U.S. patent application number 11/813068 was filed with the patent office on 2008-02-21 for cross-linked foam having a shock-absorbing means for an insole of shoes.
Invention is credited to Jang Won Park.
Application Number | 20080040948 11/813068 |
Document ID | / |
Family ID | 36615068 |
Filed Date | 2008-02-21 |
United States Patent
Application |
20080040948 |
Kind Code |
A1 |
Park; Jang Won |
February 21, 2008 |
Cross-Linked Foam Having a Shock-Absorbing Means for an Insole of
Shoes
Abstract
The present invention provides a cross-linked foam having a
shock-absorbing means for an insole of shoes comprises a
cross-linked foam body; an inner cavity structure formed in the
cross-linked foam body, the inner cavity structure formed
simultaneously with the cross-linked foam body; and a filler in the
inner cavity structure. The filler may be filled into and sealed by
a housing that is formed in the inner cavity structure. According
to the present invention, the shock-absorbing means having a
greater thickness than the cross-linked foam body can easily be
formed in the cross-linked foam body and the inner cavity structure
can be shaped along a shape of a bare foot to offer more
comfortable fitting.
Inventors: |
Park; Jang Won; (Busan,
KR) |
Correspondence
Address: |
BIRCH STEWART KOLASCH & BIRCH
PO BOX 747
FALLS CHURCH
VA
22040-0747
US
|
Family ID: |
36615068 |
Appl. No.: |
11/813068 |
Filed: |
April 16, 2005 |
PCT Filed: |
April 16, 2005 |
PCT NO: |
PCT/KR05/01099 |
371 Date: |
June 28, 2007 |
Current U.S.
Class: |
36/43 |
Current CPC
Class: |
A43B 17/14 20130101;
A43B 13/188 20130101; A43B 7/142 20130101; A43B 17/03 20130101;
A43B 7/148 20130101; A43B 13/20 20130101 |
Class at
Publication: |
036/043 |
International
Class: |
A43B 13/38 20060101
A43B013/38 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 31, 2004 |
KR |
10-2004-0118122 |
Claims
1-13. (canceled)
14. A cross-linked foam for an insole for shoes, comprising: a
cross-linked foam body having at least one inner cavity structure,
the inner cavity structure formed in the cross-linked foam body; a
housing in the inner cavity structure, the housing filled with
filler.
15. The cross-linked foam according to claim 14, wherein the inner
cavity structure having the housing is formed in the cross-linked
foam body at a position corresponding to a metatarsus of a
foot.
16. The cross-linked foam according to claim 15, wherein unevenness
is formed on a covering portion of the inner cavity structure.
17. The cross-linked foam according to claim 14, wherein the filler
is selected from at least one of gas, liquid and material that is
same as or different from the cross-linked foam body.
18. The cross-linked foam according to claim 14, wherein the
cross-linked foam body further has at least one inner cavity
structure other than the inner cavity structure having the
housing.
19. The cross-linked foam according to claim 18, wherein unevenness
is formed on a covering portion of at least one of the inner cavity
structures.
20. The cross-linked foam according to claim 18, wherein the at
least one inner cavity structure other than the inner cavity
structure having the housing is filled with filler.
21. The cross-linked foam according to claim 20, wherein the filler
is selected from at least one of gas, liquid and material that is
same as or different from the cross-linked foam body.
22. The cross-linked foam according to claim 21, wherein the filler
is filled into a housing and the housing is disposed in the inner
cavity structure.
23. The cross-linked foam according to claim 14, wherein the
cross-linked foam body further has a plurality of inner cavity
structures other than the inner cavity structure having the
housing.
24. The cross-linked foam according to claim 23, wherein at least
one of the inner cavity structures other than the inner cavity
structure having the housing is filled with filler.
25. The cross-linked foam according to claim 24, wherein the filler
is selected from at least one of gas, liquid and material that is
same as or different from the cross-linked foam body.
26. The cross-linked foam according to claim 25, wherein the filler
is filled into a housing and the housing is disposed in the cavity
structure.
27. The cross-linked foam according to claim 23, wherein unevenness
is formed on a covering portion of at least one of the inner cavity
structures other than the inner cavity structure having the
housing.
28. The cross-linked foam according to claim 23, wherein all or
some of the plural inner cavity structures are connected to each
other.
