Patent Publication Number: US-2020288811-A1

Title: Perforated Insole with Dynamic Support Layer

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     Original Non-Provisional Application 
     BACKGROUND 
     The benefits of wearing insoles are well known in the fields of sports medicine and health sciences. There are a number of common foot ailments which may be associated with either a particular lifestyle activity or a pre-existing medical condition. Runners, for instance, often suffer from plantar fasciitis, wherein the band of tissue between the toes and the heel become tight and tear, while those living and coping with diabetic neuropathy require additional stimulation across the base of the foot to increase circulation. To address these conditions people often seek out therapeutic massage to encourage oxygenation, venous return, and increased lymphatic return in order to relieve pain and reduce fatigue. 
     Use of an insole designed to massage and stimulate the tissues of the foot can provide immediate relief as well as long-term benefits in addressing these issues. A dynamic insole is one which massages the foot by transferring an internal fluid across the plantar surface of the foot in response to changing pressures produced when the wearer shifts their weight. 
     During physical activity an insole also provides protection to the foot and throughout the skeletal system by absorbing shock and pressure endured when standing for long periods of time, walking, or running. In the case of a dynamic insole, the protection is further bolstered, when compared to a traditional foam insole, as the internal fluid is able to rapidly move across the arch in order to absorb and disperse the force of the impact across a larger area of the foot. 
     A study done by The Ohio State University in 2018 quantified the benefits of a dynamic insole. The purpose of the research was to assess the effects of different insoles configurations (i.e., no additional insole, a static insole, and a dynamic insole) on the measured tibial acceleration while walking while wearing athletic shoes and while wearing work boots. Table 1 summarizes the measured acceleration while walking across the various insoles and shoe type. 
                     TABLE 1                  Tibial accelerations as a function of insole and shoe type                                 No Additional                   Insole   Static Insole   Dynamic Insole                                         Athletic Shoe   29.2 (m/s 2 )   23.6 (m/s 2 )   22.3 (m/s 2 )       Work Boot   22.5 (m/s 2 )   19.9 (m/s 2 )   18.4 (m/s 2 )                    
The complete results were published as “Quantifying the effectiveness of static and dynamic insoles in reducing the tibial shock experienced during walking” (2019, Lavender et al.)
 
     SUMMARY OF THE INVENTION 
     The present invention is a therapeutic insole which may be installed by the user on top of the existing insole of the footwear. The insole is designed with a sealed chamber which may extend across the toe, arch, or heel portion of the foot—or across any combination therein. This chamber is filled with a fluid substance that can traverse across the chamber in response to changes in pressure caused by a weight shift by the wearer. The fluid may consist of any number of materials including gas, liquid, or gel-like substance. The movement of the fluid serves to massage the foot muscles and tendons, promote the release of toxins, and encourage circulation. The chamber may also have areas with restrictions or unique shapes which restrict and guide the fluid for maximum effectiveness. 
     As each foot is unique, a retailer may be challenged to maintain shelf space to accommodate the large variety of products. The insole needs to be personally matched not only to match the user&#39;s requirements to their different activities or support level but also to the size and shape of each foot. Herein, the present invention also discloses an apparatus and method for adjusting the size and changing features without the use of tools, thus allowing the retailer to carry a limited number of products while accommodating a broad span of consumer needs. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1 .  FIG. 1  shows an upper isometric view of the therapeutic insole. 
         FIG. 2 .  FIG. 2  shows a top view of the insole. 
         FIG. 3 .  FIG. 3  shows a bottom view of the insole. 
         FIG. 4 .  FIG. 4  shows a lateral cross-section of the insole with inner fluid chambers. 
         FIG. 5 .  FIG. 5  shows a side cross-section of the base layer perforation. 
