Abstract:
A balance trainer has a board with a notional nose and tail, a rolling fulcrum for the board to perch on, and at least one hold-down link extending between one end anchored to ground and another end secured to the notional tail of the board. The board as perched on the rolling fulcrum would—in the absence constraint—afford free tipping tilt along at least one axis. However, the hold-down link supplies constraint such that free leash is given to the to the notional tail of the board so long as the hold-down link is slack. But when the nose of the board dives furthest against the hold-down link, the board either deadens in a fixed pitch angle against the tautened hold-down link, or else can be swung laterally a bit, in sort of a monkey-swing fashion in inverse, giving a training experience like riding on a long surf board.

Description:
CROSS-REFERENCE TO RELATED APPLICATION(S) 
   This application is a continuation of U.S. patent application Ser. No. 11/986,787, filed Nov. 26, 2007 now abandoned, which claims the benefit of U.S. Provisional Application No. 60/879,924, filed Jan. 11, 2007; and which is also a continuation-in-part of U.S. patent application Ser. No. 11/251,313, filed Oct. 14, 2005, U.S. Pat. No. 7,300,392, which claims the benefit of U.S. Provisional Application No. 60/618,896, filed Oct. 14, 2004. All the forgoing specifications are incorporated herein by this reference. 

   BACKGROUND AND SUMMARY OF THE INVENTION 
   The invention relates to balance boards and, more particularly, to balance boards in connection with people involved in balance and fitness training like surfing, wind-surfing, wake boarding or skate boarding. 
   The prior art is replete with balance boards for balancing on balls—or in more difficult terminology, spherical rolling fulcrums—with underside bearing surfaces formed as domes. Eg., U.S. Pat. No. 4,191,371-Armer, Jr. An issue with these prior art systems is that when a trainee causes the domed bearing-surface to climb up on the ball on the dome&#39;s periphery, gravity always wants to pull the board down such that the ball finds the high center. 
   It is an object of the invention to provide balance training apparatus including a balance board which overcome these and other shortcomings with the prior art. 
   It is a further object of the invention to provide the bearing surface of the balance board (ie., the surface which bears against the spherical rolling fulcrums) with frames to frame in the area in which the spherical rolling fulcrums can operate. 
   It is an additional object of the invention to provide a progressive series of such frames to make progressively smaller the framed-in area under the board in which the training ball can operate. 
   It is another object of the invention to combine two boards in an over and under arrangement, as separated by a spherical rolling fulcrum and tethered in part by flexible straps, to enable the trainee to tip the board on which he or she is standing and thereby more naturally simulate a real experience on a wave. 
   It is an additional object of the invention to provide an upper deck board which has a more concave shape and is separated from the receiving board by lifts to provide greater toe and heel contact for the user and a hand hold space which helps in simulating a skate board. 
   A number of additional features and objects will be apparent in connection with the following discussion of preferred embodiments and examples. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     There are shown in the drawings certain exemplary embodiments of the invention as presently preferred. It should be understood that the invention is not limited to the embodiments disclosed as examples, and is capable of variation within the scope of the skills of a person having ordinary skill in the art to which the invention pertains. In the drawings, 
       FIG. 1  is a perspective view of a balance training apparatus in accordance with the invention, wherein a trainee is illustrated to show a manner of use; 
       FIG. 2  is an enlarged scale perspective view thereof; 
       FIG. 3  is an exploded bottom perspective view thereof, except including a progressive series of difficulty-changing training balls therefor (ie., spherical rolling fulcrums); 
       FIG. 4  is an enlarged-scale bottom plan view of the board thereof; 
       FIG. 5  is a section view taken along offset line V-V in  FIG. 4 ; 
       FIG. 6  is a reduced-scale bottom perspective view the  FIGS. 4 and 5  version of the board combined with one selected training ball; 
       FIG. 7  is a bottom perspective view comparable to  FIG. 6  except showing the size of the crown cavity for  FIGS. 4 and 5  version of the board reduced in size by two progressive steps; 
