P.V.C shoe sole

Abstract

A P.V.C. shoe sole includes a foam tissue defining a plurality of apertures. The shoe sole has a top face defining a plurality of cavities. Each of the cavities has a periphery formed with a compact tissue, thereby decreasing the weight of the entire unit volume of the shoe sole, and thereby providing a better support for the shoe sole.

Description

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to a shoe sole made of polyvinyl chloride (P.V.C.), and more particularly to a P.V.C. shoe sole comprising a foam tissue formed with a plurality of apertures by blowing air into the foam tissue during the foam molding process, thereby decreasing the weight of the entire unit volume of the shoe sole by the apertures. The shoe sole has a top face defining a plurality of cavities, and each of the cavities has a periphery formed with a compact support region without any aperture formed therein, thereby providing a better support for the shoe sole so that the shoe sole functions as a thick shoe sole.

[0003] 2. Description of the Related Prior Art

[0004] In general, a shoe sole is usually made of rubber, P.V.C. or the like. Concerning the P.V.C. shoe sole, the foaming density with different values during fabrication will produce different longitudinal support strengths. When the P.V.C. shoe sole has a smaller density, it will have a smaller specific gravity with a softer feature, while the longitudinal support strength is not sufficient, so that the P.V.C. shoe sole easily produce a plastic deformation due to the pressure of the wearer's weight during a long period of time. In addition, in the components of the P.V.C. shoe sole, the additive foam agent has a greater proportion, thereby greatly increasing the cost of fabrication, so that the P.V.C. material is often used for making a shoe sole with a smaller thickness. When the P.V.C. shoe sole has a greater foaming density, it will have a better support strength, and the additive foam agent has a smaller proportion in the components of the P.V.C. shoe sole, thereby efficiently decreasing the cost of fabrication, so that the P.V C. material may be used for making a shoe sole with a greater thickness. However, the P.V.C. shoe sole having a greater foaming density will have a greater weight and stiffness due to its greater density, thereby causing load to the wearer's foot.

SUMMARY OF THE INVENTION

[0005] The present invention has arisen to mitigate and/or obviate the disadvantage of the conventional shoe sole.

[0006] In accordance with the present invention, there is provided a P.V.C. shoe sole comprising: a foam tissue defining a plurality of apertures, the shoe sole having a top face defining a plurality of cavities, each of the cavities having a periphery formed with a compact tissue, thereby decreasing a weight of an entire unit volume of the shoe sole, and thereby providing a better support for the shoe sole.

[0007] The primary objective of the present invention is to provide a P.V.C. shoe sole comprising a foam tissue formed with a plurality of apertures by blowing air into the foam tissue during the foam molding process, thereby decreasing the weight of the entire unit volume of the shoe sole by the apertures.

[0008] Another objective of the present invention is to provide a P.V.C. shoe sole comprising a plurality of cavities distributed on a toe mating portion and a heel mating portion of the shoe sole, and each of the cavities has a periphery formed with a compact support region without any aperture formed therein, thereby providing a better support for the shoe sole so that the shoe sole functions as a thick shoe sole.

[0009] In such a manner, the support region has a compact tissue without forming any aperture, so that the support region has an excellent support strength, thereby enhancing the support strength of the P.V.C. shoe sole. Therefore, when the P.V C. shoe sole has a large thickness, it will not produce a plastic deformation even being subjected to the pressure of the weight of the human body, so that the P.V.C. shoe sole can be applied for manufacturing a thick shoe sole.

[0010] Further benefits and advantages of the present invention will become apparent after a careful reading of the detailed description with appropriate reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0011] FIG. 1 is a perspective view of a P.V C. shoe sole in accordance with the present invention; and

[0012] FIG. 2 is an enlarged cross-sectional view of the P.V.C. shoe sole along line 2-2 as shown in FIG. 1.