         FIG. 6 .  FIG. 6  shows a top view of the toe area of the insole. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Any activity where a person is on their feet for a length of time can result in foot pain or fatigue. More stressful activities, such as running, can cause impact injuries which directly affect the foot and transfer throughout joints of the skeletal system. The therapeutic insole  100  disclosed employs a dynamic fluid layer  26  to provide both cushion to minimize impact and immediate therapy to the plantar tissues of the foot. Furthermore, the therapeutic insole  100  works by stimulating the muscles under the foot and promoting circulation deep into the toes—critical to those living and coping with diabetic neuropathy. This increase in circulation provides a natural healing approach while soothing damaged nerves and stimulating muscles. Users who use such an insole report impressive improvements in comfort and pain management. 
       FIG. 1  shows an isometric view of the therapeutic insole  100  designed to be placed between the user&#39;s plantar surface of the foot and the corresponding insole surface of the user&#39;s footwear. In the preferred embodiment, the insole  100  is flexible relatively thin allowing it to be placed directly on top of any existing insole manufactured by the shoemaker. Alternatively, a thicker therapeutic insole  100  may be used as a replacement for the existing insole by the user or integrated by the original shoe manufacturer. 
     Sections of the therapeutic insole  100  are shown in  FIG. 2  and may be described in terms corresponding to the user&#39;s foot including a distal toe section  18 , an intermediate arch section  24 , and a proximal heel section  14 . In a similar methodology, around the peripheral edge of the insole there exists a medial edge  28  along the inside of the foot, a distal toe edge  30 , a lateral edge  32  along the outside of the foot, and a proximal heel edge  34 . 
     The base layer  12  is manufactured as a single piece and the bottom surface of the base layer  52  is shown in  FIG. 3 . The base layer  12  is generally planar and includes a toe section  18 , intermediate arch  28 , and heel section  30 . 
       FIG. 4  shows a cross-section of the therapeutic insole  100  defined by line A-B constructed in  FIG. 2 . An upper layer  10  is positioned opposite the base layer  12  and sealed along the peripheral edges of the upper layer  36 . In the preferred embodiment, the upper layer  10  is positioned and sealed on top of the base layer  12 , however, an alternative embodiment could have the upper layer  10  positioned below the base layer  12 . A chamber  38  is formed between the upper layer  10  and base layer  12  which is configured to contain a dynamic fluid  26 . The dynamic fluid  26  may be a gas, liquid, or gel-like substance. The cross-section line A-B also bisects several of the divots in the chamber  38 —which create restrictions  16  within the chamber  38  to divert, guide, or restrict the flow of the dynamic fluid  26 . 
     Common materials used for the base layer  12  and the upper layer  10  may include closed cell foam, carbon fibers, elastic rubber, microfiber, or any other flexible material. In the preferred embodiment, the material for the base layer  12  and upper layer  10  is TPU, or thermoplastic polyurethane, which is extremely flexible and durable. The base layer  12  and upper layer  10  may also include a layer designed with a perspiration-absorbing system. 
     The upper layer  10  may be peripherally bound and sealed to the base layer  12  by means of ultrasonic welding, adhesives, stitching, or other mechanical means. The chamber  38  between the upper layer  10  and base layer  12  may reside exclusively in the heel section  14 , intermediate arch section  24 , or toe sections  18 ; or there may be a plurality of chambers  38  disposed across any combination of these sections. In the preferred embodiment, the chamber  38  extends across the distal end of the intermediate arch  24  and proximal edge of the heel section  14 . 
     As shown in  FIG. 2 , a plurality of restrictions  16  guide or restrict the movement of the fluid substance  26  may be employed. In the preferred embodiment, the restrictions  16  are formed through ultrasonic welding of the upper layer  10  and the base layer  12 . 
     The fluid substance  26  may comprise a liquid, gas, or gel or some combination therein. The fluid  26  is configured to traverse across the chamber  38 . When the fluid  26  is a non-compressible material, such as a liquid or gel, the chamber  38  is not filled to the full capacity, so that the fluid  26  can transfer from one section to the other. When the fluid  26  is a gas, the pressure of the chamber  38  is configured such that it is capable of further compression under the weight of the user. 