       FIG. 8  is a perspective view comparable to  FIG. 2  except of an alternate embodiment of a board in accordance with the invention; 
       FIG. 9  is an enlarged-scale bottom plan view of FIG.  8 &#39;s alternate embodiment of the board; 
       FIG. 10  is perspective view of an alternate embodiment of balance training apparatus in accordance with the invention, wherein two boards are combined in an over and under arrangement, as separated by a training ball and tethered in part by flexible straps, to enable the trainee to tip the board on which he or she is standing and thereby more naturally simulate a real experience on a wave; 
       FIG. 11  is a top plan view thereof; 
       FIG. 12  is a side elevational view thereof; 
       FIG. 13  is an enlarged-scale partial sectional view, with portions broken away, and as taken along line XIII-XIII in  FIG. 12 ; 
       FIG. 14  is a fragmentary detail view taken from the left of  FIG. 13 , wherein the upper board tips up to the right in the view and the lower board tips down to the right in the view; 
       FIG. 15  is a bottom plan view comparable to  FIG. 4  except showing an alternate arrangement of the sub-frame therefor; 
       FIG. 16  is a bottom plan view comparable to  FIGS. 4 and 15  except showing another arrangement of the sub-frame; 
       FIG. 17  is a bottom plan view comparable to  FIGS. 4 ,  15  and  16  except showing an additional arrangement of the sub-frame; 
       FIG. 18  is a side elevational view of  FIG. 19 ; 
       FIG. 19  is a bottom plan view comparable to  FIGS. 4 ,  15 ,  16  and  17  except showing a further arrangement of the sub-frame; and, 
       FIG. 20  is a side elevational view of an additional embodiment of a balance training apparatus in accordance with the invention. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     FIG. 1  shows a first embodiment of balance training apparatus  20  in accordance with the invention, with a trainee shown adopting a stance thereon for one non-limiting preferred manner of use thereof. 
     FIG. 3  shows that such balance training apparatus  20  in accordance with the invention comprises a balance board  22  which includes a platform  25  and progressive series of cylindrical sub-frames  32 - 34 . Said balance training apparatus  20  further comprises a progressive series of training balls  42 - 44  or, again, spherical rolling fulcrums. 
   The platform  25  that has an upper footstep surface  52  and a lower bearing surface  54  surrounded by an edge border to be described more particularly below. The progressive series of sub-frames  32 - 34  have a progressive series of cylindrical inside diameters such that a major sub-frame  32  has the largest, a minor sub-frame  34  has the smallest, and an intermediate sub-frame  33  has of course an intermediate cylindrical inside diameter. 
     FIG. 4  shows that the progressive series of sub-frames  32 - 34  preferably nest inside each other as shown with respect to a common center. At least all but the major sub-frame  32  are removable. That is, each sub-frame  32 ,  33  or  34  encircles its own framed-in area of the bearing surface  54  and thereby defines its own framed-in crown cavity. For example, the major sub-frame  32  encircles a major framed-in area of the bearing surface  54  and thereby defines a major framed-in crown-cavity. Hence the minor sub-frame  34  must be removed to expose all of the area of the bearing surface  54  framed-in by the intermediate sub-frame  33 . Correspondingly, both the minor and intermediate sub-frames  34  and  33  must be removed to expose all of the area of the bearing surface  54  framed-in by the major sub-frame  32 . 
   One non-limiting example of the invention has the platform  25  constructed of plywood about one-and-one quarter inches (˜3 cm) thick. Likewise the sub-frames  32 - 34  are constructed of plywood, to a thickness of about one-and-three quarters inches (˜4½ cm) thick.  FIG. 5  shows that all the sub-frames  32 - 34  removably attached by bolts extending up through the sub-frames  32 - 34  to tighten in nut inserts commonly used widely in furniture construction. 
     FIG. 6  shows the balance board  22  affixed with the major sub-frame  32  only and disposed on top of the one the spherical rolling fulcrums (eg.,  42 ).  FIG. 7  shows the balance board  22  affixed with the minor sub-frame  34 , as well as the intermediate and major sub-frames  33  and  32 , which in this case add little except mass to the dynamics of the balance training apparatus  20 . However,  FIGS. 6 and 7  show very different interaction between the major and minor sub-frames  32  and  34  with this selected training ball  42  (ie., spherical rolling fulcrum). 
