FOOTBEDS WITH IMPROVED CUSHIONING, STABILITY AND COMFORT AND METHODS OF MAKING SAME

Abstract

Disclosed is an insole or footbed for footwear that optimizes the comfort and performance of the footbed via a modified construction to the shoe's upper and midsole to accommodate a preferred footbed construction.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

The present disclosure claims priority to U.S. Provisional Application Ser. No. 63/214,332, filed Jun. 24, 2021, the contents of which are hereby incorporated by reference in their entirety.

FIELD OF THE DISCLOSURE

The present disclosure generally relates to footbeds used in footwear and used with footwear of all types including casual, dress, work, and athletic footwear. More specifically, the present disclosure relates to footbeds with improved performance via improved cushioning, comfort, and stability.

BACKGROUND OF THE DISCLOSURE

Footbeds (also commonly referred to as sockliners or insoles) are a common component of many types of footwear with a large variation in design, shape, materials, cost, and overall quality. Much of this variation exists between footwear categories and footwear brands to adapt the design of the footbed into the design of the shoe, the intended consumer (athlete, casual, etc.), and price point of the footwear product.

Footbeds are a primary source of comfort and function in footwear as they are in direct contact with the plantar surface of the foot where high loads and pressures are realized. Typically, footbeds are made from a relatively thin (3.0-5.0 mm) layer of foam topped by a thin polyester fabric (top cover) that is adhered to the foam.

The footbed is often a flat piece of foam that does not provide sufficient cushioning, pressure reduction, and support for the foot. Footbeds that are molded only from inexpensive foam will quickly breakdown and take a compression set. This compression set changes the shape of the footbed and reduces the cushioning capability by as much as 75%, thus effecting overall comfort and support for the foot. Additionally, standard insoles provide inferior performance due to variance in foot shapes and sizes.

The majority of shoes, regardless of type and style, are made according to the following process:

• • The upper components including upper and lining materials are stitched together.
  • The upper is lasted (pulled over a last to take the shape of the last).
  • The bottom unit (midsole, outsole) is molded and joined together.
  • The lasted upper is attached to the bottom unit via stitching, cementing, or molding processes.
  • The last is removed and a footbed is placed inside the upper on top of the lasting board.

The above process has proven to be an efficient method for creating various types of footwear. With regard to the footbed used in the above construction, there are some limitations. The upper is constructed with a “footbed lasting allowance”. The footbed lasting allowance is a dimension for the thickness of the footbed that is “allowed for” after the last is removed from the upper. This means that the upper dimensions once lasted allow for a footbed to be inserted into the upper once the last has been removed and finalizes the footwear construction process.

In general, footwear designers strive to make a shoe sleek in profile. The cost of expensive upper materials (and need to use lower yields) and the belief that footwear aesthetics are better with a sleeker profile drive these decisions. Due to the above considerations, the standard footbed allowance is 5.0 mm allowing for a maximum footbed thickness of 5.0 mm. However, in some examples, this maximum footbed thickness is not enough to provide adequate cushioning and support for the foot.

SUMMARY OF THE DISCLOSURE

In at least some examples, openings in the lasting board are made in the heel and forefoot to accept thicker portions of the footbed in matched areas. A molded footbed with thicker regions in the heel and forefoot is then inserted into the shoe. The heel and forefoot regions of thicker footbed foam can be shaped and optimized according to biomechanical principles to allow for ideal comfort in varying activities and consumers depending on functional needs.

