FOOTWEAR AND METHOD FOR MANUFACTURE THEREOF
20220354208 · 2022-11-10
Inventors
Cpc classification
International classification
Abstract
A footwear for wrapping an entire foot includes a t lain body made of foam rubber. The main body is dug to embed synthetic rubber into a heel side of a bottom of the min body made of the foam rubber. The embedded part is a part from a mid point from a toe to a heel to a heel part of the bottom of the main body. Specific gravities of the foam rubber and the synthetic rubber are 0.38 g/cm.sup.3 and 1.03 g/cm.sup.3, respectively. A center of gravity of the footwear is shifted to the heel side using a difference in the specific gravity of both to increase stability such that the footwear does not fall over when the footwear is placed upside down. An opening of the footwear is further formed to be flat with respect to a ground surface when the footwear is placed upside down.
Claims
1. A footwear for wrapping an entire foot, comprising a main body made of foam rubber, wherein the main body is dug to embed synthetic rubber into a heel side of a bottom of the main body made of the foam rubber, the embedded part is a part from a mid-point from a toe to a heel to a heel part of the bottom of the main body, specific gravities of the foam rubber and the synthetic rubber are 0.38 g/cm.sup.3 and 1.03 g/cm.sup.3, respectively, a center of gravity of the footwear is shifted to the heel side using a difference in the specific gravity of both to increase stability such that the footwear does not fall over when the footwear is placed upside down, and an opening of the footwear is further formed to be flat with respect to a ground surface when the footwear is placed upside down.
2. The footwear according to claim 1, wherein the opening of the footwear has a width in a right-left direction widened more than a width in a direction perpendicular to the right-left direction for stabilization against a side wind received by a side surface of the footwear.
3. The footwear according to claim 1, wherein the synthetic rubber is embossed for a slip resistance.
4. A method for manufacturing footwear that wraps an entire foot and is allowed to be placed upside down to avoid an inside of the footwear to get dirty with rain and dust, the method comprising: a step of manufacturing the footwear having an opening with a flat shape with foam rubber having a specific gravity of 0.38 g/cm.sup.3; a step of subsequently digging a part from a mid-point from a toe to a heel to a heel part as a part of a bottom of the footwear manufactured with the foam rubber; and a step of subsequently fitting synthetic rubber having a specific gravity of 1.03 g/cm.sup.3 in a dug groove, wherein a center of gravity of the footwear is set in a heel side using a difference in the specific gravity.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0011]
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[0014]
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[0018]
[0019]
DESCRIPTION OF THE EMBODIMENTS
[0020] The following describes embodiments of the present invention with reference to the drawings. Note that the present invention is not limited to these embodiments. In addition, the drawings include parts expressed by appropriately changing scales, for example, partially enlarged or highlighted. The drawings illustrate only one of footwears used as a left and right pair. Since the other one has a similar configuration, the illustration is omitted.
[0021] The footwear 100 is a footwear used when, for example, a person goes outdoor. As illustrated in
[0022]
[0023] The foam rubber portion 10 forms a shape of the footwear, and constitutes the main part of the footwear 100. As described above, the foam rubber portion 10 includes the opening 1 and the internal space 2, and includes a bottom portion 11 as a part of a bottom of the footwear 100, an upper portion 12 as a part of an upper of the footwear 100, a toe portion 13 as a part of a toe of the footwear 100, and a heel portion 14 as a part of a heel of the footwear 100 constituting them.
[0024] The opening 1 is formed such that the foot F of the person can be inserted into and removed from the internal space 2. A width W1 in a right-left direction of the opening 1 is configured to be smaller (shorter) than a width W2 in a direction perpendicular to the width W1 direction.
[0025] In a lower surface 11a of the bottom portion 11, a depressed portion 11b in which a part of a region is depressed is formed (see
[0026]
[0027] As described above, the opening end surface 15 is a plane formed to entirely abut on the ground surface C. That is, the opening end surface 15 is flush with and parallel to the plane equivalent to the ground surface C.
[0028] An angle (an inclined angle) θ formed by the horizontal surface H and the opening end surface 15 is configured according to, for example, the shapes and the weights of the toe portion 13 and the upper portion 12. However, when the angle θ is a comparatively small and the inclination is gentle (for example, the angle θ of less than 10°), the meaningful effect brought by the inclination cannot be obtained, and the footwear 100 placed upside down is likely to fall over toward the toe portion 13 side and therefore is unstable. On the other hand, when the angle θ is comparatively large and the inclination is steep (for example, the angle θ in excess of 30°), the rise of the position of the center of gravity of the upside-down footwear 100 makes the footwear 100 unstable conversely. That is, in this case, the problem of the decrease in stability caused by the upward movement of the position of the center of gravity is more serious than the effect brought by moving the position of the center of gravity of the footwear 100 placed upside down in the direction from the toe portion 13 side toward the heel portion 14 side. Therefore, the angle θ is set to, for example, from 10° to 30°. In this case, while the decrease in stability caused by the rise of the position of the center of gravity of the upside-down footwear 100 is suppressed, the meaningful effect brought by the inclination can be provided. Note that when the footwear 100 is placed similarly to a general footwear, the opening end surface 15 is not limited to be the plane inclined with respect to the horizontal surface H, and may be a plane parallel to the horizontal surface H.
