US20060218819A1

US20060218819A1 - Double-density elastic insert element for an outsole

Info

Publication number: US20060218819A1
Application number: US11/092,871
Authority: US
Inventors: Chi-Kung Wu
Original assignee: Individual
Current assignee: Individual
Priority date: 2005-03-30
Filing date: 2005-03-30
Publication date: 2006-10-05

Abstract

A double-density elastic insert element is composed of an inner section and an outer section enclosing the inner section. The inner section and the outer section have different density, hardness and elasticity characteristics. Preferably, the inner section and the outer section are both made of polyurethane or ethylvinyl acetate (EVA) that is solidified at different molding conditions to obtain different density, hardness and elasticity characteristics. By varying the densities of the elastic insert element, the elastic insert element can be selectively modified to have more functional capabilities to satisfy different requirements.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention
The present invention relates to a double-density elastic insert element for an outsole, and more particularly to an elastic insert element that has two different densities and degrees elasticity in different sections.
2. Description of Related Art
With reference to FIG. 6, a conventional sport shoe usually comprises a shoe body (60), an outsole (70) and an elastic insert element (50). The elastic insert element (50) is glued between the shoe body (60) and the outsole (70) to make the shoe soft and comfortable to use and has an outer surface (52). The elastic insert element (50) is made of soft material only and has specific softness and elasticity throughout the elastic insert element (50). However, the elastic insert element (50) easily deforms and in the outer surface (52) even peels off after the sports shoe is worn for a period of time. Once the elastic insert element (50) deforms and loses its elasticity, the shoe is no longer comfortable. Furthermore, the appearance of the worn shoe is disgraceful, and the service life of the sport shoe is short.
The present invention has arisen to mitigate or obviate the disadvantages of the conventional elastic insert element.

SUMMARY OF THE INVENTION

The main objective of the present invention is to provide a double-density elastic insert element for a sport shoe that is durable.
To achieve the foregoing main objective, the double-density elastic insert element comprises an inner section and an outer section enclosing the inner section. The inner section and the outer section have different densities. Preferably, the outer section has a density higher than a density of the inner section and is less elastic and soft than the inner section. The inner section and the outer area having different densities and hardnesses are both made of polyurethane or ethylvinyl acetate (EVA) that is composed of different plastic compositions and solidified at different molding conditions to obtain different density, hardness and elasticity characteristics, respectively.
By varying the densities of the elastic insert element, the elastic insert element can be selectively modified to have more functional capabilities to satisfy different requirements.
Further benefits and advantages of the present invention will become apparent after a careful reading of the detailed description with appropriate references to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a partially exploded perspective view of a sport shoe with a first embodiment of a double-density elastic insert element in accordance with the present invention;
FIG. 2 is an exploded perspective view of an outsole with two double-density elastic insert elements in FIG. 1;
FIG. 3 is an exploded perspective view of a sport shoe outsole with a second embodiment of the double-density elastic insert element in accordance with the present invention;
FIG. 4 is an exploded perspective view of a sport shoe outsole with a third embodiment of the double-density elastic insert element in accordance with the present invention;
FIG. 5 is a side view in partial section of a sport shoe with a fourth embodiment of the double-density elastic insert element in accordance with the present invention; and
FIG. 6 is a side view in partial section of a sport shoe with a conventional elastic insert element in accordance with the prior art.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

