fig1 is a three dimensional view of an overhead - suspended circular martial arts ring 10 a as an illustrative first embodiment of the present invention for typically indoor environments where overhead structure is available for net suspension . a circular concave platform 12 is configured with a concave upper surface of which a substantially flat circular central region 14 is surrounded concentrically by an inclined border region 16 . the platform 12 rests on a flat floor or ground region 18 . attached to the outer edges of platform 12 and extending upwardly therefrom , an inverted - cone - shaped constraint net 20 converges to an upper ring 22 to which net 20 is attached . ring 22 is typically suspended from building structure above , by several support members 24 which may be rods , chains , cables , tubing , electrical conduit or any tensile members suitable for this function . members 24 are preferably made somewhat elastic longitudinally at least in part utilizing bungee cords , coil springs or other stretchable items , so as to keep net 20 moderately taut with stress shared between the net 20 and the support members 24 so as to allow the overall structure to absorb and recover from any impact on net 20 . as indicated above , the net 20 is made from tough thin filament netting material , e . g . equivalent to nylon netting as utilized in golf driving ranges and tennis courts . the net 20 is typically configured to provide a closable flap or door to allow entry and exit of combatants . the top surface area of platform 12 may be covered with padding , at least in the flat region 14 . padding may be provided in the inclined border region 16 in the form of individual mats in the shape of the sectors indicated . fig2 , a central cross - sectional elevation of the general outline of a martial arts ring 10 of the present invention , e . g . the embodiment in fig1 , shows two combatants performing within the ring on platform 12 . combatant 26 , located on the inclined region 16 , benefits from the effect of earth &# 39 ; s gravity at his relatively elevated location on the inclined region 16 and thus gains a competitive advantage over combatant 28 located on the lower flat region 14 . typically from this situation , the fight activity will strongly tend to move back to the flat region 14 as combatant 26 exploits his advantage and fights his way forwardly , down and off the inclined region 16 . combatant 26 , as shown , is located close to the constraint net 20 ; if he moves back and comes into contact with the net 20 , he will first feel the net against his head and shoulders , and thus will be further motivated him to press his gravitational advantage and move the action forward and back down onto the flat region 14 . the net 20 is made strong enough to prevent a combatant from being ejected bodily , but is intended to respond to attempted bodily ejection or “ tangling ” by stretching resiliently and acting in the elastic manner of a catapult to return a combatant &# 39 ; s body back into the ring safely . furthermore , the resilient constraint net 20 of the present invention , configured full height and shaped as shown , totally prevents bodily ejection that occurs frequently in conventional half - height rope - constrained rings , and greatly reduces risk of combatant injury compared to known sports enclosures of the type that utilize constraints made from strong steel link fencing that are typically made full height and perpendicular to the floor . fig3 is a top view of the first embodiment overhead - suspended circular martial arts ring 10 a of fig1 showing ring 22 and the four overhead suspension members 24 . the perimeter of the flat portion 14 of the top platform surface is shown as a dashed outline , surrounded by the inclined portion . typically the platform is sized to have about twice the diameter of the flat region 14 , thus the total platform area is about four times that of the flat region 14 . fig4 is a three - dimensional view of a stand - alone circular embodiment of a martial arts ring 10 b in accordance with the present invention . the constraint net 20 and platform 12 are essentially the same as in fig1 , however , instead of overhead suspension which may not be practicable in some locations , e . g . in outdoor venues , net 20 is supported by a set of arched support members 30 attached to the outer edge of platform by brackets 30 a or equivalent fasteners and extending upwardly to attachment points on upper ring 22 as shown . preferably support members 30 are made of material that is sufficiently resilient to keep the net 20 moderately taut with the ability to absorb and recover from practically any impact that might occur . members 30 and / or ring 22 could be made hollow to serve as electrical conduits . fig5 is a top view of the stand - alone version of the martial arts ring 10 b of fig4 showing four support members 30 located in a radial array , attached to upper ring 22 supporting net 20 and to the outer edge of the platform by brackets 30 a or other fasteners . the circular shape of platform 12 ( fig1 , 2 , 4 ) and upper ring 22 shown in the illustrative embodiments is believed to be preferable , however the invention could be practiced with other shapes such as a polygon , i . e . triangular , square , hexagonal etc ., or elongated to an oval or rectangular shape . similarly the shape of the upper ring 22 could be made different from circular or even different from the shape of platform 12 . in the main feature of the invention , the concave configuration of the platform 12 the invention may be practiced with concave shapes other than that shown in fig2 where in cross - section the two portions each have a straight line profile . alternatively all or a portion of this cross - sectional shape could be made curved , for example the cross - sectional shape of a portion of a circular or elliptical sphere . the central flat region 14 ( fig2 ) can be made as part of platform 12 or alternatively left open so that the flat region 14 is provided by a floor indoors or a ground region outdoors , in either case typically covered by a canvas or pad . the inclined region 16 ( fig1 , 2 ) could be built as a single unit constituting the major portion of platform 12 or could be made from a polar array of individual separate sectors , e . g . eight sectors as indicated in fig1 , fastened side - by - side or by an external circumferential clamp band . especially if more and narrower sectors are utilized and made from somewhat compliant material such as cellular plastic foam , it would be possible to adjust the overall size of the platform 12 by selection of the quantity of sectors utilized : the width of the inclined border region 16 would remain substantially the same , typically eight feet , while the size of the flat region 14 would vary as a function of the overall size selected . amongst other alternatives and embellishments with which the present invention could be practiced , the structure could be made to serve as support for audio , video or lighting apparatus including illumination , spot lights and / or light show effects such as laser beam displays , and the like , other advertising media , etc . the concept of a non - flat top platform surface could be expanded to many alternate shapes including a raised central region . the invention may be embodied and practiced in other specific forms without departing from the spirit and essential characteristics thereof . the present embodiments are therefore to be considered in all respects as illustrative and not restrictive , the scope of the invention being indicated by the appended claims rather than by the foregoing description ; and all variations , substitutions and changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein .
a platform for performance of personal combat martial arts is made with a concave upper surface having a central generally flat region for main performance surrounded by a border region that slopes upwardly to the platform periphery , so that instead of the traditional impasse and fight interruption experienced when a combatant is forced into the border region , ropes or corners of conventional flat fight rings , the action tends to continue and automatically gravitate back into the main central region without interruption . a full - height constraint net that slopes upwardly and inwardly further urges combatants away from the periphery and safely prevents bodily ejection , thus protecting ringside spectators while providing all spectators with a good view of the sports action .