[0029]
[0030] Additionally, a width W3 in the right-left direction of the opening end surface 15 is configured smaller (narrower) than a width W4 (see
[0031] The foam rubber portion 10 is integrally formed by foam rubber. The foam rubber constituting the foam rubber portion 10 is rubber containing soft foam and soft rubber internally having many voids. As the soft rubber, for example, ethylene vinyl acetate rubber, polyethylene rubber, or silicon rubber is used. A specific gravity of the foam rubber portion 10 is set to be 0.38 g/cm.sup.3.
[0032] Referring again to
[0033] The synthetic rubber portion 20 is a plate-shaped member that is approximately parallel to the bottom surface of the footwear 100, and has a top surface 21, which is the main surface, as a joined surface joined to a bottom surface 11c of the depressed portion 11b. The synthetic rubber portion 20 has a thickness configured slightly larger (slightly longer) than the depth of the depressed portion 11b. In view of this, in the footwear 100, a lower surface (the main surface on the side opposite to the top surface 21) 22 of the synthetic rubber portion 20 slightly projects downward from the lower surface 11a of the foam rubber portion 10. The lower surface 22 of the synthetic rubber portion 20 constitutes the bottom surface of the footwear 100 together with the lower surface 11a of the foam rubber portion 10. The synthetic rubber portion 20 is not limited to have the plate shape, and may have, for example, a block shape and a film shape.
[0034] As illustrated in
[0035] The synthetic rubber portion 20 is integrally formed by synthetic rubber. The synthetic rubber constituting the synthetic rubber portion 20 is artificial rubber manufactured from, for example, petroleum and naphtha. For example, as the synthetic rubber, silicon rubber, acrylic rubber, and urethane rubber are used. A specific gravity of the synthetic rubber portion 20 is set to be 1.03 g/cm.sup.3.
[0036] Note that the synthetic rubber portion 20 is not limited to have the above-described shapes. For example, the synthetic rubber portion 20 may have a block shape instead of the plate shape, and may be a plate-shaped member approximately perpendicular to the bottom surface of the footwear 100. In this case, as described above, the depressed portion 11b is formed in the shape according to the shape of such a synthetic rubber portion 20. For example, when the synthetic rubber portion 20 has the plate shape approximately perpendicular to the bottom surface of the footwear 100, the depressed portion 11b is formed in the groove shape into which the plate-shaped synthetic rubber portion 20 is insertable from its width direction (the direction perpendicular to the thickness direction), and one end surface in the width direction of the synthetic rubber portion 20 is embossed.
[0037] The above-described footwear 100 is the footwear for wrapping the entire foot that includes the main body 30 (see
[0038] When the footwear 100 is placed upside down, the opening end surface 15 abuts on the ground surface C so as to close the internal space 2 and the footwear 100 is in the stable state without falling over. In view of this, placing the footwear 100 upside down outdoor by a user without use of, for example, a storage box allows reliably avoiding invasion of rain and dust into the internal space 2 beforehand. Accordingly, with the footwear 100, while the user does not use the footwear 100, only placing the footwear 100 upside down allows easily and reliably avoiding wetting and dirtying an inner surface 2a (see
[0039] Next, an example of a method for manufacturing the footwear 100 will be described with reference to the drawings.
[0040] As illustrated in
[0041] This step is performed by, for example, injection molding. In this step, first, a mold (for example, a metal mold) having the shape of the main body 30 is prepared, and then a molten resin injected into the mold to fill the form. Afterwards, the mold is removed. Thus, the main body 30 made foam rubber having a void structure is manufactured.
[0042] Next, the bottom 31 of the main body 30 is dug (Step S02).
[0043] In this step, as illustrated in
[0044] Additionally, separately from the above-described Step S01 and Step S02, a synthetic rubber main body (not illustrated) is manufactured (Step S11). Here, the synthetic rubber main body has the configuration identical to the synthetic rubber portion 20 excluding a point that the above-described embossing process is not performed on the lower surface 22. That is, the synthetic rubber main body is equivalent to the synthetic rubber portion 20 before being embossed.
[0045] This step is performed by, for example, injection molding. In this step, first, a mold (for example, a metal mold) having the shape of the synthetic rubber main body is prepared, and then a molten resin injected into the mold to fill the form Afterwards, the mold is removed. Thus, the synthetic rubber main body is manufactured.
[0046] Further, continuous with Step S11, an embossing process is performed (Step S12).
