Sole of shoe having partially adjustable height depending on inclination

A shoe sole includes a sole contact portion 42, a ground contact portion 44, a plurality of fluid casings 12 configured to include a pair of fluid casings arranged in the front and rear direction and a pair of fluid casings arranged in the left and right direction between the sole contact portion and the ground contact portion and made of an elastic material, and plurality of valve units 20 and 30 configured to connect the pair of fluid casings in the front and rear direction and the pair of fluid casings in the left and right direction and to permit a flow of a fluid only from fluid casings at a high position to fluid casings at a low position when the sole of the shoe is inclined in the front and rear direction and/or in the left and right direction.

REFERENCE TO RELATED APPLICATIONS

This application claims the priority benefit of Korean Patent Application No. 10-2015-0130834 filed on Sep. 16, 2015, the entire contents of which are incorporated herein by reference.

FIELD OF THE INVENTION

The present invention relates to the sole of the shoe and, more particularly to the sole of the shoe, which is configured to have a sense of balance by adjusting the height of a fluid casing embedded in the sole, with respect to the inclination of ground in the left and right or front and rear direction.

BACKGROUND OF THE INVENTION

In general, a variety of types of shoes, such as hiking boots and golf shoes, in addition to common walking boots frequently worn in daily life are produced and come into the market. In such shoes, one of the most important functions may be said to be comfortable feeling in the feet when walking. Such comfortable feeling of the feet may be said to be based on cushioning.

In order to provide comfortable feeling when a person wears shoes as described above, a cushion function is recognized as being one of the most important functions in the manufacture of shoes, and various proposals for the cushion function are being made. For example, shoes disclosed in U.S. Pat. No. 8,707,583 B2 provide comfortable feeling (cosiness) when a person wears the shoes and provide a less sense of fatigue while walking for a long time by providing an air cushion function through the entry and exit of air.

SUMMARY OF THE INVENTION

As described above, it may be seen that it is important to design shoes so that the shoes have a structure capable of more activating a cushion function in order for a wearer to have comfortable feeling or cosiness when walking. In addition to the air cushion function sought by many recent shoe manufacturers, however, how much can the soles of shoes maintain horizontality may be said to be an important thing when wearing shoes and when walking.

For example, if a person who wears shoes walks in the ground that perfectly forms a horizontal plane, he or she can have convenient and comfortable feeling. If a person who wears shoes walks in an inclined plane in the front and rear or left and right direction, he or she may inevitably feel inconvenient due to the slope itself although the shoes have any cushion function.

Accordingly, it may be said that convenience or inconvenience felt by a person who wears the shoes depending on the incline state of the ground rather than comfortable feeling or cosiness attributable to the cushion function of the outer soles of the shoes on which recent shoe manufacturers focus their efforts has a greater effect. The present invention has been made keeping in mind the above problems occurring in the prior art and proposes a sole capable of providing a wearer with relatively more comfortable feeling although the wearer walks in the ground having a slope.

The present invention provides the sole of the shoe, which is capable of providing a wearer with convenient and comfortable feeling by adjusting the incline state so that it becomes close to the horizontal state as much as possible although the wearer walks in the ground inclined in the front and rear direction or the ground inclined in the left and right direction.

The present invention also provides the sole of the shoe, which is capable of reducing a danger of injury and also suppressing the exhaustion of physical strength attributable to a gradient as little as possible by correcting the incline state so that it becomes close to the horizontal state in an inclined ground.

The present invention also provides the sole of the shoe, which can have a sufficient cushion function of a fluid, which is light in weight, and which has a sufficient height.

In an aspect, the sole of a shoe includes a sole contact portion configured to come in contact with a sole of a shoe wearer; a ground contact portion configured to come in contact with a ground while walking; a plurality of fluid casings including a pair of fluid casings arranged in a front and rear direction and a pair of fluid casings arranged in a left and right direction between the sole contact portion and the ground contact portion, and being made of an elastic material; and a plurality of valve units configured to connect the pair of fluid casings in the front and rear direction and the pair of fluid casings in the left and right direction respectively and to permit a flow of a fluid only from fluid casings at a high position to fluid casings at a low position when the sole of the shoe becomes a state in which the sole is inclined in at least one of the front and rear direction and the left and right direction; wherein the height of the fluid casings at low position could be increased by the flow of fluid being introduced from the fluid casings at high position to the fluid casings at low position by pressure applied to the fluid casings at high position, when the sole of the shoe is inclined.

