JP3249537U - Sandals - Google Patents

Abstract

To provide sandals that promote toe movement and correct the deformation of the foot shape simply by wearing them.
[Solution] A pair of sandals comprising a base and a thong whose front part is band-shaped and has a width in the front-to-back direction of the base, the base being a molded product made of synthetic resin, and comprising a first covering member covering the top surface of the base and a second covering member further covering a partial area of the top surface of the first covering member, the second covering member having a predetermined thickness that forms a step with respect to the surface of the first covering member at its front edge extending across the width of the foot, the front edge having a dogleg shape along a line connecting the depressions between the pads and bases of all the toes on the sole of the foot, the apex of the dogleg shape being located on the little toe side of the position where the front part is inserted into the base, and the edge line on the big toe side extending from the apex rearward of the position where the front part is inserted, and the base having a mountain-shaped convex portion integrally formed over the area where the bases of the second to fourth toes come into contact.
[Selected Figure] Figure 1

Description

This invention relates to sandals that, when worn, encourage toe movement and are expected to have the effect of eliminating deformation of the foot, which can lead to poor health.

In recent years, the health of your feet has been drawing attention as something that affects your physical and mental health. Improper foot shape and posture can cause an imbalance in your center of gravity, which can put stress on the knees, hips, and even the muscles in your back, shoulders, and neck, leading to physical and mental problems such as joint pain, stiff shoulders, and headaches.

The main cause of foot deformation is pressure on the toes caused by continuously wearing tight shoes such as high heels or tapered leather shoes. Pressure on the toes can lead to toe deformations such as eversion of the big toe, inversion of the little toe, and floating toes. These toe deformations mean that the toes cannot press firmly against the ground, and the person walks with their center of gravity biased toward the heel.

The body naturally tries to correct this imbalance in the center of gravity, causing you to walk with your knees bent and your back to round, resulting in poor posture. If this poor posture becomes a habit, it can cause stress to the joints and muscles throughout the body, resulting in the aforementioned disorders.

A variety of footwear that can be worn on a daily basis has been developed to correct the deformation of the foot's shape, allowing all toes to press down on the ground and support the body with the entire sole of the foot. The first type of footwear to be considered is one that allows the space between the toes to be spread apart. In particular, sandal-type footwear is considered to be preferable for preventing hallux valgus.

The general structure of zori is that the top surface of a base with a foot-shaped outline is covered with a decorative sheet to form a surface called the "top" where the sole of the foot rests, and a V-shaped strap is inserted into it. The strap consists of a front part that is held between the big toe and second toe at the front end, and two horizontal straps that extend backwards on both sides from the front part to rest on the instep. Therefore, simply by putting on the zori, the front part that fits between the big toe and second toe functions to separate the two toes. In addition, all the toes can move freely without being pressed from the outside to the inside.

Some zori with such straps are used as a basic model, but are also equipped with a mechanism to spread the spaces between the other toes. For example, Patent Document 1 discloses a zori with a protrusion on the toe pressure surface that is inserted between the middle of each toe, spreading the skeleton in a fan shape. Furthermore, a zori with a number of protrusions on the base surface of the zori to stimulate pressure points on the sole of the foot, promoting blood circulation and improving health through the acupressure effect, is also being considered (see Patent Document 2, for example).

Japanese Utility Model Application Publication No. 02-96902 JP 2000-287701 A

However, simply spreading the toes apart or wearing sandals with a pressure point pressing function only improves blood circulation and temporarily gives a sense of freedom between the toes. To achieve a lasting relief from the condition, active toe exercises are required that can fundamentally correct the deformation of the foot shape. For example, frequent, repeated finger movements are performed in which all toes are clenched tightly and then loosened and opened.

In consideration of the above problems, the purpose of this invention is to provide sandals that promote toe movement and eliminate the deformation of the foot shape simply by wearing them.