[0047] In this step, a surface that become the lower surface 22 of the synthetic rubber portion 20 in the synthetic rubber main body is embossed. Here, for example, the embossing process is performed by processing, such as removal of a region excluding a part becoming the plurality of grid-like projecting portions 23 in the surface 22. Through the above-described Step S11 and Step S12, the synthetic rubber portion 20 is manufactured and prepared.
[0048] Note that the above-described Step S11 and Step S12 may be performed simultaneously with the steps of Step S01 and Step S02 concurrently, or may be performed in a period before and after the steps of Step S01 and Step S02.
[0049] Subsequently, the synthetic rubber portion 20 is fitted to the foam rubber portion 10 (Step S03).
[0050] In this step, as illustrated in
[0051] The footwear 100 is completed by the above-described steps.
[0052] The above-described manufacturing method uses the method for manufacturing the footwear 100 that wraps the entire foot and is allowed to be placed upside down to avoid the inside of the footwear 100 to get dirty with rain and dust. The method includes: a step of manufacturing the main body 30 having the shape in which the opening 1 of the footwear 100 becomes flat with the foam rubber having the specific gravity of 0.38 g/cm.sup.3, subsequently, a step of digging the part from the center T between the toe and the heel to a heel portion 14 as the part of the bottom 31 of the main body 30 manufactured with the foam rubber; and subsequently, a step of fitting, the synthetic rubber having the specific gravity of 1.03 g/cm.sup.3 g/cm.sup.3 in the dug depressed portion (the groove) 11b. The center of gravity of the footwear 100 is set in the heel side using the difference in the specific gravity. The manufacturing method allows easily manufacturing the footwear 100.
[0053] Note that the footwear 100 is not limited to be manufactured by the above-described method, but may be manufactured by, for example, the following method. That is, in the above-described method for manufacturing the footwear 100, the main body 30 is manufactured (Step S01), and then the depressed portion 11b is formed on the main body 30 (Step S02) to manufacture the foam rubber portion 10. Instead of these steps, a mold having a shape of the foam rubber portion 10 having a shape corresponding to the depressed portion 11b may be prepared, and the foam rubber portion 10 may be manufactured by it molding using the mold. In the above-described method for manufacturing the footwear 100, the synthetic rubber main body is manufactured (Step S11), and after that the embossing process is performed (Step S12). Instead of this, a mold having a shape of the synthetic rubber portion 20 having a shape after an embossing process may be prepared, and the synthetic rubber portion 20 may be manufactured by injection molding using the mold.
[0054] Subsequently, modifications of the above-described footwear 100 are described with reference to the drawings. In the following description, a component that is identical or similar to that of the embodiment is indicated by the identical reference numeral, and the description thereof is omitted or simplified. Note that methods for manufacturing footwears 200, 300, 400, and 500 according to the modifications described below are similar to the method for manufacturing the footwear 100 described above.
[0055] With the footwear 100 according to the above-described embodiment, the width W3 in the right-left direction of the opening end surface 15 is configured to be larger than the width W5 in the right-left direction of the upper portion 12 and the toe portion 13. However, the configuration is not limited to this, and the following configuration is also possible.
[0056] With the above-described footwear 100 according to the embodiment, the lower surface 22 of the synthetic rubber portion 20 projects downward from the lower surface 11a of the foam rubber portion 10, but the following configuration is also possible.
[0057] Furthermore, in the footwear 100 according to the above-described embodiment, the width W1 in the right-left direction of the opening 1 is configured to be smaller (shorter) than the width W2 in the direction perpendicular to the direction of the width W1, and the width W3 in the right-left direction of the opening end surface 15 is configured to be smaller (narrower) than the Width W4 in the direction perpendicular to the direction of the width W3, but the following configuration is also possible.
[0058] The width W1 in the fight-left direction of the opening 1 in the footwear 100 according to the embodiment may be configured to have the length identical to the width W2 in the direction perpendicular to this, and the width W3 in the right-left direction of the opening end surface 15 may be configured to have the length identical to the width W4 in the direction perpendicular to this.
[0059] While the footwear 100 of the present invention, the method for manufacturing the same, the modification 200, and the like have been described above, the technical scope of the present invention is not limited to the above-described embodiments or the modifications. For example, one or more requirements described in the above-described embodiments or modifications may be omitted in some cases. Alternatively, the requirements described in the above-described embodiments and modifications can be combined as necessary.
DESCRIP HON OF REFERENCE SIGNS
[0060] 1, 51: Opening [0061] 10: Foam rubber portion (foam rubber) [0062] 11: Bottom portion of footwear [0063] 13, 213, 313: Toe portion (toe) [0064] 14: Heel portion (heel) [0065] 20: Synthetic rubber portion (synthetic rubber) [0066] 30: Main body [0067] 31: Bottom of main body [0068] 100, 200, 300, 400, 500: Footwear [0069] C: Ground surface