U.S. patent number 3,818,617 [Application Number 05/281,119] was granted by the patent office on 1974-06-25 for outer sole for a sport shoe.
This patent grant is currently assigned to Puma-Sporlschuhfabriken Rudolf Dessler KG. Invention is credited to Rudolf Dassler, Horst Dreier, Norbert Muller, Erich Strickle.
United States Patent |
3,818,617 |
Dassler , et al. |
June 25, 1974 |
OUTER SOLE FOR A SPORT SHOE
Abstract
There is disclosed a track sport shoe with an outer sole
specifically designed for use on tracks covered with a layer of
thermoplastic synthetic material. The outer sole is made of a
thermoplastic synthetic material having an elastic modulus of at
least 10,000 kp/cm.sup.2. A plurality of generally wedge-or
tooth-shaped protrusions are attached to the running surface of the
sole in spaced apart relationship. Each of the protrusions has a
large side disposed substantially normal to the surface of the sole
and a smaller secondary side defining an angle with the sole. The
tip of each protrusion forms a small surface area substantially
parallel to the sole. The protrusions in conjunction with the
elasticity of the sole provide a safe grip for the foot of an
athlete on the track without penetrating or cutting into the
same.
Inventors: |
Dassler; Rudolf
(Herzogenqurach, DT), Dreier; Horst (Worms,
DT), Strickle; Erich (Mannheim, DT),
Muller; Norbert (Mainz-Gonsenheim, DT) |
Assignee: |
Puma-Sporlschuhfabriken Rudolf
Dessler KG (Wurzburger, DT)
|
Family
ID: |
5819541 |
Appl.
No.: |
05/281,119 |
Filed: |
August 16, 1972 |
Foreign Application Priority Data
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|
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Sep 15, 1971 [DT] |
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2145982 |
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Current U.S.
Class: |
36/32R; 36/129;
36/67R; 36/134 |
Current CPC
Class: |
A43B
5/06 (20130101); A43B 13/223 (20130101) |
Current International
Class: |
A43B
13/14 (20060101); A43B 13/22 (20060101); A43B
5/00 (20060101); A43B 5/06 (20060101); A43b
013/04 () |
Field of
Search: |
;36/67R,67D,59R,2.5R,2.5AM,32R,2.5AH |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Lawson; Patrick D.
Attorney, Agent or Firm: Hane, Baxley & Spiecens
Claims
What is claimed is:
1. A track shoe for use on tracks covered with a thermoplastic
synthetic material having an elastic modulus of at least 10,000
kp/cm.sup.2, and a plurality of protrusions having a generally
wedge-shaped cross-sectional outline attached to the outer surface
of the sole in spaced apart relationship, each of said protrusions
having a primary side disposed substantially normal to the surface
of the sole, a secondary side defining an angle with the sole and
at its tip a substantially flat surface area substantially parallel
to the sole, said protrusions being so oriented that the primary
side of some of the protrusions is substantially crosswise to the
length of the sole and the primary side of other protrusions is
disposed at an angle with reference to the length of the sole.
2. The track shoe according to claim 1 wherein the primary sides of
protrusions next to the tip of the sole face rearwardly and primary
sides of protrusions at a greater distance from the tip face
substantially forwardly.
3. A track shoe according to claim 1 wherein at least protrusions
disposed along the lateral rim of the sole are so oriented that the
secondary side thereof faces outwardly.
4. The track shoe according to claim 1 wherein
5. The track shoe according to claim 1 wherein said protrusions are
made in one piece with the outer sole.
6. The track shoe according to claim 1 wherein the protrusions are
embedded, one by one, into the material of which the sole is
formed.
7. The track shoe according to claim 1 wherein said sole includes
in its outer surface grooves extending substantially crosswise of
the length of the sole, and wherein said protrusions are detachably
mounted on carrier strips, said strips and the protrusions thereon
being detachably secured in said grooves.
8. The track shoe according to claim 7 wherein each of said grooves
has an undercut cross-section and the strips have a matching
cross-section.
9. The track shoe according to claim 1 wherein said sole includes
holes there through, said protrusions being inserted into said
holes and secured therein.
Description
The present invention relates to an outer sole for sport shoes and
particularly for sport shoes as are used by track runners and
jumpers.
