance is approximately 20-24 cm. Tail  4  contains at least one tail extension channel  37  which similar in shape and dimensions as channel  33  and constitutes a continuation of channel  33  from core  5  to tail  4 . There will exist at least an equal number of tail extension channel  37  corresponding to top channel  33  and bottom channel  34  that exist on core  5 . Tail extension channel  37  will vary in length depending upon the particular performance characteristics required of board  1 . Tail extension channel  37  will vary from 50% to 90% of the distance from lower horizontal plane wall  12  to apex  38 . The longer the channel, the stiffer the tail of the board, which is better for turning but not for jumping or rail-riding. 
   Tip  3  is defined by a distance from the upper horizontal plane wall  11  to the apex of tail radius  36 . Tip  3  constructed of material similar in physical and thermal characteristics to the material used in perimeter edge  8  and is connected to tail cutin radius  41  using bonding means. Tail radius  43  is defined as the curvature needed to connect the termination of right edge  13  and left edge  14  to apex  36 . Distance from upper horizontal plane wall  11  to apex  36  is determined by the characteristics of board  1  by the riders. In this invention, the distance is approximately 26-30 cm. Tip  3  contains at least one tip extension channel  35  which is similar in shape and dimensions as channel  33  on core  5  and constitutes a continuation of channel  33  from core  5  to tip  3 . There will exist at least an equal number of tip extension channel  35  corresponding to top channel  33  and bottom channel  34  that exist on core  5 . Tip extension channel  35  will vary in length depending upon the particular performance characteristics required of board  1 . Tip extension channel  35  will vary from 50% to 90% of the distance from upper horizontal plane wall  11  to apex  36 . The longer the channel, the stiffer the tip of the board, which is better for turning but not for jumping or rail-riding. Percentage distance for tip extension channel  35  and tail extension channel  37  can be and usually is different due to performance characteristics required by the individual board. This invention focuses on the ability to rapidly change the performance of the board easily and without costly manufacturing changes. 
     FIG. 5  details the channel and stiffening members. There are at least two channel  33  each having the depth equivalent to the thickness of stiffening member  6 .  FIG. 5  details just the upper half of core  5  for clarity. Channel  33  is defined by channel sides  21  and channel bottom  22 . Stiffening member  6  is composed of a polymer based material with stiffening agents embedded therein, to produce a lightweight material with a high resistance of elastic deformation whereby the stiffening member will act like a piece of spring steel like material returning the member to it&#39;s original shape and size immediately after the action of deformation. Stiffening member  6  is placed directly onto channel bottom  22  and in proximal contact with channel sides  21 . Bonding means is used to secure stiffening member  6  to channel sides  21 . Channel  33  is milled or routed into the surface of core  5  as shown in  FIGS. 3 and 4 .  FIG. 3  describes a top side channel  33  which contains two channel sides  21  that are perpendicular to front side of core  17  and a lower side channel  34  also contains two channel sides  21  that are perpendicular to rear side of core  18 . In this embodiment of the invention that is detailed in  FIG. 3 , there is one top side channel  33  and one lower side channel  34 , the horizontal center of each channel being located along the vertical axis of core B-B. The length of channel side  21  can be equal for top side channel  33  and lower side channel  34  or the length channel side  21  may be different between top side channel  33  and lower side channel  34 , should the rider want to have a different rebound response between the flexation and compression of the stiffening members in the channels. For example, a rider who wishes to have board  1  that has a soft feel for trick riding, might wish to have a board that will bend more easily from the top of the board, but would wish for a stiffer bottom of the board to return or spring the board back to it&#39;s natural position. It is the characteristic of this invention to always have an equal number of said channel  33  inlaid on said front of core  17  and as there is channel  34  inlaid on said rear of core  18 .  FIG. 4  shows the addition of one top side channel  33  and one lower side channel  34  for a total of 2 on each side. In this embodiment of the invention, each front side channel is symmetrically placed about the vertical axis of core B-B. Each lower side channel is symmetrically placed about the vertical axis of core B-B directly opposite of the front side channel. It is the theory of this invention that the opposing forces supplied by the opposing stiffening members, one being in tension while the other is in compression, is what gives this invention the desired characteristics. This does not preclude the adaptation of variations in placement of the stiffening members in relation to one another, as that would be within the spirit of this invention. In this embodiment, said channel  33  in inlaid through the entire vertical distance of core  5  extending beyond said upper horizontal plane wall  11  and lower horizontal plane wall  12 . It is within the spirit of this invention to reduce to length of said channel  33  to lengths less than that of the vertical distance of said core  5 . 
   Core  5 , in combination with bondly attached tip  3 , tail  4  and perimeter edge  8  and along with bondly attached stiffening members  6 , constitutes body  2 . Body  2  is laminated to bottom layer  45  using bonding means. Bottom layer  45  is defined by upper bottom layer  49  and lower bottom layer  48  and bottom layer edge  50 , bottom layer  45  being made of Ultra-High Molecular Weight polyethylene. Circumscribed about bottom layer edge  50  is metal carving extension rail  46  which is bondly attached to edge  50  using bonding means. Rail  46  is a flexible metallic piece that when sharpened after installation creates an edge that is able to carve into the solid ice facilitating turning of board  1  in icy conditions. The interface between edge  50  and rail  46  differs in shape corresponding to the type of rail  46  used. In this invention,  FIGS. 3 and 4  describe a rail  46  which has an inclined angle, increasing the bonding surface area, which dictates the corresponding angle of edge  50 . Bottom layer edge  50  with the bonded rail  46  proscribes a profile in the horizontal plane that conforms to the profile of body  2 . Upper bottom layer  49 , along with rail  46  is covered with bonding strengthening material  47  and bonding means. Body  2  is placed on top of upper bottom layer and accompanying bonding materials. 
   Top layer  51  is profiled to match body  2 . Top Layer  51  is modified to accept mounting holes  19 . Body  2  is layered with bonding strengthening material  47  and bonding means and then top layer  51 . Board  1  is then subjected to pressure and heat to cure the bonding material and to shape the vertical profile of the board as shown in  FIG. 2 . After cure, vertical edge angle  52  is produced. Grinding means are used to shape a 45 degree angle emanating from the upper outer corner  53  of rail  46 , shaping the 45 degree angle in toward midpoint  31  along the entire outside surface of the rail  46 . After processing the angle  52 , board  1  is ready for final preparations for use. Bottom side of bottom layer  48  is roughed up using low grit sandpaper or similar device so that it is adapted to receive a waxing compound, which decreases friction between the board  1  and the snow. Upper layer of top layer  51  has applied thereupon multiple layers of liquid polymers, such as UV-stabilized acrylics, that will enhance the visual attributes of board  1  and will increase the surface hardness to prevent damage to the top layer of board  1 . 
   Bonding means used in the construction of board  1  incorporate those characteristics which will provide superior adhesion of unlike materials, can be strengthened using bi-directional or omni-directional reinforcing materials, such as glass, carbon, metallic or similar natural or manmade fibers and can withstand temperature deviations typical where board  1  will be manufactured and used. In this invention, epoxy  54  is used as the bonding agent along with glass fiber mesh material, described as bonding strengthening material  47 . The bonding material is subjected to heats up to 80 degrees Celsius and pressures up to 80 pounds per square inch during the curing process. The curing process is done in a press where the concave and convex shapes of the board are produced using opposing dies.