Patent Publication Number: US-11039656-B2

Title: Footwear shock attenuation system

Description:
INVENTION PRIORITY 
     This patent application claims the benefit under 35 U.S.C. § 119(e) of U.S. Provisional Application Ser. No. 61/672,440 entitled, “Footwear Shock Attenuation System,” which was filed on Jul. 17, 2012 and is incorporated herein by reference in its entirety. 
    
    
     FIELD OF INVENTION 
     The present invention is in the technical field of footwear. More particularly, the invention is in the technical field of cushioning and support systems and devices for footwear. More particularly, the invention is in the field of cushioning that utilizes elastic energy through the utilization of the concept of deflection as a method of cushioning and energy return similar to a trampoline. 
     BACKGROUND 
     Conventional cushioning devices in footwear provide cushioning using the method of compression (usually via the incorporation of a foam material within the heel and sole of a shoe) to absorb shock within the footwear as a user is walking or running and the bottom of the footwear strikes the ground. Cushioning by compression is simply the process of compressing the material that is under your foot until it bottoms out with each step or stride. The drawback of using compression as a method of cushioning is that this form of cushioning has a high level of energy loss, deforms quickly, and looses up to 30% of its cushioning capabilities within the first 200 miles of use. Two hundred miles of use is equivalent to 400,000 steps walking or 40,000 strides running. 
     The present inventor believes that a more efficient and durable method for providing cushioning in footwear would be to harness and utilize a cushioning method that uses deflection as a way to provide cushioning. A trampoline is a good example of using deflection as a way to cushion. A trampoline is durable, retains its shape over time, and has very little energy loss. 
     SUMMARY 
     The present invention provides systems and devices providing cushioning and support in association with footwear. The present invention includes technology that can be used as a shoe heel component that can be integrated into the heel of the shoe. 
     Accordingly, it is a feature of the present invention to utilize a deflection plate within the heel of a shoe or boot for providing shock attenuation and absorption. 
     It is another feature of the present invention that the plate can be provided in the form of a carbon fiber plate located in the heel of footwear, which accepts the energy, or shock, from a downward step on to the ground by a wearer of the footwear. A carbon fiber plate is preferred because carbon increases energy return, yet minimizes energy loss. 
     It is another feature of the present invention that a void can be located underneath the carbon fiber plate to allow the plate to bend when pressed down upon, accepting the energy of the downward step. 
     It is also a feature of the present invention that a post be located near/in the center of the heel underneath the carbon fiber plate to allow support and minimizes catastrophic damage (plastic deformation) to the carbon fiber plate; otherwise, damage would defeat the purpose of the intended invention to provide for shock absorption. Useful aspects of the invention are maintained if the carbon fiber plate is kept from undergoing plastic deformation. Therefore, the post can offer additional support and also prolong the service life of the carbon fiber plate. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
         FIG. 1  Is a top view of the cushioning device of the present invention; 
         FIG. 2  is an exploded view of the components of the cushioning device of the present invention; 
         FIG. 3  is a top view of the elastic plate of the present invention; 
         FIG. 4  is a perspective view of the thermoplastic housing for the elastic plate of the present invention; 
         FIG. 5  is a top view of the elastic plate inserted into the thermoplastic housing of the present invention; 
         FIG. 6  is a rear view showing how a foot flexes the elastic plate during a pressure; 
         FIG. 7  is a perspective view of a shoe midsole with cavity under which the device is placed; and 
         FIG. 8  is a cross section view of the cushioning device of the present invention in both a static and in flexed (dotted line) positions. 
     
    
    