BACKGROUND
There are now known and widely used tracks covered with a layer of
synthetic plastic material for athletic sports. Among the various
synthetic plastics used or at least tried for the purpose, one of
the best known track materials are materials having a polyurethane
base and are known under the trademarks Tartan and Recortan. Other
track materials which use a thermoplastic base material are known
under the trademarks Akus and Fastrac. There are also known tracks
using a layer having a bitumen base. Such tracks are known for
instance under the name Rubcor.
Modern tracks coated with synthetic plastic have various advantages
in that they require virtually no maintenance and have a long
lifetime. Moreover, the tracks, except the tracks using a bitumen
base, have rigidity and elasticity properties which are virtually
independent of the ambient temperature. The result is that improved
performances by the athletes are obtained and that the tracks can
be continuously used. The tracks are usually provided with a
slightly uneven surface; generally depressions of two to three mm.
in the track surface are used.
Track shoes as are customarily used, have spikes or cleats on their
sole. The use of soles of this kind is acceptable on tracks which
are covered with a natural covering such as cinder. However, soles
with spikes or cleats have several disadvantages when used on
tracks covered with a synthetic material of the kind previously
referred to. Cleats or spikes will penetrate or cut into the track
material in which they will be more or less tightly gripped by the
track material as materials used for such tracks have at least, to
some extent, self-sealing properties. Obviously, penetration of
spikes or cleats into the track material requires an extra effort
on the part of the athlete and the withdrawal of the cleats or
spikes from the track requires an even greater extra effort. As a
result, a considerable decline of the performance of athletes
wearing shoes having spikes or cleats has been observed on tracks
covered with the afore referred to synthetic materials. As is
readily apparent, such additional efforts required for each step or
jump made by an athlete adds up to a quite considerably higher
total effort which correspondingly reduces the performance of the
athlete. Such increase in effort is of course a very important
factor to an athlete as track races particularly sprints over short
distances are often won by a few or even only one step. A further
disadvantage of soles with spikes or cleats is that due to the
required increased effort the foot and leg muscles of the athlete
are exposed to a correspondingly increased strain which constitutes
a danger of injury to the tissues and tendons of the foot or leg,
especially if many twisting or bending movements are involved.
Furthermore, the track, which as pointed out before, has inherently
a very long useful life, is subjected due to the innumerable cuts
and holes caused by the penetrations and withdrawals of spikes or
cleats, to a very considerable wear and tear. It has been observed
that an extensive use of shoes with spikes or cleats causes a
gradual crumbling of the surface of the track.
As it is apparent from the previous discussion, the introduction of
the now widely used tracks covered with synthetic plastic materials
of the kind previously referred to has also introduced a host of
problems as far as the heretofore customary and satisfactory shoes
having soles with spikes or cleats are concerned.
THE INVENTION
It is a broad object of the present invention to provide a novel
and improved sport shoe, the use of which on tracks covered with a
synthetic plastic material does not have the afore pointed out
disadvantage of track sport shoes as heretofore known.
A more specific object of the invention is to provide a novel and
improved track sport shoe which is suitable for use on tracks
covered with plastic material, irrespective whether the track is
dry, wet or even covered with a slippery film.
Another more specific object of the invention is to provide a novel
and improved track sport shoe of the general kind above referred to
which is low in weight and not only makes possible a smooth
rolling-off the foot on the track but even assists such
rolling-off.
SUMMARY OF THE INVENTION
The afore pointed out objects, features and advantages and other
objects, features and advantages which will be pointed out
hereinafter are obtained by making the sole of the shoe of a
thermoplastic material which has an elastic modulus of at least
10,000 kp/cm.sup.2. Preferably, the plastic is of a type that can
be molded by a conventional injection molding technique. Material
of this kind assures that the sole retains its shape as it is
sufficiently rigid but has the necessary flexibility to permit
convenient rolling-off of the foot. Moreover, it has, and this is
very important, a shape recovery capability which assures that it
returns to its original shape after rolling-off, that is, after
lifting of the foot. These properties of the sole aid and
facilitate the rolling-off action to which the sole is subjected at
each step.