   The following table provides a non-limiting example of relative dimensions for diameters (ie., O.D. stands for outside diameter, I.D. for inside diameter) that are preferred for the progressive series of sub-frames  32 - 34  and training balls  42 - 44 . 
                                   TABLE               FRAMES   O.D.   I.D.   BALLS   O.D.                   major   15½″ ( ~ 40 cm)   12½″ ( ~ 32 cm)   major   7″ ( ~ 18 cm)       inter-   12½″ ( ~ 32 cm)   9½″ ( ~ 24 cm)   inter-   5″ ( ~ 13 cm)       mediate           mediate           minor   9½″ ( ~ 24 cm)   6½″ ( ~ 16 cm)   minor   2½″ ( ~ 6 cm)                    
It can be observed that the largest training ball  42  is larger than the inside diameter defined by the smallest sub-frame  34 .
 
   In use, the selected spherical rolling fulcrum  42 ,  43  or  44  is crowned by the platform  25  within the selected sub-frame  32 ,  33  or  34  such that the spherical rolling fulcrum  42 ,  43  or  44  is sandwiched between a ground surface and platform  25 . Moreover, the spherical rolling fulcrum  42 ,  43  or  44  is hemmed-in by the selected sub-frame  32 ,  33  or  34  in order to corresponding confine its interaction with only the area of the bearing surface  54  framed-in by that selected sub-frame  32 ,  33  or  34  (or the respective crown-cavity thereof). 
   It is a generally true rule that the spherical rolling fulcrum  42 ,  43  or  44  is free to roll sandwiched between the platform  25  and ground surface unless stopped against any portion of the selected sub-frame  32 ,  33  or  34 . However,  FIGS. 6 and 7  show very different results from application of the foregoing rule. That is, in  FIG. 7 , the spherical rolling fulcrum  42  has an outside diameter greater than the minor sub-frame  34 &#39;s cylindrical inside diameter. Indeed, the minor sub-frame  34  and spherical rolling fulcrum  42  are cooperatively sized such that the minor sub-frame  34  frictionally grips a circle on the spherical rolling fulcrum  42 . This frictional gripping stops virtually any possibility of the spherical rolling fulcrum  42  from being able to roll in the minor framed-in area of the bearing surface  54 . Accordingly, this limits the platform  25 &#39;s movement relative to the ground surface to teetering and twirling. Teetering is rocking about a horizontal axis as achieved by pumping legs up and down in alternation of each other (with balance of course). Twirling is spinning about a vertical axis and is more likely achieved by twist in the torso. 
   Preferably, at least the major and intermediate spherical rolling fulcrums  42  and  43  are inflatable. More preferential still is to utilize novelty soccer or basketballs which are commonly available in many reduced sizes compared to regulation balls used in professional sports. It is an option to provide the balance training apparatus  20  in accordance with the invention with a manual air pump as well (not shown), with an inflation needle. Inflation of the training balls  42  and  43  is achieved with the air pump, whereas deflation is best practiced by disconnecting the needle and leaking out inflated air until the training ball  42  or  43  reaches the desired level of inflation. 
   Consequently, is an aspect of the invention that the major training ball  42  is selectively inflatable to a selected inflation pressure in order to obtain an optimized frictional grip between the minor sub-frame  34  and major training ball  42  (ie., major spherical rolling fulcrum). 
   To turn now to  FIG. 6 , here the major sub-frame  32  is expansively larger than the selected spherical rolling fulcrum  42 &#39;s outside diameter. Therefore, utilizing the major sub-frame  32  to the exclusion of the progressively smaller sub-frames  33  or  34  frees up the chances of relative rolling between the spherical rolling fulcrum  42  and major framed-in area of the bearing surface  54 , unless and until stopped by abutment against the major sub-frame  32 . In consequence, this arrangement of things allows the platform  25 &#39;s possible movement relative the to the ground to include translation as well as teetering and twirling. Translation is linear displacement along the ground (eg., from one spot to another, but not necessarily in a straight line). It may be readily reckoned that there is only a limited extent of linear displacement possible before the training ball  42  limits out against the major sub-frame  32 . Nevertheless, the training dynamic between the  FIG. 7  arrangement of things and the  FIG. 6  one is readily apparent. 
