Shoe system with a resilient shoe insert
The method is for using a shoe system having a resilient shoe insert. A shoe (300) has a shoe insert (500) disposed inside the shoe. The insert has an upper leg (506) and a lower leg (514) connected by a front end (502) with a curvature (512). The legs (506, 514) have a concave segments (510, 518) and end points (520, 522), respectively; A load is put on the insert to compress the end points towards one another. This shortens the effective length of the legs (506, 514) because the legs are in contact at a contact segment (524). This makes the insert stiffer the more it is compressed. The effective length of the legs is shorter at the outside (530) compared to the inside (532) so that the outside is stiffer than the inside.
The present invention relates to a resilient shoe spring system that is intergrated with a shoe system.
BACKGROUND AND SUMMARY OF THE INVENTIONUsers and developers of elastic shoes and shoe soles are confronted with the problem of back injury and releasing the stored energy in the shoe sole in a manner which improves walking and running economy while at the same time achieving adequate bio-mechanical shoe stability and cushioning. Many shoe manufacturers have concentrated their effort on chock absorption by permanently increasing the thickness of the shoe sole. This has resulted in a slight change of the angle between the ankle and the foot that may weaken the tendons of the foot. This change of the angle may also lead to instability and reduced bio-mechanical effect.
Many efforts have been made to develop an effective spring mechanism for shoes or shoe soles. However, the earlier proposed spring designs for shoe soles have not been entirely satisfactory. Despite many elaborate shoe sole solutions, back injuries and other injuries are still common due to poorly designed shoes. Injuries due to poor shoe designs are particularly common in sports and heavy duty work activities.
One important function of a shoe, such as a running shoe, is to protect the foot from the stresses of running. The forces and motions that occur in different sports vary greatly. Because of these differences it is important that active participation in varied sports require varied shoes. For example, tennis and other racquet sports require much side-to-side motion and the shoe must provide lateral stability. If the shoe is unstable and has high heel elevation when the athlete is moving from one side to another the likelihood is great the athlete may suffer an ankle sprain. The majority of conventional shoes are not well designed. Some of insufficiencies of the current shoe designs may be overcome by the present invention.
The method and shoe system of the present invention provide a solution to the above-mentioned problems. More particularly, the method is for using a shoe system having a resilient shoe insert. A shoe has a shoe insert disposed inside the shoe. The insert has an upper leg and a lower leg connected by a front end with a curvature. The upper and lower legs 506 have a concave segments and end points. A load is put on the insert to compress the end points towards one another. This shortens the effective length of the legs because the legs are in contact at a contact segment. This makes the insert stiffer the more it is compressed. The effective length of the legs is shorter at the outside compared to the inside so that the outside is stiffer than the inside.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 15A-D are schematic flow diagrams of a pressing technique for manufacturing the shoe insert;
With reference to
The stiff aft end 16 has a cavity portion 22 that terminates in a slightly upwardly curved end section 24. A stiff middle section 26 of the member 12 is convex shaped relative to the concave cavity portions 18, 22. A holder mechanism 26 is attached to an underside 28 of the first member 12. The holder mechanism 26 includes a short end wall 30 that is perpendicular to the member 12 and a long support wall 32 that is perpendicularly attached to the end wall 30 to that the underside 28, the end wall 30 and the support wall 32 define a receiving pocket 34 that is facing the aft end 16. Preferably, the end wall 30 is attached to the underside 28 on the first member 12 at a point 29 that is at a front-end portion of the middle section 26. In the preferred embodiment, the first member 12 is stiff all the way from the place of attachment at the point 29 of the end wall 30 to the end section 24 and bendable from the point 29 to the end section 20.
A second member 36 has a fore end 38 that is insertable into the receiving pocket 34. More particularly, the second member has the fore end 38 and an opposite aft end 40. The force end 38 has a slightly downwardly curved end section 42 and the aft end 49 has an upwardly curved end section 44 so that the second member 36 is somewhat S-curved. When the second member 36 is inserted into the receiving pocket 34, the end section 44 is aligned with the end section 24 of the first member 12 so that a gap 46 is formed between the first member 12 and the second member 36.
