Abstract:
A water riding member having an upper surface upon which a person may ride and a lower surface immersible in water is described. The member has a length and a width, with the length being greater than the width, and the member extends lengthwise between first and second ends. The lower surface of the member has a medial portion between the two ends, and at least first and second ascending portions between the medial portion and the first end. The first ascending portion adjoins the medial portion, and the second ascending portion extends between the first ascending portion and the first end, with the second ascending portion being more steeply inclined than the first ascending portion.

Description:
FIELD OF THE INVENTION  
       [0001]     This invention relates to the field of members for riding on water.  
       BACKGROUND OF THE INVENTION  
       [0002]     In recent years one form of athletic recreation has involved riding a planing board while being towed through the water by a boat. Acquatic riding boards have been known for some time. One particular example of this kind of riding board involves a kind of planing member such as may popularly be termed a “wake board”. Typically, a rider stands on the wake board and is towed over a water course by a boat. A wake board may have bindings into which the rider may secure his or her feet, the better to control the ride of the board.  
         [0003]     A wake board may commonly operate in either of two regimes. First, when the wake board is running outside the cone of the wake (i.e., when the board is running outside the wavefront of the wash of the boat), it may tend to be running in substantially open water that may, in the case of a lake or slow moving river, tend to be relatively flat and calm as compared to the waves of the wake generated by the boat. In the second regime, the wake board may be operated in a direction have a substantial component of velocity transverse to the direction of travel of the tow boat, such that the wake board may tend to move in a direction to cross the wake.  
         [0004]     Part of the enjoyment of riding a wake board may be the opportunity to travel through, or over, the wake of the tow boat. Some tow boats are given extra stem ballast for the purpose of displacing more water, and hence in creating a larger wake. The wake board may have upwardly angled tips at both ends. The upward bend of the board is termed a rocker, and the amount of “rocker” may be measured at the ends of the board in inches of height from the center of the board when placed on a flat surface at rest. This is, inherently, a measure of camber, and may be 2 inches, or, taken as a ratio of the length of the board, about 3%. When the board is traveling outside the wake, more or less in the direction of travel of the tow boat, the board runs primarily on its medial, or middle, portion, with the end providing a lead-in planing face. A shallower rocker may tend to be associated with a board that may run faster in smooth water, but not necessarily jump as well as a steep rocker. If the rocker is too steep, it will tend not to run as quickly as a board with a shallower inclination.  
         [0005]     It may be that a wake board rider wishes to ride the board in such a manner as to cause it to jump out of the wake entirely, as when the rider does flips or twists in the air. The size or quality of the jump that may be made may tend to be a function of the height of the jump that can be achieved. One way to achieve a relatively high jump is to cause the wake board to gain speed in the comparatively flat water outside the wake, and then to cross the wake at a high angle of attack, with as much speed as can be managed, such that the board meets the wave front abruptly at high speed, tending to cause the board to angle upward and to jump.  
       SUMMARY OF THE INVENTION  
       [0006]     In an aspect of the invention there is a water riding member having an upper surface upon which a person may ride and a lower surface immersible in water. The member has a length and a width with the length being greater than the width. The member extends lengthwise between first and second ends. The lower surface has a medial portion between the two ends, and at least first and second ascending portions between the medial portion and the first end. The first ascending portion adjoins the medial portion, and the second ascending portion extends between the first ascending portion and the first end. The second ascending portion is more steeply inclined than the first ascending portion.  
         [0007]     The member may have third and fourth ascending portions between the medial portion and the second end. The third ascending portion adjoins the medial portion and the fourth ascending portion lies between the third ascending portion and the second end. The fourth ascending portion being more steeply inclined than said third ascending portion. The member may have a plane of symmetry extending cross-wise through the medial portion.  
         [0008]     The first ascending portion may have a mean angle of inclination in the range of 0.5 to 1.5 degrees of arc relative to the medial portion. Further, the second ascending portion may have a mean angle of inclination in the range of 1.0 to 4.0 degrees of arc relative to the medial portion. The first ascending portion may meet the medial portion on a radius of curvature of between 10 and 20 inches. Further, the second ascending portion may meet the first ascending portion on a radius of curvature of between 3 and 10 inches. The lower surface may have an overall camber of greater than 3 inches. Further, the lower surface may have an overall camber of greater than 5%. The second ascending portion may have a mean angle of inclination at least twice as great as the first ascending portion. Further, the second ascending portion may have a projected length in the range of 10 to 20% of the length of the member. The first ascending portion may have a first projected length, the second ascending portion may have a second projected length, and the first length may be greater than the second length. Further, the first ascending member may have a projected area of between 5 and 15% of the lower surface.  
         [0009]     The water riding member may have a binding mounted to the upper surface thereof. Further, the member may have at least one longitudinally running fin member between the medial portion and the second end thereof.  
