referring to fig1 a support belt 10 of the invention has an inner fabric layer 12 , an intermediate core layer 14 , an outer fabric layer 16 , a strap 18 , a buckle 20 and a torque ring 22 . an edge binding strip 24 is stitched along the edge of the belt 10 . it would also be possible , of course , to secure the binding strip 24 to the edge of the belt 10 by a suitable adhesive , either hot or cold . the buckle 20 and torque ring 22 used in the preferred embodiment 10 are disclosed in u . s . pat . no . 5 , 036 , 864 , the disclosure of which is hereby incorporated by reference . the fabric layers 12 and 16 , binding strip 24 and strap 18 may be made of the same materials and stitched together in the same way as described in u . s . pat . no . 5 , 178 , 163 , the disclosure of which is hereby incorporated by reference . what differs about the belt 10 from the prior belts is the use of a three dimensional fabric core 14 , whereas in the prior belts the core layer was made of foam . as used herein , the term three dimensional fabric means a fabric in which the thickness of the fabric at a particular location is greater than the sum of the thicknesses of the threads of the layers of the fabric at that location . the thickness is defined as the distance from one surface of the fabric to the opposite surface of the fabric when the fabric is in its natural state , so that the layers of the fabric are together but not so that the fibers of the layers of the fabric are compressed or deformed . laying the fabric flat on a table with one surface of the fabric against the table surface and so as to remove wrinkles from the fabric places the fabric in its natural state . fig2 illustrates an alternate support belt 10 &# 39 ; of the invention which is identical in all respects to the support belt 10 except for having a core 14 &# 39 ; which is three dimensional fabric of a different type than the fabric used in the belt 10 . in fig2 elements corresponding to the elements shown in fig1 are identified by the same reference numbers followed by a prime (&# 39 ;) sign . referring to fig3 and 4 , top cross - sectional views of the cores 14 and 14 &# 39 ; are shown respectively . referring to fig3 the core 14 has an inner facing layer 14i , two cushion or middle layers 14m1 and 14m2 and an outer facing layer 14o . the core 14 &# 39 ; shown in fig4 has an inner facing layer 14 &# 39 ; i and an outer facing layer 14 &# 39 ; o ( in 14o and 14 &# 39 ; o , the &# 34 ; o &# 34 ; is the letter &# 34 ; o &# 34 ;, not not a zero ), but only one cushion layer 14 &# 39 ; m . in each of the cores 14 and 14 &# 39 ;, the cushion layers define peaks 14p and 14 &# 39 ; p and valleys 14v and 14 &# 39 ; v . each peak 14p is interwoven with the inner facing layer 14i , each valley 14v is interwoven with the outer facing layer 14o , each peak 14 &# 39 ; p is interwoven with the inner facing layer 14 &# 39 ; i and each valley 14 &# 39 ; v is interwoven with the outer facing layer 14 &# 39 ; o in the manner hereinafter described . in addition , in the core 14 which has two cushion layers 14m1 and 14m2 , the two cushion layers 14m1 and 14m2 intersect at junctures 14j where the warp threads of each layer 14m1 and 14m2 pass through the interstitial spaces of the other cushion layer . fig5 illustrates the thread pattern of all of the layers of the cores 14 and 14 &# 39 ; shown in fig3 and 4 except for the layer 14 &# 39 ; o . thus , all of the layers except 14 &# 39 ; o are woven , having warp and fill threads woven together . the layer 14 &# 39 ; o is shown in fig6 and has no fill threads , having only warp threads 14 &# 39 ; w arranged in spaced apart bundles of three threads per bundle . it should be noted that in fabrics of the type shown in fig5 and 6 , the fill threads of the facing layers may not be straight . in the areas between the peaks and valleys , but may be rather wavy . fig7 illustrates the weaving pattern of the peaks 14p and layer 14i , of the valleys 14v and layer 14o , and of the peaks 14 &# 39 ; p and the layer 14 &# 39 ; i . for the two fill threads f1 and f2 which are at the top of the respective peak 14p or 14 &# 39 ; p or bottom of the respective valley 14v , the warp threads in the adjacent facing layer alternate in the weave pattern between the fill threads . for example , as shown in fig7 warp thread w1 goes under fill thread f1 at intersection u1 , 1 and goes over fill thread f2 at intersection o1 , 2 . the adjacent warp thread w2 goes over fill thread f1 at intersection o2 , 1 and goes under fill thread f2 at intersection u2 , 2 . warp thread w3 , like warp thread w1 , goes under fill thread f1 ( at intersection u3 , 1 ) and over fill thread f2 ( at intersection o3 , 2 ). fig8 illustrates the intersections of the threads of layer 14 &# 39 ; o with the layer 14 &# 39 ; m of fig4 . it is noted that in fig7 each separate warp thread is threaded through only one interstitial space in each row of interstitial spaces , whereas in fig8 three warp threads extend through a single interstitial space . in fig8 the warp threads w1 - 3 alternate in their weave pattern relative to fill threads f1 and f2 as indicated by the notations o , u , o ( over , under , over ) and u , o , u ( under , over , under ) which indicate the intersections of the respective warp threads w1 , w2 , w3 and w4 , w5 , w6 with the fill threads f1 and f2 . a preferred fabric for the core 14 illustrated in fig3 has cushion layers 14m1 and 14m2 with the warp threads spaced at approximately 18 warp threads per inch and each warp thread being a 0 . 020 inch diameter polypropylene filament . the fill threads in each cushion layer 14m1 and 14m2 are also spaced at 18 threads per inch and are 0 . 012 inch diameter polypropylene filaments . the fill threads in the facing layers 14i and 14o are also 0 . 012 inch diameter polypropylene filaments and spaced at 18 threads per inch , and the warp threads in the facing layers are 18 threads per inch with each thread being 0 . 00875 inch diameter polyethylene . such a fabric is commercially available from synthetic industries , lumite division , norcross , ga ., under style no . 