BRIEF DESCRIPTION OF THE DISCLOSURE

Various embodiments of the presently disclosed devices and methods are shown herein with reference to the drawings wherein:

FIG. 1 is an isometric view of the footwear and footbed assembly;

FIG. 2 is an isometric view of the footbed;

FIG. 3 is a top view of the shoe's lasting board and midsole with cavities for accepting the enhanced footbed;

FIG. 4 is a lateral view of the footbed with rectangular shaped heel and forefoot pods;

FIGS. 5A-C are bottom view and cross-sectional views of a footbed having pods;

FIG. 6 is a cross section view of the footbed, lasting board, and midsole with rectangular shaped pods;

FIGS. 7A-C are bottom view and cross-sectional views of a footbed dome-shaped forefoot and heel pods;

FIG. 8 is a cross section view of the footbed, lasting board, and midsole with dome shaped forefoot and heel pods;

FIG. 9 is a lateral view of a footbed with a rectangular shaped forefoot pod and dome shaped heel pod;

FIGS. 10A-C are bottom view and cross-sectional views of a footbed having a guitar-shaped pod;

FIG. 11 is a lateral view of a footbed with a rectangular shaped forefoot pod and a guitar pick shaped;

FIGS. 12A-C are bottom view and cross-sectional views of a footbed having asymmetric pods; and

FIG. 13 is a top view of another example of the shoe's lasting board and midsole with cavities for accepting the enhanced footbed.

It is to be appreciated that these drawings depict only some embodiments of the invention and are therefore not to be considered limiting of its scope.

DETAILED DESCRIPTION

Footbeds (insoles) are an extremely important component of footwear with respect to providing comfort, fit, and shock absorption. Despite many improvements in the comfort of footwear, there have been limited advances in providing optimal footbed comfort. Primarily, this is due to the nature and process of footwear manufacturing that minimizes the potential comfort of the footbed due to trying to meet footwear manufacturing efficiencies and accepted aesthetics. The current approach to footbed design and manufacturing is surprising given how important a role the footbed can play while trying to deliver comfort to the wearer. The footbed is in direct contact with the plantar foot surface and bears the load of the wearer as forces rise to 2-5 times the wearers body weight during walking and running activities.

Footbeds may include a shape in the top surface that attempts to match the contours of the foot. These footbeds can be made with more durable materials such as polyurethane foams and support structures made with composite materials such as injected plastics and carbon fiber so the footbed shape is maintained. Footbeds from corporations such as Spenco Medical Corp. and Superfeet Worldwide are examples.

Higher quality materials may be used to produce such footbeds, including materials that are more durable, stiffer, and shaped to match the foot. It should be understood that using more durable, higher quality materials will reduce the breakdown of materials and maintain the like-new performance. However, the limited dimensions available for footbed thickness may limit the performance.

A footbed for an article of footwear that demonstrates an ideal geometry for comfort, foot control and stability, and ambulatory efficiency is disclosed in U.S. Pat. No. 10,653,204, the disclosure of which is hereby incorporated by reference in its entirety. The footbed described in the '204 Patent is the result of extensive research, development, and mathematical modeling of thousands of human feet. Footbeds using the geometry disclosed in the '204 Patent provide excellent performance in stability and comfort, and the use of a large number of human subjects contributing to the scanned data ensure that footbed represents an ideal geometry for the majority of the population.

The above-mentioned patent addresses, among other parameters, the top geometry of the footbed and how it interacts with the foots morphology and biomechanics. While the top surface geometry is extremely important for comfort and support, providing additional footbed foam would be beneficial in providing additional cushioning, comfort, and support.

Therefore, there is a need for further improvements to the devices, systems, and methods of forming footbeds. Among other advantages, the present disclosure may address one or more of these needs.

Just as the top geometry of a footbed is shaped to provide the foot with comfort and stability, the bottom surface of a footbed can be designed to provide improved performance. The only thing preventing an improved footed bottom surface is conventional footwear manufacturing norms.

Footwear midsoles may play a role in cushioning by providing compliance to the wearer as they walk or run. However, midsoles also have critical importance in the overall construction of the shoe. For instance, in athletic, casual, and other types of footwear the upper is stitched or cemented to the midsole and the outsole is stitched or cemented to the midsole. One familiar in the art will understand that these operations require certain physical properties for the midsole. For instance, the midsole is exposed to the outside world and should possess a certain level of abrasion resistance, resistance to staining and yellowing (in the case of white midsoles), resistance to hydrolysis, and the ability to maintain embossed and debossed graphics. Moreover, the midsole foam must have enough tensile and tear strength to resist the upper or outsole being torn away from the midsole during normal use. One skilled in the art will understand without sufficient strength properties, the foam will tear under normal loading rendering the footwear useless.

