fig1 depicts a prior art snowboard 100 designed to support the weight of a person and to enable motion on snow . the snowboard 100 contains at least one rigid element , wherein each rigid element has an upper surface ( not shown ), a lower surface 203 and one or more stiffened peripheral edges 101 ( a ) and ( b ). edges 101 ( a ) and ( b ) are located on left and right ends and , in some embodiments , may line the entire periphery of the system . edges 101 may be made of metal , alloy or any other suitable material . fig2 depicts a cross - sectional detail of the prior art snowboard of fig1 . the snowboard 100 has an upper surface 201 , a lower surface 203 , and a plurality of inner - layers 202 positioned between the upper surface 201 and lower surface 203 . edges 101 ( a ) and ( b ) are located on left and right ends , respectively . the lower surface 203 rests on the snow surface 204 . the downward force 206 is transferred through the system 100 and is balanced by the normal force 207 . upper surface 201 may be made of a glossy material , which serves as a medium to place graphic designs and also a uv protectant layer . lower surface 203 is typically a polyethylene and serves to reduce friction between the bottom of the system and the surface of travel . inner - layers 202 are made of hardwood placed in between layers of fiberglass . during operation , the snowboard 100 reaches a physical equilibrium state wherein the normal force 207 is equal to downward force 206 . the downward force 206 is determined , in part , by weight of the person on the snowboard 100 . the normal force 207 is distributed across the snow 204 on an area snow - to - board contact ( not shown ), which is determined , in part , by the width of snow - to - board contact 205 . for the prior art snowboard , the width of contact 205 remains constant even as the downward force 206 increases . fig3 depicts one embodiment of the snowboards described herein . specifically , fig3 depicts the lower surface of a snowboard having two rails separated by a recess . as shown , the snowboard 300 has an upper surface ( not shown ), a lower surface 305 , and one or more stiffened peripheral edges 304 ( a ) and ( b ), which are located on the left side and right side of the board , respectively . the peripheral edges 304 a and 304 b may form a single edge that surround the full periphery of the snowboard 300 . alternatively , in other embodiments , the edges 304 a and 304 b are separate edges on opposing longitudinal sides of the board . the lower surface 305 is continuous across the rails 301 and a recessed region 302 is arranged between the two rails 301 a and 301 b . in some embodiments , the board is laminated from a series of layers . typically the layers are wood , fiberglass and / or plastic , although other materials may be employed . these form the inner structure of the snowboard 300 and the inner layers ( not shown ) may be contoured in a shape that is similar to that of the lower surface 305 . in other embodiments , the inner layers ( not shown ) may be formed as a generally flat board and the rails 301 may be distinct components of the system that are attached separately to the lower surface 305 . in either case , the contour of the lower surface 305 may be similar . when in use , the system makes contact with the snow across the width of contact 306 . the dimensions of the snowboard 305 may vary , and typically will be between 90 - 170 cm in length as measured along a longitudinal axis extending along the length of the snow board 305 and between 20 - 30 cm in width as measured along a beam axis extending perpendicular to the longitudinal axis . the snowboard 305 has a generally hourglass shape , with curved lateral sides . typically , both the front end and the back end are curved upward to lift the ends of the snowboard off the surface of eh snow when the lower surface 305 is placed on the snow surface . other dimensions and shapes may be used without departing from the scope of the invention . fig4 depicts a cross - sectional detail of one embodiment of the snowboards described herein . according to one embodiment , system 300 has an upper surface 401 and a lower surface 305 . the lower surface 305 is continuous across the left rail 301 ( a ), the recessed region 302 and the right rail 301 ( b ). stiffened peripheral edge 304 ( a ) and edge 304 ( b ) are located at the left end and right ends , respectively . the downward force 406 is determined , in part , by weight of the person using the snowboard . the normal force 407 is distributed across the snow 404 on an area snow - to - board contact ( not shown ), which is determined , in part , by the width of snow - to - board contact 305 . as the downward force 406 increases , the width of contact 305 may also increase . likewise , as the