US 3722113 A
An article of footwear has uppers which may in form of straps, and a sole of yieldable elastomeric material which is provided at least on its upper and, according to some embodiments, on its lower surface with projections which extend substantially normal to the general plane of the respective surface. The projections may be of different length.
Description (OCR text may contain errors)
[ Mar. 27, 1973 United States Patent [191 Birkenstock 9/1938 Montano.................... 6/1967 m 9 H 5 www ,2 593 822 9 3 2 2 3 0 4 m S r e m 3 H m E wmn T n e0 w F B m Ffl we C m t n m mm mm  Filed: May 6, 1971 Primary Examiner-Patrick D. Lawson o Att0rney-Michae1 S. Striker ABSTRACT An article of footwear has uppers which may in form  Foreign Application Priority Data June 20, 1970 70 23 2574 of straps, and a sole of yieldable elastomeric material which is provided at least on its upper and, according to some embodiments, on its lower surface with pro-  US. 128/582  Int. Cl. 3/12 36/115, 43, 8.1; 128/581,
jections which extend substantially normal to the general plane of the respective surface. The projections may be of different length.
 Field of Search 128/582, 614, 615, 25.2
 References Cited UNITED STATES PATENTS 16 Claims, 4- Drawing Figures 3,595,244 7/1971 Kugler.................................e.36/l1.5
ARTICLE OF FOOTWEAR BACKGROUND OF THE INVENTION The present invention relates generally to an article of footwear, and more particularly to the construction of a sole member in such an article of footwear.
Sole members of the type in question are already known, especially for use in sandles. However, they are also known as innersoles which can be worn in regular shoes other than sandles. In either case, however, the purpose is to provide a sole member having elastic projections which engage the underside of the foot of a wearer and during walking in effect will massage the foot, providing improved circulation and generally facilitating the well-being of a user. The known constructions utilize either synthetic plastic material or rubber and have a smooth underside which may or may not be connected with an essentially rigid carrier sole, for instance consisting of wood. The upper ends of the relatively closely adjacent projections on the upper side of such soles have been made rounded and are so located that together they are disposed essentially in a profiled plane, meaning a general plane of the upper ends which conforms as much as possible to the anatomic contour of the underside of a human foot. However, it has been found that despite all efforts to date a proper even message of the entire underside of the foot, and a similarly proper and even support of the entire underside of the foot, have not been obtained satisfactorily.
The reasons for this are manifold. Firstly, the known projections have a relatively high resistance to deformation in their longitudinal direction, that is in vertical direction, but they are relatively unresistant to lateral deflection. Even if they are made quite thick relative to their length, this does not change especially if the projections are provided on a sole member of rubber or analogous elastomeric material, because at their base they are of course still elastically anchored in or of one piece with the actual sole member and thus can yield. It is also necessary to consider that the height and the thickness of such projections must remain within certain limits if sufficient massaging action on the foot is I still to be obtained.
In known constructions, particularly known sandles having a rigid wooden sole provided with a sole member having the upwardly extending projections, the foot of the user is well supported in its essentially planar center portion, but the rather strongly upwardly inclined lateral regions of the foot are in effect not supported at all because the projections on which they are intended to be supported cannot be sufficiently long and still provide the necessary support and massaging action, and also are constantly laterally deflected during walking. Thus, a massaging effect is obtained really only in the center of the foot, that is the center of the lower surface of the foot. This, on the other hand, is also disadvantageous in certain respects because the rigid wooden supporting sole will cause the projections always to press against the same portions of the foot whereas other portions -that is the lateral portions for instance are not supported despite the fact that the projections are relatively closely located together. Thus the massaging action is really only concentrated at local points and not evenly distributed. It is hardly necessary to point out that proper massaging action requires that there be a constant change of the surface portions of the human anatomy -that is here the footwhich undergo massaging. On the other hand it is not possible to obtain the desired improvement by making the projections more flexible on the rigid carrier sole, because then they will no longer properly support the weight of the body. If they are yieldably and elastically anchored to their base, then they can be too rigidly deflected laterally when the weight of the users body rests on them, and walking becomes unsure and unsafe. Finally, the known constructions have an additional disadvantage in that they are of several components which must be assembled and connected, consisting of different material, and this makes them rather expensive in their construction.
SUMMARY OF THE INVENTION It is, accordingly, an object of the present invention to overcome the aforementioned drawbacks of the prior art.
More particularly it is an object of the present invention to provide an improved article of footwear which avoids these disadvantages.
A concomitant object of the invention is to provide such an improved article of footwear which provides for proper and even support and massaging of the foot of a wearer.
A concomitant object of the invention is to provide such an improved article of footwear which is relatively inexpensive to produce and therefore to sell.