In order to achieve the above object, the invention of claim 1 provides a pair of sandals comprising a base, a strap having a front end inserted and fixed into a front mounting hole formed in the front of the base, and two horizontal straps extending from the front end to the left and right rear ends inserted and fixed into two rear mounting holes formed near the left and right edges of the rear of the base, the front end being a band-like strap having a width in the front-to-rear direction of the base,
the base is a molded product made of synthetic resin, and includes a first covering member that covers an upper surface of the base, and a second covering member that further covers a partial area of the upper surface of the first covering member;
the second covering member has a predetermined thickness that forms a step with respect to a surface of the first covering member at a front edge in a lateral width direction of the foot,
The front edge has a dogleg shape along a line connecting the depressions between the pads and the bases of all the toes on the sole of the foot, and the apex of the dogleg shape is located on the little toe side of the position where the front part is inserted into the base, and the edge line on the big toe side extends from the apex to the rear of the position where the front part is inserted,
The base is provided with a mountain-shaped protrusion integrally over the area where the bases of the second to fourth toes come into contact.

The zori according to the invention described in claim 2 is the zori described in claim 1, characterized in that the thickness of the front edge that forms the step of the second covering member is 2 mm to 10 mm.

The invention of claim 3 relates to the zori described in claim 1, in which the front part has a maximum thickness of 5 to 8 mm.

The zori according to the invention in claim 4 is the zori according to claim 1, characterized in that the two side straps of the thong have a band shape with a certain width, the width of the side strap on the thumb side is maximized at the base of the thumb, and the maximum width is 1.2 to 3 times larger than the width of the side strap on the little finger side, which is located in the symmetrical position.

In the sandals of this invention, simply by putting them on, the space between the big toe and the second toe is widened, and when stepping out, the tips of all the toes get caught in the step formed by the thickness of the front edge of the second covering member, creating a natural fist-like grip, so that simply walking encourages the toes to open and close their fist, which has the effect of strengthening the muscles in the toes and correcting any deformations in the foot shape. Therefore, it is expected that the effect of eliminating various physical and mental disorders caused by deformations in the foot shape can also be expected.

1A is a schematic overall diagram of a left-foot zori as one embodiment of the present invention, in which (a) is a side view of the big toe side, (b) is a perspective view of (a) at a slight angle, (c) is a perspective view from the toe side, and (d) is a diagram of the zori of (c) when worn. 2A is an enlarged side view of the toe portion of the sandals of FIG. 1(b), and FIG. 2B is a schematic enlarged cross-sectional view of the toe portion taken along line AA of FIG. 1(c), showing only the base. 2A and 2B are schematic diagrams showing the overall configuration of the sandals of FIG. 1 as viewed from the little toe side, in which FIG. 2A is a perspective view, and FIG. 2B is a diagram showing the state when the sandals of FIG.

The zori of the present invention comprises a base, a strap with a width in the front-to-rear direction of the base, the tip of the front part being inserted and fixed in a front mounting hole formed in the front part of the base, and the ends of two horizontal straps extending from the front part to the left and right rear sides being inserted and fixed in two rear mounting holes formed near the left and right edges of the rear part of the base, the front part being a band-like strap having a width in the front-to-rear direction of the base, the base being a molded product made of synthetic resin, a first covering member covering the upper surface of the base, and the first covering member and a second covering member that further covers a portion of the upper surface of the shoe, and the second covering member has a predetermined thickness that forms a step with respect to the surface of the first covering member at its front edge in the lateral width direction of the foot, and the front edge has a dogleg shape along a line that connects the depressions between the pads and bases of all the toes on the sole of the foot, with the apex of the dogleg shape located on the little toe side of the position where the front part is inserted into the base, and the edge line on the big toe side extends from the apex to the rear of the position where the front part is inserted.

With the above configuration, when the sandals of the present invention are worn, first, in the natural state, the front part is sandwiched between the big toe and the second toe, spreading the space between the two toes. Moreover, since the front part is a band with a width in the front-to-back direction, it urges the two toes in a direction away from each other along the length of the toes, and is particularly effective in resisting the valgus of the big toe. Hallux valgus is a condition in which the MTP joint (consisting of the distal metatarsal and proximal proximal phalanx) at the base of the big toe protrudes outward, and the tip of the toe bends toward the little toe so that it overlaps with the second toe. Therefore, the tip of the big toe continues to receive a urging force in a direction away from the second toe, which helps to eliminate hallux valgus.

