Patent Application
20130074366
1. Field of Invention
The invention relates to a light shoe and, in particular, to a compound structure of mid-sole and insole. Not only is the total weight of the disclosed shoe reduced, it also provides best comfort to the user in vibration absorption.
2. Related Art
According to researches of the American Podiatric Medical Association, the reaction imposed on the feet during normal walking is about 1.5 to 2 times the body weight. It is as much as 2 to 3 times the body weight during running. Therefore, the people often feel fatigue and pain in the feet. In the long run, there can be damages to knees, waist and even spine.
To reduce the burden on feet during walking or running, the concept of ‘lightweight shoe’ has become popular in the industry of shoes.
For example, ROC Pat. No. M317186 discloses a lightweight shoe. The recess part of the outer sole is provided with an air pad so that the shoe is largely reduced in its weight. The surface of the air pad is wavy. The hollow interior is filled with air. When a foot rests on the air pad, the enclosed air makes the air pad elastic and evenly distributes the force on the foot bottom.
According to the disclosed compound structure of mid-sole and insole, the solid PU outer sole with the density of about 0.6 is made into a trough shape. This reduces the use of material in the bottom and thus the weight thereof. The mid-sole and insole are made of EVA with the density of 0.2 into a compound, and disposed in the trough. Different blocks of the compound are formed from EVA of different hardnesses and properties. Not only is the total weight of shoe effectively reduced to achieve the design of a ‘lightweight shoe’, the invention also provides best comfort to the user.
These and other features, aspects and advantages of the invention will become apparent by reference to the following description and accompanying drawings which are given by way of illustration only, and thus are not limitative of the invention, and wherein:
The present invention will be apparent from the following detailed description, which proceeds with reference to the accompanying drawings, wherein the same references relate to the same elements.
In order to support the insole 3, the mid-sole 2 is made of EVA or the mixture of EVA and corkwood, with a hardness between 65 and 70.
The surrounding frame 31 of the insole 3 provides appropriate wrapping function to the foot. To prevent deformation, it is made of EVA with a hardness between 50 and 55.
The insole body 32 directly in touch with the foot has to have sufficient elasticity in order to provide best comfort to the user. It is made of elastic EVA with a hardness between 40 and 45.
The area corresponding to the inner side of the forefoot on insole body 32 is set as a vibration absorption area 33. A vibration absorption material is used to reduce the pressure imposed on the foot. The vibration absorption area 33 is made of vibration-absorbing EVA with a hardness between 40 and 45.
According to the invention, the solid PU outer sole with a density of 0.6 is made into a trough. The material used in and thus the weight of the PU outer sole are significantly reduced. The mid-sole and insole are formed into a compound with a density of 0.2. The compound is disposed in the trough of the outer sole. Different blocks of the compound are integrally formed from EVA of different hardnesses and properties. Not only is the total weight of the disclosed shoe reduced, it also provides best comfort to the user in vibration absorption.
Although the invention has been described with reference to specific embodiments, this description is not meant to be construed in a limiting sense. Various modifications of the disclosed embodiments, as well as alternative embodiments, will be apparent to persons skilled in the art. It is, therefore, contemplated that the appended claims will cover all modifications that fall within the true scope of the invention.