29. The cross-linked foam according to claim 28, wherein at least
one of the inner cavity structures other than the inner cavity
structure having the housing is filled with filler.
30. The cross-linked foam according to claim 29, wherein the filler
is selected from at least one of gas, liquid and material that is
same as or different from the cross-linked foam body.
31. The cross-linked foam according to claim 30, wherein the filler
is filled into a housing and the housing is disposed in the inner
cavity structure.
Description
TECHNICAL FIELD
[0001] The present invention relates to a cross-linked foam, and
more specifically a cross-linked foam having a shock-absorbing
means for an insole of shoes that can be manufactured by a simple
manufacturing process and effectively serves to reduce an impact
applied to a foot.
BACKGROUND ART
[0002] We usually spend most of the time standing with shoes on
feet. The shoe was developed to protect the bare feet of men.
However, an importance of the shoes has been increasingly
emphasized nowadays. Accordingly, the function of the shoes has
been improved to protect a spinal column, a knee joint and an ankle
joint as well as the feet.
[0003] Therefore, the shoe makers have been trying to give various
function to mid-sole and out-sole contacting the ground and uppers
contacting the feet. However not many researches have been made in
the field to improve insole contacting the feet directly and
delivering the impact to the feet. Recently, various models using
an air tube have been suggested to improve a human sensation of the
shoes by reducing the impact applied to the feet or increasing a
contact property with the feet. Most of the suggestions are about
methods in which a housing formed of flexible film type material is
filled with an air and then inserted or attached to the insole to
improve a function of shock-absorption of the insole. These methods
may be regarded as a progressive technology in that they utilizes a
property of an air as a shock-absorbing means by inserting or
attaching the housing filled with the air to the insole. However,
those methods have some disadvantages as follows.
[0004] FIG. 11 is a plan view of an insole according to the related
art and FIG. 12 is a cross-sectional view of an insole taken along
a line A-A' of FIG. 11. Generally, an insole 10 mainly comprises a
body 12 having a thickness .DELTA.t and an edge portion 16 formed
along sides of the body 12. The edge portion 16 is tapered in a way
that a thickness becomes smaller as it goes to an edge. The edge
portion slopes up considering a form of the feet.
[0005] A reference number 18 in the figure is a finishing material
such as a cloth and a non-woven fabric attached to the body 12.
[0006] The housing is usually formed of flexible material to
maximize a shock-absorbing function of the air filled therein. Once
the housing is filled with the air, a form of the housing is
changed and deformed according to a pressure applied to the
housing.
[0007] According to related art, the housing having a
three-dimensional shape must be attached to the planar insole, but
the housing cannot easily be attached to the insole owing to a
difference of the shape. This problem becomes more serious
considering the housing is likely to be deformed by an external
pressure. Even if the housing is attached to the insole through a
complex process and a high cost, the housing is likely to be
separated from the insole during a use of the shoe owing to a
repeated bending of the insole.
[0008] Meanwhile, it is a very tricky work to insert the housing
having a relatively great thickness into the insole having a
relatively small thickness .DELTA.t in FIG. 12. This problem
becomes more serious considering that the housing must be located
on the insole at a position 14 in FIG. 12 corresponding to the
metatarsus and be extended to an edge portion of the insole having
a very small thickness
[0009] In an alternative to overcome those problems, a certain
portion of the formed body to which the housing is attached may be
depressed or the housing may be disposed between two sheets of
formed material at a proper position and then the two sheets of
formed material are attached together. This method has following
disadvantages.
[0010] Because this method requires an additional process and
materials, a manufacturing cost becomes increased. Besides, because
the insole around the housing is anfractuous, a human sensation of
the shoes is bad and a durability of the insole cannot be
secured.
DISCLOSURE OF INVENTION
Technical Problem
[0011] Accordingly, the present invention has been made keeping in
mind the above problems occurring in the related art, and an object
of the present invention is to provide a cross-linked foam for
insole that can fulfill a shock-absorbing function without
attachment or insertion of an additional shock-absorbing device to
the insole.
[0012] Another object of the present invention is to provide a
cross-linked foam for insole of which filler can stably fulfill a
shock-absorbing function in the insole.
