US 3133544 A
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May 19, 1964 c. w. COPLANS COMPENSATING DEVICE FOR FOOTWEAR 2 Sheets-Sheet 1 Filed Aug. 18, 1961 w r v y 19, 1964 c. w. COPLANS 3,133,544
COMPENSATING DEVICE FOR FOOTWEAR Filed Aug. 18, 1961 2 Sheets-Sheet 2 INV EN TOR.
United States Patent 3,133,544 COMPENSATING DEVICE FOR FOOTWEAR Carl Waddington Coplans, Cape Town, Cape Province,
Republic of South Africa, assignor to Orthostance (Proprietary) Limited, Cape Town, Cape Province, Re-
public of South Africa, a limited-liability corporation of Republic of South Africa Filed Aug. 18, 1961, Ser. No. 132,489 Claims priority, application Republic of South Africa Sept. 2, 1960 1 Claim. (Cl. 128--611) This invention relates to a compensating and corrective device for use in footwear for the amelioration of flatfoot, and for minor deformities of the longitudinal arch which may be responsible for fatigued or tired feet. It further possesses what may be described as a demand mechanism in that it will supply approximately the amount of correction and compensation that is required of it at any particular stage of locomotion.
Normally the human foot bears the body weight chiefly at three supporting areas. These are: the head of the metatarsal of the big toe; the head of the metatarsal of the small toe, and the calcaneum or heel bone. The foot is, therefore, a tripod, the posterior pier or heel bone being the variable member.
In fiat or weak feet, the calcaneum tilts inwardly, so that the longitudinal arch loses its architectural efficiency and rolls downwards and inwards, causing the inner border of the foot to tend to become convex, thus distorting the inner wall of the shoe, which cannot normally resist the descending and rotating arch.
Known devices hitherto used in footwear for the above purpose, have depended for their corrective force upon a fixed or rigid design. It is, accordingly, an object of this invention to provide for use in footwear, a device which varies its corrective force to the degree of deformity or error of the flat or weak foot.
According to the invention, a compensating device includes a transversely disposed flexible sling or bowstringlike element having an upper end fast with a reinforced inner side wall of a shoe counter, or its equivalent, and the opposite downwardly and outwardly disposed or lower end fast with the outer marginal part of the inner sole, or its equivalent, the arrangement being such that the required corrective action is exerted by the sling and said side wall of the shoe counter, against the tilting calcaneum or posterior pier of a wearers foot, when it is weightbearing in an article of footwear fitted with the device.
The upper end of the sling is fixed in a position rearwardly of the talonavicular joint of the wearers foot, and the lower end is firmly fixed towards the outer marginal part of the inner sole, in line with or rearwardly of the upper end attachment. The sling is in the form of a flat band or strap of sufiicient width and so arranged as to correct the wearers foot in comfort.
The invention may include one or more of the following features:
The sling may be a strap or band of preferably fanshape and may be made of a substantially non-stretch material, such as leather, plastic, metal or the like, or it may have a certain degree of elasticity. The broad end of the sling is fixed at a suitable angle to the reinforced inner side wall of the shoe counter, so that the posterior border or margin of the strap lies flush with the inner 3,133,544 Patented May 19, 1964 sole. The upper attached end of the sling is so angulated to the inner sole that it forms a suitable or convenient angle to it. Thus the anterior or free edge of the sling must necessarily lie at a greater height than the posterior or flush edge. Nevertheless, by reason of the attachment of the lower end of the sling towards the outer portion of the inner sole, there will be a gradual descent of the sling from the inner wall of the shoe counter to the lateral side of the inner sole.
When the weight-bearing foot exerts its pressure on the sling, it does so in the following order:
(1) As the foot becomes weight-bearing, the outer border of the foot presses on the outer part of the sling, thus tautening the remaining inner portion.
(2) As the load on the foot increases, the longitudinal arch tends to roll inwards, the inner border of the foot tends to lose the concave contour that it possesses in the non-weight-bearing state, and tends to assume a convex contour.
(3) As the above stages progress, weight is thrust upon the remaining inner portion of the sling, thus tightening it further. This further tightening is due to the relative shortening of the remaining inner portion of the sling, caused by the descending roller-like action of the arch.
This in turn produces two important effects:
1) The tightening and relative shortening of the sling produces a bowstring effect, and the inner surface of the stiffened upper is drawn forcibly against the inner border of the foot, with a force approximately equal and opposite to that exerted upon it by the foot. This eifect is made possible by the method in which the inner wall of the 'upper is reinforced, and by the tension exerted by the tightening of the sling upon it. While the stiifener should be of such a strength as successfully to resist buckling under the vertical and angular stress to which it is subjected during weight-bearing by the foot, its lower end must possess the common hinge-like action of a normale upper at its attachment to the sole of the shoe.
