SHOE HAVING SPRING SYSTEM

Abstract

A shoe spring kit for a shoe includes a V-shaped spring portion having a lower platform portion and a raised springboard portion, the raised springboard portion intersecting the lower platform portion at an intersection point to form an angle relative to the lower platform portion such that the raised springboard portion is spaced apart from the lower platform portion by a distance at a location opposite the intersection point. The raised springboard portion is configured, at a static position, to bend and move closer to and away from the lower platform portion so as to provide a cantilever spring effect. The V-shaped spring portion can be placed inside of the shoe or outside of the shoe.

Claims

1. A shoe spring kit for a shoe, comprising: a fulcrum configured to be coupled to a sole of the shoe; a V-shaped spring configured to be disposed inside the shoe; and a front spring having a front end and a back end, the back end of the front spring configured to be coupled to the fulcrum.

2. The shoe spring kit according to claim 1, wherein the V-shaped spring comprises a lower platform portion and a raised springboard portion coupled to the lower platform portion, the lower platform portion and the raised springboard portion intersect at an intersection location to form an angle, the raised springboard portion being configured to move closer to and away from the lower platform portion so as to provide a cantilever spring effect by pushing on the sole.

3. The shoe spring kit according to claim 2, wherein the lower platform portion and the raised springboard portion are integrally formed as one piece from a single material.

4. The shoe spring kit according to claim 2, wherein the lower platform portion is configured to contact a back sole portion at an interior surface of the sole.

5. The shoe spring kit according to claim 2, wherein the raised springboard portion is spaced apart from the lower platform portion by a distance at a location opposite the intersection location.

6. The shoe spring kit according to claim 5, wherein the distance is from 0.25 inch to 4.0 inches.

7. The shoe spring kit according to claim 2, wherein the V-shaped spring is coupled to the sole using an adhesive or fasteners, or both.

8. The shoe spring kit according to claim 1, wherein the front spring has a curved portion between the front end and the back end, the curved portion being configured to contact ground and to provide spring recoil.

9. The shoe spring kit according to claim 1, wherein the front spring comprises a composite material.

10. The shoe spring kit according to claim 1, further comprising a front strike plate configured to be coupled to a front of the sole, wherein the front spring includes a polymer material tip at the front end of the front spring to facilitate slipping forward of the front end when the front end of the front spring meets the front strike plate.

11. The shoe spring kit according to claim 10, wherein the front end of the front spring is spaced apart from the front strike plate by about 1.5 inches.

12. The shoe spring kit according to claim 1, wherein the fulcrum comprises a flexible material.

13. The shoe spring kit according to claim 1, wherein the fulcrum is configured to be coupled to the sole of the sole at a mid-point of the sole, the fulcrum being configured to facilitate shifting of a weight of a wearer of the shoe from back to front to sequentially accelerate shifting of the weight between the V-shaped spring and the front spring, and to facilitate a movement of a foot in leaving ground.

14. The shoe spring kit according to claim 1, wherein lower surfaces of the V-shaped spring and the front spring that are configured to meet the ground include a layer of rubber material or polymer material to enhance traction of a wearer of the shoe.

15. A shoe comprising: a sole configured to support a foot of a wearer; an upper portion configured to cover the foot of the wearer; a fulcrum configured to be coupled to the sole; a V-shaped spring disposed inside the shoe; and a front spring having a front end and a back end, the back end of the front spring being coupled to the fulcrum, wherein the front end of the front spring is spaced apart from the sole, and the V-shaped spring is in contact with an interior surface of the sole.

16. The shoe according to claim 15, further comprising a front strike plate configured to be coupled to a front of the sole, wherein the front spring includes a polymer material tip at the front end of the front spring to facilitate slipping forward of the front end when the front end of the front spring meets the front strike plate.

17. A shoe spring kit for a shoe comprising: a V-shaped spring portion having a lower platform portion and a raised springboard portion, the raised springboard portion intersecting the lower platform portion at an intersection point to form an angle relative to the lower platform portion such that the raised springboard portion is spaced apart from the lower platform portion by a distance at a location opposite the intersection point, wherein the raised springboard portion is configured to bend and move closer to and away from the lower platform portion so as to provide a cantilever spring effect.

18. The shoe spring kit according to claim 17, wherein the lower platform portion is configured to contact a sole of the shoe and the raised springboard portion is configured to support a heel of a foot of a wearer.

19. The shoe spring kit according to claim 17, wherein the lower platform portion is configured to contact the ground and the raised springboard portion is configured to contact a sole of the shoe at a heel area of the shoe.

20. The shoe spring kit according to claim 17, wherein the distance between the raised springboard portion and the lower platform portion at the location opposite the intersection point is from 0.25 inch to 4.0 inches.

21. The shoe spring kit according to claim 17, further comprising a springboard fulcrum disposed between the lower platform portion and the raised springboard portion, the springboard fulcrum being configured to counter react to a force applied to the raised springboard portion and spring load a position of an ankle of a foot of a wearer.

22. The shoe spring kit according to claim 17, wherein the V-shaped spring portion is an integral single piece made from a resilient composite material.

23. The shoe spring kit according to claim 17, further comprising a springboard fulcrum attached to the raised springboard portion, wherein the springboard fulcrum is configured to be positioned on the raised springboard portion at a desired distance from the intersection point to adjust a stiffness of the raised springboard portion.

24. The shoe spring kit according to claim 17, further comprising a fulcrum configured to be coupled to a sole of the shoe; and a front spring having a front end and a back end, the back end of the front spring configured to be coupled to the fulcrum.

25. The shoe spring kit according to claim 1, wherein, when mounted to the shoe, the front end of the front spring is spaced apart from the sole, and the V-shaped spring is in contact with an interior surface of the sole.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0009] FIG. 1 is a perspective view of a shoe having a shoe spring having a V-shaped spring, according to an embodiment of the present disclosure.

[0010] FIG. 2 shows a V-shaped spring, according to another embodiment of the present disclosure.

[0011] FIG. 3 is a perspective view of a shoe having a torsion spring, according to an embodiment of the present disclosure.

[0012] FIG. 4 is a see-through view of an interior of the shoe having a torsion spring and at least one arm connected to the torsion spring extending into the interior of the shoe, according to an embodiment of the present disclosure.

[0013] FIG. 5 is a perspective view of an exterior of the shoe at the sole showing a front spring, according to an embodiment of the present disclosure.

[0014] FIG. 6 is a perspective view of a shoe having a shoe spring having a V-shaped spring and a springboard fulcrum attached to a top of a springboard portion of the V-shaped spring, according to another embodiment of the present disclosure.

[0015] FIG. 7 is a perspective view of a shoe having a shoe spring having a V-shaped spring and a fulcrum, according to yet another embodiment of the present disclosure.

[0016] FIG. 8 is a perspective view of a shoe having a front spring and a back spring, according to another embodiment of the present disclosure.

[0017] FIG. 9 is a perspective view of a shoe having the front spring and the back spring, according to another embodiment of the present disclosure.

[0018] FIG. 10 is a perspective view of a shoe having a spring coupled to a fulcrum, according to another embodiment of the present disclosure.

[0019] FIG. 11 is a perspective view of a shoe having a V-shaped spring and a front spring coupled to a fulcrum, according to yet another embodiment of the present disclosure.

[0020] FIG. 12 is a perspective view of a shoe having two springs (a V-shaped spring at the back of the shoe and a front spring at the front of the shoe) coupled to a fulcrum and to an intermediate platform, according to yet another embodiment of the present disclosure.

DETAILED DESCRIPTION OF THE INVENTION

[0021] Shoe systems are provided that improve the mechanics, efficiency, and/or performance of shoes in use. In use, the initial impact in the heel area of the foot is of special interest with runners because, in general, the heel area initially absorbs the highest amount of impact energy with the ground while providing a stable landing, but depending on the millisecond that occurs before the shift of weight, the runner will gain momentum or will slow down. Currently, shoes are provided with a rubber sole or air bladders enhanced at the heel area with additional rubber or foam thickness to provide additional cushioning of the foot during the initial impact of the heel area with the ground. The unintended consequence is that the shift of weight is more than likely delayed, interfering with forward momentum. Thus, improvement is still needed to enhance the mechanics, efficiency, and energy return, allowing superior performance of shoes in use and reduce injury and wear and tear.

[0022] A detailed running technique is described in Running Technique Principle 5: Utilise Your Natural Springs, by Brad Beer, dated Feb. 15, 2016, Running, https://www.pogophysio.com.au/blog/running-technique-principle-5-utilise-your-natural-springs/, the entire content of which is incorporated herein by reference. The fifth principle to running with great technique is to utilize what is referred to as a runner's natural springs. The same anatomical foot and leg structures that assist in lessening the loads on the legs on impact, such as the muscles, tendons, and fascia, also assist with propulsion.