[0013] Another object of the present invention is to provide a
cross-linked foam for insole of which shock-absorbing means can be
formed in any portion of the insole.
[0014] Another object of the present invention is to provide a
cross-linked foam for insole of which shock-absorbing means is
formed in the insole simultaneously with the insole so that it
offers more comfortable fitting.
[0015] Another object of the present invention is to provide a
cross-linked foam for insole of which shock-absorbing means can be
stably kept in the insole so that a durability can be improved.
Technical Solution
[0016] To achieve these and other advantages and in accordance with
the purpose of the present invention, as embodied and broadly
described, a cross-linked foam for an insole for shoes comprises a
cross-linked foam body having at least one inner cavity structure,
the inner cavity structure formed in the cross-linked foam body; a
housing in the inner cavity structure, the housing filled with
filler.
[0017] In the above, the inner cavity structure having the housing
may be formed in the cross-linked foam body at a position
corresponding to a metatarsus of a foot.
[0018] In the above, unevenness may be formed on a covering portion
of the inner cavity structure.
[0019] In the above, the cross-linked foam body may further have at
least one inner cavity structure other than the inner cavity
structure having the housing.
[0020] In the above, the cross-linked foam body may further have a
plurality of inner cavity structures other than the inner cavity
structure having the housing.
[0021] In the above, all or some of the plural inner cavity
structures may be connected to each other.
[0022] In the above, at least one of the inner cavity structures
other than the inner cavity structure having the housing is filled
with filler.
[0023] In the above, the filler may be filled into the housing and
the housing may be disposed in the inner cavity structure.
[0024] In the above, the filler may be selected from at least one
of gas, liquid and material that is same as or different from the
cross-linked foam body.
[0025] In the above, unevenness may be formed on a covering portion
of at least one of the inner cavity structures other than the inner
cavity structure having the housing.
[0026] It is to be understood that both the foregoing general
description and the following detailed description are exemplary
and explanatory and are intended to provide further explanation of
the invention as claimed.
ADVANTAGEOUS EFFECTS
[0027] According to the present invention, a shock-absorbing means
having a greater thickness than a cross-linked foam body can easily
be formed in the cross-linked foam body at a predetermined
position.
[0028] The shock-absorbing means can be formed in an inner cavity
structure formed simultaneously with the cross-linked foam body
without damaging a cross-linked foam. And therefore, the shape of
the cross-linked foam can be maintained without any damage or
deformation.
[0029] In addition, a human sensation of shoes can be greatly
improved by filling certain material into the inner cavity
structure or into a housing disposed in the inner cavity
structure.
[0030] The inner cavity structure can be shaped along a shape of a
bare foot to improve a human sensation of shoes and the insole
having an effective shock-absorbing function can be provided with a
low manufacturing cost.
BRIEF DESCRIPTION OF THE DRAWINGS
[0031] The above and other objects, features and other advantages
of the present invention will be more clearly understood from the
following detailed description taken in conjunction with the
accompanying drawings, in which:
[0032] FIG. 1 is a plan view of an insole having a shock-absorbing
means according to the present invention;
[0033] FIG. 2 is a cross-sectional view of an insole taken along a
line B-B' of FIG. 1;
[0034] FIG. 3 is a cross-sectional view of an insole taken along a
line C-C' of FIG. 1;
[0035] FIG. 4 is a perspective view of a shock-absorbing means
according to the present invention;
[0036] FIGS. 5 to 10 are illustrating a manufacturing process of an
insole having a shock-absorbing means according to the present
invention;
[0037] FIG. 11 is a plan view of an insole according to the related
art; and
[0038] FIG. 12 is a cross-sectional view of an insole taken along a
line A-A' of FIG. 11.
MODE FOR THE INVENTION
[0039] Reference will now be made in detail to the preferred
embodiment of the present invention, which is illustrated in the
accompanying drawings.
[0040] FIG. 1 is a plan view of an insole having a shock-absorbing
means according to the present invention, FIG. 2 is a
cross-sectional view of an insole taken along a line B-B' of FIG. 1
and FIG. 3 is a cross-sectional view of an insole taken along a
line C-C' of FIG. 1. A cross-linked foam 100 of the present
invention mainly comprises a cross-linked foam body 120 and inner
cavity structures 124 and 128. The cross-linked foam body 120 is
formed by a cross-linked foaming method. The cross-linked foam body
120 can be manufactured by foaming various foaming material known
in the field by various foaming method known in the field.