In pursuance of the above objects, and of others which will become apparent hereafter, one feature of the invention resides, briefly stated, in an article of footwear comprising upper means, and sole means of yieldable elastomeric material provided on the upper means and including a sole member having a normally upper surface adapted to face the underside of a human foot. The sole member is provided with a plurality of projections of different heights which are distributed over the surface thereof and which project upwardly from this surface so as to extend at least substantially normal to the underside of a foot on which the article is worn.
By resorting to the present invention there is obtained an article of footwear which not only provides proper support for the foot, but which massages the foot at constantly changing points thereof. The article according to the present invention is also inexpensive to construct, as pointed out before, and substantially lighter than what has been known heretofore.
The present invention is based on the realization that a proper and even massaging of the underside of a human foot can be obtained only if the profile defined by the upper ends of the various upwardly directed projections corresponds as closely as possible to the profile of the underside of the foot so that not only the middle portion of the foot is supported on the projections but may extend upwardly'almost normal to the underside of the foot but slightly inclined inwardly, whereas in the portion surrounded by the marginal circumferential portion the projections may extend completely normal to the underside of the foot. The underside of the sole member itself may be smooth. It is advantageous that the sole member be flexible both in its longitudinal and in its transverse direction so that it can readily adapt itself to variations in the ground in order to assure that the projections depending upon flexing of the sole memberwill move towards and away from one another constantly and provide a constant and intensive massaging effect over the entire underside of the human foot without concentrating on unvarying individual points.
According to a further and particularly advantageous embodiment the underside of the sole member may be provided with additional projections which extend downwardly and each of which is coaxial with -that is an axial extension of one of the upwardly extending projections. These downwardly extending projections are so deflected apart when a weight comes to bear upon the sole member, that the upwardly extending projections will be correspondingly deflected during walking, resulting in an improvement of the massaging effect obtained. It is particularly advantageous if according to a further embodiment of the invention each of the downwardly directed projections has the same length as the respectively coaxial upwardly extending projections. Advantageously the profile defined by the downwardly extending projections will be identical or nearly identical with the profile defined by the upper ends of the upwardly extending projections.
The projections are distributed over the surface area of the sole member in accordance with the anatomic contour of the underside of a human foot, being of different lengths in accordance with the dictates of this anatomic contour. However, when the downwardly extending projections are provided which are each of the same length as the respectively coaxial upwardly extending projections, these projections which are located in the marginal circumferential regions of the sole member at the upper side thereof may be shorter than the anatomic contour of the foot underside would normally require because the length of the upwardly extending and coaxial downwardly extending projections is additive, meaning that the longer projections in the marginal circumferential region of the sole member are deflected to a more substantial extent --when weight rests on themin upward direction by the downwardly extending projections than those of the inner or center portion at whose underside the projections are shorter, just as they are at the upper side thereof. Especially if the sole member is made flexible.
the projections are constantly deflected towards and away from one another when the user walks, both longitudinally and transversely of the sole member, and this results in the desired even and uniform massaging effect without concentrating on particular pressure points at the underside of the foot.
It is possible to provide a projecting edge portion extending upwardly and downwardly of the sole member,
if desired, for purposes of stiffening the sole member to improve the massaging effect as well as the strength and stability of the sole member. This edge portion may be at least substantially circumferentially continuous.
The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawing.
BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a perspective view of a sandal embodying the present invention;
FIG. 2 is a side view as seen from the right-hand side of FIG. 1;
FIG. 3 is a section taken on line IIllII of FIG. 2, showing the sandal with weight resting on the projections; and
FIG. 4 is a section analogous to FIG. 3 but illustrating another and simplified embodiment of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS Discussing now the drawing in detail, and firstly FIGS. 1-3 thereof, it will be seen that the article of footwear per se is identified with reference numeral 1 and here illustrated as a sandal. It is preferably composed of high-molecular synthetic plastic foam or cellular material, such as polyurethane foam, or of an elastic cork-latex mixture. The sole member is formed of one piece with two straps 2 which constitute the upper means in the illustrated embodiment.
The upper side of the sole member is provided with upwardly directed projections 3 which are distributed over the surface of the upper side and are of different heights in accordance with the anatomic contour of the underside of the foot of a human being. In addition the sole member is provided with a substantially circumferentially continuous edge portion 4 which in the illustrated embodiment projects both slightly above and slightly below the sole member and is interrupted only where the sole member 5 merges with the strap members 2 which in the illustrated embodiment are identical on their upper side and their lower side. FIG. 2 shows that in the illustrated embodiment there are further provided substantially parallel downwardly extending projections 13 at the underside of the sole member 5, each of them being coaxial with one of the upwardly extending projections 3. Each of the projections 13 has the same length as its respectively coaxial projection 3 so that the sandal l is identical at its upper side and at its lower side, and in the illustrated embodiment it will be seen that this identity extends also to the configuration of the edge portion 4 and to the appearance and configuration of the two opposite major sides of the straps 2.