Furthermore, in accordance with a first embodiment of the present invention, each of the valve units include, an valve body having an internal passage through which the fluid within the fluid casing is able to pass, a pair of ball seating portions formed on both inner end of the internal passage, a check ball configured to permit a flow of the fluid only in one direction when the check ball is seated in any one of the ball seating portions and to permit a bidirectional flow of the fluid when it is in the middle of internal passage, and a pair of connecting passages connected to the fluid casings in the front and rear direction and the fluid casings in the left and right direction, respectively, through the ball seating portions. And the check ball is made of a material having a greater specific gravity than the fluid, so it sinks in the fluid. And the connecting passages connect fluid casings and valve bodies in opposite directions. And the check balls will be seated in the ball seating portion at low positions when the valve unit are inclined, so that the fluid flows only from the fluid casings at high positions to the fluid casings at low positions.

Furthermore, in accordance with a second embodiment of the present invention, each of the valve units includes, a valve body having an internal passage through which the fluid within the fluid casing is able to pass, a pair of ball seating portions formed on both inner end of the internal passage, a check ball configured to permit a flow of the fluid only in one direction when the check ball is seated in any one of the ball seating portions and to permit a bidirectional flow of the fluid when it is in the middle of internal passage, and a pair of connecting passages connected to the fluid casings in the front and rear direction and the fluid casings in the left and right direction, respectively, through the ball seating portions. Here, the check balls are made of a material having a smaller specific gravity than the fluid, so having buoyant force in the fluid. And the connecting passages connect valve bodies and adjacent fluid casings. The check ball are seated in the ball seating portion at high positions when the valve unit are inclined, so that the fluid flows only from the fluid casings at high positions to the fluid casings at low positions.

In an embodiment of the present invention, the fluid casing may be made of a material having an elastic restoring force.

Furthermore, in an aspect, a sole for a shoe includes, a sole contact portion configured to come in contact with a sole of a shoe wearer; a ground contact portion configured to come in contact with a ground while walking; a pair of fluid casings arranged in a front and rear direction between the sole contact portion and the ground contact portion, and being made of an elastic material; and a valve unit configured to connect the fluid casings and to permit a flow of a fluid only from a fluid casing at a high position to a fluid casing at a low position when the sole of the shoe is inclined in the front and rear direction. The height of the fluid casing at low position could be increased by the flow of fluid being introduced from the fluid casing at high position to the fluid casing at low position, by pressure applied to the fluid casing at high position, when the sole of the shoe is inclined.

In an aspect, a sole for a shoe includes, a sole contact portion configured to come in contact with a sole of a shoe wearer; a ground contact portion configured to come in contact with a ground while walking; a pair of fluid casings arranged in a left and right direction, between the sole contact portion and the ground contact portion and being made of an elastic material; and a valve unit configured to connect the pair of fluid casings and to permit a flow of a fluid only from a fluid casing at a high position to a fluid casing at a low position when the sole of the shoe is inclined in the left and right direction. Here, the height of the fluid casing at low position could be increased by the flow of fluid being introduced from the fluid casing at high position to the fluid casing at low position, by pressure applied to the fluid casing at high position, when the sole of the shoe is inclined.

In accordance with the sole of the shoe according to the present invention, height is increased in the ground inclined in the front and rear direction or the ground inclined in the left and right direction because a fluid is introduced into the fluid casing placed at a low position. Accordingly, a slope or inclination of the upper surface of the sole can be adjusted so that the address of a person who wears the shoes becomes close a horizontal state. If the slope in the front and rear direction and the left and right direction is corrected or adjusted as described above, advantages in which a person who wears the shoes can have comfortable feeling when walking and a danger of an accident can also be sufficiently prevented.

For example, the sole according to an embodiment of the present invention can provide a basic function that facilitates more easy hiking because the height of the heel portion is increased more than usual when a person who wears the shoes walks in an uphill, such as hiking. In the case of a downhill, the height of the heel portion will be reduced. Accordingly, advantages, such as comfortable walking and safe walking, can be expected because the height of an incline in the front and rear direction or an incline in the left and right direction is corrected so that it becomes close to horizontality as described above.

For another example, if the sole according to an embodiment of the present invention is applied to golf shoes, there are significant advantages in that an address posture in an area having slopes in the left and right direction and/or the front and rear direction is very convenient and a stable posture can be taken. Furthermore, if a stable address is provided as described above, it is considered to be directly connected to the improvement of athletic performance.

In addition to golf shoes and hiking boots, an advantage in which convenience and safety are further ensured can be expected because an angle of inclination is corrected so that it becomes close to horizontality in common hiking or walking. Furthermore, there can be expected an advantage in that the exhaustion of physical strength attributable to the slope of the ground can be reduced.