Ethylene-vinyl acetate (EVA) based resin having diverse vinyl
acetate contents (VA %) or polyethylene (PE) based resin having
diverse density may desirably be selected as a raw material for the
foaming material. However, the foaming material is not confined to
those materials.
[0041] The inner cavity structure is formed in the cross-linked
foam body 120 simultaneously with the cross-linked foam body 120.
That is, the cross-linked foam body 120 and the inner cavity
structure are foamed at a time. The inner cavity structure 128 for
a metatarsus is desirably formed in the cross-linked foam body 120
at a position corresponding to the metatarsus of the feet. Though a
shape of the inner cavity structure 128 for the metatarsus is not
confined to a certain shape, a covering portion 126 of the inner
cavity structure 128 for the metatarsus is desirably formed along
an outline of the metatarsus of the feet so that a human sensation
of the shoes can be greatly improved.
[0042] There may be formed another inner cavity structure other
than the inner cavity structure for the metatarsus in the
cross-linked foam body 120 at a position corresponding to a bottom
of the feet. The shape and number of the additional inner cavity
structure can be changed diversely according to a given condition.
In FIG. 2, a single inner cavity structure 124 except the inner
cavity structure for the metatarsus is formed in the cross-linked
foam body 120, i.e. insole, at a position of a middle-foot. In FIG.
3, plural inner cavity structures 124 except the inner cavity
structure for the metatarsus are formed in the cross-linked foam
body 120, at a position of a fore-foot.
[0043] All or some of the additional inner cavity structures may be
connected to each other or the additional inner cavity structure
may be connected only to the adjacent additional inner cavity
structure. The connected structure of the inner cavity structure is
not limited and can be controlled considering various
conditions.
[0044] Though it is not illustrated in the figures, unevenness may
be formed on covering portions 122 and 126 of the inner cavity
structures to increase a human sensation of the shoes and aesthetic
feeling.
[0045] The inner cavity structure may be filled with various
materials. A filler of the inner cavity structure may be gaseous
material such as an air or a material that is same as or different
from the cross-linked foam body 120. If the number of the inner
cavity structure is plural, each of the plural inner cavity
structures may be filled with different materials. A phase of the
filler is not limited and it may be gas, liquid or solid including
a molded material. Those filler may be filled into an additional
housing 160 and the housing may be disposed in the inner cavity
structure. The FIG. 2 illustrates one of many possible embodiments
in which the housing 160 filled with the filler 168 is formed in
the inner cavity structure 128 for the metatarsus. The housing 160
may desirably be formed of a flexible material. That is, though the
material for the hosing 160 is not confined to a certain material,
it may desirably be formed of TPU (thermoplastic polyurethane). A
reference number 162 is an injecting portion through which the
filler is injected when the filler is injected into a space of the
housing 160, and it is sealed after an injection process. A
reference number 180 is a finishing material for the insole.
[0046] A manufacturing process of the cross-linked foam for an
insole of the shoes comprises the following steps. In a first step,
foaming material is prepared. In a second step, an interfacing
pattern is formed on the foaming material. In a third step, the
foaming material having the interfacing pattern goes through a
cross-linked foaming process. In a fourth step, a shock-absorbing
means is formed in the cross-linked foam. A step of re-molding may
further be included in the manufacturing process.
[0047] The manufacturing method and process of the present
invention will be described more in detail hereinafter with
reference to attached figures. FIGS. 5 to 10 are illustrating a
manufacturing process of an insole having a shock-absorbing means
according to the present invention.
[0048] In the first step, a source material for the foaming
material is selected from various materials such as the above
mentioned materials for the cross-linked foam body 120 considering
a use and a physical property of the cross-linked foam. After
planning the material composition, the source material and the sub
materials are weighed by desired amounts in accordance with the
material composition plan, and then the source material and sub
materials are mixed in the properly selected mixing device. The
mixed chemical compound is then processed into a foaming material
with a cross-linked foaming suppressed by a calender or an
extruder.