Since the length of an individual's toes varies depending on the foot size, the effective minimum width of the front part between the big toe and the second toe also varies. On the other hand, since it is common for sandals to be available in different foot sizes, for example, S, M, L, and LL, the width of the front part can be changed stepwise according to the various sizes, but it is preferable to set it in a range of 10 mm to 20 mm. In addition, by tilting the front part backward with respect to the base surface, the biasing area in the direction in which the big toe and the second toe are separated increases along the inclination of the interdigital space, and the action of spreading the big toe outward is more effectively exerted. The backward inclination angle of this front part with respect to the base surface is preferably in the range of 45 degrees to 65 degrees, which corresponds to the inclination of the interdigital space. Outside this range, it does not follow the inclination of the interdigital space, and if the inclination is too steep, it will be difficult to insert the front part between the toes, making it difficult to wear, and if it rises too high above the upper limit, the area biasing the two toes in the direction in which they are separated from each other will be small, reducing the effect of the biasing force.

In addition, the front part needs to have a certain thickness in order to effectively exert a biasing force in the direction of separation between the big toe and second toe. Preferably, the maximum thickness is in the range of 5 mm to 8 mm. If the thickness is smaller than this lower limit, the space between the two toes is small and the biasing force is difficult to generate. If the thickness is larger than this upper limit, the spaces between the toes will be too wide, which may cause pain and make it difficult to continue wearing the sandals. Even if the front part is relatively thick, by incorporating a cushioning material inside the front part, it is possible to reduce irritation to the spaces between the toes and make it easier to continue wearing the sandals of this invention.

Furthermore, in this invention, the front edge of the second covering member, which is further provided on the upper surface of the first covering member that covers the upper surface of the base, forms a step in a dogleg shape along the line connecting the depressions between the pads and the bases of all the toes on the sole of the foot, so that when you put on the sandals and push your toes forward, the rear parts of the pads of all the toes, including the big toe, get caught on the step and naturally make a fist-clenching motion to grab the edge, and the fist-clenching motion is naturally encouraged and repeated as you walk while wearing the sandals.

In this invention, the apex of the L-shaped front edge that forms the step is located on the little toe side of the front base's insertion position, and the edge line on the big toe side extends from the apex behind the front base's insertion position, positioning the big toe so that it can securely grasp the step with a fist movement, strengthening the muscles of all the toes and making it easier to correct the overall deformation of the foot shape. The positioning of the edge line on the big toe side is aimed at being able to accommodate the big toe of almost everyone.

In particular, since the length of the big toe varies from person to person and is not exactly the same even for people with the same foot size, it was found that it is best to set the step slightly closer to the base of the toes based on the results of measurements of the ratio of the toe length to the total length of many people's feet. Specifically, it is preferable for the distance from the center position of the edge line on the big toe side of the front edge of the L-shape to the front end of the base to be in the range of 18 to 22% of the maximum length of the sandals in the front-to-back direction, which corresponds to the total length of the foot, and more preferably 19 to 20% on average.

The thickness of the front edge that forms the step should be in the range of 2 mm to 10 mm, at which point the fingertips can easily catch. If the thickness is smaller than this lower limit, there is insufficient traction and there is little difference between the presence or absence of a step. If it is too thick, exceeding 10 mm, the step may be too high, making it difficult to walk.

The sandals of the present invention are also desirably lightweight so that they can be used frequently in daily life other than when going out, such as commuting to work or school. In conventional sandals, lightweight types use cut cork or molded synthetic resins such as polyurethane (PU) or ethylene vinyl acetate (EVA) resin as the base. It is preferable to use a similarly lightweight material for the base of the sandals of the present invention. Among them, EVA resin is preferable because it is lighter and there is no need to worry about deterioration over time due to hydrolysis, unlike polyurethane. It is also possible to blend other resins into EVA to create a material with improved abrasion resistance and durability.

In addition, if the material used is thermoplastic and can be molded using a mold, including EVA, the base can be molded into any shape. For example, it is easy to integrally form anti-slip protrusions and grooves on the underside of the base, which forms the bottom of the sandals. In addition, the base can be molded using a mold to create a curved cross-sectional shape where the thickness changes continuously along its entire length, such as by curving the toe or making the center concave.