         [0010]     In another aspect of the invention there is a wake board having a middle portion, first rocker portions extending lengthwise from said middle portion, and second rocker portions extending lengthwise from said first rocker portions, with the second rocker portions being more steeply rockered than the first rockered portions. The second rocker portions may adjoin the first rocker portions at a sharper transition than the first rocker portions adjoin the middle portion. Further, the first rocker portions may have an overall rocker height of between 4 and 7% of board length. Still further, the second rocker portions may have a rocker differential of between 50% and 75% of overall rocker height of the wake board. Yet still further, the second rocker portion may have a cross-wise camber of less than 20%.  
         [0011]     These and other aspects and features of the invention may be understood with reference to the detailed descriptions of the invention and the accompanying illustrations as set forth below. 
     
    
     BRIEF DESCRIPTION OF THE FIGURES  
       [0012]     The principles of the invention may better be understood with reference to the accompanying figures provided by way of illustration of an exemplary embodiment, or embodiments, incorporating principles and aspects of the present invention, and in which:  
         [0013]      FIG. 1  shows a plan view of a planing board as seen from above;  
         [0014]      FIG. 2  shows a cross-sectional view of the planing board of  FIG. 1  taken along the longitudinal centerline thereof, as indicated by section ‘ 2 - 2 ’ of  FIG. 1 ;  
         [0015]      FIG. 3  shows a plan view of the planing board of  FIG. 1  as seen from below;  
         [0016]      FIG. 4  shows an end view of the planing board of  FIG. 1 ;  
         [0017]      FIG. 5  shows a detail on partial section ‘ 5 - 5 ’ of  FIG. 1  showing an edge profile of the planing board of  FIG. 1 . 
     
    
     DETAILED DESCRIPTION  
       [0018]     The description that follows, and the embodiment or embodiments described therein, are provided by way of illustration of an example, or examples, of particular embodiments of the principles of the present invention. These examples are provided for the purposes of explanation, and not of limitation, of those principles and of the invention. In the description, like parts are marked throughout the specification and the drawings with the same respective reference numerals. The drawings are not necessarily to scale and in some instances proportions may have been exaggerated in order more clearly to depict certain features of the invention.  
         [0019]     In terms of general orientation and directional nomenclature, for the planing board of the various Figures, the longitudinal direction is defined as being coincident with the forward planing direction of the planing board when the rider is being towed behind a boat in the usual course of operation. It is coincident with the long axis of the planing board. It should be understood that while the planing board is customarily operated to travel in this direction, generally, it is expected that the board may operate with a significant amount of leeway. That is to say, as the rider is being towed, and the board is being operated in a direction having a significant component of velocity transverse to the direction of motion of the towing boat, the board may wish to cheat, or skid sideways, in the direction of the tow. This leeway may be resisted, for example, by the rider leaning away from the towing boat and angling the distant edge of the board more sharply into the water, and edging the lee edge out of the water, or by adding fins or keels to the underside of the planing board. In some instances this component of motion may be deliberately incurred, as when a rider “grinds” the wake, by riding the board with a very small, or zero, component of velocity in the lengthwise direction of the board, and the long axis of the board positioned substantially perpendicular to the direction of tension in the tow rope.  
         [0020]     The planing board may be considered to have a pitching motion, namely a rotational degree of freedom about an horizontal axis of rotation perpendicular to the long axis of the board, and may thereby be adjustable in terms of a fore and aft angle of trim, depending on where the rider locates his or her center of gravity relative to the center of lift of the board. Similarly, the planing board may have an angle of roll according to the angular position of the board relative to the long axis of the board, from a horizontal datum, and may have a yaw angle about a vertical axis in turning, relative to the direction of travel of the towing boat, for example. In general, there may be several different angles of attack relevant to the motion of the board. A first angle of attack is the angle of the weight bearing planing surface to the mean water surface (for this purpose, a horizontal, dead calm planar undisturbed water surface may be considered). A second angle of attack may be the angle of the long axis of the board to the direction of travel of the towing boat, as seen in plan view from above. A third angle of attack may be the roll angle of the planing surface. A fourth angle of attack may be defined between the long axis of the board (or, perhaps more rigorously, the velocity vector) of the board and the non-planar wave-front as seen from above. A fifth angle of attack may be defined between the leading portion of the board and the wave front.  