DETAILED DESCRIPTION OF THE INVENTION

Embodiments of the present invention are described in detail below with reference to the accompanying drawings. First, a basic function of the sole of the shoe according to an embodiment of the present invention is described with reference toFIGS. 1 and 2.FIG. 1shows a change of the sole in the ground inclined in the front and rear direction with respect to a walking direction. As shown, when a wearer walks in a horizontal ground, the sole maintains a basic horizontal state (i.e., a basic setting state) without a change of the thickness A, B of the sole as shown inFIG. 1(A). When the sole meets an uphill, it is changed to the state, such as that shown inFIG. 1(B). It may be seen that the state shown inFIG. 1(B)is the state in which the height “A-a” of the back portion of the sole has been lowered and the height “B+b” of the rear portion of the sole has been increased.

Furthermore,FIG. 2shows a change of the sole in the ground inclined in the left and right direction with respect to a walking direction. As shown, when a wearer walks in a horizontal ground, the sole maintains a basic horizontal state (i.e., a basic setting state) without a change of the thickness C, D of the sole as shown inFIG. 2(A). When the sole meets the ground inclined in the left and right direction in such a walking state, the height “C-c” of the sole at a high position (i.e., a left portion inFIG. 2(B)) is reduced, and the height “D+d” of the sole at a low position (i.e., a right portion inFIG. 2(B)) is increased. Accordingly, the right portion of the sole becomes high.

As described above, in an embodiment of the present invention, when a person who wears the shoes walks in the ground close to horizontality, the soles of the shoes maintain the set basic state. When the wearer walks in the ground inclined in the front and rear or left and right direction, the height of the sole at a lower position of the inclined ground becomes high, thereby compensating for the inclined plane. Accordingly, the wearer can walk in the state close to a horizontal plane.

Detailed embodiments of the present invention are described below. As may be seen fromFIGS. 3 to 5, a plurality of fluid casings12FL,12FR,12RL, and12RR (all of fluid casings are hereinafter collectively assigned12) is embedded in the sole10of the shoe according to an embodiment of the present invention. The fluid casings12have fluids filled therein and are connected to adjacent fluid casings through valve units20and30. For convenience of description, as shown inFIGS. 3 and 4, the valve units that connect the left fluid casings12FL and12RL and the right fluid casings12FR and12RR respectively are assigned with numeral20. And, as shown inFIGS. 3and5, the valve unit that connect the front fluid casings12FL and12FR and the rear fluid casings12RL and12RR are assigned with numeral30.

In the embodiment ofFIGS. 3 to 5, the fluid casings12includes a plurality of fluid casings, for example, pairs of the fluid casings12FL and12RL arranged in front and rear direction FR, and a pair of the fluid casings12FL and12FR,12RL and12RR arranged in the left and right direction RL.

The fluid casings12FL,12FR,12RL, and12RR are connected with each other that are adjacent to each other in the front and rear or left and right direction by the valve units20and30respectively. For example, each of the pairs of fluid casings12FL and12RL,12FR and12RR arranged in the front and rear direction FR is connected by the valve unit20(FIG. 4). Each of the pairs of fluid casings12FL and12FR,12RL and12RR arranged in the left and right direction RL is connected by the valve body30(FIG. 5).

Such connection relationships between the fluid casings12are described below. It may be said that the pair of fluid casings arranged in the front and rear direction and the pair of fluid casings arranged in the left and right direction are connected so that fluids within the pair of fluid casings can move through the valve units20and30, respectively. Furthermore, the movement of the fluid from one fluid casing to an adjacent fluid casing within the connected fluid casings is determined by the state of the valve units20and30. In the embodiments described above, the sole10as shown includes four (4) fluid casings12FL and12FR,12RL and12RR. However, the present invention is not limited thereto, and the sole may have other number of fluid casings. For example, the sole may have two (2) fluid casings, one at a front side and the other at the rear side of the sole, or alternatively, one at the left side and the other at the right side of the sole, in which the two fluid casings are connected via the valve unit engaged there-between.

As described above, the fluid within one fluid casing12according to an embodiment of the present invention can move to the other fluid casing including the fluid connected to the fluid within the fluid casing12, and the fluid from the other fluid casing can enter one fluid casing12. Furthermore, the fluid casing12may be made of a flexible material. Each fluid casing12can increase the height of the sole when the fluid from one fluid casing enters into another fluid casing12. In an embodiment of the present invention, the height of the fluid casing installed within the sole of the shoe is configured to be changed when the fluid moves from one fluid casing12to the other fluid casing because the width of the sole of the shoe is limited. Furthermore, the fluid casing12may be made of a material having an elastic restoring force so that it can return to its original state when an external force is not applied to the fluid casing12.