Furthermore, if a mountain-shaped convex portion is integrally formed on the base over the area where the bases of the second to fourth toes come into contact, this mountain-shaped convex portion will appear on the top surface even after the first covering member and the second covering member are placed on top of each other. This convex portion pushes up the bases of the second to fourth toes in a slightly mountain-like shape, making it easier to maintain an arch along the left and right width of the foot. This widthwise arch, along with the front-to-back vertical arch known as the arch of the foot, is necessary for the spring action that generates power when stepping out, the cushioning action that absorbs shock when touching the ground, and the stability when standing on one foot, but even when this arch is crushed and the feet are spread apart, it is thought that twisting forces are easily applied to the base of the big toe, making it easier to develop hallux valgus.

The thongs, which are made up of two straps, one on the big toe side and one on the little toe side, extend backwards from the front part of the foot in a V-shape and rest on the instep. However, in order to make the sandals of this invention easier to wear and walk in on a daily basis except when going out, the straps are not thin strings, but are rather wide enough to be gentle on the instep.

In addition, it is preferable to design the side strap on the thumb side to be wider than the side strap on the little finger side so that it can cover the MTP joint part that protrudes outward from the base of the thumb. When wearing regular sandals with hallux valgus, the normal thin side strap hits the protruding part at the base of the thumb, causing pain, but by using a wide side strap that comes into contact with the base so as to widely cover it, pain can be avoided. It can also support the force that moves the thumb outward from the second toe without pain.

Specifically, for example, the little finger side strap should have a width of about 1.5 to 2.5 cm, and the thumb side strap should be shaped so that the part that touches the base of the thumb is the widest, with a maximum width of about 3 to 5 cm. Alternatively, the width should be about 1.2 to 3 times the width of the little finger side strap, which is located symmetrically to the widest point of the thumb side strap.

It is also desirable for the cross straps to have cushioning properties. For example, a cross strap with cushioning properties can be easily produced by filling a piece of fabric of a specified shape with a cushioning material such as polyurethane foam, folding it, and sewing the ends together. The tip that will become the front part can be formed integrally with the cross strap, and the tip parts of the left and right cross straps can be sewn together to form the front part. In this case, there is no need to prepare a separate member for the front part, and when cutting the fabric, the width, slope, and other design details of the part corresponding to the front part can be freely determined.

In the construction of the sandals of this invention, since the second covering member is what actually comes into direct contact with the sole of the foot, it is desirable to select a material that provides a pleasant feel. For example, it is preferable to first select a material that can eliminate the discomfort caused by dampness on the sole of the foot. For this reason, a tatami mat sheet made of natural or artificial rush grass materials is a suitable material. Rush grass has humidity control functions and moisturizing and insulating properties. Natural rush grass has a unique fragrance that gives a feeling of cleanliness and freshness.

The method of placing such a tatami covering sheet on top of the first covering member as the second covering member can be not only pasting with an adhesive or the like, but also sewing. However, to prevent the edge of the tatami covering sheet from directly touching the soles of the feet, the tatami covering sheet should be sewn to the base with the edges covered by another edge cloth around the entire circumference, in the same way as sewing through the tatami edges of normal tatami coverings.

The first covering member is not particularly limited as long as it has a reasonably smooth surface, since the surface of the first covering member is essentially only touched by the pads of the toes protruding from the second covering member. However, since a material with relatively high mechanical strength and tear resistance, yet low cost and easy to mold, is desired, a synthetic resin material such as polypropylene or polyester is preferable. It can also be attached to the top surface of the base by bonding with adhesive or fusion, or by sewing in the same manner as the second covering member.

Figures 1 to 3 show a pair of zori according to an embodiment of the present invention. For ease of explanation, the zori for the left foot is used as an example of a pair of zori that are symmetrical on both sides, and illustration and explanation of the zori for the right foot are omitted. In Figure 1, (a) is a side view of the big toe side, (b) is a perspective view of (a) tilted slightly, (c) is a perspective view from the toe side, and (d) is a diagram of the state when the zori in Figure (c) is worn. In Figure 2, (a) is an enlarged side view of the toe part on the little toe side, and (b) is a schematic enlarged view of the toe part showing only the base in a partial cross section taken along the line A-A in Figure 1(c). In Figure 3, (a) is an overall perspective view from the little toe side, and (b) is a diagram of the state when the zori in Figure (a) is worn and stepped out.