     DETAILED DESCRIPTION 
     Referring to  FIGS. 1 through 4 , the invention is shown detail. An elastic cushioning device includes an elastic plate  10  that is inserted into grooves  16  of a thermoplastic housing  11  and can also be assembled in a manor so that the elastic plate  10  is free floating within the thermoplastic housing  11 . This can be advantageous because the elastic plate can flex unrestricted when placed under a load by the heel of a user&#39;s foot on the elastic plate during activity. The elastic plate  10  when assembled into the thermoplastic housing  11  can be placed over a cavity  14  formed in the midsole  12  of a shoe so that the plate  10  when put under load by the foot can deflect downward into the cavity  14 . A post  15  placed at, or formed within, the center of the cavity can limit the amount of deflection into the cavity. 
     The preferable material used for the plate shown alone in  FIG. 3  is elastic materials such as carbon fiber and/or other elastic composite materials that have a very high rate of rebound (energy return) and a high resistance to breakdown when stressed and released under pressure. These types of elastic materials can be engineered so that the spring constant properties can be modified to accommodate the user&#39;s different weights by shoe size, activity, and function. As shown in  FIG. 4 , the thermoplastic housing can be made of a durable mix of rigid plastic, synthetic, and nylon materials. Although it is envisioned that the housing could also be made of metal, a thermoplastic housing is preferred because it will reduce weight and manufacturing costs. 
     The elastic plate  10  can be designed with a shape as shown in  FIG. 3  and  FIG. 5  so that it does not completely cover the cavity  14  in the midsole  12  when it is placed to rest upon the thermoplastic housing  11  so that air under the elastic plate  10  can escape up and out of the cavity  14  through gaps formed where edges of the elastic plate  10  do not contact the thermoplastic housing  11  when it is flexed downward by the foot, and so that air pressure does not affect the function of the total device. 
     Referring to the function of the invention, when the elastic plate  10  is put under load from activities such as walking and running, as shown in  FIG. 6 , a high level of energy return can be achieved due to the fact that the plate is not anchored or restricted at any point, thus allowing it to bend and return freely. The invention functions similar in a way a trampoline functions by storing, releasing, and retuning a high amount of elastic energy. 
     In further detail, still referring to the invention of  FIG. 1  and  FIG. 2 , but also  FIGS. 7 and 8 , the midsole  12  of a shoe has a cavity  14  formed therein in a manner that a soft post  15  remains formed therein and centered within the cavity  14 . The soft post  15  functions as a fail safe stop so the elastic plate  10  will not flex  17  excessively and break as shown in  FIG. 8 . Flexion beyond the post  15  within the cavity could result in the elastic plate  10  breaking or shattering. 
     Referring to  FIG. 8 , when the load is released by the heel as the motion of the foot pronates forward, the plate  10  will use kinetic energy to return to its original shape thus providing energy return to the wearer. 
     The construction details of the present invention as shown in  FIG. 1  and  FIG. 2  consists of a elastic plate  10 , depicted in  FIG. 3  that is positioned inside grooves  16  of thermoplastic housing  11  in such a way as the elastic plate  10  is free floating allowing such elastic plate to flex downward  17  of  FIG. 8  and to return unimpeded so as to take full advantage of the high energy return properties of such elastic plate  10 , thus providing for a cushioning device and energy return that avoids the negatives (high energy loss &amp; rapid breakdown) of current typical compression based cushioning devices. Thermoplastic housing  11  may have a u-shape main body  70  with a top side and a bottom side engageable with the midsole, as illustrated in  FIG. 4 , main body  70  having a back end portion  72  leading into two spaced side wall portions  74  with a protrusion  76  on each sidewall portion  74  and back end portion  72  whereby protrusions  76  extend laterally outward from main body  70  and are parallel with main body  70  along a vertical axis. Protrusions  76  on back portion  72  and sidewall portions  74  may have a rounded leading end  80  with a rear surface  81  extending from the portions  72  and  74 . The protrusion  76  on back end portion  72  may be connected to each of protrusions  76  on sidewall portions  74  by a concave curve  86 , whereby protrusions  76  are shaped such that two ellipses portions  82  of the midsole are visible when the thermoplastic housing  11  is inserted into the midsole. Grooves  16  may have a u-shaped upper surface  92  and u-shaped lower surface  94  extending inward from and separated by a surface  96  of thermoplastic housing  11  such that for elastic plate  10  to be positioned inside of grooves  16 , elastic plate  10  is laterally slid or inserted between the upper surface and lower surface of grooves  16 . When received in grooves  16 , elastic plate  10  rests below upper surface of grooves  16  as illustrated in  FIG. 1 . 
     The advantages of the present invention include without limitation superior cushioning compared to current cushioning technology, energy return in a manner and degree not utilized in current footwear cushioning shock attenuation systems, light weight than current systems, simple design and construction for ease of manufacturing, superior durability than current shock attenuation systems, and tenability for varied weight loads or functions. 
     The broad embodiment of the present invention is a cushioning device that is designed to be used in the heel area of a variety of types of footwear not limited to but including athletic, casual, military, hiking, and dress shoes. 
     While the foregoing written description of the invention enables one of ordinary skill to make and use what is considered presently to be the best mode thereof, those of ordinary skill will understand and appreciate the existence of variations, combinations, and equivalents of the specific embodiment, method, and examples herein. The invention should therefore not be limited by the above described embodiment, method, and examples, but by all embodiments and methods within the scope and spirit of the invention as claimed.