In some examples, the footbed foam may not require similar physical strength properties. One familiar in the art will understand the footbed is contained in the interior of the shoe and therefore not subjected to abrasive objects, UV light, dirt, or grime. Moreover, the footbed does not join other components of the shoe via stitching or cementing (midsole to upper, midsole to outsole). This drastically reduces the strength and tear requirements of footbed foam. Without these additional material property requirements footbed foam can be optimized to provide cushioning, support, and comfort to the foot. However, in order to provide the best footbed comfort, one must include more footbed foam. As mentioned above, providing additional optimized footbed foam is a challenge given the footwear manufacturing norms that limit the thickness of footbeds to a nominal 5.0 mm in the heel and 3.5 mm in the forefoot.

Previous attempts to construct footwear have used thicker footbeds in an attempt to improve the cushioning response in footwear. While the thicker footbed foam will provide improved cushioning it also introduces a problem.

All footbed foams will take a compression set over time. The shoe upper is constructed with a lasting allowance that “allows” for a footbed to be inserted once the upper is attached to the bottom and the last removed. Thus, using a thick footbed will affect the fit of the shoe over time as the footbed foam takes a compression set. Thicker footbeds will take a greater absolute compression set (millimeters of compression set) and will negatively affect the fit of the shoe as more volume is allowed, essentially making the fit larger than desired.

What is needed is a method that creates a footbed with thicker foam in significant areas for support and comfort while not affecting overall fit.

The present disclosure includes a footbed with improved cushioning and support in significant comfort areas (typically the heel and forefoot) while not creating a looser fit over time due to compression set of the foam. The proposed footbed maintains industry standard thickness through the midfoot and perimeter of the footbed to keep compression set values at industry norms. However, in the significant comfort areas of the forefoot and heel, additional footbed foam is provided by allowing the foam to protrude through the lasting board of the shoe. One skilled in the art will understand that the overall thickness, surface area, shape, and placement of the foam areas protruding through the lasting board can be adjusted in shape, size, depth, and surface area, to create different levels of comfort and support with variations specific to certain activities or wearers (specific sports and activities, gait adjustment, user population).

Turning now to the details of the present disclosure in FIGS. 1-13, certain examples of footwear are shown according to the present teachings.

FIG. 1 shows an isometric view of a proposed design that enhances underfoot comfort and support. An enhanced article of footwear 10 is presented that provides improved cushioning and comfort in the footbed. In this example, the footwear 10 includes a footbed or insole 20, the insole 20 having one or more projecting interlocking features or pods 25 formed in a lower surface thereof. In this example, the interlocking features or pods 25 of footbed includes heel pod 21 and forefoot pod 22 formed of thicker portions in the heel region 70 and the forefoot region 60, respectively. Footwear 10 also includes a midsole 30, the midsole having one or more matching cavities 35 to accept the interlocking features 25 (e.g., thicker footbed heel region and forefoot region). In this example, midsole 30 includes two cavities including a heel cavity 31 and a forefoot cavity 32 aligned with pods of the footbed 20, which may be molded into the midsole 30. An upper 5 is joined to the midsole 30. As will be readily apparent, the shape, exact position, and thickness of the interlocking features or pods may be modified to address different wearing needs and still provide the desired benefits. Specifically, the midsole midfoot 38, perimeter around the heel and forefoot, and the toe regions may all be varied as desired.

FIG. 2 is an isometric view of a footbed 220 for use in footwear with improved comfort, cushioning and support. The footbed 220 has interlocking features 225 or pods in the form of thicker portions in the forefoot region 260 and heel region 270 that provide added comfort in significant areas that are associated with high pressure areas in the heel (calcaneus) and forefoot (MP Joints). As previously described, the interlocking features or pods in the forefoot 260 and heel 270 are matched to the cavities in the midsole forefoot and heels shown in FIG. 1.