(2) By reason of the vertical rigidity of the forwardly prolonged heel stiffener or counter, which now acts as a vertical support for the sling, the inner border of the foot is slung and supported, and therefore cannot descend any further, or roll further inwards.
This establishes part of the principle of this device, in that it maintains the normal shape of the foot by preventing the posterior pier of the tripod from falling inwards.
When the foot is not weight-bearing, there is little or no action upon the sling and consequently no corrective force is experienced by the foot. The angle of the sling is so designed that the normally arched foot will not activate it.
The sling, as above described, may be built into a shoe during manufacture, or may be built into the shoe after manufacture. The reinforced counter, considered separately from the shoe, may be made of any suitable material, the medial or inner wall being sufficiently strengthened to resist buckling from vertical or angular stresses. The sling is attached to the reinforced counter in the manner described above, the lower end of the sling lying free, ready to be fixed when introduced into the shoe.
Alternatively, the sling may be incorporated in a foot support device capable of being used separately, so that it may be inserted into an article of footwear. In this case, the sling is supported in a metal or like frame or bracket, which must be designed so as to resist the vertical stress and yet be so hinged or suitably flexible that it gives the same effect as the reinforced medial wall of the shoe described above. To achieve this result the frame or bracket comprises a base or sole plate part to one side of which a vertical plate is hingedly or flexibly attached so that it is capable of being deflected or canted inwardly.
The vertical plate and the base or sole plate may be covered with leather or other suitable material to increase the comfort of the user. Arrangements may be made for adjusting the sling, such as by the use of a buckle or the like. The base of the frame or bow-like bracket may be conveniently slotted and the free lower end of the sling may be provided with a clasp or hook, which will engage with this slotted member for the purpose of adjustment.
It is understood that the vertical plate is shaped to conform to the inside border of the foot and may extend as far forwardly as the talonavicular joint. The base or sole plate extends rearwardly a sufiicient distance to receive the weight of the heel.
To enable the invention to be more clearly understood and carried into practice, reference is now made to the accompanying drawings, in which like references denote like parts throughout the several views.
In the drawings:
FIGURE 1 is a side elevation of a human foot indicating the area thereof over which the device of the invention is designed to apply corrective pressure.
FIGURE 2 is a diagrammatic cross section of the heel part of a shoe showing the position of the sling before weight is applied to it.
FIGURE 3 is a view similar to that of FIGURE 2, but showing the position tended to be taken up by the sling and the inner side wall of the shoe counter, when a wearers foot becomes weight bearing.
FIGURE 4 is a plan view of a shoe showing the relative position of the sling built into it during manufacture.
FIGURE 5 is a fragmentary side view of the heel portion of the shoe of FIGURE 4, looking in the direction arrow V and with the outer side wall cut away.
FIGURE 6 is a pictorial view of an insertable inner sole member embodying the invention.
FIGURE 7 is a sectional end view of the metal bracket member of FIGURE 6 with the sling attached to it.
FIGURE 8 is an end view of the metal bracket and sling showing use of a padding insert.
FIGURE 9 is a plan view of a heel insert embodying the invention and adapted to be built into the counter of a shoe.
FIGURE 10 is a side view taken on FIG. 9; and
FIGURE 11 is a pictorial view of a modified shoe insert embodying the invention.
Referring to FIGURE 1 of the drawings, reference 1 denotes the area of a human foot 2, over which corrective pressure is applied by the invention.
Referring to FIGURES 2 and 3, a sling 3 of flexible sheet material has its upper end secured to the reinforced inner side wall 4 of a shoe counter, while the opposite lower end is fixed adjacent to the outer edge of the inner sole of the shoe, close to the lower end of the opposite outer side wall 5, so that the sling forms a downwardly curved loop or bight.
The inner side wall 4 is reinforced by a medial stiffener 6 of suitable sheet material, so that it will not buckle when a weight-bearing foot applies downward pressure to the sling 3. When this happens the radius of curvature of the sling is reduced with the result that the increased tension induced thereby, tends to cause the inner side wall 4 to be deflected or canted inwardly as shown in FIG- URE 3, and thereby to apply corrective pressure to the side of the wearers foot adjacent to the arch thereof.