   The foregoing is highly desirable because this variability in the balance training apparatus  20  in accordance with the invention provides trainees with an indeterminate number of levels of training difficulty. 
   To turn to matters of the platform  25 &#39;s planform, and its edge border, the drawings show that the platform  25  has spaced cantilevered shoulders  60  projecting oppositely beyond over not only the minor sub-frame  34  but also the major sub-frame  32 . The continuations of the upper footstep surface  52  over to the shoulders  60  are fashioned with grip areas which are intended to encourage trainees to adopt a preferred stance on the platform  25 . Their feet preferably would be planted on the grip areas, with legs straddling the center of the sub-frames  32 - 34  (eg., the center of geometry of the platform  25  too).  FIG. 1  provides illustration of one such preferred stance and/or manner of training. 
   Generally each shoulder  60  extends in a plane generally between spaced parallel sides  62  and a transverse end  64 . However, the each shoulder  60  further comprises a pair of spaced diagonal edges  66 , and these originate in the parallel sides  62  of the respective shoulder  60  and terminate in the transverse end  64 . That way, these diagonal edges  66  eliminate sharp corners between the sides  62  and transverse end  64 . Accordingly, trainees more safely ground out the platform  25  on the diagonal edges  66  on the ground surface than if there were sharp corners. Grounding out is considered a wipe out because if such were done in reality on a wake board, surf board, snow board or whatever, surely then the rider would have wiped out (fallen, wrecked). Conversely, stepping off the grip areas and tromping on the flanked center in order to keep one&#39;s balance is, while perhaps bad form, not always going to correspond with wiping out. In reality, perhaps such would have corresponded to some chance of recovery. 
     FIGS. 8 and 9  show an alternate embodiment of the platform  125  in accordance with the invention, one with narrower shoulders  60  and more simulative of a surfing experience on a surf board or the like. 
   Other matters in view of this description of the invention include a remark on what has been described here for convenience in this written description as the ground surface. The ground surface can be any base support surface (planar or not, flat or not), including without limitation outdoor pavement, indoor tiled or carpeted or hard/soft wood floors, beach-side boardwalks, or perhaps even compacted beach sand. However, the ground surface can greatly affect the training dynamics of the balance training apparatus  20  in accordance with the invention. Needless to say, smooth pavement will provide a harder experience than shag carpet, which is where perhaps novices should start. 
   Whereas preferably the major and intermediate training balls  42  and  43  are inflatable, it is correspondingly preferred if the minor training ball  44  has a solid construction of a suitable polymeric or resinous material. 
   Wherein preferably the framed-in areas of the bearing surface  54  are flat, because the training experience is totally different, the invention does not exclude a domed bearing surface (this is not illustrated). Since it is preferred to make the bearing surface  54  flat, it is a significant aspect of the invention that trainees can train first with a minor sub-frame  34  and a frictionally-captured major-size training ball  42  before progressively advancing to more difficult combinations. In the more difficult combinations of, say for example, the major sub-frame  32  and the major training ball  42  inflated hard, when a wipe out is about to occur at least the training ball  42  (or  43  and/or  44  for that matter) stops against the major sub-frame  32  to more safely terminate the failed training experience than if the sub-frame  32  (or  33  and/or  34  for that matter) were not there at all. 
     FIGS. 10 through 12  show an alternate embodiment of balance training apparatus  120  in accordance with the invention. In  FIGS. 10 through 12 , a board  22  having a platform (or deck)  25  in accordance with  FIGS. 1 through 7  is not upright but inverted, with the footstep surface  52  facing down and the bearing surface  54  facing up. A second board  122  having a platform (or deck)  125  in accordance with  FIGS. 8 &amp; 9  is situated upright, with the bearing surface  154  thereof facing down of course and footstep surface  152  facing up. Hence the two platforms or decks  25  and  125  are combined in an over and under arrangement  120 . 