DETAILED DESCRIPTION OF THE INVENTION

[0013] Referring to FIGS. 1 and 2, a P.V.C. (polyvinyl chloride) shoe sole in accordance with the present invention comprises a foam tissue defining a plurality of apertures 21. The shoe sole has a top face defining a plurality of cavities 11 distributed on a toe mating portion and a heel mating portion of the shoe sole. Each of the cavities 11 has a periphery formed with a compact tissue including a support region 22 encompassing the periphery of the cavity 11, thereby decreasing the weight of the entire unit volume of the shoe sole by means of the apertures 21, and thereby providing a better support for the shoe sole by means of the support region 22.

[0014] The P.V.C. shoe sole in accordance with the present invention includes a plurality of components mixed with each other, wherein the weight ratios (wt %) of the components are indicated as follows: 1 Components Weight ratio (%) P.V.C. powder 50%˜80% Grease 15%˜45% Titanium dioxide 0.5% Stabilizer   1% Foam agent 3.5% Preferably, the grease is D.O.P. (dioctyl phthalate).

[0015] The above-mentioned components are initially mixed, then heated and pressurized, and then poured into a forming mold to foam into a form. The forming mold includes an aluminum mold having air inlet holes, air outlet holes, and cooling water holes. The forming temperature is ranged between 160° C. and 220° C., and the forming pressure is ranged between 100 lb/in2 and 140 lb/in2. During the foam forming process of the forming mold, air is blown into the mold through the air inlet holes to perform a blowing foam process so as to make the P.V.C. shoe sole as shown in FIG. 1 having a specific gravity ranged between 0.4 and 0.8. During the foam process, air is blown into the mold through the air inlet holes, so that the foam tissue of the P.V.C. shoe sole is distributed with a plurality of apertures 21 as shown in FIG. 2, thereby decreasing the weight of the entire unit volume of the P.V.C. shoe sole. When the P.V.C. shoe sole is pressed, the apertures 21 can be used to provide a cushion space for allowing deformation and distortion of the foam tissue, so that the P.V.C. shoe sole has a good elasticity. In addition, the forming mold is provided with mold posts (not shown) whereby the top portion of the formed P.V.C. shoe sole is formed with a plurality of cavities 11 located on specific regions of the shoe sole such as the toe mating portion, the heel mating portion, etc. of the show sole. When the P.V.C. shoe sole is formed by the foaming process, each of the mold posts is disposed at a low temperature state relative to the forming temperature due to action of the cooling water holes of the forming mold. In such a manner, when the fused P.V.C. is injected into the mold cavity of the forming mold, the P.V.C. disposed at a relative high temperature is in contact with the mold posts to be cured previously, thereby forming a support region 22 having a compact tissue around the periphery of each of the cavities 11. The support region 22 has a compact tissue without forming any aperture, so that the support region 22 has an excellent support strength, thereby enhancing the support strength of the P.V.C. shoe sole. Therefore, when the P.V.C. shoe sole has a large thickness, it will not produce a plastic deformation even being subjected to the pressure of the weight of the human body, so that the P.V.C. shoe sole can be applied for manufacturing a thick shoe sole.

[0016] In conclusion, the P.V.C. shoe sole in accordance with the present invention comprises a foam tissue distributed with a plurality of apertures, thereby decreasing the weight of the entire unit volume of the shoe sole, so that the shoe sole has a light weight. In addition, the support region has a compact tissue without forming any aperture, so that the support region has an excellent support strength, thereby enhancing the support strength of the P.V.C. shoe sole.

[0017] Although the invention has been explained in relation to its preferred embodiment as mentioned above, it is to be understood that many other possible modifications and variations can be made without departing from the scope of the present invention. It is, therefore, contemplated that the appended claim(s) will cover such modifications and variations that fall within the true scope of the invention.

Claims

1. A P.V.C. shoe sole comprising:

a foam tissue defining a plurality of apertures, said shoe sole having a top face defining a plurality of cavities, each of said cavities having a periphery formed with a compact tissue, thereby decreasing a weight of an entire unit volume of said shoe sole, and thereby providing a better support for said shoe sole.

2. The P.V.C. shoe sole in accordance with claim 1, wherein said compact tissue includes a support region encompassing said cavity.

3. The P.V.C. shoe sole in accordance with claim 1, Wherein said cavities are distributed on a toe mating portion and a heel mating portion of said shoe sole.