U.S. patent number 3,722,113 [Application Number 05/140,691] was granted by the patent office on 1973-03-27 for article of footwear.
Invention is credited to Karl Birkenstock.
United States Patent |
3,722,113 |
Birkenstock |
March 27, 1973 |
ARTICLE OF FOOTWEAR
Abstract
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.
Inventors: |
Birkenstock; Karl (BAD Honnef,
DT) |
Family
ID: |
6612501 |
Appl.
No.: |
05/140,691 |
Filed: |
May 6, 1971 |
Foreign Application Priority Data
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|
|
|
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Jun 20, 1970 [DT] |
|
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G 70 23 257.4 |
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Current U.S.
Class: |
36/11.5; 36/141;
36/43 |
Current CPC
Class: |
A43B
7/146 (20130101); A43B 13/184 (20130101); A43B
7/141 (20130101); A43B 7/142 (20130101); A43B
13/00 (20130101) |
Current International
Class: |
A43B
13/18 (20060101); A43B 3/10 (20060101); A43B
13/00 (20060101); A43b 003/12 () |
Field of
Search: |
;36/11.5,43,8.1
;128/581,582,614,615,25.2 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Lawson; Patrick D.
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 underside of a human foot and a normally lower surface
facing away from the human foot; and a plurality of first
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 projections provided on
said lower surface and extending 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.
Description
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 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 foot-- which 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 also
the outer or marginal portions. This requires according to the
present invention that all projections at least in the use of the
novel article of footwear extend at least approximately normal to
the underside of the foot, that is to that portion of the underside
with which they are to be engaged. The projections provided on the
marginal circumferential portion of the sole member, particularly
those in the region of the heel, 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 member--
will 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 them-- in 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 III--III 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 1 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.
* * * * *