   The under deck  25  rests footstep surface  52  down on the base support surface, stationary. The over deck  125  is propped up in spaced balanced on the spherical rolling fulcrum (eg., training ball)  43 , and is tethered as shown by way of non-limiting example in the drawings by two straps  172  along the left and right rail edges and a third strap  172  on the tail. Hence the nose or tip edge is cantilevered in space as shown. 
   Briefly, this over and under arrangement  120  enables the trainee to tip the platform  125  on which he or she is standing and thereby more naturally simulate a real experience on a wave. Perhaps the simulated experience is not so much like the steep downward angle of a surf board sliding nose first down the trough of a wave but instead the less steep downward angle of a surfer angling along the mid-face of a wave, staying just ahead of the whitewater. Alternatively, the training experience might be like that of a surfer riding on a long surf board, on which it is possible to have a stance at the nose of the board, even so much so as to be able to dangle toes over the nose. By way of background, long surf boards had their heyday in the 1960&#39;s (but whose popularity is again on the upswing after an extended downswing), and typically measure about nine feet (˜2¾ m) long or longer. In contrast, the more modern short surf boards measure in the range of between about six and eight feet (˜1⅞ and ˜2½ m) long. 
   Again, the under deck  25 &#39;s frame  32  faces up and forms a shallow base cavity for containing the training ball  43 . In contrast, the over deck  125 &#39;s counterpart frame  32  faces down and forms a low crown cavity for containing the training ball  43 . One selected training ball  43  is sandwiched (trapped) between these two frames  32  and  32 . This configuration allows a truly adventurous trainee to balance himself on the cantilevered nose end of the over deck  125 . Presumably, this training experience simulates something like surfing on a long board, as when a surfer tiptoes to the very nose end and “hangs ten.” 
     FIGS. 10 through 14  show the arrangement of the straps  172  between the over and under decks  125  and  25 . The over and under deck  125  and  25  are connected by two side straps  172  and a tail strap  172 . There is no strap on the nose end of the decks  125  and  25 . The straps  172  are preferably connected to the decks  125  and  25  by a quick connect/disconnect arrangement. The drawings show the straps  125  connected to the under deck  25  by metal footman loops  174  nested inside a corresponding recess therefor in the under deck  25 . Alternatively, the straps  172  connect at their opposite extremes by threading through a corresponding slot in a buckle  176  which has a flat hook  178 . The over deck  125  has a corresponding set of three apertured strike plates  182  in which the three flat hooks  178  of the three buckles  176  latch into as shown by  FIGS. 13 and 14 . The purpose of the straps  172  and their placement is that, when the trainee is standing on the balance board  120  and leans the over deck  125  downward where his or her toes are near the nose end of the over deck  125 , the straps  172  will provide some positional stability to the over deck  125  to stimulate the experience of a surf board on a wave. However, the trainee must still possess a talented amount of balance to prevent from the over deck  125  from twirling out under him or her clockwise or counterclockwise. The foregoing arrangement  120  of things allows the trainee to hold a position that is most used when surfing to strengthen those particular muscles used. 
     FIG. 12  shows that when the nose of the over deck  125  is pushed down on the nose end (which is absent a strap), the tail end will lift up, and the tail strap  172  (if properly adjusted) will tighten and keep the over deck  125  from tipping down on its nose. 
     FIG. 13  shows that the straps  172  are preferably adjustable in length by way of either strap adjusters or slides  184 . The straps  172  can therefore be lengthened or shortened, according to the skill of the trainee. The looser the straps  172 , the more the over deck  125  will be free to flop about which makes training more difficult. The tighter the straps  172 , the less the over deck  125  will can flop about, making training a bit easier. The trainee may start out with the straps  172  tighter and work his or her way to the straps  172  being looser, the more skilled he or she becomes. 