         [0021]     The term lateral, or laterally outboard, refers to a distance or orientation relative to the longitudinal centerline of the board, and may be taken from either lateral edge, in context. If the long axis of the planing board is considered the x-axis, lateral distances might be considered to be distances in the y-direction. The term “longitudinally inboard”, or “longitudinally outboard” is a distance taken relative to a mid-span lateral section of the board, or from wither tip of the board, in context, and might be considered to be distances in the x-direction. The terms upward and downward, or upper and lower, may tend to be taken in the vertical directioin assuming an at rest condition of the planing board, and might be considered to be motions or distances in the vertical or z-direction, but it will be understood that in motion there may be upward and downward components of direction and motion according to the pitch, roll and yaw of the planing board, and the terms must be understood in context.  
         [0022]     By way of general overview, then, a planing board, such as may be a “wake board” is indicated generally in the Figures as  20 . Planing board  20  has an upper surface  22  upon which a rider may ride, be it standing, kneeling, sitting, or prone as the case may be. Planing board  20  also has an undersurface, or generally downwardly facing surface  24  that may tend to contact, be partially immersed in and ride upon, the water surface. Undersurface  24  may have a central region  26 , adjacent fore-and-aft near to central regions  28 ,  30 , and more fore-and-aft distant regions  32 ,  34 . In flat water operation, such as may occur outside the wake, the angle of attack of the board to the water surface for planing may tend to be governed by the angle of the first portion of the surface, such as that of region  28 . In attacking the wave front of the wake, distant region  32  may meet the wave, and may tend to help cause the board to jump more abruptly. Board  20  having regions  26 ,  28 ,  30 ,  32 , and  34  may be referred to as a “five-stage rocker”.  
         [0023]     In greater detail, then, planing board  20  is shown in plan view from above in  FIG. 1 . Board  20  has a major, or long axis identified as CL Board, and a mid-span transverse axis identified as CL Transverse. Board  20  may have a central portion  33  of greatest width in the lateral direction, and adjoining fore-and-aft near portions  35  and  37 , and fore and aft distant, or end regions,  38 ,  40 . As seen from above, the lateral margins  42 ,  44  of board  20  may be gently curving, and may be symmetrical, yielding a planform shape that is narrowest in the middle, and most sharply narrowing at the ends. Each end may have protruding left and right hand horns,  46 ,  48  and a relieved or drawn back intermediate leading edge portion  50  (or, trailing edge portion  52 , as may be).  
         [0024]     Mounting fitting inserts  53  may be spaced along the board centerline in an array, and such an array may included several spaced groups  54 ,  56 ,  58  and  60  such as may be used to attach rider engagement fittings, such as may be in the nature of handles or foot bindings  57  (shown in  FIG. 2  only). In one embodiment board  20  may be made of laminated wood or molded composite material, and inserts  53  may be threaded inserts such as half inch deep ¼ inch diameter screw inserts.  
         [0025]     Lateral margins  42 ,  44 , may have a diminished profile, like a nosing, as shown in  FIG. 5 , in which the major portion of board  20  may have a continuous undersurface margin,  66 , yet have an upper relief, or downward bevel  68 , a lip  70 , and an edge chamfer  72  at the far end of lip  70  that meets undersurface margin  66  at its laterally most distant extremity. This lip may be greatest in depth at mid span, with a lip width of perhaps 1½″, or 5-10% of overall board width, and a lip depth of ⅜ to ¾″.  
         [0026]     Viewed from the end, as in  FIG. 4 , planing board  20  may be seen to have an undersurface that is not flat, but rather contoured. Near the leading portion there is a “center tunnel” region  74  that is gently relieved as compared to the adjacent longitudinally extending contours of the hull. The center tunnel is relatively shallow, with a maximum central depth of about ¼″ over a width between the hull contour high points of 8″. This central tunnel diminishes aftward toward the center of the board, at which the profile is as shown in  FIG. 4 , as identified at item  78 . Longitudinally extending features in the nature of an inboard, or first rail  80 , and a more laterally outboard second rail  82  may be molded into the underside of the board. First rail  80  may extend from the tip  84  of the board  20  along the hull, and, at mid section, may be 50-70% of the hull half width from the centerline to the laterally outboard margin. Second rail  82  may commence longitudinally inboard of tip  84 , and may lie laterally outboard of first rail  80  by a further 10-20% of the lateral half-width, with position of the second rail at the longitudinal mid-point of the board being between ⅔ and ⅘ of the lateral half width of the board away from the longitudinal centerline. Each of the first and second rails  80 ,  82  may tend to have a steep face, or flank, or shoulder  86  on the laterally inboard side, and a gentler slope on the laterally outboard side. The first and second rails may tend to function as keels, or fins, or edges, to discourage lateral skidding in the water, such as when the angle of motion of the board is sharply divergent from the direction of tension in the tow line. Furthermore, in some embodiments planing board  20 , may be provided with attachable keel or fin members  90  having a major axis running in the longitudinal direction and projecting outward from the undersurface, such as may be fixed in place by the engagement of threaded fasteners in threaded inserts  92 . There may be a general transverse curvature to the underside of the board, and this camber may be less than 20% of the width of the board more generally.  
