the binding of the present invention consists of a uni - flexible sole plate 1 attached securely to the ski or other equipment 15 at the forward end of the sole plate 1 with a toe clamp plate 2 , and mounting screws 3 . the heel portion of the sole plate 1 is sandwiched between a heel clamp plate 4 below , and a heel top plate 5 above , which are fastened securely together with heel plate screws 6 and nuts 7 . toe brackets 8 and 9 are inserted , one into each side , in the channels of the toe clamp plate 2 , and are held securely in place when the toe clamp plate 2 is tightened down against the sole plate 1 and the ski 15 with mounting screws 3 . heel brackets 10 and 11 are inserted , one into each side , in the channels of the heel clamp plate 4 , and are held securely in place when the heel clamp plate 4 is tightened up against the sole plate 1 , and the heel top plate 5 with heel plate screws 6 and nuts 7 . this assembly is clearly shown in fig1 , and 5 . an alternate arrangement of the parts could have the sole plate attached to the ski or other equipment at a point forward of the toe clamp plate , and the toe clamp plate and toe brackets would be attached to the sole plate with nuts , bolts , and top plate in the same manner as the heel clamp plate . a toe strap 12 is attached to the toe brackets 8 and 9 , as shown in fig3 . fig6 shows an alternate method of attaching the toe strap 12 . a heel strap 13 is attached to the heel brackets 10 and 11 , and held in position by the slotted heel pad 14 , as shown in fig4 . fig5 shows both the toe strap 12 and heel strap 13 in a side elevation view . the uni - flexible sole plate 1 may be of sheet plastic or any other material that will flex easily about an axis lying in the plane of the sheet surface , but which resists flexure about an axis perpendicular to the sheet surface . other desirable properties include resistance to cracking and breakage when flexed continually at low winter temperatures , and a resistance to physical deterioration when exposed to sunlight , water , and other environmental factors present during winter skiing . the uni - flexible sole plate 1 may also consist of a combination of parts that together form a hinge , or series of connected hinge joints mechanically providing the required uni - directional flexure , thus allowing the heel to lift , but preventing lateral heel movement . the toe brackets 8 and 9 , and the heel brackets 10 and 11 provide raised portions at each side of the toe and heel to restrain the toe and heel , preventing lateral movement of the foot . the toe and heel brackets are illustrated in the drawings as formed from wire . formed wire brackets require the use of a toe clamp plate 2 to secure the wire toe brackets to the toe portion of the sole plate 1 , and a heel clamp plate 4 and heel top plate 5 to secure the wire heel brackets to the heel portion of the sole plate 1 . alternately , the toe brackets 8 and 9 and heel brackets 10 and 11 could be stamped from sheet metal or moulded from plastic or other materials , in which case the toe clamp plate 2 , and heel clamp plate 4 would not be required because sheet metal or plastic toe and heel brackets can be provided with the necessary holes for direct attachment to the sole plate . however , formed wire toe and heel brackets represent the preferred embodiment because they provide smoothly rounded strap attachment points , they allow a wide adjustment range and easy assembly , and they are generally cheaper to manufacture than stamped or moulded parts . the raised portions of the toe brackets 8 and 9 extend upward on each side of the toe , generally perpendicular to the plane of the sole plate 1 , and adjacent to the sides of the boot . the upward extending portions of the toe brackets are formed at an angle converging toward a point forward of the toe , matching the usual shape of the toe portion of a boot , as shown in fig2 . the forwardly converging raised toe bracket portions prevent the boot from sliding forward in the binding , and prevent lateral movement of the toe . the raised portions of the heel brackets 10 and 11 extend upward on each side of the heel and prevent lateral movement of the heel . a toe strap 12 passes through the toe brackets 8 and 9 , and the ends are fastened together on top of the toe as shown in fig3 . a cross section of a similar toe strap arrangement is shown in fig6 . the toe strap in fig6 is attached to one of the toe brackets by means of a short loop of strap . other strap configurations may also be used , such as separate toe strap sections attached to each toe bracket and openably fastened together over the toe . in the preferred embodiment , shown clearly in fig3 and 6 , the toe strap is fastened together with square rings 16 , and a release loop 17 , provided