The section in FIG. 3 is taken through the embodiment of FIGS. 1 and 2 to illustrate the same in loaded condition, that is when the weight of a human body rests on it. It will be seen that the projections 3a which are located in the margin circumferential zone of the sandal are deflected upwardly substantially more strongly by their lower counterparts 13a, than the shorter projections 3b which are located inwardly in the portion of the sandal which is surrounded by this outer marginal circumferential portion. This can also be stated conversely by saying that the inner portion 5 with the shorter projections 3b, 13b is deflected downwardly under the influence of the weight of the wearer more strongly than the marginal circumferential portion, so that the underside of the sole of a foot of a wearer is evenly supported everywhere in accordance with its anatomic contour.
All of the projections 3 and 13 are deflected when weight rests upon the sandal 1- both longitudinally and transversely of the sandal during walking movements, so that the underside of the foot of a wearer is constantly and evenly massaged by constantly changing engagement of the various projections with different portions of the underside of the foot. in other words, the transverse movements of the projections 3, 3a and 3b resulting from the support of the differentially long projections 13, 13a and 13b, constantly varies the point of contact of the projections 3, 3a and 3b with the underside of the foot, but despite this the projections 3, 3a and 3b will nevertheless extend at all times at least substantially normal to the underside 6 of the foot which transmits pressure to them. This means that the projections are always predominantly subjected to longitudinal pressure, rather than to flexing in lateral direction.
The straps 2 may be provided with suitable closure means, such as buckles or the like, by means of which their free ends are connected after they have been placed about the human foot.
The embodiment illustrated in FIG. 4 differs from the preceding embodiment in that the projections 3a which are provided in the marginal circumferential portion at the upper side of the sandal are somewhat inwardly inclined. However, the length of the projections 3a is necessarily limited if they are not to be too readily deflectable, so that this construction is feasible only for smaller shoe sizes, whereas the embodiment in FIGS. 1-3 can be used for all shoe sizes, and also for particularly large shoe sizes as well.
I have found that the embodiment according to the present invention in which the projections on the underside and the projections on the upperside of the sole member are configurated identically, has the additional advantage that one and the same tool can be used for producing both the sole member and projections for the left foot as well as for the right foot. The straps 2 are preferably of one piece with the sole member, if the article of footwear is to be used as a sandal, but of course the sole member with the projections can be utilized in a manner other than as a sandal, that is without the straps.
It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of constructions differing from the types described above.
While the invention has been illustrated and described as embodied in an article of footwear, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.
Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can by applying current knowledge readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the following claims.
What is claimed as new and desired to be protected by Letters Patent is set forth in the appended:
1. An article of footwear, comprising upper means; sole means of yieldable elastomeric material provided on said upper means and including a sole member having a normally upper surface adapted to face the underside of a human foot and a normally lower surface facing away from the human foot; and a plurality of first substantially cylindrical projections of different heights distributed over said upper surface and projecting upwardly therefrom so as to extend at least substantially normal to the underside of a foot on which said article is worn, and a plurality of second substantially cylindrical projections provided on said lower surface and extending downwardly therefrom, all of said projections being yieldable in all directions.
2. An article as defined in claim 1, wherein said elastomeric material is natural or synthetic rubber.
3. An article as defined in claim 1, wherein said elastomeric material is a synthetic plastic material.
4. An article as defined in claim 1, said sole member having a marginal outer circumferential region and an inner region surrounded by said outer region; and wherein said first projections in said inner region extend at least substantially normal to said upper surface and the first projections in said outer region are at least slightly inwardly inclined towards said inner region.
5. An article as defined in claim 1, said sole member having a longitudinal and a transverse direction, and being flexible in both directions.
6. An article as defined in claim 1, said second projections on said additional lower surface extending downwardly from the latter in at least substantial parallelism with each other.
7. An article as defined in claim 1; and further comprising a circumferential edge portion provided on said sole member and projecting transversely to the respective general planes of said upper and lower surfaces.
8. An article as defined in claim 7, wherein said edge portion is at least substantially circumferentially complete.
9. An article as defined in claim 1, wherein said material is a high-molecular foamed material.
10. An article as defined in claim 9, wherein said material is foamed polyurethane.
11. An article as defined in claim 1, wherein said material is a cork-latex mixture.
12. An article as defined in claim 1, said upper means comprising straps of one piece with said sole means and having free end portions, and connecting means for connecting said free end portions when said straps have been placed about a foot.
13. An article as defined in claim 12, said straps each having two at least substantially identical major sides.
14. An article as defined in claim 12, wherein said sole means has a marginal circumferential portion, and wherein said straps are of one piece with the same.
15. An article of footwear, comprising upper means; sole means of yieldable elastomeric material provided on said upper means and including a sole member having a normally upper surface adapted to face the underextending downwardly therefrom in at least substantial parallelism with each other, each of said second projections being coaxial with one of said first projections.
16. An article as defined in claim 15, wherein each of said second projections has a length corresponding to that of the first projection with which it is coaxial.