[0023] Therefore, when a runner over-strides and subsequently heel strikes, not only are they by-passing their own shock absorbers they are also in effect bypassing their body's very own natural springs. The natural springs are the tendon-related structures in the foot and lower leg, including the Achilles tendon, calf muscle complex, and plantar fascia of the foot. When a runner lands on their mid-or forefoot, these natural spring structures generate energy and propulsion as they are stretched and then released.

[0024] The principle in biomechanics is known as elastic recoil. Elastic recoil applies to the tendons of the human body. The energy that is created by recoiling is generated by the plantar fascia of a runner's feet, the Achilles tendon, and the tendons in the calf complex. This occurs when a runner impacts the tendons stretch as they absorb load, before they recoil and provide the runner with propulsion.

[0025] Structurally, tendons can undergo stretching or deformation of somewhere between 4 and 6 per cent of their original length. When at rest, the tendon fibers, called collagen, run parallel in wavy lines (think of rolling hills in the countryside). Under load (such as at the time of foot impact), the collagen fibers are aligned as they straighten and store energy. As the lower limb muscles contract the tendons then release their stored-up energy. Amazingly, the recoil generated by a runner's leg tendons under the weight bearing or stance phase of the gait cycle provides up to 50 per cent of the propulsive forces required for each stride.

[0026] This elastic energy is released as kinetic (movement producing) energy during the toe off part of the running cycle. Elastic recoil requires very little energy, and is available for runners, unless these springs are bypassed by over-striding or running with less than an ideal technique.

[0027] When a runner over-strides, they inadvertently rob themselves of this free propulsive energy. Efficient runners store energy from one stride to the next and release it for push off. If it appears as though these runners have springs in their shoes, it is because they actually do in the form of tendon-springs.

[0028] The role that the tendons play in efficient and sustained distance running is evidenced by the body frames of elite distance runners. Typically, an elite distance runner's frame is composed of very little muscle mass, leaving just bones and tendons as the main propulsive structures. The fact that such a large proportion of their body mass is tendon tissue highlights the importance of tendons in fast and economical running.

[0029] In order to run pain and injury free, and also faster, it is also helpful to have stiff tendons. Stiffer tendons are able to store more energy because greater energy is required to stretch them. This greater energy is stored in the tendons and released at toe off as the muscles of the calf and lower leg contract. To improve the elastic recoil of your lower limb tendons you need to make your tendons stiffer. This can be achieved by strengthening the fibers that make up the tendons with exercises such as single leg calf raises and by supplementing the tendon recoil by using a stiff spring having a composite material (e.g., carbon graphite reinforced material) that move like tendons in the same motion and timing as required by the runner.

[0030] FIG. 1 is a perspective view of a shoe having a V-shaped spring comprising a stiff composite material (e.g., a stiff carbon graphite reinforced material) that bends to absorb and release energy as the wearer shifts weight, according to an embodiment of the present disclosure. The shoe is shown as being transparent to show various features of the shoe provided inside the shoe. The shoe 100 comprises a lower portion 102 including a sole 104 for supporting a foot of a wearer and an upper portion 106 for covering the foot of the wearer. The sole 104 includes a front sole portion 104A for supporting the ball and toes of the foot of the wearer and a back sole portion 104B for supporting the heel of the foot of the wearer. In an embodiment, the shoe 100 includes a shoe spring 110. The shoe spring 110 includes a front platform 110A separately comprising a composite material (e.g., a carbon graphite reinforced material) that deforms and straightens under pressure and releases energy at lift off when the front platform 110A snaps back to its original shape and V-shaped back portion 110B. The front platform 110A is provided at the front of the shoe 100. The back portion 110B (e.g., V-shaped) is provided near the heel region of the shoe 100. The front platform 110A together with V-shaped back portion 110B form a Y-shape, as shown in FIG. 1.

[0031] The V-shaped spring portion 110B has a lower platform portion 112 and a raised springboard portion 114 that intersect at intersection point 116 to form an angle with the lower platform portion 112. The front platform 110A is configured to contact the front sole portion 104A. The lower platform portion 112 is configured to contact the back sole portion 104B. The raised springboard portion 114 is configured to support the heel of the wearer of the shoe 100. The raised springboard portion 114 is spring-loaded relative to the lower platform portion 112. The raised springboard portion 114 forms the angle relative to the lower platform portion 112. The raised springboard portion 114 is spaced apart from the lower platform portion 112 by distance d at a location opposite the intersection point 116. The distance d can be from 0.25 inch to 4.0 inches (for example, from 0.25 inch to 2.5 inches) depending on a height of the flat (not raised) heel area of the shoe 100 and the height of the shell of the shoe or sandal. The intersection point 116 can be positioned over a fulcrum 118 of the shoe 100. The raised springboard portion 114 is configured to move closer to and away from the lower platform portion 112 as it bends so as to provide a cantilever spring effect on an arc to assist in the transfer of the weight of the wearer to the fulcrum that tips the weight to the front spring. When the back spring begins its cycle, it bends as the shoe tips back on the fulcrum, the calf muscles and foot tendons and fascia are extended and lengthened (as in calf stretch). As the shoe tips forward, the calf muscles and foot tendons release energy and propel the wearer forward. The shoe spring 110 can be attached to the sole 104. For example, the shoe spring 110 can be provided as an insert. In an embodiment, the raised springboard portion 114 of the back portion 110B (e.g., V-shaped) can be made from a resilient composite material such as a carbon graphite reinforced material. In an embodiment, the front platform 110A together with back portion 110B (e.g., V-shaped) forming the Y-shape can be made from a resilient composite material such as a carbon graphite reinforced material.

[0032] The fulcrum 118 can be made from a flexible material such as rubber or other compressible plastic. In an embodiment, the fulcrum 118 is provided at the mid-point of the sole 104. The fulcrum 618 is configured as an essential pivot to propel forward momentum created by the back springboard rising in an arc causing an immediate shift of the weight from the bounce of the shoe heel striking the ground to force the shift of weight toward the ball of the foot causing amplified pressure on the front spring that accelerates the movement and height of the foot leaving the ground. This is consistent with the cycle of running mechanics. The quicker the foot leaves the ground, milliseconds are saved and acceleration is enhanced. The fulcrum 118 can have a cylindrical shape. The fulcrum 118 can have a cylindrical diameter between about 0.5 inch and 1 inch, for example 0.75 inch. The fulcrum 118 can be fastened to the sole 104 using fasteners 118A (e.g., fastened to an exterior surface of the sole 104) or by adhesive to a flexible composite material (e.g., a carbon graphite reinforced material) plate that is glued to the bottom of the shoe. The fasteners 118A can be one or more screws or clips, etc. In an embodiment, the shoe 100 can include the fulcrum 118 during the manufacturing of the shoe 100. In another embodiment, the shoe 100 can be adapted to receive the fulcrum 118 after manufacturing of the shoe 100. Hence, the fulcrum 118 can be sold separately from the shoe 100 and any shoe can be adapted to receive the fulcrum 118. The interior of the back end of the shoe has extra space that allows the springboard to compress and raise in an upward arc without friction from the interior of the shoe.

[0033] In an embodiment, the shoe spring 110 can be incorporated into the shoe 100 during manufacturing of the shoe. In another embodiment, the shoe spring 110 is configured to be slipped into the shoe 100 over the sole 104, or be attached to a flexible graphite plate attached to the sole by adhesive, after manufacturing of the shoe 100. Therefore, any shoe can be modified by adding the shoe spring 110 with the back portion 110B (e.g., V-shaped).

[0034] In an embodiment, the shoe spring 110 includes stiff composite material (e.g., stiff carbon graphite reinforced material) that can bend under the weight of the wearer. In an embodiment, a spring member 120 can be provided between the lower platform portion 112 and the raised springboard portion 114 of the shoe spring 110. In an embodiment, the lower platform portion 112 can be attached to the raised springboard portion 114 via a static hinge 122 provided at the intersection point 116. The spring member 120 is configured to counter react to a force applied to the raised springboard portion 114.

[0035] In use, when walking or running, the back sole portion 104B for supporting the heel of the foot of the wearer impacts the ground first. Under the weight of the wearer, the heel of the foot of wearer will push on the raised springboard portion 114 of the shoe spring 110 as a springboard. As a result, the raised springboard portion 114 bends closer to the lower platform portion 112 and the distance d decreases. As the spring snaps up, the raised springboard portion 114 raises the heel in a forward arc, the fulcrum tips the shoe forward. The weight of the person then naturally shifts forward onto the ball of the foot that compresses the forward spring. The forefoot and toe region of the foot provide the last contact with the ground as the front spring rolls forward, deforms and releases its kinetic energy causing the foot to lift from the ground, while the fulcrum continues to tip forward. The front sole portion 104A touches the ground. The back sole portion 104B also lifts from the ground which allows the back spring to return to its potential open state until the foot in dorsiflexion contacts the ground and the spring contracts while it stores energy to be released as weigh is shifting.