Furthermore, the valve units20and30according to an embodiment of the present invention function to regulate the fluid. The valve units20and30can transmit the fluid only in one direction depending on the slope direction of the sole of the shoe. In the state shown inFIG. 1, that is, in the case of a plane inclined in the front and rear direction FR, more specifically, when a wearer walks in an uphill, the height of the sole for an uphill road can be adjusted only when the height of the fluid casings12RL and12RR placed in the rear of the sole10of the shoe is increased. Furthermore, as another example of the ground inclined in the front and rear direction, when a wearer walks in a downhill, the height of the sole for a downhill road can be corrected only when the fluid casings12FL and12FR placed ahead are billowed and increased in height.

In order for the height of the sole to be corrected with respect to the ground having an incline in the front and rear direction, the fluid needs to move from the fluid casing12placed at a high position to the fluid casing12placed at a low position in a sole. This means that the fluid should not be moved from the fluid casing12at a low position to the fluid casing12at a high position. As described above, the valve unit20according to an embodiment of the present invention must operate so that the fluid moves from the fluid casing12at a high position to the fluid casing12at a low position and a flow of the fluid in an opposite direction is not generated.

The valve units20and30according to an embodiment of the present invention are described in more detail below.FIG. 6shows the connection relationship between the fluid casings12FL and12RL or12FR and12RR placed in the front and rear direction and connected by the valve units20respectively. As shown inFIG. 6, the valve units20according to an embodiment of the present invention includes, a valve body22having an internal passage23through which the fluid can flow and a check ball28which is embedded in the internal passage23of the valve body22and which moves according to the slope or inclination of the sole.

The internal passage23may be said to be a connection passage through which the fluid within the fluid casing12can flow. Ball seating portions24aand24bare formed at both inner ends of the internal passage23. Each of the ball seating portions24aand24bhas a shape corresponding to part of the appearance of the check ball28so that the check ball can closely seat or adhere to the ball seating portion24aor24bwhen it enters and the ball seating portion. In this case, the bottom of the internal passage between the ball seating portions24aand24bmay be formed to have a horizontal plane so that the check ball28can easily move from side to side.

And the both inner ends of the internal passage23in which the ball seating portions24aand24bhave been formed are connected to other fluid casing12through connecting passage26aor26b, respectively. Accordingly, the fluid within one fluid casing12flows to the other fluid casing12via one of connecting passages26aor26b, internal passage23of valve body, and another connecting passages.

FIG. 7shows the connection relationship between the fluid casings12FL and12FR or12RL and12RR placed on the left and right sides and connected by the valve body30. The sole ofFIG. 7has the same construction as that ofFIG. 6. For convenience of description, however, the fluid casing12FL or12RL on the left side is illustrated as being connected to the connecting passage26don the right side of the valve body22, and the fluid casing12FR or12RR on the right side is illustrated as being connected to the connecting passage26con the left side of the valve body22. Furthermore, a ball seating portion24cis illustrated as being formed on the left inner side of the valve body22, and a ball seating portion24dis illustrated as being formed on the right inner side of the valve body22.

In accordance with a first embodiment of the present invention ofFIG. 6, the check ball28may be made of a material having greater specific gravity than the fluid in the valve body, and the connecting passages26aand26bformed on both inner sides of the valve body22are connected to the fluid casings12placed in opposite directions. That is to say, the connecting passage26aconnects the left side (front portion in the sole) of valve body to fluid casing12RL which is in right side (rear portion in the sole). And the connecting passage26bconnects the right side (rear portion in the sole) of valve body to fluid casing12FL which is in left side (front portion in the sole).

In this case, the fact that check ball28may be made of a material having greater specific gravity than the fluid means that, for example, the fluid may be made of gas, such as air, and the check ball28may be made of a metallic material having sufficient strength. In case that the fluid is a liquid, and the check ball28should be made of a metallic material having greater specific gravity than the liquid fluid.

The internal passage23means the space through which the fluid can flow. A flow of the fluid within the internal passage23is not regulated by the check ball28. That is, if the check ball28is placed in the internal passage23without being close contact to any one of the ball seating portions24aand24b, the fluid can flow through the internal passage23to any connection portions. Furthermore, if the check ball28is close contact state to any one of the ball seating portions24aand24b, a flow of the fluid to at least one side is regulated. Furthermore, such a description is likewise applied to the fluid casings arranged in the left and right direction and connected by the valve body30inFIG. 7.