The invention also provides that the sole is provided with wedge-or
tooth-shaped protrusions, which have a large primary or main flank
or side which is disposed substantially normal to the surface of
the sole and a small secondary flank or side which defines an angle
with reference to the surface of the sole. Such shaping of the
protrusions is based on the finding that protrusions on the running
sole of a sport shoe to be advantageous for use on tracks covered
with synthetic plastic material must not penetrate into the track
material and should grip or clutch the surface of the track in a
manner sucn that there is no danger of slipping of the athlete. In
particular, the protrusions must be capable of controlling the
lateral or centrifugal forces acting upon an athlete when running
through a curve. The tooth-shaped protrusions on the sole according
to the invention cause-and this is particularly important-only a
superficial elastic deformation of the surface of the track. Such
temporary deformation assures a sufficient protection against
slipping of the athlete but avoids as aforementioned additional
physical effort as they do not penetrate into the track. In other
words, the inherent properties of a sole according to the invention
eliminate the afore referred to additional effort necessitated by
track shoes having cleats or spikes. The afore referred to primary
flank of the protrusion which is oriented normal to the surface of
the sole assists for each step a pushing away of the foot from the
track as is of course highly desirable. The angularly oriented
other flank results in the wedge-or tooth profile of the
protrusions thereby facilitating the afore referred to elastic
deformation of the surface of the track and the rolling-off of the
sole on the track.
A particular significance of the secondary flanks of the
protrusions is that they prevent the penetration or cutting into
the surface of the track. Moreover, when the track is covered with
a slippery surface film or layer, it is assured that each layer is
cut through when a runner or jumper places his foot off the track
thereby causing the afore described desired temporary deformation
of the track surface even if the same is coated with some slippery
substance.
According to a further feature of the invention, the wedge-or
tooth-shaped protrusions are preferably so arranged that with some
of the protrusions the primary flank thereof is disposed crosswise
of the length of the shoe, while the primary flank of other
protrusions on the sole defines an angle with reference to the
length of the shoe. The provision of the crosswise protrusions
assures that the runner or jumper can push himself off a track
surface without difficulty in the direction of his forward movement
and the protrusions disposed at an angle help the runner to resist
the lateral forces to which he is subjected when running through a
curve. It has been found to be advantageous to arrange the
angularly disposed protrusions at an angle of about 45.degree. with
reference to the length of the sole.
According to a further aspect of the invention, it has been found
advantageous to make the protrusions from the same hardening
material which is used for the track. The protrusions and the
running sole itself are preferably made out of similar material.
Advantageously, the protrusions are formed with reinforcements such
as incorporation of glass fibers.
The protrusions can be produced independently of the sole and then
incapsulated by the material of the sole as the same is produced by
injection molding. However, the protrusions can also be mounted on
strips which are exchangeably insertable into grooves provided in
the sole for the purpose. These grooves are preferably disposed
crosswise of the length of the sole. The strips and the protrusions
thereon are then suitably secured in the correct position; for
instance, mechanically, by gluing or by heat sealing. The grooves
have preferably an undercut or keystoned cross-sectional outline;
they may for instance be swallow-tailed, T-shaped or otherwise
shaped in crosssection. The strips to be inserted into the grooves
must, of course, have a matching cross-section.
It is further possible to provide holes in the sole into which the
protrusions are inserted by means of pins which in turn are
suitably secured, for instance, by gluing. Such arrangement has the
advantage that the protrusions can be arranged as to number and
location in accordance with the specific sport and track for which
the shoes are intended.
As it is evident, soles, according to the invention, avoid the
disadvantage of shoes, the soles of which have spikes or cleats
attached thereto. As it is also evident, the protrusions according
to the invention do not cut or penetrate into the material of the
track and thus may result in a considerable improvement in the
performance of an athlete wearing shoes according to the invention.
It is also important that the protrusions are very reliable as to
function, irrespective whether the track is dry, wet or slippery.
In contradistinction to the often observed fact that an athlete
using spikes or cleats always has the feeling that such spikes or
cleats give the impression of walking or stilts, a shoe equipped
with a sole according to the invention has the advantage that the
sole conveys the impression to an athlete that his foot fully rests
on the surface of the track.
As previously explained, the running sole is made of a
thermoplastic synthetic material, having an elastic material,
having an elastic modulus of at least 10,000 kp/cm.sup.2 and is
capable of being produced by injection molding. Suitable
thermoplastics are for instance polyamides, polyformaldehydes,
polyolefines or also polyurethanes.
A particular advantage that can be obtained with a sole according
to the invention is that the protrusions according to the invention
in contrast to spikes or cleats can be placed close to the rim of
the sole due to the shape of the protrusions. It has been found
that such closeness of the protrusions to the rim greatly improves
the running capabilities of an athlete as his foot rolls-off on the
running surface. This advantage is particularly noticeable when an
athlete runs through a curve.