[0036] The initial impact in the heel area of the foot is of special interest with runners because, in general, the heel area absorbs initially the highest amount of impact energy with the ground while providing a stable landing, which as suggested previously, might slow down the runner. Currently, many shoes are provided with a rubber sole enhanced at the heel area with additional rubber or foam thickness to provide additional cushioning of the foot during the initial impact of the heel area with the ground. However, the use of additional rubber or foam thickness does not provide useful cushion and/or substantial return of energy and propulsion. On the other hand, when the spring member 120 is used, the spring member 120 comprising stiff composite material (e.g., stiff carbon graphite reinforced material) which initially becomes compressed under the weight of the wearer and absorbs most if not all of the shock. In that instant, the spring decompresses (like a tendon) as the wearer shifts his/her weight forward to propel the heel of the wearer forward. As a result, not only the shoe spring 110 softens the landing of the foot of the wearer on the ground, the shoe spring 110 also helps to propel the foot of the wearer forward, thus adding to the wearer forward momentum.

[0037] FIG. 2 shows a shoe spring, according to another embodiment of the present disclosure. As shown in FIG. 2, the shoe spring 210 includes a front platform portion 210A and V-shaped back portion 210B. The front platform portion 210A can be provided at the front of the shoe 100. The V-shaped back portion 210B is provided near the heel region of the shoe 200.

[0038] The V-shaped spring portion 210B has a lower platform portion 212 and a raised springboard portion 214 that intersect at intersection line 216 to form an angle with the lower platform portion 212. The front platform 210A is configured to contact the front sole portion 104A (shown in FIG. 1). The lower platform portion 212 is configured to contact the back sole portion 104B (shown in FIG. 1). The raised springboard portion 214 is configured to support the heel of the wearer of the shoe 100. The raised springboard portion 214 is spring-loaded relative to the lower platform portion 212. The raised springboard portion 214 is spaced apart from the lower platform portion 212 by distance d at a location opposite the intersection line 216. The distance d can be between about 0.25 inch to 4.0 inches (for example, from 0.25 inch to 2.5 inches) depending on a heigh of the heel area of the shoe 100. The intersection line 216 can be positioned over the fulcrum 118 of the shoe 100 (shown in FIG. 1). The shoe spring 210 can be attached to the bottom of the sole 104 (shown in FIG. 1). The lower platform portion 212 and the raised springboard portion 214 that intersect at intersection line 216 to form an angle with the lower platform portion 212 are joined together using an adhesive material 216A, such as for example epoxy. The raised springboard portion 214 and the lower platform portion 212 can be reinforced and supported and joined together by a triangular wedge 216B.

[0039] In an embodiment, the shoe spring 210 can be made from a flexible composite material (e.g., a flexible carbon graphite reinforced material). In an embodiment, the raised springboard portion 214 can be made from a resilient composite material such as a carbon graphite reinforced material. In an embodiment, a resilient member 220 can be provided between the lower platform portion 212 and the raised springboard portion 214 of the shoe spring 210. In an embodiment the resilient member 220 can be made of flexible composite material such as a carbon graphite reinforced material. When the heel of the foot of a wearer pushes on the raised springboard portion 214, the resilient member 220 flexes or bends and when the wearer shifts weight, the heel of the foot of the wearer rises forward, in an arc as the runner shifts weight and the resilient member 220 expands and returns to its natural state. As a result, not only shoe spring 210 significantly softens the landing of the foot of the wearer on the ground, the shoe spring 210 through the resilient member 220 also helps to coordinate the natural movement of the knee, ankle and foot to complete the cycle to propel the wearer forward thus adding to the wearer forward momentum.

[0040] FIG. 3 is a perspective view of a shoe having a torsion spring, according to an embodiment of the present disclosure. As shown in FIG. 3, the shoe 300 is similar in many features with the shoe shown in in FIG. 1. The shoe 300 includes a torsion spring 302. The torsion spring 302 is provided within a fulcrum 304. The fulcrum 304 is located at the mid-point of the sole 306. The fulcrum 304 is configured facilitate shifting of the weight of the wearer from the back to the front to accelerate the movement of the foot in leaving the ground. The fulcrum 304 can be made from rubber or other compressible plastic. For example, the fulcrum 304 can have a cylindrical shape. The fulcrum 304 can have a cylindrical diameter between about 0.5 inch and 1 inch, for example 0.75 inch. The fulcrum 304 is attached to a surface of the sole 306 that is configured to contact the ground.

[0041] The shoe 300 further includes at least one arm 302A connected to the torsion spring 302. The at least one arm 302A extends through holes (shown in FIG. 4) provided within the sole 306 into the interior of the shoe 300.

[0042] FIG. 4 is a see-through view of an interior of the shoe 300 depicting the at least one arm 302A connected to the torsion spring 302 extending into the interior of the shoe 300, according to an embodiment of the present disclosure. For example, two arms 302A are shown extending into the interior of the shoe 300 through openings or holes 308 provided with the sole 306. Therefore, while the torsion spring 302 is provided within the fulcrum 304 on the sole 306 outside of the shoe 300, the at least one arm 302A is connected to the torsion spring 302 and extends to the interior of the shoe 300.

[0043] In an embodiment, at least one arm 302A can be curved at the back of the heel area of the shoe 300 to conform to the general shape of the heel of the foot of the wearer. In an embodiment, the at least one arm 302A can be curved or looped at the back 302B, as depicted in FIG. 3. In another embodiment, two arms 302A can be provided and the two arms 302A can be connected to each other at the back 302B. In an embodiment, the back 302B can be bent upward, as shown in FIG. 3. In an embodiment, a plurality of ties 302C (shown in FIG. 4) can be provided to connect the two arms 302A to provide support to the heel of the foot of the wearer. In another embodiment, instead of or in addition to the plurality of ties 302C, a fabric or flexible material (e.g., plastic, leather, etc.) may also be provided.

[0044] As shown in FIG. 3 and FIG. 4, the shoe 300 may also include a stop 310 to block the at least one arm 302A from raising above a certain distance h from the sole 306. In an embodiment, the back 302B can be configured to abut the stop 310 so as to limit an upward extension of the at least one arm 302A. The distance h can be between about 1 inch to about 3 inches.

[0045] As shown in FIG. 3, the shoe 300 may also include a harness 311. The harness 311 may include a band 312 and a buckle 314. The harness 311 including the band 312 and buckle 314 are configured to hold the foot of the wearer inside the shoe 300 when the heel of the foot of the wear is propelled by the at least one arm 302A pushed by the torsion spring 302. In an embodiment, the band 312 can be an elastic band.

[0046] As shown in FIG. 3, the shoe 300 also includes a front spring 316 disposed at the front portion of the sole 306. The front spring 316 can be made of resilient composite material such as a carbon graphite reinforced material. In an embodiment, the front spring 316 can have a U-shape (or an exaggerated Bobby pin shape) with an open portion 316A of the U-shape is oriented forward relative to the shoe 300. In an embodiment, the front spring 316 has a shape that is similar to a clothes pin shape. The front spring 316 has a bottom portion 316B. The bottom portion 316B is configured to stretch or bend under an applied force (e.g., a force applied by the weight of person wearing the shoe 300 when the weight shifts forward onto the ball of the foot). The front spring 316 has a top portion 316C. The top portion 316C contacts the sole 306 of the shoe 300. The top portion 316C has a shape that substantially follows the shape of the sole 306 at the front portion of the sole 306 but can extend about 0.25 inch on each side of the sole to enhance stability. In an embodiment, the top portion 316C of the front spring 316 can be longer than the bottom portion 316B of the front spring 316. For example, the top portion 316C can be longer than the bottom portion 316B by about 1 inch to 1.5 inches that allows the bottom portion to compress and slide forward on the top portion. The front spring 316 is described further while referring to FIG. 5.

[0047] FIG. 5 is a perspective view of an exterior of the shoe 300 at the sole showing the front spring 316, according to an embodiment of the present disclosure. As shown in FIG. 5, the bottom portion 316B of the front spring 316 is wider than the sole 306. In an embodiment, the bottom portion 316B extends about 0.5 inch on both sides of the sole 306 of the shoe 300, as shown in FIG. 5. The shoe 300 includes a plurality of channels 502. The plurality of channels 502 are mounted to the sole 306 and are configured to receive the front spring 316. The front spring 316 can slide into the plurality of channels 502. By providing the plurality of channels 502, the front spring 316 can be easily replaced if worn or damaged. For example, the plurality of channels 502 can be two channels provided on each side of the sole 306. The front spring 316 can also be removed from an adhesive and replace the front spring 316 with a new front spring, if worn or damaged. The front bottom of the shoe 300 is topped by the front spring 316 that is mounted on a flexible graphite plate that extends past the fulcrum 304. The fulcrum 304 can be mounted to the plate same flexible plate, as shown in FIG. 7. The front spring 316 may be covered by a thin rubber sole to provide traction.