In the illustrated embodiment, the plurality of fluid casings12are connected with each other so that the fluid can move or flow from one fluid casing12to the other fluid casing12as described above. Furthermore, the fluid casings12are connected in the front and rear direction and the left and right direction respectively. The fluid casings12FL and12RL placed in the front and rear direction are connected by valve unit20and fluid casings12FR and12RR placed in the front and rear direction are connected by valve unit20. And the fluid casings12FL and12FR placed on the left and right sides are connected by valve unit30and fluid casings12RL and12RR placed on the left and right sides are connected by valve unit30.

In the embodiment shown inFIG. 6, the fluid casings12and the connecting passage26aand26bof the valve unit20are connected in opposite directions, as explained above. In other words, referring toFIGS. 3 and 6, the connecting passages26aand26bformed on both sides of the internal passage23are connected to the respective fluid casings12placed in the opposite directions. That is, the fluid casings12FL and12FR placed in front direction are connected to the respective connecting passages26bplaced in the rear, and the fluid casings12RL and12RR placed in the rear portion are connected to the respective connecting passages26aplaced in front portion.

Such connections in the opposite directions are the same for the left and right direction RL. FromFIGS. 3 and 7, it may be seen that the fluid casings12FL and12RL on the left side are connected to the connecting passages26don the right side of the valve bodies22and the fluid casings12FR and12RR on the right side are connected to the connecting passages26con the left side of the valve bodies22.

In the present embodiment, the check ball28has a setting force in the fluid because it has higher specific gravity than the fluid. That is to say, the check ball28sinks in the fluid. Accordingly, as shown inFIG. 6, when the sole10of the shoe becomes a horizontal state, the check ball28is placed in the central portion of the internal passage23without any close contact to the ball seating portions24aand24b. Furthermore, in this state, when an external force is not applied to the fluid casing12or when the same external force is applied to the fluid casings12on both sides through both connecting passage26aand26b, the fluid does not move.

As may be seen from the aforementioned embodiment, the fluid casing12needs to be made of a material having elastic restoring force, so that the fluid casing could be swelled or be inflatable by the entry of the fluid. Thus the height of the sole of the shoe partially is increased. And when the fluid exits from the fluid casing12, the height of the sole of the shoe is reduced.

As shown inFIGS. 4 and 5, the plurality of fluid casings12may be placed between a sole contact portion42contacting the sole of a wearer and a ground contact portion44that contacting ground while walking. And as described above, the height between the ground contact portion44and the sole contact portion42may be increased depending on a change of height attributable to a change of the volume of the fluid casing12.

Furthermore, in an embodiment of the present invention, another parts may be used so that the height of the fluid casing12is sufficiently changed when the fluid enters the fluid casing12according to a movement of the fluid within another fluid casing. For example, a member configured to come in contact with a side forming member46or an edge portion of the fluid casing12so that the height of the fluid casing12is increased by the entry of the fluid may be used. In some embodiments, the fluid casing12according to an embodiment of the present invention may be installed in a partition between the ground contact portion44and the sole contact portion42so that the height of the fluid casing is changed by the entry of the fluid.

A change of the state when the sole of the shoe according to an embodiment of the present invention is used is described below with reference toFIGS. 6 to 9. When a shoe to which the sole10according to an embodiment of the present invention has been applied is completed as shown inFIG. 4, the shoe has a basically designed state. The basic setting state is the state in which the shoe has not been worn and an external force has not been applied to the sole.

In the basic setting state, the sole10of the shoe has a predetermined height. For example, the front portion42F and rear portion42R of the sole contact portion42basically have a predetermined height by the plurality of fluid casings12. The predetermined height may be set to be slightly higher than the height of the rear portion42R. That is, in this specification, the basic setting state may mean the state in which the front fluid casings12FR and12FL and the rear fluid casings12RL and12RR include the predetermined amount of the fluid and have a predetermined height in the front portion42F and rear portion42R. Furthermore, in this state, any external force is not applied to all of the fluid casings12.

In such a basic setting state or the state in which a wearer walks in the ground having a horizontal plane as shown inFIGS. 1(A) and 2(B), the height of the sole10of the shoe is not changed generally. In the aforementioned embodiment, the check ball28has a setting force for the fluid because it has greater specific gravity than the fluid. Accordingly, as shown inFIG. 6, when the sole10of the shoe becomes a horizontal state, the check ball28is placed in the central portion of the internal passage23without any close contact to any one of the ball seating portions24aand24b. In this state, when an external force is not applied to the fluid casing12or the same external force is applied to the fluid casings12on both sides, the fluid does not move.