[0049] The foaming material has a planar shape, such as film or
sheet, or a three-dimensional shape, such as a pellet. The foaming
material according to the present invention is not limited to a
specific shape or type, but it may desirably have a planar shape,
particularly a film shape, which has a low surface roughness,
because the foaming material is weighed every time the foaming
process is performed when it is used as a particle or sheet type.
Further, when the foaming material is applied to the specific
embodiment, the foaming material is recommended to have a planar
shape, particularly a film shape, which has a low surface
roughness, regarding the advisable use. If the obtained foaming
material has a shape such as the pellet or the sheet having a rough
surface, it may desirably be re-processed into a thin film having a
low surface roughness. However, the shape of the foaming material
is not limited as long as it can be processed into a certain shape
with the cross-linked foaming suppressed and an interfacing pattern
can be formed thereon later in the process. Though the foaming
material 200 has a shape corresponding to the insole in FIG. 5, the
foaming material of the present invention is not confined to
this.
[0050] In the second step, at least one interfacing pattern is
formed on the foaming material with different material from the
foaming material to intercept a physical and chemical action among
particles of the foaming material.
[0051] The material for the interfacing pattern may be liquids
having viscosity, powder or solid having a certain shape such as
films, which is able to prevent the interaction between the foaming
materials during the cross-linked foaming process. For example, the
interfacing material may be selected from a group consisting of
natural or synthetic paints or inks, natural or synthetic resins,
papers, textiles, non-woven fabrics, and rubbery materials.
Additionally, when selecting the interfacing material, it is
considerable to be easily attached to the foaming material, to have
the repeated reappearance during the foaming process, to have the
possibility of obstructing the cubical expansion of the foam during
the foaming process, or to have the easy elimination from the
cross-linked foam if required after the foaming process.
[0052] The formation of the interfacing pattern may be achieved by
printing, transcription, coating, deposition, lamination, spray,
cloth attachment, inserting, attaching or a modification thereof,
and any other method can be possible only if it is able to form the
interfacing material on the surface of the foaming material.
However, when the ink or the like containing various kind of resins
dissolved is used as an interfacing material, the printing method
is desirably adopted in forming the interfacing pattern.
[0053] Further, if more than two interfacing patterns are formed,
each of the interfacing patterns may be formed with same or
different material. A foaming agent, which is the same as or
different from a foaming agent contained in the foaming material,
may be added to the interfacing material.
[0054] Moreover, a step of combining at least one foaming material
having no interfacing pattern with the foaming material having the
interfacing pattern may be further added.
[0055] The foaming material having no interfacing pattern may be
the same material as or different material from the foaming
material having the interfacing pattern. A step of adding material
same as or different from the foaming material having the
interfacing pattern to the combined foaming material may be further
added.
[0056] There may be formed a plurality of interfacing patterns
without a connection to each other, or all or some of the plural
interfacing patterns may be connected to each other. Besides, the
interfacing pattern may be connected only to the neighboring
interfacing pattern.
[0057] In FIG. 5, two thin film type foaming material 200 is
prepared and interfacing patterns 320 and 360 having a certain
shape are formed on one of the foaming material 200. The
interfacing pattern 360 is formed on the foaming material 200 at a
position corresponding to the metatarsus of the feet and the
interfacing pattern 320 is formed on the foaming material 200 at a
position corresponding to the rest portion of the feet except the
metatarsus.
[0058] A reference number 362 is an interfacing pattern for a
cutting process that will be explained later. The interfacing
pattern 362 for the cutting process is for opening the inner cavity
structure 128 without damage to the cross-linked foam, i.e., the
insole, during a cutting process of a portion of the insole.
[0059] In the third step, the cross-linked foam having a shape of
the insole is formed by cross-linked foaming the foaming material
having the interfacing pattern thereon. The cross-linked foaming of
the foaming material may be performed by one of a pressure
cross-linked foaming method and normal pressure cross-linked
foaming method, or a modified or combined method thereof. But the
cross-linked foaming method is not confined to those. In FIG. 5, a
press type method using a molding die 400 is selected as one of the
pressure cross-linked foaming methods.
[0060] If the heat is applied to the foaming material or if the
electron rays are irradiated on the foaming material during the
cross-linked foaming process, the foaming material is cross-linked
in a gel state by the heat infliction or the electron irradiation.