The sandals 1 according to this embodiment are based on a base 10 made of non-foamed EVA, and have an upwardly curved toe section 11 and a heel section 12 with chamfered edges, with numerous anti-slip projections 14 and grooves 15 formed on the bottom surface 13. Furthermore, the top surface is gently concave from the toe to the heel, and has a mountain-shaped protrusion 16 over the area where the bases of the second to fourth toes come into contact. A base 10 of this shape can be easily manufactured as a one-piece molded product, for example, by injection molding a thermoplastic material into a mold, or by pressurizing and heating a pellet-like material in a mold.

The top surface of the base 10 is covered with a first covering member 17 made of a plastic sheet with relatively low water absorption, such as polypropylene or polyester. The first covering member 17 is attached to the base surface by sewing it through a separate border cloth 18 that is hemmed all around.

On the front (top) surface of the base 10 to which the first covering member 17 is attached, a front attachment hole 30 is formed from the center of the front toward the thumb, and two rear attachment holes (31, 32) are formed near the left and right edges of the rear portion in order to attach the thong 40.

A second covering member 20 is further attached to the top surface of the first covering member 17, covering a portion of the upper surface. The front mounting hole 30 and rear mounting hole (31, 32) are set to be located outside the area of the second covering member 20. The second covering member 20 is a tatami mat sheet made of natural rush grass material or artificial rush grass material such as washi paper, and is sewn onto the base 10 via another border cloth 21 that borders the entire perimeter.

The front edge 22 of the second covering member 20 in the lateral width direction of the foot has a thickness of 2 to 10 mm and forms a step 24 with respect to the surface of the first covering member 17. This front edge 22 is V-shaped along a line connecting the depressions between the pads and bases of all the toes on the sole of the foot, and of this V-shaped front edge 22, the edge line 23 on the big toe side extends from the top of the V shape to the rear of the front attachment hole 30 for the front base insert. Specifically, the distance Y from the center position of the edge line 23 on the big toe side to the front end of the base is 19 to 20% of the maximum overall length X of the sandals that corresponds to the foot size.

Here, the present embodiment will be exemplified by an S-size pair of sandals 1 with a maximum overall length X of 23 cm. In these sandals 1, the distance Y is 45 mm, which is approximately 19.6% of the overall length X. These sandals 1 are designed so that, for most S-size feet, when the toes are made to make a fist, the big toe can also securely grasp the step 24 on the edge line 23 on the big toe side with the pad of its tip.

The front attachment hole 30 and the left and right rear attachment holes (31, 32) formed in the area of the first covering member 17 are inserted and fixed to the tip of the front part 41 of the thong 40, and the ends of the little finger side side strap 42 and the thumb side side strap 43 that extend from the front part 41 to the rear on both the left and right sides.

The thong 40 in this embodiment is composed of two cross-thong base materials. That is, an extension is provided at the front end of each cross-thong (42, 43), and these extensions are sewn together to form the front part 41. Therefore, the thong 40 is continuous with the front part 41 and each cross-thong (42, 43). Each of the two cross-thong base materials is made by folding a single piece of fabric, filling it with a cushioning material such as polyurethane, and sewing the ends together to form a strip of a specified width. A wide variety of commonly used fabrics can be used for the fabric, such as polyester, cotton, or a mixture of these.

In this embodiment, the little toe side strap 42 has a gentle curve from the front end to the back end so that it is slightly wider in the middle. In this small size sandal 1, the width of the front and back ends is about 15 mm, and the width of the middle part is about 25 mm. Similarly, the thumb side strap 43 is formed into a strip by folding a single piece of fabric, filling it with cushioning material, and sewing it together. This kind of width and cushioning of the straps (42, 43) makes them gentle on the instep and makes them easy to wear on a daily basis.