FIG. 3 shows a midsole 330 and lasting board 340 for this special construction that enable the use of the improved footbed 20. As previously described, midsole 330 includes one or more cavities 335 in the heel and forefoot that match and align with the footbed pods. Corresponding holes or cutouts 341,342 are formed in the lasting board so the footbed pods can protrude through the lasting board 340 and mate with the midsole 330. In at least some examples, the cutouts of the lasting board and the cavities of the midsole are aligned with one another and have a same shape, perimeter and/or size.

FIG. 4 shows a lateral view of the footbed 420 with a heel pod 421 and a forefoot pod 422. This embodiment of the disclosure shows that the forefoot pod 422 is thinner than the heel pod 421, however, one skilled in the art will understand that the heel 421 and forefoot 422 pods may be of different thickness to achieve variations in the overall performance of the footbed 400. The midfoot region 424 and perimeter surfaces 426 of the bottom surface of the footbed 420 are of standard industry thicknesses to keep footbed compression set to a minimum.

FIG. 5A shows a bottom view of a footbed 520 with thicker pods in the heel 521 and forefoot 522. FIG. 5B is a cross section through the forefoot at arrows “BB” and shows the thicker forefoot 522 pod. FIG. 5C is a cross section through arrows “CC” through the heel and shows the thicker heel pod 521. In this particular embodiment the thickness of forefoot pod 522 is less than the thickness of heel 521 and the shape of the pods are different. Specifically, while the pods or interlocking feature are both generally rectangular through the section, the upper perimeter of the heel 521 has a general oval shape and the upper perimeter of the forefoot 522 is trapezoidal. One familiar in the art will know that the exact shape and size may be changed to address different functional needs, particular shoe construction, or to increase cushioning or support.

FIG. 6 shows a sectional view of footwear construction 600 using a footbed 620 with thicker heel and forefoot pods 621,622. In this example, midsole 630 configured to be molded with heel and forefoot cavities 631,632, and to align with the footbed pods. Cutouts 641,642 are formed into the lasting board 640 in the forefoot and heel areas to allow the footbed 620 to pass through the lasting board 640 and mate with the midsole 630 in the heel and forefoot.

FIG. 7A-C show an embodiment with a variation in the shape of the heel pod 721 of the footbed 720. As one skilled in the art will appreciate, the invention allows different shapes and dimensions to be designed since the thickness of the footbed is not limited to industry standards. In certain instances, a more organic shape may be desired. FIG. 7A shows a footbed 720 with a forefoot pod 722 and a domed shaped in the heel 721 that matches with a domed shape in the heel region midsole cavity. FIG. 7B shows a medial-lateral cross section of the domed shape 721.

FIG. 8 is a depiction of the construction of footwear 800 with a footbed 820 with a dome-shaped heel pod 821, assembled into a shoe's midsole 830 through cutouts 841 formed into the lasting board 840 of the shoe. As can be seen in FIG. 8, the construction of the footbed 820 and footwear 800 does not change except for the shape of the footbed pods and the associated cavity 831 in the midsole.

FIG. 9 shows a lateral view of a preferred footbed 920 with rectangular shaped forefoot pod 922 and a dome shaped heel pod 921.

FIGS. 10A-C show a footbed 1020 that utilize a heel pod shape 1021 similar to a guitar pick. As was disclosed in U.S. Pat. No. 10,653,204, additional cushioning under the calcaneus bone of the heel can be advantageous in absorbing ground reaction forces. The heel pod on this preferred embodiment is positioned under the heel to align with the sharpest point of the calcaneus. The shape of the guitar pick is arranged to provide cushioning and shock absorption at significant points. The ideal “guitar pick” shape provides the needed cushioning without loss of stability and control. FIG. 11 shows the lateral view of the footbed 1020 utilizing a guitar pick shape for the heel cushioning pod.