       FIGS. 2  and  FIGS. 3  provide a top view and bottom view respectively of the therapeutic insole  100 . The toe section  18  of  FIG. 3  and  FIG. 4  illustrate a where a series of perforations  20  and  22  exist in the base layer  12  to enable the user to remove distal sections of the base layer  12  and adjust the overall size to fit within the user&#39;s shoe. The series of perforations  20  and  22  are arranged such that they generally form a curved line which are inset from the peripheral edge of the toe section  18  and extend outward to points of the medial peripheral edge  28  and lateral peripheral edge  32  near the intermediate arch section. 
     Similar series of perforated arrangements for sizing the toe section  18  may be made in the base material  12  of the heel section  14 , wherein the perforations are inset from the proximal peripheral edge of the heel  34 . 
     The following example is provided to illustrate a method of use whereby the user may possess an unaltered factory insole which is preconfigured to fit a large shoe sizes (such as men&#39;s 11-13). If the user requires a smaller size, he/she may tear at the first perforation  20  to accommodate a medium shoe size (such as men&#39;s 9-10.5), or tear at the second perforation  22  to accommodate a small shoe size (such as men&#39;s 7-8.5). 
     In the preferred embodiment, the series of perforations  20  and  22  are created in the base material through a die cutting process. It is common for perforated materials created by die cut methods to have a series of cuts regularly spaced across the face of the material which passes from the top side of the material and through the bottom side of the material. Perforations in a durable material, such as TPU, may be difficult to tear with the common method of perforation described.  FIG. 5  illustrates an improvement from the common method for creating die-cut perforations.  FIG. 5  shows a closeup of the perforation  20  in the base material  12  being die cut by an alternating series of deep cuts  42 , wherein a section of the cutting edge of a die passes through the top side of the base material  50  and exits through the bottom side of the base material  52 , and a series of shallow cuts  44  positioned between the deep cuts  42 , wherein the cutting edge of the die passes through the top side of the base material  50  but does not exit through the bottom side of the base material  52 . The combination of deep cuts  42  and shallow cuts  44  reduce the strength of the remaining attached base material  48  such that a user is able to quickly size the insole without the use of cutting tools, such as knives, scissors, etc. In the preferred embodiment, the deep cuts  42  and shallow cuts  44  exist along the same curve, alternating between deep  42  and shallow cuts, and wherein the deep cuts  42  and shallow cuts  44  in combination are continuous along the top side of the base material  50 . 
     A unique feature of the therapeutic insole  100  is the ability for the user to configure the insole to function with thong sandals. Thong sandals are generally defined as having a strap, pipe, or post which passes between the big toe (first phalanges of the foot) and the second toe (second phalanges of the foot) to connect the midfoot strap and the sole of the shoe. In one embodiment the therapeutic insole  100  may be designed with a strap plug  46  formed within the base material  12  and generally corresponding between the first and second phalanges of the user to create an opening for the post of the thong sandal. The strap plug  46  may be removed by the user to create an opening within the base material  12  through which the thong strap may pass through. The strap plug  46  may preferably be elliptically shaped and have a diameter greater than 5 mm. Additionally, a strap insertion path  56  comprising a generally straight line connecting from the peripheral edge of the base material to the edge of the strap plug  46  and intended to be cut or torn by the user such that the user may position the therapeutic insole on the pre-existing factory insole without removing the thong strap from the sole of the shoe. The strap plug  46  and strap insertion path  56  may be formed as a perforation during the die cut process and may be formed by deep cuts  42 , shallow cuts  44 , or a combination therein as described within this specification. 
     The therapeutic insole  100  may further comprise an adhesive layer on the bottom of the base layer  52  to aid in positioning the therapeutic insole to the existing insole of the shoe. The adhesive layer is preferably configured as adhesive strip  54  with a non-adhesive release liner. Alternatively, the adhesive layer may cover the entirety of the bottom of the base layer  52  and wherein there are deep cut  44  perforations present in the bottom of the base layer  42 , the adhesive layer may also be perforated.