[0048] FIG. 6 is a perspective view of a shoe having a V-shaped spring, according to another embodiment of the present disclosure. The shoe 600 is shown as being transparent to show various features of the shoe provided inside the shoe. The shoe 600 comprises a lower portion 602 including a sole 604 for supporting a foot of a wearer and an upper portion 606 for covering the foot of the wearer. The sole 604 includes a front sole portion 604A for supporting the ball and toes of the foot of the wearer and a back sole portion 604B for supporting the heel of the foot of the wearer. In an embodiment, the shoe 600 includes a shoe spring 610. The shoe spring 610 includes a V-shaped spring portion 610B provided near the heel region of the shoe 600. The present embodiment is different from the embodiment shown in FIG. 1 in that the shoe spring 610 does not have a front platform (such as the front platform 110A in the shoe 100).

[0049] The V-shaped spring portion 610B has a lower platform portion 612 and a raised springboard portion 614 that intersect at intersection point 616 to form an angle with the lower platform portion 612. In an embodiment, as shown in FIG. 6, the V-shaped spring portion 610B is provided inside the shoe 600 toward the heel portion or the back sole portion 604B. In an embodiment, the lower platform portion 612 of the V-shaped spring portion 610B is configured to contact the back sole portion 604B at the interior of the sole 604. The raised springboard portion 614 is configured to support the heel of the wearer of the shoe 600. The raised springboard portion 614 is spring-loaded relative to the lower platform portion 612. The raised springboard portion 614 forms the angle relative to the lower platform portion 612. The raised springboard portion 614 is spaced apart from the lower platform portion 612 by distance d at a location opposite the intersection point 616. The distance d can be from 0.25 inch to 4.0 inches (for example, from 0.5 inch to 2.5 inches), depending on a height of the heel area of the shoe 600. In an embodiment, the intersection point 616 can be positioned over the fulcrum 618 of the shoe 600 or near a mid-point the sole 604. The raised springboard portion 614 is configured to move closer to and away from the lower platform portion 612 so as to provide a cantilever spring effect without contacting the back of the shoe 600. The shoe spring 610 can be attached to the sole 604. The raised springboard portion 614 may include a curved portion 610C provided at a back area of the shoe 600 at a location opposite the intersection point 616.

[0050] In an embodiment, the shoe spring 610 can be incorporated into the shoe 600 during manufacturing of the shoe 600. In another embodiment, the shoe spring 610 is configured to be slipped into the shoe 600 over the sole 604 after manufacturing of the shoe 600. Therefore, any shoe can be modified by adding the shoe spring 610 with the V-shaped spring portion 610B. In an embodiment, the shoe spring 610 can be made from a resilient composite material including, for example, a flexible carbon graphite reinforced material and/or a flexible glass fiber reinforced material. The resilient composite material of the shoe spring 610 can be selected according to desired spring properties of the V-shaped spring portion 610B. In an embodiment, the raised springboard portion 614 can be made from a resilient composite material such as a carbon graphite reinforced material. The V-shaped spring portion 610B can be made as a single integral piece of composite material.

[0051] As illustrated in FIG. 6, the V-shaped spring portion 610B can be provided inside the shoe 600 toward the heel portion or the back sole portion 604B. In another embodiment, as illustrated in following figures (e.g., FIG. 11) and described further in the following paragraphs, the V-shape portion 610B can be provided outside the shoe 600 towards the heel portion or the back sole portion 604B. In this case, the lower platform portion 612 of the V-shaped spring portion 610B is configured to contact the ground and the raised springboard portion 614 is configured to contact the back sole portion 604B at the exterior of the sole 600 (for example, as shown in FIG. 11 for the V-shaped spring 1102).

[0052] In an embodiment, the shoe 600 may further include the fulcrum 618. The fulcrum 618 can be made from a flexible material such as rubber or other compressible plastic. In an embodiment, the fulcrum 618 is provided at the mid-point of the sole 604. The fulcrum 618 is configured to facilitate shifting of the weight of the wearer from the back to the front to sequentially accelerate the shifting of weight between the springs and the movement of the foot in leaving the ground. The fulcrum 618 can have a cylindrical shape. The fulcrum 618 can have a cylindrical diameter between about 0.5 inch and 1 inch, for example 0.75 inch. The fulcrum 618 can be fastened to the sole 604 using one or more fasteners 618A (e.g., fastened to an exterior surface of the sole 604, or attached with an adhesive). The one or more fasteners 618A can be screws or clips, etc. In an embodiment, the shoe 600 can include the fulcrum 618 during the manufacturing of the shoe 600. In another embodiment, the shoe 600 can be adapted to receive the fulcrum 618 after manufacturing of the shoe 600. Hence, the fulcrum 618 can be sold separately from the shoe 600 or be attached to a composite material (e.g., a carbon graphite reinforced material) plate that also includes the front spring, and any shoe can be adapted to receive the fulcrum 618.

[0053] As shown in FIG. 6, the shoe 600 may also include a front spring 620 disposed at the front portion of the sole 604. The front spring 620 can be made of resilient composite material such as a carbon graphite reinforced material. In an embodiment, the front spring 620 can have a U-shape (or an open Bobby pin shape) with an open portion 620A of the U-shape oriented forward relative to the shoe 600. In an embodiment, the front spring 620 has a shape that is similar to a Bobby pin shape. The front spring 620 has a bottom portion 620B. The bottom portion 620B is configured to stretch or bend under an applied force (e.g., a force applied by the weight of person wearing the shoe 600 when the weight shifts forward onto the ball of the foot) and snaps back as the foot leaves the ground. The front spring 620 has a top portion 620C. The top portion 620C an exterior surface of the sole 604 of the shoe 600. The top portion 620C has a shape that substantially follows the shape of the sole 604 at the front portion of the sole 604. In an embodiment, the top portion 620C of the front spring 620 can be longer than the bottom portion 620B of the front spring 620. For example, the top portion 620C can be longer than the bottom portion 620B by about 1 inch to 1.5 inches. The front spring 620 may be similar to the front spring 316 shown in FIG. 3.

[0054] Therefore, there is provided a front spring 620 for a shoe 600 and/or adapted to be mounted to any shoe. The front spring 620 includes the top portion 620C configured to contact the sole 604 at a front of the shoe 600. The front spring 620 also includes a bottom portion 620B connected to the top portion 620C, the bottom portion 620B configured to stretch and deform under an applied force and to snap back when the applied force is released. The top portion 620C and the bottom portion 620B form a U-shape and an open portion of the U-shape is oriented forward relative to the shoe 600. The front spring 620 is configured to be disposed at the front portion of the sole 604, the front spring 620 being made of resilient material. In an embodiment, the resilient composite material comprises a flexible stiff carbon graphite. In an embodiment, the U-shape includes a Bobby pin shape. In an embodiment, the force comprises at least a portion of a weight of a wearer of the shoe. In an embodiment, when the weight shifts forward onto the ball of the foot, the bottom portion 620B snaps back as the foot leaves the ground. In an embodiment, the top portion has a shape that substantially follows a shape of the sole 604 at the front of the sole 604. In an embodiment, the bottom portion 620B is curved to provide a spring recoil effect. In an embodiment, the top portion 620C is longer than the bottom portion 620B. In an embodiment, the top portion 620C is longer than the bottom portion 620B by about 1 inch to about 1.5 inches. In an embodiment, the width of the bottom portion 620B is greater than the width of the shoe 600, for example by about 0.25 inch. The top portion 620C may be a part of a flexible stiff composite material (e.g., a carbon graphite reinforced material) plate that extends past the back of the fulcrum 618, as shown in FIG. 7. This plate can be bent in front of the fulcrum 618 as the heel is raised by the shoe spring 610 so that pressure is amplified on the front spring 620. There may be provided a slight raise inside the shoe 600 above the fulcrum 618 to support the arch of the foot.

[0055] In an embodiment, a springboard link 630 may also be provided between the front spring 620 and the fulcrum 618. The springboard link 630 may further enhance the spring recall of the shoe 600 after bending of the shoe 600 during running.

[0056] In an embodiment, the shoe spring 610 may also include a springboard fulcrum 632 to adjust the stiffness of the raised springboard portion 614. The springboard fulcrum 632 can be provided in the V-shaped spring portion 610B of the shoe spring 610. For example, the springboard fulcrum 632 can be attached to the raised springboard portion 614, as shown in FIG. 6. Alternatively, this springboard fulcrum 632 can be attached to the lower platform portion 612. The springboard fulcrum 632 can be slidable to adjust a distance between the springboard fulcrum 632 and the intersection point 616. Alternatively, the springboard fulcrum 632 can be placed at a desired position by the user. When the raised springboard portion 614 moves closer to the lower platform portion 612, the springboard fulcrum 632 meets the lower platform portion 612. As a result, the recoil force of the raised springboard portion 614 is increased propelling the heel of the foot of the wearer forward. The springboard fulcrum 632 can be slidable to adjust a distance between the springboard fulcrum 632 and the intersection point 616 to adjust a spring constant of the shoe spring 610 to change the recoil force of the raised springboard portion 614, depending on a weight of the wearer, for example. The greater the distance between the springboard fulcrum 632 and the intersection point 616, the greater is the recoil force of the raised springboard portion 614. The springboard fulcrum 632 can be made, for example, from a resilient material such as a rubber or a plastic.