FIG. 12 demonstrates that changes to the geometry of the footbed 1220 can have positive effects on the biomechanics of gait. It is commonly known in the art that firmer materials on the medial side of a shoe can help prevent overpronation. During the walking or running gait the foot naturally pronates as the heel strikes the ground and then rotates internally about the subtalar joint. The center of force path moves medio-laterally during the heel strike phase of gait and too much movement to the medial side is defined as over-pronation and can have deleterious effects on the ankle and knee if not corrected. FIG. 12C shows the heel pod with an asymmetric design. The heel pod is thicker on the lateral side and thinner on the medial side. Given that foams used in footbeds are generally softer and less dense than midsole foams, reducing the amount of footbed foam on the medial side will provide firmer medial support and help to alleviate over-pronation.

Materials used in the molding of the preferred footbed will be known by those familiar in with the art. Open or closed cell foams made from ethyl-vinyl acetate (EVA), thermoplastic polyurethane (TPU), Polyurethane (PU), Polyolefins (PO), and others can be used to create the molded shapes from foam. Importantly, the foams should be molded to provide enhanced comfort and cushioning. For instance, foams with a specific gravity ranging from 0.15-0.40 may be used. The foam hardness can range from 10-70 on the asker C scale depending on the desired application, activity, and type of footwear the footbed is being used in.

In some embodiments, the lasting board is modified to allow for ease of manufacturing. One familiar in the art of shoe making will understand that the current disclosure might present challenges during the lasting of the shoe's upper. Typically, the lasting board is made from textiles or fiber boards that have low elongation properties. The lasting board defines the bottom parameter of a shoe's upper and maintaining the bottom dimensions of a shoe upper is important during manufacturing procedures as well as achieving the desired fit in a finished shoe.

FIG. 3 shows a view of the lasting board with a trapezoidal hole cut in the forefoot and an oval cutout in the heel to accept a footbed with matching projections in those areas. With standard footwear lasting operations, the lasting board is stitched or otherwise bonded to the bottom aspect of the upper. The upper is then “lasted” which requires the insertion of the shoe last. As one familiar in the art will know, the lasting operation will place outward tension on the lasting board. The outward tension may deform the shape of the oval and trapezoidal holes in the lasting board. As the holes deform it changes the fit of the upper to the last and may affect the placement of the footbed's forefoot and heel projections through the lasting board.

FIG. 13 shows a unique solution to deformation of holes in the lasting board during lasting. In this example, midsole 1330 and lasting board 1340 are provided for this special construction that enable the use of an improved footbed. As previously described, midsole 1330 includes one or more cavities 1335 in the heel and forefoot that match and align with the footbed pods. Corresponding holes or cutouts 1341,1342 are formed in the lasting board so the footbed pods can protrude through the lasting board 1340 and mate with the midsole 1330. In at least some examples, the cutouts of the lasting board and the cavities of the midsole are aligned with one another and have a same shape, perimeter and/or size.

During die-cutting of the lasting board, cross-supports 1371,1372 may be left in the lasting board. These cross-supports 1371,1372 are part of the original lasting board material and are simply left in place during the die-cutting operation. The cross-support pieces may provide structure to the hole during the lasting operation and keep the hole from deforming. In at least some examples, the cross-supports 1371,1372 can be thin and still provide ample support. Cross-supports of 3-6 mm in width are typical. Of course, the cross-supports can be of any width the resists deformation of the hole opening. However, 3-6 mm provides ample support and is still easily removed during the next step. As shown in FIG. 13, the cross-supports may include a horizontal strip extending across the lasting board. Alternatively, cross-supports may include a vertical strip (e.g., in the axial direction from heel to toe). In at least some examples, a cross-support may include both horizontal and vertical components to create a cross-shaped pattern across cutouts 1341,1342.

Once the shoe upper is lasted, the upper is then joined to the shoe bottom through various standard methods such as cementing, stitching, or injecting the midsole on to the upper. With the shoe upper firmly attached to the shoe bottom, the cross-support 1371,1372 of the lasting board can be removed with no effect on the fit or performance of the shoe since the lasting board is now supported by other means (e.g., bonded to the midsole).