An important feature of the present invention is that the second member 36 is springy and resilient while the first member 12 is generally stiff except for a bendable toe portion. As is explained below, a heavier person may select a stiffer second member than a lighter person to prevent the second member 36 from abutting or resting against the first member 12 when the heavier person is standing on the first member 12 with the second member 36 inserted into the receiving pocket 34. Preferably, the second member 36 should be sufficiently stiff so that the second member 36 does not bottom out even though the person is actively using the shoe insert 11 disposed in the shoe. For example, when a person is standing straight up (as is shown in
Other factors that determine what stiffness to use for the second member 36 include the type of activity the shoe is going to be used for and whether the walking/running surface is hard, soft and uneven. The shape of the second member 36 may also be varied depending on the needs of the user. For example, a second member having a more bent fore end creates a bigger gap 46 between the second member and the first member when the second member is inserted into the holder 32. A bigger gap 46 may reduce the risk of bottoming out and also changes the angle between the foot and the ankle.
Because the first member 12 is stiff, the shape of the first member is maintained and the foot is provided a full support although the second member 36 may move relative to the first member 12. In other words, the first member 12 provides good support to the foot although the second member 36 may be compressed against the first member 12 and later permitted to move back to the relaxed expanded position depending upon how the shoe is used in, for example, a sport activity.
As best shown in
An important feature is that the shoe sole defines an angular curved groove 60 that is dimensioned to receive the second member 36. The groove 60 extends backwardly and angularly downwardly towards a heel 62 of the shoe 48. A triangular wedge 64 is disposed between the upper surface 52 and the groove 60. The wedge 64 is removably attached to the sole 50 so that the wedge 64 easily be removed to make it convenient to insert and remove, particularly, the second member 36 of the shoe insert 11. The wedge 64 is made of a very flexible material so when the second member 36 is urged towards the first member 12 by the weight of the user, the wedge 64 is deformed and compressed accordingly.
The shoe 48 may also be used with the shoe insert 11 placed on the upper surface 52 but with the wedge 64 removed. An one-way valve 66 is attached to a back end 68 of the shoe 48. A channel 70 may be defined in the shoe sole 50 so that the valve 66 is in fluid communication with a space 72 that is formed between the first member 12 and the second member 36. Of course, the wedge 64 may extend all the way back to the section 58 of the shoe sole 50 so that there is no need for a channel.
When the second member 36 is pressed towards the first member 12 so that the shoe insert 11 is in a compressed position, an over pressure is formed in the space 72 that may flow into the channel 70 and out through the valve 66 to provide good mechanical ventilation inside the shoe. Any under pressure that may be formed in the space 72 when the second member 36 is permitted to move from the compressed position back to its original expanded position away from the first member 12 may be equalized by sucking in air from an upper part 74 of the shoe 48 such as the opening 76 or the open areas adjacent to the shoe laces 78. It should be understood that the valve 66 may also be a two-way valve so that the valve may be used to compensate for both over-pressure and under-pressure in the space 72. In this way, the valve 66 may function to circulate and possibly bring in or suck cool air into the inside of the shoe when the second member 36 is permitted to expand from the compressed position. A filter 79 may also be placed in the valve 66 to prevent dust and other undesirable particle from entering into the inside of the shoe 48 when the shoe inlet 11 is expanding.
As best shown in
As best shown in
An important feature is that the segment 306 is stiff and is attached to the sole so that the segment 306 does not move relative to the shoe although the lower segment 308 may move relative to the upper segment 306. This means that a foot inserted into the shoe 300 remains in the same position regardless of the flexural movements of the lower segment 308. When the lower segment 308 is in an expanded unloaded position (see
An important feature of the present invention is that upper segment 306 is disposed at a distance (X) from an upper rim 314 both when the lower segment 308 is in the expanded position, as shown in
With reference to FIGS. 15A-D, the shoe insert of the present invention is preferably made by using a unique pressing method. The method relies on a tool 400 having a upper component 402 and a lower component 404. The component 402 has a cavity 406 defined therein that has the same shape as the upper segment 306 and the component 404 has a cavity 408 defined therein that has the same shape as the lower segment 308. As best shown in
The component 412 has an elongate front-end portion 413 and an elongate back portion 415. A U-shaped third component 414 is placed between components 410, 412 to improve the physical properties of a finished insert 424. The component 414 has continuous fibers extending along the entire component 414 from one end of the U-shaped component to an opposite end of the component 414. Surprisingly, the component 414 substantially reduces fiber breakage and other failure characteristics of the insert 424. Preferably, a sandwich construction is used so that the stiffer carbon fibers may be placed on each side of the U-shaped component 414 that is, preferably, made of the less stiff glass fibers. Glass fibers have better springing characteristics compared to carbon fibers due to the high fatigue resistance properties of glass fibers. In general, glass fibers are not as brittle as carbon fibers. Carbon fibers may be used to partially or fully in the components 410, 412. However, carbon fibers may also be used on the inside of the component 414 in the form of carbon fiber tapes that extend from a back portion 411, 415, respectively, of the components 410, 412 towards a bottom 421 of the component 414. More particularly, the component 414 has the bottom 421, an upper leg 416 and a lower leg 418. The upper leg 416 is placed along an inside 420 of the back end portion 411 and the lower leg 418 is placed along an inside 422 of the back portion 415. In this way, both the upper leg 416 and the end portion 411 are placed inside an elongate back end 417 of the cavity 406 and the both the lower leg 418 and the back end portion 415 are placed inside an elongate back end 419 of the cavity 408. This means that the above described sandwich construction may be used on the legs 416, 418 of the components 410, 412 together with the component 414. Preferably, the sandwich construction is not used for the portions 409, 413. A resilient filler piece 423 may be placed between the legs 416, 418 prior to compression of the tool. The hardness of the piece 423 may be adjusted depending upon the weight of the user. For example, a more rigid piece 423 may be used if the user is heavy and a softer piece 423 may be used if the user is relatively lightweight.