And for example, assuming that a wearer walks in the ground having a horizontal plane, there is no change in the height of the sole because the entire sole of the shoe uniformly pressurizes the sole contact portion42when the sole of the shoe generally comes in contact with the ground. More particularly, assuming that a wearer walks in a flatland, when the wearer starts walking in the state in which the sole generally comes in contact with the sole contact portion42, the heel of the shoe is first lifted up, and thus the sole of the shoe has an incline state in which the front is low. At this time, the front portion of the feet pressurize the front portion42F of the sole contact portion42of the sole of the shoe.

Such an incline state in which the front is low is an incline state having a direction opposite the direction ofFIG. 8. In this case, the check ball28is seated in the ball seating portion24aplaced ahead or in front direction. Accordingly, the fluid can flow from the fluid casing12FL or12FR placed ahead to the internal passage23, but the fluid cannot exit from the internal passage23to the connecting passage26aplaced ahead because the check ball28has closely adhered to the ball seating portion24aplaced ahead. Accordingly, in this state, although the ball of the foot presses the front portion42F of the sole contact portion42, there is no change in the height of the sole of the shoe because the fluid does not exit from the fluid casing12FL or12FR placed ahead.

In this state, the shoe consecutively detaches from the ground. When the shoe detaches from the ground, there is no change in the height of the fluid casing because an external force (i.e., pressure according to the sole) is not applied to the sole contact portion42. Furthermore, the rear portion43R of the sole contact portion42is pressurized because the heel of the foot first comes in contact with the ground in the process of the shoe landing on the ground.

However, at the moment when a foot lands on the ground while walking, the shoe has an incline state in which the rear portion is low and becomes the same state as that shown inFIG. 8. Furthermore, in this state, pressure is applied to the fluid casings12RL and12RR placed in the rear. However, in the state, such as that shown inFIG. 8, a movement of the fluid from the rear fluid casings12RL and12RR to the front fluid casings12FL and12FR is impossible because the check balls28have closely adhered to the ball seating portions24bplaced in the rear.

As may be seen from the above description, while a wearer walks in the ground having a horizontal plane, there is no change in the height of the sole of the shoe because the fluid does not enter or exit from the fluid casings12. In this case, when the ball of a foot presses the front portion42F or the heel of the foot presses the rear portion42R in the state in which the entire bottom of the shoe comes in contact with the ground, the fluid may slightly flow from the fluid casings on one side to the fluid casings on the other side. However, only a small amount of the fluid may flow because the check balls28are seated in the ball seating portions24a,24b,24c, and24dby the flow of the fluid. Such a flow of the small amount of the fluid may not cause a change in the gradient of the sole of the shoe and may assign a cushion function to the shoe. Accordingly, when a wearer walks in a flatland, there is no change in the height of the sole because there is no change in the volume of the fluid within the fluid casings12. This may be said to be the state in which a restoring force for enabling the plurality of fluid casings12in the basic setting state to maintain their original predetermined shape has been applied.

A change in the height of the sole10of the shoe in the state in which a flatland changes to an inclined plane (e.g., an uphill) is described below. When a wearer enters the ground inclined in the front and rear direction as shown inFIG. 8, for example, an uphill road from the horizontal state ofFIG. 6, the shoe comes in contact with the inclined plane. In this state, the check ball28having greater specific gravity than that of fluid (e.g., gas in the present embodiment) is backward pushed and seated in the ball seating portion24bplaced in the rear. Accordingly, a flow of the fluid from the internal passage23to the connecting passage26bis blocked, and only a flow of the fluid introduced into the internal passage23through the connecting passage26bis permitted.

Accordingly, only a flow of the fluid from the connecting passage26bplaced in the rear, connected to the fluid casing12FL or12FR placed ahead, to the inside of the internal passage23and from the inside of the internal passage23to the fluid casing12RL or12RR placed in the rear through the connecting passage26aplaced ahead is possible. In this state, when the sole of a foot pressurizes the sole in the state ofFIG. 8as a wearer walks in an inclined ground, the fluid flows from the fluid casing12FL and12FR placed ahead to the fluid casings12RL and12RR placed in the rear.