With the lasting board permanently secured to the shoe bottom, the cross-supports of the lasting board are simply cut out of the lasting board with a sharp tool such as scissors or a sharp blade allowing for the protrusions of the footbed to be inserted into the matching holes of the lasting board.

Described above is a design and method of creating a footbed with improved cushioning and support. The design and methods described optimize the characteristics of the footbed to bring higher performance to a shoe. Various footbed shapes, material density and hardness, and the use of different polymers may be used to improve overall cushioning and comfort.

It will be appreciated that the various dependent claims and the features set forth therein can be combined in different ways than presented in the initial claims. It will also be appreciated that the features described in connection with individual embodiments may be shared with others of the described embodiments.

Claims

1. A shoe comprising:

a shoe upper;

a midsole having at least one cavity formed in an upper surface thereof;

an insole having at least one projecting interlocking feature formed in a lower surface thereof; and

a lasting board coupled to the shoe upper, the lasting board having at least one cutout for accepting the at least one projecting interlocking feature, the at least one cutout being aligned with the at least one cavity of the midsole.

2. The shoe of claim 1, wherein the at least one cavity includes two cavities, the at least one projecting interlocking feature includes two projecting interlocking features, and the at least one cutout includes two cutouts.

3. The shoe of claim 2, wherein the two projecting interlocking features include a first projecting interlocking feature adjacent a heel region and a second projecting interlocking feature adjacent a forefoot region.

4. The shoe of claim 3, wherein the first projecting interlocking feature and the second projecting interlocking feature include thicknesses that are greater than thickness of remaining portions of the insole.

5. The shoe of claim 3, wherein the first projecting interlocking feature and the second projecting interlocking feature include at least one rectangular-shaped pod.

6. The shoe of claim 3, wherein the first projecting interlocking feature and the second projecting interlocking feature include at least one dome-shaped pod.

7. The shoe of claim 1, wherein the at least one cutout and the at least one cavity have a same perimeter.

8. The shoe of claim 1, wherein the at least one cavity is configured to accept and mate with the at least one projecting interlocking feature.

9. A shoe comprising:

a midsole having at least one cavity formed in an upper surface thereof; and

an insole having at least one projecting interlocking feature formed in a lower surface thereof, the at least one projecting interlocking feature having a complementary shape to that of the a least one cavity and being configured to aligned therewith.

10. The shoe of claim 9, wherein the at least one cavity includes two cavities, and the at least one projecting interlocking feature includes two projecting interlocking features.

11. The shoe of claim 10, wherein the two projecting interlocking features include a first projecting interlocking feature adjacent a heel region and a second projecting interlocking feature adjacent a forefoot region.

12. The shoe of claim 11, wherein the first projecting interlocking feature and the second projecting interlocking feature include thicknesses that are greater than thickness of remaining portions of the insole.

13. The shoe of claim 11, wherein the first projecting interlocking feature and the second projecting interlocking feature include at least one rectangular-shaped pod.

14. The shoe of claim 11, wherein the first projecting interlocking feature and the second projecting interlocking feature include at least one dome-shaped pod.

15. The shoe of claim 9, further comprising a lasting board disposed between the midsole and the insole, the lasting board having at least one cutout defining a cross-support, the at least one cutout being configured to accept the at least one projecting interlocking feature of the insole and align with the at least one cavity of the midsole.

16. The shoe of claim 15, wherein the at least one cutout and the at least one cavity have a same perimeter.

17. A method of manufacturing footwear, comprising:

providing a shoe upper;

providing a midsole having at least one cavity formed in an upper surface thereof;

providing an insole having at least one projecting interlocking feature formed in a lower surface thereof; and

providing a lasting board, the lasting board having at least one cutout for accepting the at least one projecting interlocking feature.

18. The method of claim 17, further comprising coupling the lasting board to the shoe upper.

19. The method of claim 17, further comprising aligning the at least one cutout of the lasting board to the at least one cavity of the midsole.

20. The method of claim 17, further comprising receiving the at least one projecting interlocking feature of the insole within the at least one cutout of the lasting board and the at least one cavity of the midsole.