60617000 . in the industry , this is known as a &# 34 ; spacer &# 34 ; type weave . with threads of the dimensions , spacing and pattern stated above , substantial open interstitial spaces are defined between the threads such that this is an &# 34 ; open weave &# 34 ; fabric . in general , an open weave fabric is defined as any fabric having open interstitial spaces between the threads which make up the fabric . open weave fabrics are especially preferred for the core in a belt of the invention to provide light weight and ventilation . a fabric for the core shown in fig4 is also commercially available from synthetic industries , lumite division , as a &# 34 ; spacer &# 34 ; type weave . this fabric has the commercial designation style no . 60645000 . in this fabric , the cushion or middle layer 14m has warp and fill threads spaced at 26 threads per inch with the warp threads being 0 . 0117 inch diameter polypropylene filaments and the fill threads being 0 . 0096 inch diameter polypropylene filaments . the inner facing layer 14 &# 39 ; i has warp and fill threads spaced at 26 threads per inch with the warp threads being 0 . 010 inch diameter polyethylene filaments and the fill threads being 0 . 0096 inch diameter polypropylene filaments . the threads of the outer facing layer 14 &# 39 ; o are 0 . 010 inch diameter polyethylene filaments spaced at 21 threads per inch in bundles of three threads so that there are seven bundles per inch . it should be noted that the above two noted particular fabrics are just two of the possible fabrics which can be used to practice the invention and that other fabrics could be used to practice the invention . the preferred core layer materials are fabrics made of synthetic thermoplastic threads . as such , the threads can be heated to their melting points and welded together . this is especially desirable to do at any cut edges of the core layer so as to join the ends of the threads together at the cut edges to prevent unravelling of the threads of the core . this is known in the industry as heat sealing the edges of the fabric and can be accomplished with any suitable heat source such as a radiant heat element , a heat gun or an open flame . it is particularly desirable with a three dimensional fabric core as described above to apply the binding strip 24 around its edges since the edges of the core , whether heat sealed or not , can be rather scratchy to a user . in the belts 10 and 10 &# 39 ; shown in fig1 and 2 , the core layers are covered by inner and outer fabric layers . these fabric layers are preferably as described in u . s . pat . no . 5 , 178 , 163 , and in general are a stretchable or expandable fabric such as &# 34 ; lycra &# 34 ;, which is a trademark of e . i . dupont de nemours or a brushed polyester or nylon stretchable fabric . although of a closed weave , the inner and outer layers of fabric are relatively breathable and allow for the passage of air and perspiration through them . the core 14 or 14 &# 39 ; can be secured to the layers 12 , 12 &# 39 ; and 14 , 14 &# 39 ; in any of a variety of ways . one such way is to create a fabric pocket by sewing the edges of the layers 12 and 14 together and then slipping the core inside the pocket before the pocket is completely sewn closed . another way to secure the inner and outer fabric layers to the core is to directly sew the layers to the core . still another way is to laminate the fabric layers to the core using a suitable hot or cold adhesive . using a hot adhesive &# 34 ; flame combining &# 34 ; technique as described in u . s . pat . no . 5 , 178 , 163 may be applied in some applications to laminate the fabric layers 12 and 16 to a three dimensional fabric core . after the body 26 of the belt is made ( the body 26 includes the core 14 , inner and outer layers 12 and 16 and the binding strip 24 ), the strap 18 is secured to the body 26 by sewing it thereto , preferably with two seams which extend substantially all the way around the body 26 near to the respective edges of the strap 18 . an alternate embodiment 10 &# 39 ;&# 39 ; shown in fig9 is the same in all respects as the belts 10 and 10 &# 39 ;. the embodiment 10 &# 39 ; may be made with either of the three dimensional fabric cores 14 and 14 &# 39 ; used in the belts 10 and 10 &# 39 ; or with a different three dimensional fabric core . in fig9 no inner or outer fabric layers corresponding to the layers 12 or 16 are provided . for comfort , the belt 10 &# 39 ;&# 39 ; is intended to be worn over the clothing of a user although , dependent upon the user &# 39 ; s preference , it could be worn directly over the user &# 39 ; s skin . the belt 10 &# 39 ;&# 39 ; is provided without inner or outer closed weave fabric layers so as to provide maximum ventilation through the belt . as shown in fig9 the strap 18 &# 39 ;&# 39 ; is sewn to the core 14 &# 39 ;&# 39 ; along two spaced apart seams 40 and the binding strip 24 &# 39 ;&# 39 ; is also sewn to the edges of the core 14 &# 39 ;&# 39 ;, shown by seam 42 . such seams 40 and 42 may also , of course , be used to make the belts 10 and 10 &# 39 ;. many modifications and variations of the preferred embodiments described above will be apparent to those of ordinary skill in the art . for example , although in the preferred embodiments the corrugations of the cushion layers of the belt run in the direction of the length of the belt because the cushion layer is in general stiffer orthogonal to the corrugation direction , the corrugations could be oriented at a different angle relative to the length of the belt . therefore , the invention should not be limited to the preferred embodiments described , but should be defined by the claims which follow .
a support belt has a core layer made of a three dimensional fabric in which a cushion layer has a serpentine undulating cross - sectional shape in at least one dimension so as to define peaks and valleys which space inner and outer surfaces of the core such that the thickness of the core at a given location is greater than the sum of the thicknesses of threads of the fabric at that location . the core may have multiple cushion layers and may be covered with a closed weave fabric on one or both sides thereof . preferably , a strap encircles the core and a buckle is provided for adjustably securing the strap around a body with the core between the strap and the body .