In other words, while the wearer walks in the inclined plane as shown inFIG. 8, the sole of the shoe generally maintains the incline state in which the front is high. And pressure is applied to the sole10of the shoe when the shoe comes in contact with the ground and thus weight of the wearer is applied to the sole contact portion42. Furthermore, although the sole contact portion42of the sole10of the shoe is pressurized as described above in the uphill, shown inFIG. 8, the fluid can flow only from the fluid casings12FL and12FR placed ahead to the fluid casings12RL and12RR placed in the rear. Accordingly, the height of fluid casings12RL and12RR placed in the rear will be increased and the height of the rear portion42R of the sole10is inevitably raised.

Accordingly, in the shoe to which the sole according to an embodiment of the present invention has been applied, the fluid moves to the fluid casings12RL and12RR placed in the rear in an uphill, thereby increasing the height of the rear portion42R. Furthermore, such a partial change of the height may be said to provide a function through which a wearer can walk in an uphill road more conveniently and safely.

A movement of the fluid in such an uphill is summarized below. It may be said that the fluid moves in the state in which at least part of the shoe has come in contact with the ground. In the uphill, the shoe generally has a shape in which the front portion42F is placed on the upper side. In this state, the fluid cannot move from the front fluid casing to the rear fluid casing because the check ball28is seated in the ball seating portion24dplaced in the rear in the valve unit20between the fluid casings12placed in the front and rear direction.

Accordingly, although the body weight is applied to the sole of the invention, only when a force that presses the fluid casings12FR and12FL of the front portion42F is greater than a force that presses the fluid casings12RL and12RR of the rear portion42R, the fluid can flow from the front fluid casings to the rear fluid casings. And such a principle may be likewise applied to an inclined ground, such as a downhill, and may also be applied to the ground inclined on the left and right side.

A process in which a wearer passes through such an uphill slope and reaches the ground having a horizontal plane and the shoe comes in contact with the ground is described below. The rear portion42R of the sole first comes in contact with the ground. In such a state, the shoe itself has an incline state in which the front has been lifted up, and the heel of a foot has pressurized the fluid casings12RL and12RR placed in the rear of the shoe. Furthermore, the entire surface of the sole of the shoe comes in contact with the ground, the lift portion42R of the sole is lift up, and thus only the front portion42F of the sole comes in contact with the ground. That is, a change in the slope of the sole of the shoe in the one step process of a foot is described below. The slope of the sole of the shoe gradually changes from an incline state in which the front portion42F is high to a horizontal state and then to an incline state in which the front portion42F is low. Furthermore, the position of the check ball28may also be changed depending on such a state.

Furthermore, in the state in which the wearer has passed through the uphill slope and reached the ground having a horizontal plane, the fluid casings12RL and12RR placed in the rear have been billowed and become high. Accordingly, unlike in the case where a wearer continues to walk in a flatland, a force applied to the fluid casings12RL and12RR having the high state is relatively greater. Accordingly, as described above, at the moment when the fluid can move from the rear fluid casings12RL and12RR to the front fluid casings12FF and12FL in the one-step process, that is, during the remaining time other than the state in which the check balls28have closely adhered to the rear ball seating portions24b(i.e., while the check balls are placed in the front ball seating portions24aor in the internal passages23), if a force in which the heel of the foot pressurizes the rear portion42R is greater than a force in which the ball of the foot pressurizes the front fluid casings, the fluid can flow from the rear fluid casings12RL and12RR to the front fluid casings12FL and12FR.

That is, in the state in which the wearer has walked up on the uphill, the fluid moves from the rear fluid casings12RL and12RR to the front fluid casings12FR and12FL, and thus the sole returns to the basic setting state. The return to the basic setting state as described above will be completed by an operation of several steps not by a one-step operation. In this case, in the first two steps, a relatively large amount of the fluid can flow (from the rear fluid casings to the front fluid casings). Furthermore, it is determined that the elastic restoring force of the fluid casing12may contribute to the return of the state of the fluid casings to the basic setting state to some extent.

Furthermore, an example in which a wearer walks in a downhill in a plane inclined in the front and rear direction may be taken into consideration. When the wearer walks in the downhill, the fluid casing12is changed in the direction opposite the direction when the wearer walks in an uphill. Accordingly, since the fluid is introduced into the front fluid casings12FL and12FR, the front portion43F of the sole10of the shoe becomes high. Furthermore, when the sole reaches a horizontal ground again, the sole returns to the basic setting state according to the same principle as that in the process from the uphill to the flatland.

A change of the sole of the shoe in a plane inclined in the left and right direction while walking is described below with reference toFIGS. 5, 7, and 9. A change in the plane inclined in the left and right direction also has the same principle as a change in the plane inclined in the front and rear direction. When the sole reaches an inclined plane in which the left is high as shown inFIG. 9in the state of a horizontal ground shown inFIG. 7, the check ball28enters the ball seating portion24dplaced on the right and closely adheres thereto.