The thumb-side strap 43 has the same width at the front and back as the pinky-side strap 42, but the width D of the part that touches the base of the thumb is more than 1.5 times wider than the width d of the pinky-side strap 42, which is located symmetrically. In the S-size sandals 1 here, the width d of the pinky-side strap 42 is about 20 mm, while the maximum width D of the thumb-side strap 43 is about 35 mm. This wide part of the thumb-side strap 43 touches and covers the base of the thumb, so even if the thumb has hallux valgus, it wraps around the protruding part, making it easy to wear without feeling any pain. The front part 41 also supports the thumb in resisting the valgus and urging it away from the second toe.

As mentioned above, the front part 41 of the thong 40 is formed by sewing together the extensions from the front ends of the two horizontal straps (42, 43), and both parts contain cushioning material, so even if the front part 41 is relatively thick, it can urge the big toe and second toe in a direction away from each other without causing pain between the toes. Furthermore, the front part 41 is band-shaped with a width in the front-to-back direction of the base and is inclined backwards, so that the urging force acts effectively along the length of the toes, allowing the big toe and second toe to be spread apart well just by wearing it. In the S-size zori 1 of this embodiment, the maximum thickness of the front part 41 is about 5 mm, the width is 10 to 15 mm, and the backward inclination angle α from the base surface is 55 degrees.

In addition, the base 10 has a mountain-shaped convex portion 16 that extends over the area where the bases of the second to fourth toes of the sole of the foot come into contact, so that the convex portion 16 is visible even when the first covering member 17 and the second covering member 20 are overlapped. This convex portion 16 makes it easier to maintain the arch of the sole in the left and right width directions. When the arch is collapsed, a twisting force is applied to the base of the big toe, which can worsen hallux valgus, but this can be avoided.

When wearing the sandals 1 of this embodiment with the above configuration, the space between the big toe and second toe is first widened. Then, as shown in FIG. 3(b), when you start to take a step, you bend the top of your foot upward while bracing your toes and gripping the ground, and the pads of all your toes get caught on the steps 24 on the front edge 22 of the second covering member 20, naturally making a fist-clenching motion by grabbing the steps 24. By simply continuing to walk, the fist-clenching motion is promoted and can be easily repeated.

In the above example, an example of an S-size sandal was shown, but the material of each part is not limited to this and can be selected as appropriate. In addition, if the numerical values are set according to the conditions for each size, such as M, L, LL, etc., and products are prepared, the effects of this invention can be achieved by people with various foot sizes.

1: Zori 10: Base 11: Toe 12: Heel 13: Bottom 14: Projection 15: Groove 16: Convex 17: First covering member 18: Border 20: Second covering member 21: Border 22: Front edge 23: Edge line on thumb side 24: Step 30: Front mounting holes 31, 32: Rear mounting hole 40: Toe strap 41: Front base 42: Little toe side strap 43: Thumb side strap

Claims (4)

A pair of sandals comprising a base, a front part having a tip inserted and fixed into a front mounting hole formed in the front part of the base, and two horizontal straps extending from the front part to both the left and right rear ends inserted and fixed into two rear mounting holes formed near the left and right edges of the rear part of the base, the front part being a band-like strap having a width in the front-to-rear direction of the base,
the base is a molded product made of synthetic resin, and includes a first covering member that covers an upper surface of the base, and a second covering member that further covers a partial area of the upper surface of the first covering member;
the second covering member has a predetermined thickness that forms a step with respect to a surface of the first covering member at a front edge in a lateral width direction of the foot,
The front edge has a dogleg shape along a line connecting the depressions between the pads and the bases of all the toes on the sole of the foot, and the apex of the dogleg shape is located on the little toe side of the position where the front part is inserted into the base, and the edge line on the big toe side extends from the apex to the rear of the position where the front part is inserted,
The base is provided with a mountain-shaped protrusion integrally over an area where the bases of the second to fourth toes come into contact. The zori described in claim 1, characterized in that the thickness of the edge that forms the step of the second covering member is 2 mm to 10 mm. The sandals described in claim 1 are characterized in that the front part has a maximum thickness of 5 to 8 mm. The zori sandals according to claim 1, characterized in that the two side straps of the thong have a band-like shape with a certain width, the width of the side strap on the thumb side is maximized at the base of the thumb, and the maximum width is 1.2 to 3 times larger than the width of the side strap on the little finger side, which is located at the symmetrical position.

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