[0057] The V-shaped spring portion 610B of the shoe spring 610 can be sold alone for mounting to shoe or sold as a kit with the front spring 620 and/or the fulcrum 618. The shoe spring 610 may also be sold as the V-shaped spring portion 610B and having the curved portion 610C with or without the springboard fulcrum 632.

[0058] FIG. 7 is a perspective view of a shoe having a V-shaped spring, according to yet another embodiment of the present disclosure. The shoe 700 shown in FIG. 7 is similar in many aspects to the shoe 600 shown in FIG. 6. Therefore, the description of similar features will not be repeated. It is noted, however, that the shoe 700 differs from the shoe 600 in some aspects. For example, the lower platform portion 612 of the V-shaped spring portion 610B of the shoe spring 610 has a sleeve 702. The sleeve 702 can be made from a cloth or other polymer or composite material that does not stretch. The sleeve 702 can be provided the shoe 700 and attached to the sole of the shoe 700 to allow sliding in or removing of the V-shaped spring portion 610B of the shoe spring 610 from the shoe 700.

[0059] The top portion 620C may be a part of a flexible composite material (e.g., a carbon graphite reinforced material) plate 620D that extends past the back of the fulcrum 618, as shown in FIG. 7. The flexible composite material plate 620D can be bent in front of the fulcrum 618 as the heel is raised by the shoe spring 610 so that pressure is amplified on the front spring 620.

[0060] FIG. 8 is a perspective view of a shoe 800 having a front spring and a back spring, according to another embodiment of the present disclosure. The shoe 800 is shown as being transparent to show the position of a wearer's foot 801 inside the shoe 800. The shoe 800 comprises a lower portion 802 including a sole 804 for supporting the foot 801 of the wearer and an upper portion 806 for covering the foot 801 of the wearer. The sole 804 includes a front sole portion 804A for supporting the ball and toes of the foot 801 of the wearer and a back sole portion 804B for supporting the heel of the foot 801 of the wearer. In an embodiment, the shoe 800 includes a back spring 810 and a front spring 820. The shoe 800 also includes a fulcrum 830.

[0061] In an embodiment, the back spring 810 and the front spring 820 can be made from a resilient material including, for example, a composite material such as a flexible carbon graphite reinforced material. The resilient material of the back spring 810 and the front spring 820 can be selected according to desired spring properties and according to a weight of the wearer. For example, the shoe 800 having the back spring 810 and the front spring 820 can be rated and sold to support a certain weight, for example, by stating shoe supports wearers with a weight between 120 lbs and 160 lbs, or shoe supports wearers with a weight between 170 lbs and 200 lbs, etc. In another embodiment, the back spring 810 and the front spring 820 can be changeable to accommodate the weight of the wearer. Hence, the back spring 810 and the front spring 820 can be sold as a kit separately from the shoe 800.

[0062] In an embodiment, as shown in FIG. 8, the back spring 810 and the front spring 820 include a curved plate. A back end 820B of the front spring 820 is connected to the fulcrum 830. A front end 810A of the back spring 810 is also connected to the fulcrum 830, for example, glued or fastened using an appropriate fastener. A front end 820A of the front spring 820 is spaced apart from the front sole portion 804A. The back end 810B is spaced apart from the back sole portion 804B. In an embodiment, the shoe 800 also includes a strike plate 822. The strike plate 822 is coupled to the front sole portion 804A. the strike plate 822 can be made of composite material, plastic, metal, or the like.

[0063] The front end 820A of the of the front spring 820 is spaced apart from the strike plate 822 by a distance d, when the front spring 820 is not compressed. The distance d can be from 0.5 inch to 2.5 inches (for example, about 1.5 inches). The front end 820A is configured to abut against the strike plate 822, when the front spring 820 is compressed by the weight of the wearer.

[0064] Similarly, the back end 810B of the back spring 810 is spaced apart from the back sole portion 804B by a distance h, when the back spring 810 is not compressed. The distance h can be from 0.5 inch to 3.0 inches (for example, between 1 inch and 2.5 inches). A compressible element 812 (e.g., a rubber flex element) is provided near the back end 810B of the back spring 810. The compressible element 812 is coupled to the back sole portion 804B. The back end 810B of the back spring 810 is configured to abut against the compressible element 812, when the back spring 810 is compressed by the weight of the wearer. The compressible element 812 is configured to provide additional shock absorption when the heel of the foot 801 strikes the ground.

[0065] The fulcrum 830 can also be made from a flexible material such as rubber or other compressible plastic. In an embodiment, the fulcrum 830 is provided at the mid-point of the sole 804. In another embodiment, the fulcrum 830 can also be provided at a position shifted relative to the mid-point of the sole 804. The fulcrum 830 is configured to facilitate shifting of the weight of the wearer from the back to the front to sequentially accelerate the shifting of weight between the back spring 810 and the front spring 820, and facilitate the movement of the foot in leaving the ground. The fulcrum 830 can have a cylindrical shape. The fulcrum 830 can have a cylindrical diameter between about 0.5 inch and 1 inch, for example 0.75 inch. The fulcrum 830 can be fastened to the sole 604 using one or more fasteners 830A (e.g., fastened to an exterior surface of the sole 804, or attached with an adhesive). The one or more fasteners 830A can be screws or clips, etc.

[0066] In an embodiment, the shoe 800 can include the fulcrum 830 during the manufacturing of the shoe 800. In another embodiment, the shoe 800 can be adapted to receive the fulcrum 830 after manufacturing of the shoe 800. Hence, the fulcrum 830 can be sold separately from the shoe 800. The fulcrum 830 and the back spring 810 and the front spring 820 can also be sold together as a kit for mounting to the shoe 800 that does not have the fulcrum 830, the back spring 810 and the front spring 820 or to replace a damaged fulcrum 830, damaged back spring 810 and/or damaged front spring 820.

[0067] In operation, the back spring 810 and the front spring 820 are compressible under a force generated by a weight of a wearer of the shoe when walking, running, or jumping. Initially, the force is applied towards the heel of the foot 801 to compress the back spring 810. When the weight shifts forward onto the ball of the foot 801, the front spring 820 is compressed while the back spring 810 is released to help propel the foot 801 forward. The fulcrum 830 is configured as a pivot to propel forward momentum created by the back spring 810 causing an immediate shift of the weight from the bounce of the shoe heel striking the ground to force the shift of weight toward the ball of the foot 801 causing amplified force on the front spring 820 that accelerates the movement and height of the foot leaving the ground. This is consistent with the cycle of running mechanics. The quicker the foot leaves the ground, milliseconds are saved and acceleration is enhanced.

[0068] FIG. 9 is a perspective view of a shoe 900 having the front spring 820 and the back spring 810, according to another embodiment of the present disclosure. The shoe 800 is similar in many aspects to the shoe 800 shown in FIG. 8. Therefore, the description of similar features is nor repeated. One main difference between shoe 800 and shoe 900 is that shoe 900 includes a cover 902 at the back end 904 (heel) of the back sole portion 804B. The cover 902 is coupled to the back sole portion 804B. The cover 902 can be made of a flexible material such as rubber or flexible plastic. The cover 902 is provided to cover a gap 906 between the back spring 810 and the back sole portion 804B. A strike plate 908 similar to strike plate 822 can also be provided at the back end 904 (heel) of the back sole portion 804B. The strike plate 908 is coupled to the back sole portion 804B. The strike plate 908 can be made of composite material, plastic, metal, or the like. The back end 810B of the of the back spring 810 is spaced apart from the strike plate 908 by a distance h, when the front spring 820 is not compressed. The distance h can be about from 0.5 inch to 3 inches (for example, 1.5 inches). The back end 810B is configured to abut against the strike plate 908, when the back spring 810 is compressed by the weight of the wearer.

[0069] FIG. 10 is a perspective view of a shoe 1000 having a spring 1002 coupled to a fulcrum 1004, according to yet another embodiment of the present disclosure. The shoe 1000 is similar in many aspects to the shoe 800 shown in FIG. 8. Therefore, the description of similar features is nor repeated. One main difference between shoe 800 and shoe 1000 is that, instead of having a front spring and a bag spring, the shoe 1000 has a spring 1002 coupled to the fulcrum 1004. The spring 1002 is a single unitary spring having a front spring portion 1002A and a back spring portion 1002B. The front spring portion 1002A and the back spring portion 1002B of the spring 1002 are curved and together form a W-like shape, as shown in FIG. 10. In an embodiment, a trough of front spring portion 1002A is spaced apart from the sole 1006 between 0.5 inch to 3 inches (for example, about one inch). The spring 1002 is connected to the fulcrum 1004 at about a mid-point between the front spring portion 1002A and the back spring portion 1002B. For example, the spring 1002 can be fastened to the fulcrum 1004 using a fastener or glued. The spring 1002 can be made for example from a compliant material such as a composite material (e.g., a carbon graphite reinforced material or a glass fiber reinforced material). The fulcrum 1004 together with the spring 1002 is mounted to the sole 1006 of the shoe 1000. A height or thickness of the fulcrum can be from 0.5 inch to 1.5 inches (for example, 0.75 inch).

