JPS6227126Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a midsole for shoes that maintains cushioning properties while running, prevents lateral vibration, improves flexibility, and has both shock absorption and stability.

During running, the lower limbs move inward so that the lower limbs land on the center line of the body. This movement acts as a rolling phenomenon of the inside of the foot even after landing. Particularly during long-distance running or jogging, landing is often done on the heel, but when landing, an impact of 2.5 to 3 times the body weight is applied.
In addition, the pressure applied to the hindfoot after landing moves from the lateral side of the foot through the lateral arched curvature to the medial side, and the structure of the joint between the large bones and calcaneus is also taken into account, and force is applied to the medial side of the heel. It turns out.

In recent years, with the development of polymer chemistry, high-quality foams have been developed and are used in the midsoles and heel wedges of running shoes, greatly reducing the impact of landing. However, improved cushioning promotes a certain amount of rolling when landing and shifting weight, making running unstable.If you continue running in this state, the rolling becomes even more excessive (overpronation), resulting in the ankles and knees. Running injuries such as knee pain can occur due to unnatural force being applied to the joints.

In order to overcome such injuries, the present invention provides a midsole for shoes that is formed to approximately follow the contour of the outsole by layering polymer foams with different specific gravity in each part, and improves flexibility and stability. The purpose is to simultaneously satisfy the following functions: improvement, shock absorption, prevention of lateral vibration, and prevention of excessive pronation. Consisting of a polymeric foam layer, this polymeric foam layer has a substantially mountain-shaped foam A1 with the outer shank side edge at the foot on the upper surface of the base foam D4 near the treading part. is,
A substantially rectangular foam B2 is layered on the outer heel side of the lower surface of the heel, and a substantially rectangular foam C3 is layered on the inner heel side of the heel, and the length of the foam C3 is equal to the toe side position. Foam B2 is pulled out in the foot length direction.
The hardness of each of the foams A, B, C, and D satisfies the relationships A<D<B and D<C.

The mid-sole of the present invention is made by layering foam A1, which has the lowest hardness, on the outer side of the upper surface near the stepping part, so that the compression ratio is highest on the outer side of the stepping part, and the compression ratio is highest from the tip to the inner side of the stepping part. The compression ratio of the foam D4 passing through the heel side to the rest area and finally to the center of the heel is the second lowest, and the foam B2 with high hardness is layered on the lower surface of the heel and on the outside of the heel. The compression ratio is lower on the heel side, and if the foam C3, which has a higher hardness than the foam D4, is layered on the inner heel side of the heel, and the hardness of the foam C3 is lower than the hardness of the foam B2, the foam C3 The height is made higher than the height of the foam B2 so that the compressibility is lowest on the inner heel side of the heel.

Therefore, in the midsole of the present invention, the vertical pressure or impact applied when the runner lands is absorbed by the elasticity of the foam D4, as well as the foam B2 and the foam C3, and is then absorbed as the runner's weight shifts. When pronation occurs, the pronation timing is delayed or the pronation angle is restricted by the medium and high hardness foams B2 and C3. Pronation was kept within a certain range, and it was possible to improve shock absorption and stability. In addition, since the foam A1 is layered in a mountain shape on the outer heel side near the stepping area, it significantly improves the flexibility of the toes, reduces fatigue in the runner's foot, and shifts the weight from the outer heel side to the inner heel side. We were able to smoothen the pronation that occurs when moving to the side of the head.

In addition, the length of the foam C3 of the midsole is longer than the length of the foam B2 in the foot length direction so that the foam C3 extends toward the toe side, and the height of the foam C3 is greater than the height of the foam B2 in the thickness direction. Since the structure is configured such that the foot pressure is higher when landing, the movement of the stepping pressure at the time of landing is guided to the outer leg side, and as the foot moves from the outer leg side to the inner leg side, the foot does not rotate too much towards the inner leg side. We were able to prevent excessive pronation force as much as possible, thereby preventing damage to the foot and the like.