However, the foaming materials neighboring each other across the
interfacing pattern are not physically/chemically coupled and
interconnected until they reach the step of foaming. At this state,
the foaming materials cubically expand at a specific rate and then
the cross-linked foams are made as shown in FIG. 6.
[0061] As shown in FIGS. 6 to 7, portions of the foaming materials
corresponding to the interfacing patterns 320 and 360 are also
cubically expanded at the similar ratio to the other portions
during the foaming process. However, because the physical and
chemical connection of the foaming material is prevented by the
interfacing pattern 320 and 360 and the interfacing pattern is
foamed at a different ratio from the foaming material, a certain
shape of space is formed in the cross-linked foam at a position
corresponding to the interfacing pattern.
[0062] As shown in FIG. 7 illustrating a cross-sectional view of
the cross-linked foam taken along a line D-D' of FIG. 6, the spaces
formed in the cross-linked foam body are inner cavity structures
124 and 128. Gases such as nitrogen (N.sub.2) and carbon dioxide
(CO.sub.2) that is generated by a decomposition action of the
foaming agent during the foaming process is trapped in the inner
cavity structures 124 and 128 and thus keep the interior of the
inner cavity structure at a certain pressure. The interior pressure
of the gases in the inner cavity structures 124 and 128 can be
properly controlled by adding a foaming agent to the interfacing
material before the cross-linked foaming process.
[0063] The shape and structure of the inner cavity structures 124
and 128 and a projection of surfaces 122 and 126 of the
cross-linked foam 100 can be modified diversely by controlling
shapes of the interfacing patterns or changing interfacing
materials regardless of shapes and kinds of the tools and devices
for the cross-linked foaming process.
[0064] Though it is not shown in FIG. 5, unevenness may further be
formed in a cavity 420 of the molding die 400.
[0065] In the fourth step, the shock-absorbing means is disposed in
the cross-linked foam 100 for the sole. The disposing process of
the shock-absorbing means mainly comprises following steps. In a
first step, the inner cavity structure is open by cutting a portion
of the inner cavity structure. In a second step, the housing is
disposed in the inner cavity structure. In a third step, a filter
is filled into the housing. In a fourth step, the housing is
sealed. In a fifth step, the open portion of the inner cavity
structure is closed.
[0066] A specific portion of the inner cavity structure 128 is cut
to open the inner cavity structure 128 so that the housing can be
introduced into the inner cavity structure 128. It is desirable
that the cutting process be performed near a portion 127 of the
inner cavity structure 128 that is formed by the interfacing
pattern 362 shown as "a" in FIG. 7 to reduce a possibility of
damage of the cross-linked foam body 120 and to make it easy to
seal and close the open inner cavity structure 128.
[0067] As shown in FIG. 8, once the inner cavity structure 128 is
open, the housing 160 in FIG. 4 is introduced into the open inner
cavity structure 128 and then filled with the filler "b" by
connecting an external injector 500 to an injecting portion 162 of
the housing 160.
[0068] Once the filling process is completed, the injecting portion
162 is sealed using a high frequency or a supersonic waves, etc.,
as shown in FIG. 9, and then the open portions of the cross-linked
foam body are closed by various attaching means such as a press
machine shown as "C" in FIG. 10. Finally, an insole having a
shock-absorbing means in FIG. 1 is obtained.
[0069] After the closing process of the open portion of the
cross-linked foam body, the cross-linked foam 100 may be re-formed
to treat an edge of the cross-linked foam 100 to be fit for the
feet. Besides, the open portion of the cross-linked foam body 120
can be more firmly attached in the re-forming process.
[0070] While FIGS. 6 to 10 shows the case that an edge portion of
the insole having a slope is formed to have a curved outline during
the cross-linked foaming process, the tapered edge portion of the
insole may be formed through a re-forming process after the
cross-linked foaming process.
[0071] Unevenness may be formed in a cavity of a molding die for
the re-forming process at a position corresponding the covering
portions 122 and 126 or at an arbitrary position.
[0072] It will be apparent to those skilled in the art that various
modifications and variations can be made in the cross-linked foam
for the insole of shoes without departing from the spirit or scope
of the invention. Thus, it is intended that the present invention
cover the modifications and variations of this invention provided
they come within the scope of the appended claims and their
equivalents.
* * * * *