In this state, the fluid within the fluid casings12FL and12RL on the left side can move to the internal passages23through the connecting passages26dand move from the internal passages to the fluid casings12FR and12RR on the right side via the connecting passages26c. At the same time, a flow of the fluid from the fluid casings12FR and12RR on the right side to the fluid casings12FL and12RL on the left side is blocked by the check balls28.

Accordingly, in the inclined plane, such as that ofFIG. 9, when a user pressurizes the fluid casing12through the sole contact portion42, the fluid flows from the fluid casing placed at a high position to the fluid casing placed at a low position. Accordingly, the inclined plane is corrected by the movement of the fluid as shown inFIG. 2(B), and thus the user becomes close to the horizontal state within a possible range.

And an example of the inclined plane in which the left is high has been described with reference toFIGS. 7 and 9, but the same principle is applied to a flow of the fluid for the correction of a left and right slope in an inclined plane in which the right is high. Furthermore, when the sole returns to a horizontal ground again after walking in the left and right inclined plane, the sole may return to the basic setting state according to the same principle in which the sole returns from the plane inclined in the front and rear direction to the horizontal ground.

The examples in which a weaker walks in the plane inclined in the front and rear direction and the ground inclined in the left and right direction have been separately described above. In most cases, however, the ground has a complex incline in the left and right and front and rear directions. In a complex inclined ground including an incline in the left and right direction and an incline in the front and rear direction as described above, it may be said that the aforementioned flows of the fluids will be complexly generated at the same time.

Furthermore, in the aforementioned embodiment, the fluid within the fluid casing12has been illustrated as being gas and the check ball28has been illustrated as being made of a metallic material having greater specific gravity and thus has a setting force. A second embodiment of the present invention shown inFIGS. 10 and 11may be said to be an embodiment in which the fluid within the fluid casings12A and12B is a liquid and the check ball28is made of a material that has smaller specific gravity than the liquid and thus has buoyancy, that is, a material having smaller specific gravity than that of fluid.

In the second embodiment, when a wearer walks in an inclined plane, the slope of the sole can be adjusted only when the fluid casing placed at a low position becomes high. Accordingly, as shown inFIGS. 10 and 11, a first fluid casing12A and a second fluid casing12B are connected by a valve unit20so that a fluid can move within the first fluid casing12A and the second fluid casing12B.

And in the present embodiment, as in the aforementioned embodiment, ball seating portions24A and24B are formed on both inner sides of a valve body22in which an internal passage23has been formed. In this case, connecting passages26A and26B formed through the insides of the ball seating portions24A and24B are connected to the respective fluid casings12A and12B in the same direction.

That is, the fluid casing12A on the left side is connected to the connecting passage26A formed on the left side of the valve body22, and the fluid casing12B on the right side is connected to the connecting passage26B formed on the right side of the valve body22. And in the present embodiment, since a check ball28has buoyancy, a top surface of the valve body22may have a horizontal plane.

In such an embodiment, a change of the fluid casings12A and12B when a wearer walks in a flatland is the same as that of the aforementioned embodiment. And when the sole reaches an inclined plane as shown inFIG. 11, the check ball28closely contacts the ball seating portion24A placed at a high position because it has buoyancy. In this case, the fluid can flow only from the fluid casing12A at a high position to the fluid casing12B at a low position.

Accordingly, if the fluid is a liquid and the check ball is made of a material having smaller specific gravity so that it has buoyancy as in the present embodiment, the connecting passages connect the fluid casings to adjacent side of valve body. Thus, the fluid can flow from the fluid casing at a high position to the fluid casing at a low position in an inclined ground. Furthermore, even in such an embodiment, a substantial operation is the same as that of the aforementioned embodiment, and a redundant description thereof is omitted.

As described above, in the embodiments of the present invention, when a wearer walks in an inclined ground or stops in the inclined ground, the fluid casing at a low position is billowed so that the height of the sole becomes high. Furthermore, if the fluid is gas, there are advantages in that the weight of a shoe can be reduced and a certain operation can be provided because the check ball having sufficient strength, such as a metallic material, can be used. Furthermore, if the fluid is a liquid and the check ball having buoyancy is used, there is an advantage in that the connecting passages on the left and right (front and rear) of the valve body can be connected to the fluid casings more conveniently.

As described above, those skilled in the art to which the present invention pertains may modify the present invention in various ways without departing from the technical spirit of the present invention, and the scope of the present invention should be interpreted based on the claims.