Embodiments of the present invention will be described with reference to the drawings. Figure 1 is a plan view of this embodiment, Figure 2 is an outside side view of Figure 1, Figure 3 is an inside side view of Figure 1, and Figure 4 is a side view of Figure 1.
It is a back view of the heel side of a figure. Various types of polymer foams can be used in this example, including foams of polyolefin resins such as polyethylene, ethylene-vinyl acetate copolymer (EVA), rubber, and mixtures thereof, but here all EVA foams were used. shall use the body. The midsole of this embodiment is an EVA foam that is attached between the outsole and the sleeve and has a contour that roughly follows the outsole. The foam D4, which is the base of the midsole, is an EVA foam with a hardness of 35 degrees on the Asker hardness scale C type, and is formed to follow the contour of the outsole. Foam A1 is layered on the upper surface of the foam D4 in the vicinity of the treading part, on the outside side, in the shape of a mountain-shaped sea with the outside edge as the base, approximately 5 mm thick, and having a hardness of 30 degrees on the Asker hardness scale C type. Then, on the outer heel side of the lower surface of the heel, a substantially rectangular parallelepiped foam B2 having a hardness of 40 degrees on the Asker hardness scale C type is layered, and on the inner heel side of the heel, the foam B2 is layered. A foam C3 with a hardness of 40 degrees on the Asker hardness scale C type is layered. The hardness of each foam is 25 to 40 degrees for foam A1, foam B2, and foam C3.
50 to 75 degrees, foam D4 in the range of 40 to 60 degrees is suitable, and by selecting and combining members in this range, the outer heel side of the stepping part, the outer heel side of the heel part, the inner heel part The compression ratio is set to decrease in order of success. Foam D
The thickness of No. 4 is the thickest at the heel, 23 mm, and 11 mm at the tread portion, becoming thinner toward the toe, and the top, bottom, and side surfaces of each foam are made to match this foam D4. The upper surface of the foam B2 is in close contact with the foam D4 and is formed to have an upward slope toward the outer shell side. The length of the foam C3 is formed to be longer than the length of the foam B2 in the foot length direction, and the foam C3 is layered so as to protrude from the foam B2 at a position closer to the toe. In this example, since the hardness of foam C3 and foam B2 is made equal, the height of foam C3 is equal to that of foam B in the thickness direction.
2, so that the compression ratio on the inner heel side of the heel is lower than the compression ratio on the outer heel side.

Therefore, the midsole of this example is made of foam B2.
By forming the upper surface with an upward slope toward the outer heel side, when the pressure applied to the outer heel side of the heel moves through the outer heel side to the stepping part, the foot moves toward the outer heel side. You can prevent as much as possible from trying to move to.

Moreover, if the colors of the foams constituting the midsole of this embodiment are the same or different colors, the aesthetic appearance of the different-colored soles can be improved when these are used for shoe soles. Furthermore, since the midsoles are all made of the same EVA foam, their bonding is extremely reliable.
Manufacture can be either integral molding or pasting molding, and is extremely simple.

[Brief explanation of the drawing]

Figure 1 is a plan view of this embodiment, Figure 2 is an outside side view of Figure 1, Figure 3 is an inside side view of Figure 1, and Figure 4 is an inside side view of Figure 1.
The figure is a rear view of the heel side of FIG. 1. 1... Foam A, 2... Foam B, 3... Foam C, 4... Foam D.

Claims (1)

[Scope of utility model registration request] It consists of a polymeric foam layer with a contour that roughly follows the outsole and is attached between the outsole and the sleeve cover. A substantially mountain-shaped foam A1 with the outer heel side edge at the foot is layered on the side, a substantially rectangular parallelepiped-shaped foam B2 is layered on the outer heel side of the lower surface of the heel, and an approximately rectangular parallelepiped-shaped foam B2 is layered on the inner heel side of the heel. A rectangular parallelepiped-shaped foam C3 is layered, and the length of the foam C3 is longer than the length of the foam B2 in the foot length direction so that it can be pulled out toward the toe side, and each foam A,
A midsole characterized by being configured such that the hardness of B, C, and D is in the relationship of A<D<B and D<C.