The better and more uniform distribution of the wedge-or
tooth-shaped protrusions over the entire outer surface of the sole
also results in a less tiresome load on the feet of the athlete.
The structure of the protrusions also makes less likely injury to
the athlete; injuries often occur when spikes are used; in fact,
the protrusions of the invention practically preclude the
likelihood of injuries. As a result, the safety of a sport shoe
with an outer sole according to the invention is markedly
increased.
Finally, the protrusions being exchangeably attached to the sole if
desired can be colored, thereby increasing the attractiveness of
the shoe; even multi-colored protrusions can be used.
If desired, the protrusions can be also provided on the heel
portion of the sole in the same manner as has been previously
described for the forward portion of the running surface of the
shoe.
Finally, the protrusions can be secured to the sole by means of
threaded studs as they are frequently used for golf shoes.
Further objects, features and advantages of the invention shall be
pointed out hereinafter.
BRIEF DESCRIPTION OF THE DRAWING
In the accompanying drawing a preferred embodiment of the invention
is shown by way of illustration and not by way of limitation.
In the drawing:
FIG. 1 is a perspective view of a sport shoe having a sole
according to the invention;
FIG. 2 is a fragmentary bottom view of FIG. 1 on an enlarged
scale;
FIG. 3 is a perspective view of one of the protrusions on the sole
on a further enlarged scale;
FIG. 4 is a sectional view taken along line IV--IV of FIG. 2; and
FIG. 5 is a sectional view of FIG. 3.
DETAILED DESCRIPTION OF AN EMBODIMENT OF THE INVENTION
Referring now to the figures in detail, the sport shoe a as shown
in FIG. 1 is of a generally conventional design except for the
outer sole b. This sole is made of a thermoplastic synthetic
material, preferably of a type that can be molded by conventional
injection molding techniques and advantageously has an elastic
modulus of at least 10,000 kp/cm.sup.2. To increase the flexibility
of the sole, the same may be provided with a plurality of grooves c
which extend crosswise of the length of the sole.
As shown, a plurality of wedge-or tooth-shaped protrusions or
cleats d are attached to the sole. The number and distribution of
these protrusions are selected in accordance with the specific
sport activity for which the shoe is intended. Each of the
protrusions has a large primary side or flank e which is disposed
substantially normal to the sole and a smaller secondary side or
flank f which defines an angle with the sole, preferably an angle
of about 45.degree.. The sides e `and f need not to be joined by an
apex line but may be flattened to define a small top surface q.
Similarly, the side f may be joined to the base h of the protrusion
by a surface i parallel to side e. The protrusions are preferably
reinforced, for instance, by glass fibers as it is indicated at m
in FIG. 5.
As can best be seen in FIG. 2, the row of protrusions d nearest to
the tip of the sole are disposed so that the primary side e face
rearwardly as seen in the direction of forward movement of a person
wearing the shoe while the secondary sides f face forwardly.
Moreover, the center protrusion is disposed crosswise of the length
of the sole while the two outer protrusions define an angle
therewith. The protrusions in the second row from the tip are all
disposed at an angle to the length of the sole, preferably the
protrusions define angles of about 45.degree. and so that the
secondary sides f are always located on the forwardly facing side
of the protrusions. The orientation of the protrusions in the two
rows closest to the tip end of the sole due to their orientation
assist in a rapid start of a runner as they help him to push his
feet sharply against the track surface. Similarly, at each step,
they tend to push the foot up from the track after the rolling-off
of the sole on the track.
In the last two rows there are shown protrusions x and y which are
so oriented that their secondary sides face outwardly and their
primary sides face forwardly. Moreover, the protrusions x and y are
disposed symmetrically with respect to lines extending in the
lengthwise direction of the sole.
The sole and the protrusions attached thereto may be advantageously
formed of the same material which is used by the layer on the track
on which they are intended to be used though the material used for
the sole and the protrusions may be more hardened than the material
used for the track. As it is shown in FIG. 4, the protrusions may
be secured to the sole by suitable undercut grooves n into which a
matchingly shaped foot p on the protrusions is slid and then
fastened by a suitable adhesive.
While the invention has been described in detail with respect to a
certain now preferred example and embodiment of the invention, it
will be understood by those skilled in the art, after understanding
the invention, that various changes and modifications may be made
without departing from the spirit and scope of the invention, and
it is intended, therefore, to cover all such changes and
modifications in the appended claims.
* * * * *