         [0027]     Considering the longitudinal section of  FIG. 2 , in one embodiment the planing board  20  may have a central region. Central region  26  of undersurface  24  may adjoin the adjacent fore-and-aft near to central regions  28 ,  30  at a first rocker,  94 ,  96  that may have a first radius r 1 , such that regions  28 ,  30  may tend to be inclined upward relative to central region  26  at an angle α from the horizontal. In some embodiments α may lie in the range of 0.5 to 1.5 degrees. Radius r 1  may be relatively large, such as in the range of 10 inches to 20 inches, such that the transition from central region  26  to either of regions  28  or  30  may be very gentle. Fore-and-aft distant regions  32 ,  34  may adjoin regions  28  or  30 , as may be, at a second rocker  98 ,  100 , that may have a radius of curvature r 2 . In some embodiments r 2  may lie in the range of 3 to 10 inches. In some embodiments r 2  may be smaller, and perhaps much smaller, than r 1 , such that the transition from region  32  or  34  to  28  or  30 , as may be, may tend to be more abrupt than the transition from central region  26  to either region  28  or region  30 . The angle of the second rocker may be β such that the overall rocker angle of the end regions  32 ,  34  is φ from the horizontal, where φ is the sum of α plus β. φ may be in the range of 1.0 to 4.0 degrees. The total rocker height (or camber) as measured by elevation δ at the end of the board may be about 3 to 3¾ inches, or, in one embodiment, may be about 3⅓ inches. Alternatively, this may be expressed as a ratio of board length, being greater than about 5%, and, in one embodiment, about 6%, or somewhat more than 6%. It may be that the angle of inclination of the end portions is about, or slightly greater than, twice the angle of inclination of the near portion. That is, φ may be in the range of twice as great as α, and may be in the range of 5/3 to 12/5 times as large as α. Taking this in terms of rocker height, the ascending height differential of the first (or longitudinally inboard) rocker stage may be indicated as δ 1 , and the ascending height differential may be indicated as δ 2 . In one embodiment, δ 2  lies in the range of ⅘ to 3 times as large as δ 1 . In one embodiment, δ 1  and δ 2  are approximately equal (+/−20%).  
         [0028]     The length of the major axis of the board may vary. One factor related to the length of the board may be the weight of the intended user. Wake boards tend not to exceed about 60 to 65 inches in length. The maximum width of the board may tend to be about 18 inches, and may tend to be in the range of 12 to 18 inches, giving a length to width aspect ratio of about 3:1 to 5:1. In one embodiment, for example, the overall length may be about 56 inches, and the overall width may be about 17⅛″ in width, giving an aspect ratio of about 3.3:1.  
         [0029]     In one embodiment, the end regions  32 ,  34  of the undersurface of board  20  may be in the range of about 5 to 8 inches, and in one embodiment may be about 6½ inches (+/−½ inches) from the mid-point of the second rocker to the extreme tip of the board  20 . Alternatively, this may be expressed as a proportion of board length, and as a proportion of the shallower rocker length. That is, the end, or outer, or secondary rocker regions may have a length in the range of 8% to 20% of the board length, and, more narrowly, may be in the range of 10% to 15% of board length.  
         [0030]     In one embodiment, the inboard rocker regions  28 ,  30  may have a length in the range of 8 to 14 inches, and in one embodiment may be about 10½ inches (±1 inch). This may alternatively be expressed as a proportion of the overall length of the board  20 , and as a proportion of the length of the central region. For example, this region may be in the range of 12% to about 25% of the length of the board, and in one embodiment may be about 18% of the overall length of the board  20 . It may also be about 40% to 60% of the length of the central region  26 , and in one embodiment may be about 50% of the length of the central region  26 .  
         [0031]     Expressed differently yet again, the first ascending portion (such as  35  or  37 ) has a first projected length when viewed from above (or below), and the second ascending, or longitudinally outermost region (such as  38  or  40 ) has a second projected length, the first projected length being greater than the second projected length. The end rocker region may between about ½ and ¾ the length of the more longitudinally inboard rocker region, and in one embodiment may be about 60% of that length. Expressed still differently, the end rocker region  38  or  40  may be about ¼ to ⅖ of the length of the central region  33 , and in one embodiment may be about ⅓ of the length of the central region  33 .  
         [0032]     Expressed differently again, the most longitudinally outboard ascending portion (outboard of the second transition) may have a projected area of between about 5 and 15% of the projected area of the board  20  more generally.  
         [0033]     Various embodiments of the invention have now been described in detail. Since changes in, or additions to, the above-described embodiments may be made without departing from the nature, spirit or scope of the invention, the invention is not to be limited to those details but only by the appended claims.