As best shown in the
When the components 410, 412, 414 are cured into an integrated shoe insert 424, the tool components 402, 404 are separated from one another and the insert 424 is removed from the components 402, 404, as shown by an arrow A4 in
With reference to
While the present invention has been described in accordance with preferred compositions and embodiments, it is to be understood that certain substitutions and alterations may be made thereto without departing from the spirit and scope of the following claims.
Claims
1. A method of using a shoe system having a resilient shoe insert, comprising:
- providing a shoe having a shoe insert disposed inside the shoe, the shoe insert having an upper leg and a lower leg connected by a front end with an attachment segment, the upper leg having an upper concave segment, the upper leg having an upper end point and the lower leg having an lower end point that is separated from the upper end point by a distance (d1), the insert having an effective length (l1);
- putting a first load on the shoe and the insert;
- compressing the upper end point towards the lower end point until a concave the upper concave segment is in contact with a lower concave segment of the lower leg at a contact point is being remote from the attachment segment at the front end so that a loop is formed between the attachment segment and the contact segment, the contact segment being remote from both the upper and the lower end points; and
- the upper concave segment being pressed against and facing the lower concave segment;
- bending the attachment segment until a contact point is formed when the upper concave segment comes into contact with the lower concave segment;
- putting a second load on the shoe and the insert, the second load being substantially greater than the first load;
- bending the upper leg and the lower leg at the contact point to form a contact segment that extends from the contact point towards the upper and lower end points and terminates at a separation point to progressively increase a stiffness of the upper and lower legs;
- the contact segment reducing the effective length (l1) to an effective length (l2), the length (l2) extending from the contact segment to the upper and lower end points.
2. The method according to claim 1 wherein the method further comprises extending the contact segment from an outside to an inside, the segment being substantially parallel to the front end, the front end forming an acute angle to a longitudinal axis (A) of the insert.
3. The method according to claim 2 wherein the method further comprises further compressing the upper end point towards the end point to reduce the distance (d2) to a distance (d3) that is shorter than the distance (d2) and forming a contact area between the upper leg and the lower leg.
4. The method according to claim 3 wherein the method further comprises shortening the effective length (l2) to an effective length (l3) at a mid-portion of the contact segment, the length (l3) being shorter than the length (l2).
5. The method according to claim 4 wherein the method further comprises providing the insert with an effective length (l30) at the outside, the effective length (l30) being shorter than the effective length (l3) at the mid-portion.
6. The method according to claim 5 wherein the method further comprises providing the insert with an effective length (l3i) at the inside, the effective length (l3i) being longer than the effective length (l3) at the mid-portion.
7. The method according to claim 1 wherein the method further comprises providing the attachment point with a curvature.
8. (canceled)
9. The method according to claim 1 wherein the method further comprises aligning the upper concave segment with the lower concave segment.
Type: Application
Filed: Oct 8, 2003
Publication Date: Mar 9, 2006
Inventors: Wilhelm Lindqvist (Stockholm), Hans Larsson (Mjolby), Leif Lindh (Danderyd), Kjell Lindh (Danderyd)
Application Number: 10/531,116
International Classification: A43B 13/28 (20060101);