A double-density elastic insert element in accordance with the present invention comprises an inner section and an outer section enclosing the inner section. The outer section and the inner section have different densities to make the elastic insert element possess various physical characteristics. Preferably, the inner section and the outer section are both made of polyurethane (PU) or ethylvinyl acetate (EVA) that is composed of different plastic compositions and cured at different molding conditions to cause different density, hardness and elasticity characteristics. The inner section and the outer section are thermally fused together to achieve the double-density elastic insert element. By varying the densities of the elastic insert element, the elastic insert element can be selectively modified to have more functional capabilities to satisfy different requirements.
With reference to FIG. 1, a first preferred embodiment of the double-density elastic insert element (10) in accordance with the present invention is mounted between a shoe body (20) and an outsole (30) and comprises an inner section (12) and an outer section (14). The outer section (14) encloses the soft inner section (12). Correspondingly, the outsole (30) has a top face and a recess (32) defined in the top face to accommodate the double-density elastic insert element (10).
The double-density elastic insert element (10) is oval-shaped, and the soft inner section (12) and the hard outer section (14) have different hardnesses. Preferably, the soft inner section (12) and the hard outer section (14) are made of the same material or different materials and fused together to form an integral piece having different densities and elasticities.
For example, a soft inner section (12) and a hard outer section (14) made of polyurethane may be subjected to different molding conditions or a hardening agent may be added to the hard outer section (14) to achieve different hardness and elasticity characteristics in comparison with the soft inner section (12). When the inner soft section (12) and the outer hard section (14) are made of two different materials, the two different materials are fused together, and the hard outer section (14) preferably has an excellent abrasion-resistance by selecting a proper material. Moreover, the soft inner section (12) and the hard outer section (14) further preferably are different colors and have different densities to make the elastic insert element (10) attractive in appearance when the outsole (30) or the shoe body (20) is partially transparent to reveal the elastic insert element (10).
In this example, the hard outer section (14) provides a protective and shaping feature for the soft inner section (12) and keeps the soft inner section (12) from permanently deforming. Therefore, the elasticity of the elastic insert element (10) is not easily fatigued, and the elastic insert element (10) is durable and has a long service life. Additionally, even though the elastic insert element (10) may be partially exposed to the environment, the hard outer section (14) further provides abrasion-resistance to keep the appearance of the outsole (30) neat.
In another embodiment of the outsole in accordance with the present invention, the elastic insert element (10) is modified to have a hard inner section and a soft outer section. The hard inner section and the soft outer section also can be made of the same material or different materials with a hardening agent as described in the foregoing description. The hard inner section is harder than the soft outer section but still has applicable elasticity to provide a resilient feature to the outsole (30). By adjusting the hardness of the hard inner section, the elastic insert element (10) can have more modifications to satisfy various outsoles for different kind of shoes.
The elastic insert element (10) is mounted in the outsole (30) at a location to absorb the most severe stress loads, such as a heel portion of the outsole (30). Preferably, the outsole (30) further contains another elastic insert element at a front portion under the ball of the foot.
With reference to FIGS. 3 and 4, the elastic insert elements (10A, 10B) may have different shapes such as a footprint shape or a shield shape.
In FIG. 5, the elastic insert element (10) may be mounted between the shoe body (20) and the outsole (30) to make the outer hard section (14) visible. In this arrangement, the elastic insert element (10) having a soft inner section (12) and a hard outer section (14) is suitable because the outer hard section (14) has high hardness and excellent abrasion resistance characteristics. Therefore, the elastic insert element (10) does not easily peel off at a surface of the outer hard section (14). Therefore, the appearance of the shoe continues to be neat without abrasion.
Characteristics of the double-density elastic insert element in the present invention have the following advantages.
1. The elastic insert element (10) having different hardness, elasticity and density characteristics can be modified to improve the resilience of the outsole (30) in various manners and shapes.
2. The elastic insert element (10) can be conveniently modified to have different density, hardness and elasticity characteristics by varying the molding conditions and plastic material compositions or choosing different materials. Therefore, the elastic insert element (10) is easily manufactured to satisfy different demands of different consumers.
Although the invention has been explained in relation to its preferred embodiments, many other possible modifications and variations can be made without departing from the spirit and scope of the invention as hereinafter claimed.

Claims

1. A double-density elastic insert element for an outsole, the double-density elastic insert element comprising:

an inner section; and

an outer section enclosing the soft inner section, wherein the outer section and the inner section have different density, elasticity and hardness characteristics.

2. The double-density elastic insert element as claimed in claim 1, wherein the inner section and the outer section are made of polyurethane (PU) and solidified at different molding conditions to obtain different density, hardness and elasticity characteristics in the inner section and in the outer section; and

the inner section and the outer section are thermally fused together.

3. The double-density elastic insert element as claimed in claim 1, wherein the inner section and the outer section are made of ethylvinyl acetate (EVA) and solidified at different molding conditions to obtain different density, hardness and elasticity characteristics in the inner section and in the outer section; and

the soft inner section and the hard outer section are thermally fused together.

4. The double-density elastic insert element as claimed in claim 1, wherein the inner section and the outer section are different colors.

5. The double-density elastic insert element as claimed in claim 1, wherein the outer section has a density higher than a density of the inner section and is less elastic and softer than the inner section.

6. The double-density elastic insert element as claimed in claim 1, wherein the inner section has a density higher than a density of the outer section and is less elastic and softer than the outer section.