[0070] The front spring portion 1002A has a front end 1008A and a back end 1008B. The back spring portion 1002B has a front end 1010A and a back end 1010B. The back end 1008B of the front spring portion 1002A is connected to the front end 1010A of the back spring portion 1002B. The front end 1008A of the front spring portion 1002A is provided with a polymer material tip 1012A to facilitate slipping forward when the front end 1008A of the front spring portion 1002A meets a front strike plate 1014 coupled to a front area of the sole 1006 of the shoe 1000, when the front spring portion 1002A is compressed. The front strike plate 1014 can be made of composite material, plastic, metal, or the like. The front end 1008A of the front spring portion 1002A is spaced apart from the front strike plate 1014 or the sole 1006 from 0 inch to 1 inch (for example, about 0.25 inch).

[0071] Similarly, the back end 1010B of the back spring portion 1002B is provided with a polymer material tip 1012B to facilitate slipping forward when the back end 1010B of the back spring portion 1002B meets a back strike plate 1014B coupled to a back area of the sole 1006 of the shoe 1000, when the back spring portion 1002B is compressed. The back strike plate 1014B can be made of composite material, plastic, metal, or the like. The back end 1010B of the back spring portion 1002B is spaced apart from the back strike plate 1014B or the sole 1006 from 0 inch to 1 inch (for example, about 0.25 inch). The shoe 1000 may also include a ribbed extension 1016 (e.g., made of rubber or polymer) provided at a heel or back area of the sole 1006 to provide additional area so as to extend the back strike plate 1014B towards the back.

[0072] FIG. 11 is a perspective view of a shoe 1100 having two springs (a V-shaped spring at the back of the shoe and a front spring at the front of the shoe) coupled to a fulcrum, according to yet another embodiment of the present disclosure. The shoe 1100 has a sole 1101. The sole 1101 has a front sole portion 1101A and a back sole portion 1101B. The shoe 1100 has a V-shaped spring 1102, a front spring 1104, and a fulcrum 1106. The V-shaped spring 1102 and the front spring 1104 are coupled to the fulcrum 1106. The shoe 1100 is similar in many aspects to the shoe 700 shown in FIG. 8. However, in the embodiment shown in FIG. 11, the V-shaped spring 1102 is located outside of the shoe 1100. The V-shaped spring 1102 is provided near the heel region of the shoe 1100.

[0073] The V-shaped spring 1102 has a lower platform portion 1102A and a raised springboard portion 1102B (upper platform portion) coupled to the lower platform portion 1102A. The raised springboard portion 1102B and the lower platform portion 1102A intersect at an intersection location 1102C (e.g., intersection point or intersection line) to form an angle . The lower platform portion 1102A and the raised springboard portion 1102B can be integrally formed from a single material (e.g., a composite material such as a carbon fiber reinforced material or glass fiber reinforced material) as one piece to form the V-shaped spring 1102. The raised springboard portion 1102B is configured to contact the back sole portion 1101B at an exterior surface of the sole 1101 opposite the interior of the shoe 1100. When mounted to the shoe 1100, the V-shaped spring 1102 is coupled to an exterior surface of the sole 1101 such that the V-shaped spring 1102 in its entirety is located outside of the shoe 1100. The raised springboard portion 1102B is spring-loaded relative to the lower platform portion 1102A. As shown in FIG. 11, the raised springboard portion 1102B can be longer than the lower platform portion 1102A. However, the length of the raised springboard portion 1102B and/or the length of the lower platform portion 1102A can be selected as desired. The length of the raised springboard portion depends on a size of the shoe 1100. The length can be, for example, 5 inches. The raised springboard portion 1102B is spaced apart from the lower platform portion 1102A by distance d at a location opposite the intersection location 1102C. The distance d can be from 0.25 inch to 4.0 inches (for example, from 1 inch to 2.5 inches), depending on a configuration of the shoe 1100. The intersection location 1102C can be positioned near or over the fulcrum 1106. The lower platform portion 1102A is configured to contact the ground. The lower platform portion 1102A can be generally planar, as depicted in FIG. 11, but can also have a slightly curved shape, or an undulated shape to provide additional grip when contacting the ground.

[0074] The raised springboard portion 1102B is configured to move closer to and away from the lower platform portion 1102A so as to provide a cantilever spring effect by pushing on the back sole portion 1101B of the sole 1101. The lower platform portion 1102A can contact the ground to provide compression and a cantilever spring effect to the raised springboard portion 1102B. The V-shaped spring 1102 can be coupled to the sole 1101 using an adhesive or fasteners, or both. The V-shaped spring 1102 can be incorporated into the shoe 1100 during manufacturing of the shoe 1100. The V-shaped spring 1102 can be attached to the shoe 1100 after manufacturing of the shoe 1100. Therefore, any shoe can be modified by adding the V-shaped spring 1102. In an embodiment, the V-shaped spring 1102 can be made from a resilient material including, for example, a composite material (e.g., a glass fiber material or a carbon graphite reinforced material). The resilient material of V-shaped spring 1102 can be selected according to desired spring properties of V-shaped spring 1102.

[0075] The shoe 1100 also includes a front spring 1104. In an embodiment, the front spring 1104 can be connected to the V-shaped spring 1102 at the fulcrum 1106. The front spring 1104 has a front end 1104A and a back end 1104B. The back end 1104B is coupled to the fulcrum 1106. In an embodiment, the front spring can be made of a composite material (e.g., a glass fiber reinforced material or a carbon graphite reinforced material). The shoe 1100 also includes a front strike plate 1108 coupled to the front sole 1101A of the sole 1101. In an embodiment, the front end 1104A of the front spring 1104 can be provided with a polymer material tip at the front end 1104A to facilitate slipping forward of the front end 1104A when the front end 1104A meets the front strike plate, when the front spring 1104 is compressed. The front strike plate 1014 can be made of composite material, plastic, metal, or the like. The front end 1104A of the front spring 1104 is spaced apart from the front strike plate 1108 or the sole 1006 from 0 inch to 2 inches (for example, by about 1.5 inches). The front spring 1104 also has a curved portion 1104C between the front end 1104A and the back end 1104B, as shown in FIG. 11. The curved portion 1104C being configured to contact the ground and to provide spring recoil. In an embodiment, a length of the curved portion 1104C of the front spring 1104 is selected according to a size of the shoe 1100. The length of the curved portion can be about 3.5 inches.

[0076] The fulcrum 1106 can be made from a flexible material such as rubber or other compressible plastic. In an embodiment, the fulcrum 1106 is coupled to the sole 1101 at the mid-point of the sole 1101. In another embodiment, the fulcrum 1106 can also be provided at a position shifted relative to the mid-point of the sole 1101. The fulcrum 1106 is configured to facilitate shifting of the weight of the wearer from the back to the front to sequentially accelerate the shifting of weight between the V-shaped spring 1102 and the front spring 1104, and to facilitate the movement of the foot in leaving the ground. The fulcrum 1106 can have a cylindrical shape. The fulcrum 1106 can have a cylindrical diameter between about 0.5 inch and 1 inch, for example 0.75 inch. The fulcrum 1106 can be fastened to the sole 1101 using one or more fasteners (not shown) or attached with an adhesive.

[0077] In an embodiment, the shoe 1100 can be provided with the fulcrum 1106 during the manufacturing of the shoe 1100. In another embodiment, the shoe 1100 can be adapted to receive the fulcrum 1106 after manufacturing of the shoe 1100. Hence, the fulcrum 1106 can be sold separately from the shoe 800 or can be sold with the front spring 1104 and V-shaped spring 1102 as a kit for mounting to any shoe that does not have the fulcrum 1106, the V-shaped spring 1102 and the front spring 1104 or to replace a damaged fulcrum 1106, a damaged V-shaped spring 1102 and/or damaged front spring 1104.

[0078] Lower surfaces of the V-shaped spring 1102 and the front spring 1104 that can come in contact with the ground include a layer of rubber material or polymer material to enhance traction of the wearer of the shoe 1100 during movement of the shoe 1100. For example, a layer of rubber or polymer can be applied to lower surfaces of the lower platform portion 1102A of the V-shaped spring 1102 and the curved portion 1104C of the front spring 1104 that meet the ground to enhance traction during movement of the shoe 1100.

[0079] In operation, the V-shaped spring 1102 and the front spring 1104 are compressible under a force generated by a weight of a wearer of the shoe 1100 when walking, running, or jumping. Initially, the force is applied towards the heel of the foot of the wearer of the shoe 1100 to compress the V-shaped spring 1102. When the weight shifts forward onto the ball of the foot, with the assist of the fulcrum 1106, the front spring 1104 is compressed while the V-shaped spring 1102 is released to help propel the foot of the wearer of the shoe 1100 forward. The fulcrum 1106 is configured as a pivot to propel forward momentum created by the V-shaped spring 1102 causing an immediate shift of the weight from the bounce of the shoe heel striking the ground to force the shift of weight toward the ball of the foot causing amplified force on the front spring 1104 that accelerates the movement and height of the foot leaving the ground. This is consistent with the cycle of running mechanics. The quicker the foot leaves the ground; milliseconds are saved and acceleration is enhanced.