for easy opening , is attached to the lower ring . alternate toe strap fastening means such as round rings and rings of other shapes , tabler buckles , tongue buckles , and web strap buckles may also be used . the heel strap 13 prevents the foot from sliding backward , keeping the toe firmly locked under the toe strap , and the heel portion of the sole plate 1 up against the heel . when the sole plate 1 is held firmly up against the heel by the heel strap 13 , the heel brackets 10 and 11 prevent lateral movement of the heel relative to the ski or other equipment . in the preferred embodiment a single strap is passed around the right side of the ankle , behind the heel , through the raised portion of the left heel bracket , back around the heel , through the raised portion of the right heel bracket , back behind the heel , and up around the left side of the ankle where it is fastened to the other end of the heel strap . the three portions of the strap passing behind the heel are threaded through a heel pad 14 in the area of strap intersection , thus holding the heel strap in position and providing a cushion where the heel strap passes behind the heel of the boot . fig4 and 5 clearly show the preferred arrangement of the heel strap 13 , and the heel pad 14 . other heel strap configurations , such as separate heel strap sections attached to each heel bracket , crossing behind the heel , passing around each side of the ankle , and openably fastened together may also be used without departing materially from the heel strap configuration illustrated in the figures . in the preferred embodiment the heel strap is openably fastened together with square rings 16 , and a release loop 17 , provided for easy opening , is attached to the lower ring in the same manner as described and illustrated for the toe strap . alternate heel strap fastening means such as round rings and rings of other shapes , tabler buckles , tongue buckles , and web strap buckles may also be used . the binding of the present invention may be easily adjusted to fit boots over a wide range of sizes and shapes . loosening the mounting screws 3 that pass through the toe clamp plate 2 allows the toe brackets 8 and 9 to be adjusted to any desired spacing normally required . two or more sets of mounting holes in the toe portion of the sole plate 1 allow two or more major length adjustments . loosening the heel plate screws 6 allows the heel brackets to be adjusted to any desired spacing normally required . two or more sets of heel plate holes in the heel portion of the sole plate 1 plus the option of turning the entire assembly of heel clamp plate 4 , and heel top plate 5 around 180 ° allows four or more minor length adjustments . the heel strap 13 provides a final exact length adjustment when it is pulled snug and fastened . i have illustrated the present invention as a ski binding because this represents a particularly prominent use of the invention . however , this invention may be used for any application where there is a need to attach a persons foot to an object in such manner as to allow the heel to freely raise , and where there is a requirement to restrain lateral movement of the foot relative to the attached equipment . furthermore , the heel strap arrangement in combination with any conventional means of restraining movement of the toe , such as a toe strap located ahead of the widest part of the foot or other material bracketing or enveloping the toe , thus restraining forward , upward , and lateral movement of the toe , and with a flexible , non - elastic connecting means provided beneath the foot to act as a sole plate connecting the heel strap to the toe restraining means , may be used for any application where lateral restraint is not as critical as is required for skiing . a snowshoe binding is a good example of such an application of the present invention requiring less lateral restraint . the foregoing disclosure has described and illustrated the preferred embodiment of the present invention . a few alternate configurations have also been described briefly and other changes and modifications will be apparent to those skilled in the art . it is intended that this invention include all such changes and modifications falling within the scope of the appended claims .
a binding comprised of a flexible sole plate attached to a ski or other equipment at the toe , adjustable brackets attached to the sole plate at the sides of the toe and heel to restrict lateral movement of the toe and heel relative to the ski , and toe and heel straps to secure the foot to the binding . the toe strap passes over the toe and is attached to the front portion of the sole plate . the heel strap passes around the ankle , crosses behind the heel , and is attached to the rear portion of the sole plate .