downward force 406 decreases , the width of contact 305 may also decrease . in operation , the snowboards described herein adjust to varying snow conditions . in soft snow , the board sinks lower in the snow thereby increasing the width of contact 306 , which increases the normal force supporting the rider . in some soft snow conditions , the width of contact 306 may be large enough to include the entire width of the lower surface 305 , including the surface area of rails 301 and the recessed region 302 . in hard snow , the snowboard may rise toward the top of the surface and thereby decrease the area of contact 306 . in some hard snow conditions , the width of contact 306 may be small and may only include the peak of rails 301 ( a ) and ( b ) and not the surface of the recessed region 302 . for conditions in between the soft and hard , the amount of board - to - snow contact varies as needed , such that the downward force 406 is equal to the normal force 407 . turning to fig3 and 4 , the rails 301 run the length of the board . thus , the length of contact is not altered relative to the conventional design but the width of contact is decreased . by keeping the length of contact between the system and the snow constant , and by decreasing the width of contact between the system and the snow , the claimed system is able to attain higher speeds on snow than a conventional system . not to be bound by theory , but the snowboard having the two rails on the bottom surface , may be faster than a conventional snowboard . for the same physical principles that a pair of skis is faster than a standard snow board of the same length , and a catamaran is faster than a mono - hull boat of the same length . also depicted in fig4 , the twin rails 301 , may optionally not be rectangular in shape . instead , they may be angled upwards from the peak of the rail towards the periphery of the board . thus , the rails have a tapered surface that progresses from the interior of the board to the peripheral edge . this design feature raises the edges 304 up above the snow when the operator is initiating a turn while operating the snowboard . the raised edges allow the user to travel on width of contact 306 , without fear of unintentionally catching an edge . the result is increased comfort and , in part , safety and stability at high speeds . to initiate a carving turn , the rider must rotate the claimed system slightly further than the conventional system , ensuring that any edge - to - snow contact is intentional . fig5 depicts the snowboard of fig3 and 4 placed on a snow surface that is less firm and compact than the snow surface of fig4 . specifically , fig7 illustrates the snowboard 300 disposed over a snow surface 404 . a force 406 , typically the weight of the rider , pushes the snowboard 300 against the snow surface 404 . in the conditions represented by fig5 , the rails 301 ( a ) and 301 ( b ) press more deeply into the snow surface 404 than under the conditions depicted by fig4 . the areas of contact 306 ( c ) and 306 ( d ) of the rails 301 ( a ) and 301 ( b ) against the snow 404 are larger than the areas of contract 306 ( a ) and 306 ( b ) depicted in fig4 . in still less firm conditions , the snow 404 may contact the recessed region 302 and press against the snowboard 302 , at the rails 301 ( a ) and 301 ( b ) and at the recessed regions . fig6 depicts the lower surface 305 of the snowboard 300 and partially depicts binders and boots of a rider . as shown , the binders or bindings grip the rider &# 39 ; s boot and hold the boot on the upper surface of the snowboard 300 . the binding is arranged to position the heel of the boot 602 over one rail 301 b and a toe of the boot ( not shown ) over a different rail 301 a . to turn , the rider can lean forward or back to tip the snowboard 300 onto an edge 304 to carve a turn into the snow . fig7 depicts a cross - sectional detail of one embodiment of the claimed system designed to support and to enable motion for a person across a surface snow . the cross section of fig7 is one alternative to the cross section of fig4 . the lower surface 505 is continuous across the left rail 501 ( a ), the recessed region 502 , and the right rail 501 ( b ). edges 504 ( a ) and 504 ( b ) are located on the left side and right side of the board , respectively . rails 501 extend along the full length of the long axis of the board and are raised relative recessed region 502 . in an alternative embodiment rails 501 may only extend a portion of the length of the board . recessed region 502 rises up to a lofted running surface , allowing the amount of surface area in contact with snow 510 to vary based on , for example , the type of snow ( e . g ., hard snow , soft snow ), the weight of the user , the action performed by the user ( e . g ., slightly turning , sharply turning ), the stance of the user ( e . g ., squatting stance , standing up straight , leaning ). inner edges 503 ( a ) and 503 ( b ), which form a first edge located on the lower surface of the board rise up from rails 501 up to a flat region of the lower surface of the board followed by outer edges 504 ( a ) and 503 ( b ). outer edges 504 ( a ) and 504 ( b ) form a second edge located at a periphery of the upper surface . the first edge is thus at a different vertical location than the second edge , with the first edge being lower than the second edge as shown in fig7 . the first edge is also closer to the longitudinal axis than the second edge . the surface of the board located between the first or inner edge and the second or outer edge is concave , such this portion of the board surface is not in direct contact with the snow on the ground . and inner edges 503 ( a ) and 503 ( b ) form soft edges and are made of the same material as the bottom surface of the board ( e . g ., p - tex ). outer edges 503 ( a ) and 503 ( b ) form hard edges and are made of a stiff material ( e . g ., metal , rigid plastic ). the combination of the inner and outer edges allows the rider or user to control the amount of board - to - snow contact . when the outer hard edges 504 ( a ) and 504 ( b ) engage the snow , a full carve or stop can be obtained . having both the hard edges and the soft edges allow users to break contact between the snow and the hard edge which has a higher coefficient of friction , and to obtain contact between the snow and the soft edge , with a lower coefficient of friction . these inner or soft edges 503 allow users to ride without catching an edge and can be used to drift , ‘ butter ,’ turn and surf the snow . when a user leans the board beyond the soft edge , the outer hard edges 504 ( a ) and 504 ( b ) can once again engage the snow . for experienced users , the inner edges increase the ability to perform tricks , and flat spins without engaging the outer edges . the inner edges also benefit beginning snowboarders by allowing them to learn in a more intuitive and forgiving manner , resulting in less injuries . system 500 outperforms a conventional system in acceleration , maneuverability , and versatility based , in part , on the above features . inner edges 503 ( a ) and 503 ( b ) sit below and inside of outer edges 503 ( a ) and 503 ( b ). the “ soft ” inner edges 503 ( a ) and 503 ( b ) allow the rider to make small adjustments to direction without engaging the corresponding hard outer edge 503 ( a ) or 503 ( b ) with the snow . in addition , inner edges 503 ( a ) and 503 ( b ) allows the rider to drift their board without catching an edge ( i . e . without unintentionally engaging hard outer edge 503 ( a ) or 503 ( b )) which feels smooth to the user , much like the carve of a surfboard . when the rider chooses to turn sharply or come to a stop , they may engage the hard outer edge 503 ( a ) or 503 ( b ). when traveling on hard snow ( e . g ., hard - packed snow ) the board ( e . g ., systems 300 , 500 ) rides up on the rails thereby reducing the surface area in contact with the snow and thus reducing drag , allowing the rider to accelerate faster , and attaining higher maximum speeds . when traveling on soft snow ( e . g ., powder - like snow ), the board sinks down slightly thereby increasing the surface area in contact with the snow and generating greater support for the user . thus , the board enables a user to easily transition between different types of snow ( e . g ., hard snow , soft snow ) by rising or sinking in the snow . the board performs well both as a race board ( e . g ., for high acceleration and speed ) and in soft snow based , in part , on the variable surface area in contact with the snow . when used in a snowboard half - pipe , the board affords a user the ability to accelerate more quickly and reach high speeds faster than conventional systems , which yields improved performance ( e . g ., higher jumps , more time in the air after a jump to perform tricks ). the design of the edges ( e . g ., edges 304 , 503 , 504 , or the combination thereof ) provides a more forgiving surface when landing tricks , similar to the reverse camber design , but it does not sacrifice “ pop ” like reverse camber does . moreover , the increased acceleration rate allows a user to recover more quickly after an error than conventional systems . the shape of the board also allows the board to be stronger and thinner than conventional snowboards . strength and durability of the board are improved , while the board is thinner and thus lighter than standard adult snowboards . the cross - section of the board includes four sigmoid , or s - shape surfaces : between outer edge 504 ( a ) and inner edge 503 ( a ), between surface 501 ( a ) and recess ( 502 ), between recess ( 502 ) and surface 501 ( b ), and between inner edge 503 ( b ) and outer edge 504 ( b ). these s - shaped surfaces provide sidewalk that extend orthogonally , or substantially orthogonally , to the upper surface of the board . this provides the board with a shape that increases the board &# 39 ; s resistance to shear forces acting to crack or break the board along a line that is traverse to the sidewalk . additionally , these s - curve surfaces may act as springs , storing potential energy when the board is flexed , and causing the board to produce significant ‘ pop ’ quickly . advantageously , the shape of the board eliminates chatter at high speeds . the inner edges 503 ( a ) and 503 ( b ) are offset from the hard edges 504 ( a ) and 504 ( b ), respectively . inner edges 503 ( a ) and 503 ( b ) may be between 8 and 11 mm closer to the board &# 39 ; s longitudinal axis than outer edges 504 ( a ) and 504 ( b ). the thickness of the board varies both transversely , as shown in the cross - section of fig7 , and longitudinally . in the longitudinal direction the board is thickest where the rider &# 39 ; s feet are located , and gradually thinner both to the left and to the right of the rider &# 39 ; s feet , i . e . closer to the ends of the board . accordingly , as shown in fig7 the thickness varies between 1 . 5 mm and 6 . 5 mm at the longitudinal axis , and the thickness of the rails 501 ( a ) and 501 ( b ) varies between 3 and 8 mm . empirical research has shown that a board with the features described above can accelerate up to 25 % faster than a standard board . empirical research has also shown that this board is 1 . 5 to 2 times stronger than a standard board , and the risk of breakage is significantly reduced . those skilled in the art will know or be able to ascertain using no more than routine experimentation , many equivalents to the embodiments and practices described herein . for example , the claimed system and the knowledge disclosed herein may be utilized to modify or to create systems designed to carry a person or objects across a surface of water , sand , or other materials . more specific example applications may include , among other things , snowboards , water skis , wake boards , kayaks , winder surfers , or paddle boards . the manufacture of the disclosed snow board may be accomplished employing methods that are familiar to those skilled in the art . for example , the layers of the disclosed snowboard may be constructed , in part , using a mold , which is designed having a shape consistent with the contours of the claimed system . other example manufacturing methods may have an expandable bladder , placed in an enclosure with the layers of the system and the mold . as the bladder expands , it applies pressure to the layers , forcing them against the mold and imparting the contours of the mold . in some embodiments of a manufacturing system struts , made of wood , are used to help distribute the pressure from the bladder to the layers of the system . in other embodiments of a manufacturing method , the layers of the system may be pressed together using a pneumatic press , which applies pressure to the layers , forcing them against the opposing surface of the press and imparting the contours of the claimed system . in other embodiments , the layers of the system are attached to one another using adhesives , epoxy , or other suitable attachment systems . those skilled in the art will know or be able to ascertain using no more than routine experimentation , many equivalents to the embodiments and practices described herein . for example , the claimed system and the knowledge disclosed herein may be utilized to modify or to create systems designed to carry a person or objects across a surface of water , sand , or other materials . more specific example applications may include , among other things , snowboards , water skis , wake boards , kayaks , winder surfers , or paddle boards . accordingly , it will be understood that the invention is not to be limited to the embodiments disclosed herein , but is to be understood from the following claims , which are to be interpreted as broadly as allowed under the law .
the disclosure herein is directed toward systems and methods for supporting a person and enabling motion of a person across a surface of snow while satisfying the countervailing requirements of increasing surface area for weight - carrying capacity on soft snow and reducing the opposing forces , like for example drag and friction , in hard snow . more specifically , a snowboard described herein includes an inner edge and an outer edge , and allows the rider to control the amount of board - to - snow contact . this snowboard is configured to improve rider support , increase speed and enhance safety performance .