[0080] FIG. 12 is a perspective view of a shoe 1200 having two springs (a V-shaped spring at the back of the shoe and a front spring at the front of the shoe) coupled to a fulcrum, according to yet another embodiment of the present disclosure. The shoe 1200 is similar in many aspects to the shoe 1100 shown in FIG. 11. However, in this embodiment, the back (V-shaped) spring is not coupled directly to the sole 1101 of the shoe 1200. Instead, the shoe 1200 includes an additional intermediate platform 1202 (layer of material). In an embodiment, the intermediate platform 1202 can be made of a compliant material such as plastic or the like. The back (V-shaped) spring 1102, the front spring 1104 and the fulcrum 1106 are coupled to the intermediate platform 1202. For example, the back (V-shaped) spring 1102, the front spring 1104 and the fulcrum 1106 together with the intermediate platform 1202 can be sold together as a kit for mounting to any shoe. For example, the intermediate platform 1202 can be sized according to a size of the shoe.

[0081] The intermediate platform 1202 has a top surface 1202A and a bottom surface 1202B. The intermediate platform 1202 can be coupled or attached to the shoe 1200 by contacting the top surface 1202A of the intermediate platform 1202 to the sole 1101 using an adhesive or other attachment mechanism. For example, the intermediate platform 1202 can be provided with an adhesive at the top surface 1202A. The adhesive can be protected by a plastic sheet cover (not shown). The plastic sheet cover can be removed or peeled off to expose the adhesive before contacting the sole 1101 to the intermediate platform 1202. For example, the purchaser of the kit including the intermediate platform 1202, the back spring 1102, the front spring 1104, and the fulcrum 1106 can be instructed to stand on the intermediate platform 1202, after removing the plastic sheet cover, with the foot inside the shoe, for several minutes so that the sole 1102 contacts the intermediate platform 1202 until the adhesive is set or cured.

[0082] In an embodiment, the V-shaped back spring 1102 is coupled to the bottom surface 1102B of the intermediate platform 1202. The front spring 1104 is also coupled to the bottom surface 1102B of the intermediate platform 1202. The fulcrum 1106 is also coupled to the bottom surface 1202B of the intermediate platform 1202. The front strike plate 1108 can also be coupled to the bottom surface 1202B of the intermediate platform 1202.

[0083] In an embodiment, a clip (not shown) can be provided at the heel section of the sole 1101. The intermediate platform 1202 together with the raised springboard portion 1102B of the back spring 1102 can be attached to the sole 1101 using the clip. For example, the clip can be provided within a notch of the sole 1101. In another embodiment, the clip can be provided on the intermediate platform 1202 and the raised springboard portion 1102B is inserted into the clip or attached to the intermediate platform 1202 using the clip. The clip can be made of metal (e.g., steel) or other high strength material. The front spring 1104 can be attached to the intermediate platform 1202 by sliding the front spring 1104 into the fulcrum 1106 to allow for easy replacement. The front spring can be inch to inch wider than the sole 1101 to provide more stability to the wearer of the shoe 1200.

[0084] In some embodiments, the back (V-shaped) spring, the fulcrum and the front spring operate in synchronized order to propel the wearer forward. For example, when the active arm of the back spring that is coupled to the sole is at rest, the spacing between the sole and the ground can be about 2 inches. However, as the active arm bends and compresses as the wearer moves forward, the forward shift of weight relieves weight and pressure from the heel and reduces the spacing between the active arm and the ground to the height of the fulcrum (e.g., of an inch to 1 inch). At this moment, the fulcrum accelerates the momentum by assisting the wearer to leaning forward. Prior to this phase, the fulcrum is not active, and the fulcrum does not support the full weight of the wearer. However, as the weight of the wearer shifts forward, the back spring continues decompressing, resulting in raising the heel in an arc from the force of the back spring, catapulting the weight of the wearer forward on to the fulcrum that functions as a pivot. The fulcrum continues the forward momentum by tipping the balance of the wearer forward, compounding the pressure on the forefoot to activate the front spring. As the wearer leans forward, all of the wearer's weight becomes focused on the ball of the foot, causing the front spring to be further compressed by the total weight and pressure of the wearer as the foot prepares to push off the ground. As indicated above, the fulcrum can have a height (e.g., of an inch to 1 inch) that is less than the uncompressed height of the front spring (e.g., about 1.5 inches). The compressed front spring can be deformed to be almost flat before it snaps back to its original shape propelling the runner to leave the ground.

[0085] The weight of the wearer shifts from the back spring to the fulcrum, and then to the front spring (i.e., heel to toe forward movement). This repetitive dynamic cycle is repeated ensuring that the wearer is propelled forward with lesser effort, greater speed, and proper walking and running mechanics.

[0086] As it can be appreciated from the above paragraphs, an aspect of the present disclosure is to provide a shoe, or a separate kit that converts a shoe, having a first spring placed inside the shoe under the heel of the wearer, a second spring on the bottom of the shoe centered under the ball of the foot, and a fulcrum. The first spring and the second spring are separated by the fulcrum placed under the middle of the shoe, exterior to the shoe. The fulcrum tips the wearer forward when weight is shifted. The first spring, the fulcrum, and the second spring are sequentially aligned to assist, support, and accelerate the innate movements of the foot, ankle, and calf required for each step taken while running or walking. In particular, the first spring and the second spring mimic and enhance the natural functions of tendons, fascia, and muscles as they coordinate movements during running and walking activities. Those innate body adjustments that shift weight, maintain balance, and create forward momentum, naturally occur in milliseconds, and without pause for conscience thought.

[0087] For example, the first spring of the shoe is a large V-shaped spring, positioned inside the rear half of the shoe, laid on one side resting on the interior lining of the sole, open toward the back of the shoe. The top side of the V-shaped spring slants (like a shoe-horn) from the back of the shoe to the center balance point. The slanting side of the V-shaped spring functions as the primary springboard. That springboard bends slightly under weight of the wearer (keeping the wearer up straight), bends significantly from pressure under shifting weight (absorbing passive energy), and/or bottoms out from shock (though not experienced as such) while running. After absorbing the energy from a bending event, the springboard immediately snaps back in a milli second, as weight shifts returning energy in an arc lifting the heel, pushing the wearer to automatically continue shifting weight tipping forward on the fulcrum, and activating the second spring (the front spring) to absorb energy from weighted pressure that results in the release of energy amplifying the lift off of the foot as the foot leaves the ground.

[0088] Various aspects and features of the present disclosure are reflected in the following clauses.

[0089] An aspect of the present disclosure provides a shoe spring for a shoe. The shoe spring includes a V-shaped back portion having a lower platform portion configured to contact a sole of the shoe and a raised springboard portion that is configured to support a heel of a foot of a wearer, the raised springboard portion intersecting the lower platform portion at an intersection point to form an angle relative to the lower platform portion such that the raised springboard portion is spaced apart from the lower platform portion by a distance at a location opposite the intersection point. The raised springboard portion is configured, at a static position, to bend and move closer to and away from the lower platform portion so as to provide a cantilever spring effect.

[0090] The shoe spring according to the preceding clause, further including a front platform provided at a front of the shoe, wherein the front platform and the V-shaped back portion form a Y-shape.

[0091] The shoe spring according to any preceding clause, wherein the distance between the raised springboard portion and the lower platform portion at the location opposite the intersection point is from 0.25 inch to 4.0 inches.

[0092] The shoe spring according to any preceding clause, further including a spring member disposed between the lower platform portion of the V-shaped back portion and the raised springboard portion of the V-shaped back portion, the spring member being configured to counter react to a force applied to the raised springboard portion and spring load a position of the ankle of the foot of the wearer.

[0093] The shoe spring according to any preceding clause, wherein the shoe spring is made from a resilient material.

[0094] The shoe spring according to any preceding clause, wherein the resilient material comprises a composite material.

[0095] The shoe spring according to any preceding clause, wherein the V-shaped back portion is made of a resilient material.

[0096] The shoe spring according to any preceding clause, wherein the resilient material comprises flexible stiff composite material or material with similar qualities.

[0097] The shoe spring according to any preceding clause, further including a springboard fulcrum attached to the raised springboard portion, wherein the springboard fulcrum is configured to be positioned on the raised springboard portion at a desired distance from the intersection point to adjust a stiffness of the raised springboard portion.

[0098] A further aspect of the present disclosure provides a shoe including a lower portion including a sole configured to support a foot of a wearer, an upper portion configured to cover the foot of the wearer, and a shoe spring having a V-shaped back portion provided near a heel region of the shoe, the V-shaped back portion having a lower platform portion and a raised springboard portion that is configured to support a heel of the foot of the wearer. The raised springboard portion intersects the lower platform portion at an intersection point to form an angle relative to the lower platform portion such that the raised springboard portion is spaced apart from the lower platform portion by a distance at a location opposite the intersection point. The raised springboard portion is configured at a static position, to move closer to and away from the lower platform portion as it bends so as to provide a cantilever spring effect without having contact with a back of the shoe.