FIGURES 4 and 5 show a shoe 7 in which the sling 3, made of leather, is built into it during manufacture. In addition of course a reinforcing element (not shown) is 4 inserted in the inner side wall part of the shoe counter 8. As shown, the posterior margin 9 of the sling 3 is flush with the inner sole, while the anterior margin 10 is spaced above it so that the sling 3 conforms to the shape of the underside of the foot just forwardly of the heel and below the arch thereof.
FIGURES 6, 7 and 8 illustrate an inner sole insert embodying the invention. In this case a right-angle shaped metal bracket 11, preferably made of thin spring steel strip, is fixed to an inner sole 12 which is provided with a stiff upstanding inner wall part 13 corresponding to the inner side wall of a shoe counter, to which the vertical leg 14 of the bracket 11 is secured. The horizontal leg 15 is fixed to the inner sole l2 and, towards its outer end, is provided with a plurality of slots 16. A sling 17 is fixed by its upper end to the vertical leg 14 of the bracket 11, while its lower end is provided with a hook 18 adapted to engage selectively with one of the slots 16 in the horizontal leg 15 thereof. In this way the tautness of the sling 17 can be varied to suit different abnormal foot conditions. To provide comfort a padding piece 19 is laid over the sling 17. The bracket 11 is sufficiently resilient to ailow cf the vertical leg 14 and the inner wall part 13 being deflected or canted inwardly when a weightbearing foot acts downwardly on the sling 1'7, which may be leather, canvas or other suitable flexible material.
FIGURES 9 and 10 illustrate one method of embodying the invention in the counter of a shoe as shown in FIG- URES 4 and 5 by means of a built-in insert. This built-in insert comprises a shaped heel embracing part 20 of suitable material such as compressed fibre, fibre glass or a suitable plastic. The inner wall thereof is stiffened by a reinforcing, fiat, shaped element 21 which may be of metal, fibre glass or other suitable material, and which is secured thereto by rivets 22. A sling 3a has its upper end secured to the reinforcing element 21 by some of the rivets 22, after passing through a slit in material of the insert, while its lower end is left free to be lasted to the sole of the shoe by nails or like fastening elements. This insert is adapted to be located between the inner and outer layers of the material forming the shoe counter.
FIGURE 11 illustrates a modified form of a heel insert made preferably of metal and comprising a vertical plate part 23 which is flexibly connected to a sole plate part 24. A sling 25 has its upper end fixed to the vertical plate part 23 and its lower end fixed to the outer margin of the sole-plate part 24. Preferably this outer margin of the sole-plate part 24 is bent upwardly to form a small side flange 26.
Finally it is desired to emphasize the bowstring action of the sling. When the wearers foot is weight-bearing in a shoe fitted with the invention, the medial wall of the shoe is drawn up against the inner border of the wearers foot and at this stage the sling acts as a tight strap or loop which slings the infero-medial aspect of the posterior pier thereof.
In order to further clarify the particular description of applicants invention, the heel structure of the various modifications may be identified as follows: In FIGS. 2, 3, 4 and 5 the heel structure 27 comprises the heel end of a shoe. In FIGS. 6, 7 and 8 the heel structure 28 comprises the metal bracket 1'1, the rear portion of the inner sole 12 and the inner wall part 13. In FIGS. 9 and 10 the heel structure 29 comprises the insert having the shaped heel-embracing part 20, and the inner wall stiffened by the element 21; in this embodiment the marginal portion 30 corresponds to the rear portion of an inner sole. In FIG. 11 the heel structure 31 comprises the vertical plate part 23 constituting the inner side wall, and the sole plate part 24 having the side flange 26 constituting an outer edge.
In a compensating and corrective device for an article of footwear having front and heel sections with an arch section therebetween, the combination comprising a heel structure having lateral inner and outer edges, and inner 5 side wall extending upwardly from a portion of said inner edge, a flexible sling member transversely disposed to the heel section and adapted to be engaged rearwardly of the talo-navicular region of a Wearers foot, said flexible sling member having horizontal and vertical leg elements and a sling element, said horizontal leg element being fixed to said heel section and having a plurality of spaced slots adjacent said outer edge, said vertical leg element being fixed to said inner side wall, said sling element extending downwardly and outwardly from a top portion of said inner side wall toward said outer edge whereby said inner side Wall deflects inwardly to provide corrective pressure 5 in response to a force applied by a wearers heel to the sling element, and hook means on said sling element selectively engaging one of said spaced slots on said horizontal leg element whereby said sling element is laterally adjustable.
References Cited in the file of this patent UNITED STATES PATENTS 1,144,740 Teehan June 29, 1915 2,640,282 Wisbrun June 2, 1953 2,834,272 Sloat Apr. 22, 1958 2,933,834 Bourland Apr. 26, 1960