     FIG. 14  better shows the buckle  176  that has the flat hook  178  which secures to the strike plate  182  in the over deck  125 .  FIG. 14  also shows better one of the metal footman loops  174  nested inside a recess therefor in the under deck  25 . The strike plate  182  is secured to the over deck  125  by screw fasteners or the like. The over deck  125  has a sunken-in well recessed into it underneath the aperture in the strike plate  182  to allow insertion of the flat hook  178  therein. To connect the flat hook  178 , a user inserts the flat hook  178  into the aperture of the strike plate  182 . This will firmly hold the buckle  176  and its attached strap  172  to the over deck  125 , and allows the strap  172  to be readily disconnected as well. The strap  172  stays with the buckle  176  and when wanted, the trainee simply attaches the flat hook  178  to the strike plate  182  on the over deck  125 . This provides for quick changeover from and over and under arrangement  120  as shown by  FIGS. 10 through 14  to either of the alternative arrangements  20  as shown by either  FIGS. 1 through 7  or  FIGS. 8 and 9 . 
     FIG. 15  is comparable to  FIG. 4  except showing the platform  25  provided with an alternate arrangement of a sub-frame, indicated here by reference numeral  232 . 
   As mentioned previously, one non-limiting example of construction of the invention has the platform  25  constructed of plywood about one-and-one quarter inches (˜3 cm) thick. Conversely to what was mentioned previously, it would be preferred without limitation to have the option of constructing the sub-frame  232  not out of plywood but out of any beam-style dimensional construction material, such as and without limitation wooden two-by-two&#39;s (ie., square stock material measuring about one-and-three quarters inches or ˜4½ cm on a side). 
   That way, the sub-frame  232  is more readily fabricated with less waste left-over material in a series of straight courses. As  FIG. 15  shows, the sub-frame  232  is constructed out of a spaced pair of longitudinally-extending side beams spaced apart by a spaced pair of laterally-extending cross beams to enclose a rectangular bearing surface  254 . 
   Despite that the previous views depict sub-frames enclosing a circular bearing surface area  54  or  154 , this is a design preference only and production considerations may weigh in favor of non-circular geometries so that the sub-frame (eg.,  254 ) may be constructed out of beam-style dimensional construction material. Preferably the beams of the sub-frame are attached by fasteners or bolts that tighten into nut inserts as commonly used widely in furniture construction, which are sunk into the platform  25 . 
   Persons ordinarily skilled in art would readily recognize that other geometries can be readily adopted and still be constructed of beam-style dimensional construction material, including as shown by way of a non-limiting example in  FIG. 16 . 
   To turn to  FIG. 16 , it shows the platform  25  provided with another arrangement of a sub-frame, indicated here by reference numeral  231 .  FIG. 16  shows the sub-frame  231  is constructed out of six similarly-shaped beams to enclose a six-sided or hexagonal bearing surface  251 . 
     FIG. 17  shows the platform  25  provided with an additional arrangement of a sub-frame, indicated here by reference numeral  304 .  FIG. 17  shows the sub-frame  304  is constructed out of two elongated beams parallel to each other bearing surface  302 . 
     FIGS. 18 and 19  shows the platform  25  provided with a further arrangement of a sub-frame, indicated here by reference numeral  306 .  FIGS. 18 and 19  show the sub-frame  306  is constructed out of two crescent shaped beams facing each other bearing surface  308 . 
     FIG. 20  shows an additional embodiment of a balance training apparatus  310  in accordance with the invention. An upper deck  312  is mounted on mounting blocks  314  mounted on platform  25 , which has sub-frame  32  and rolling fulcrum  42 . The upper deck  312  is shaped to simulate a skate board deck. 
   The upper deck provides greater toe and heel contact for the user which better simulated skateboarding. It might also create a quicker response time during the balancing activity. 
   The invention having been disclosed in connection with the foregoing variations and examples, additional variations will now be apparent to persons skilled in the art. The invention is not intended to be limited to the variations specifically mentioned, and accordingly reference should be made to the appended claims rather than the foregoing discussion of preferred examples, to assess the scope of the invention in which exclusive rights are claimed.