[0099] The shoe according to the preceding clause, wherein the shoe spring further includes a front platform provided at a front of the shoe, and wherein the front platform and the V-shaped back portion form a Y-shape.

[0100] The shoe according to any preceding clause, wherein the distance between the raised springboard portion and the lower platform portion at the location opposite the intersection point is from 0.25 inch to 4.0 inches.

[0101] The shoe according to any preceding clause, wherein the shoe spring is made from flexible stiff composite material (e.g., a carbon graphite reinforced material).

[0102] The shoe according to any preceding clause, further including a spring member disposed between the lower platform portion of the V-shaped back portion and the raised springboard portion of the V-shaped back portion, the spring member being configured to counter react to a force applied to the raised springboard portion.

[0103] The shoe according to any preceding clause, wherein the raised springboard portion is configured, in the static position, to bend and to move closer to and away from the lower platform portion so as to provide a cantilever springboard effect wherein the intersection point is positioned over a fulcrum of the shoe.

[0104] The shoe according to any preceding clause, wherein the shoe spring is attached to the sole.

[0105] The shoe according to any preceding clause, wherein the shoe spring is configured to be slipped into the shoe.

[0106] The shoe according to any preceding clause, wherein the shoe spring is made from a resilient material.

[0107] The shoe according to any preceding clause, wherein the resilient material comprises flexible stiff composite material.

[0108] The shoe according to any preceding clause, further including a fulcrum attached to the sole of the shoe and provided at about a mid-point of the shoe, the fulcrum being configured to facilitate shifting of a weight of the wearer of the shoe from back to front to accelerate a movement of the foot in leaving the ground when walking or running.

[0109] The shoe according to any preceding clause, further including a front spring disposed at a front portion of the sole of the shoe.

[0110] The shoe according to any preceding clause, wherein the front spring is made of a resilient material.

[0111] The shoe according to any preceding clause, wherein the front spring has a sideways U-shape with an open portion of the sideways U-shape oriented forward relative to the shoe, and a top side of the sideways U-shape is about 1.5 inches longer than a lower side of the sideways U-shape.

[0112] The shoe according to any preceding clause, wherein the front spring has a bottom portion configured to compress and disfigures as it stretches under an applied force and to snap back to return energy, and a top portion mounted to an exterior surface of the sole of the shoe.

[0113] The shoe according to any preceding clause, wherein the top portion of the front spring is longer than the bottom portion of the front spring.

[0114] Another aspect of the present disclosure is to provide a front spring for a shoe. The front spring includes a top portion configured to contact a sole at a front of the shoe, and a bottom portion connected to the top portion, the bottom portion configured to compress, stretch and deform under an applied force and to snap back when the applied force is released. The top portion and the bottom portion form a sideways U-shape and an open portion of the sideways U-shape is oriented forward relative to the shoe. The front spring is configured to be disposed at a front portion of the sole, the front spring being made of resilient material.

[0115] The front spring according to the preceding clause, wherein the resilient material comprises a flexible composite material.

[0116] The front spring according to any preceding clause, wherein the sideways U-shape includes a Bobby pin shape.

[0117] The front spring according to any preceding clause, wherein the applied force comprises at least a portion of a weight of a wearer of the shoe.

[0118] The front spring according to any preceding clause, wherein when a weight of a wearer of the shoe shifts forward onto the ball of the foot of the wearer, the bottom portion snaps back as the foot leaves the ground.

[0119] The front spring according to any preceding clause, wherein the top portion has a shape that substantially follows a shape of the sole at the front of the sole, and the top portion is 0.25 inch wider on each side of the sole.

[0120] The front spring according to any preceding clause, wherein the top portion is longer than the bottom portion.

[0121] The front spring according to any preceding clause, wherein the top portion is longer than the bottom portion by about 1 inch to about 1.5 inches.

[0122] A further aspect of the present disclosure is to provide a shoe spring kit for a shoe, including a fulcrum configured to be coupled to a sole of the shoe, a front spring having a front end and a back end, the back end of the front spring being connected to the fulcrum, and a back spring having a front end and a back end, the front end of the back spring being connected to the fulcrum. When mounted to the shoe, the front end of the front spring is spaced apart from the sole and the back end of the back spring is spaced apart from the sole.

[0123] The shoe spring kit according to the preceding clause, wherein the front spring and the back spring include a curved plate.

[0124] The shoe spring kit according to any preceding clause, wherein a distance between the front end of the front spring and the sole is about 1.5 inches.

[0125] The shoe spring kit according to any preceding clause, wherein a distance between the back end of the back spring and the sole is about 2.5 inches.

[0126] The shoe spring kit according to any preceding clause, wherein the front spring and the back spring are made of a resilient material.

[0127] The shoe spring kit according to any preceding clause, wherein the resilient material includes flexible composite material.

[0128] The shoe spring kit according to any preceding clause, wherein the fulcrum is made of a flexible material.

[0129] The shoe spring kit according to any preceding clause, wherein the flexible material comprises rubber or other compressible material.

[0130] The shoe spring kit according to any preceding clause, wherein the fulcrum is positioned at a mid-point of the sole of the shoe, the fulcrum being configured to facilitate shifting of a weight of a wearer of the shoe from back to front to sequentially accelerate the shifting of weight between the back spring and the front spring and accelerate a movement of a foot of the wearer of the shoe in leaving the ground.

[0131] The shoe spring kit according to any preceding clause, wherein the fulcrum is configured to be fastened to the sole of the shoe using a fastener, and the fulcrum has a cylindrical shape.

[0132] The shoe spring kit according to any preceding clause, wherein a diameter of the cylindrical shape is between 0.5 inch and 1 inch.

[0133] Another aspect of the present disclosure is to provide a shoe including a lower portion including a sole configured to support a foot of a wearer, an upper portion configured to cover the foot of the wearer, a fulcrum configured to be coupled to the sole, a front spring having a front end and a back end, the back end of the front spring being connected to the fulcrum, and a back spring having a front end and a back end, the front end of the back spring being connected to the fulcrum. The front end of the front spring is spaced apart from the sole and the back end of the back spring is spaced apart from the sole.

[0134] The shoe according to the preceding clause, wherein the front spring and the back spring include a curved plate.

[0135] The shoe according to any preceding clause, wherein a distance between the front end of the front spring and the sole is about 1.5 inches.

[0136] The shoe according to any preceding clause, wherein a distance between the back end of the back spring and the sole is about 2.5 inches.

[0137] The shoe according to any preceding clause, wherein the front spring and the back spring are made of a resilient material.

[0138] The shoe according to any preceding clause, wherein the fulcrum is made of a flexible plastic.

[0139] The shoe according to any preceding clause, wherein the fulcrum is positioned at a mid-point of the sole of the shoe, the fulcrum being configured to facilitate shifting of a weight of the wearer of the shoe from back to front to sequentially accelerate the shifting of weight between the back spring and the front spring and accelerate a movement of the foot in leaving the ground.

[0140] The shoe according to any preceding clause, further comprising one or more strike plates coupled to the sole, the front end of the front spring or the back end of the back spring, or both are configured to abut against the one or more strike plates, when the front spring or the back spring, or both is compressed by a weight of the wearer.

[0141] The shoe according to any preceding clause, further comprising a cover coupled to a back sole portion, the cover being configured to cover a gap between the back spring and the back sole portion.

[0142] The shoe according to any preceding clause, further comprising a compressible element provided near the back end of the back spring, the compressible element being coupled to the sole, wherein the back end of the back spring is configured to abut against the compressible element, when the back spring is compressed by the weight of a wearer of the shoe.

[0143] Another aspect of the present disclosure is to provide a shoe spring kit for a shoe including a fulcrum configured to be coupled to a sole of the shoe, a spring having a front spring portion and a back spring portion integrated as one unit, the front spring portion having a front end and a back end, the back spring portion having a front end and a back end, the back end of the front spring portion being connected to the fulcrum, and the front end of the back spring portion being connected to the fulcrum. When mounted to the shoe, the front end of the front spring portion is spaced apart from the sole and the back end of the back spring portion is spaced apart from the sole.

[0144] The shoe spring kit of the preceding clause, wherein the spring has a W-like shape and is made of a compliant material.

[0145] Only exemplary embodiments of the present invention and but a few examples of its versatility are shown and described in this disclosure. It is to be understood that the invention is capable of use in various other combinations and environments and is capable of changes or modifications within the scope of the inventive concept as expressed herein. For example, any feature of any embodiment of the shoe can be combined with other features of other embodiments of the shoe.

[0146] Although the foregoing description is directed to the preferred embodiments of the invention, it is noted that other variations and modifications will be apparent to those skilled in the art and may be made without departing from the spirit or scope of the invention. Moreover, features described in connection with one embodiment of the invention may be used in conjunction with other embodiments, even if not explicitly stated above.