Abstract:
An exercise belt for a treadmill is provided having a modified surface that simulates natural ground terrain for the purpose of strengthening the muscles of the exerciser&#39;s ankles. The modified surface is produced by regions of variable effective thickness which may be protrusions or attached pads of varied shape, thickness, hardness and spacing. In another aspect, a kit is provided having a large number of pads of varied shape, thickness and hardness adhesively attachable to the belt.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    This invention relates to exercise machines, and more particularly concerns treadmill machines having a modified exercise surface that simulates natural ground terrain. 
         [0003]    2. Description of the Prior Art 
         [0004]    Exercise treadmills in widespread use enable exercise-conscious persons to simulate a controlled walking, running, or jogging exercise program indoors with a minimum amount of space. The speed of exercise, the duration of the exercise period, and the work expended may be readily controlled by regulating the speed and inclination of the treadmill belt, and the length of the exercise period. 
         [0005]    Typically, an exercise treadmill includes an endless belt entrained around a pair of spaced-apart rollers, with one of the rollers being driven at a predetermined speed such that the upper reach of the belt moves from a front to rear direction. In order for the user to remain stationary relative to a handlebar or the frame of the treadmill, the user must walk or run on the upper reach of the belt. By increasing or decreasing the surface speed of the belt, and by changing the inclination of the belt, the degree of physical energy expended by the user to keep pace with the belt may be selectively varied. 
         [0006]    The upper reach of the belt must be supported by support means interposed between the upper and lower reaches of the belt. The support means may typically be a stationary flat slider plate having a very low friction surface or polymeric sheet that is in contact with the belt. Alternatively, the support means may be a series of parallel rollers positioned orthogonally to the direction of movement of the belt, said rollers minimizing frictional interaction with the belt. Both the interior and exterior surfaces of the belt are typically flat. As a consequence, the exerciser is provided with a constantly smooth exercise surface, quite unlike the experience of walking or running outdoors on moist or loose soil, grass or woodland trails or on a gravel shoulder surface adjacent a suburban road. In such outdoor running or walking sessions, irregularities in the terrain impart varied stresses to the exerciser&#39;s feet and ankles. The stresses cause flexion of the ankles in lateral, forward and rearward directions, and serve to strengthen the associated muscles. 
         [0007]    It is accordingly an object of the present invention to provide a treadmill apparatus which provides a modified exercise surface that simulates natural terrain. 
         [0008]    It is another object of this invention to provide a treadmill of the aforesaid nature wherein said modified surface is incorporated into the belt component of the treadmill apparatus. 
         [0009]    It is a further object of the present invention to provide treadmill apparatus of the aforesaid nature wherein the nature of said modified surface is adjustable. 
         [0010]    These objects and other objects and advantages of the invention will be apparent from the following description. 
       SUMMARY OF THE INVENTION 
       [0011]    The above and other beneficial objects and advantages are accomplished in accordance with the present invention by an endless belt of flexible construction bounded by interior and exterior surfaces and parallel side edges, and adapted to tightly embrace front and rear rollers of a treadmill machine whereby said belt is caused to have horizontally elongated upper and lower reaches in vertically spaced apart juxtaposition with intervening support means acting upon said upper reach, said upper reach constituting a foot path that moves rearwardly at a controlled speed, said belt incorporating regions of variable effective thickness associated with said exterior surface in a manner to simulate natural ground terrain. 
         [0012]    In one embodiment, the regions of variable effective thickness are provided by a series of protrusions disposed along the length and width of the belt. The size, shape and distribution of the protrusions can be variable and disposed in a random or uniform pattern. The elevation of such protrusions and their inclination with respect to the surface of the belt should be adequate to induce reasonable but not excessive inclination of the exerciser&#39;s ankle, so as to safely strengthen the associated leg muscles. 
         [0013]    In addition to said height and inclination of the elevated regions, the deformability of the elevated regions under the load imparted on them by the foot of the person using the treadmill is low, causing tilting of the ankle. It is preferred that the protrusions have some deformability under load in order to avoid hard impact upon the bottom of the foot of the exercising person. Consequently, it is desired to have some flatness or curvature to the tip, that is highest point, of the elevated regions in order to prevent any sharp pointed object like experience to the foot of the person walking or running on the treadmill. The person may be wearing shoes or may be bare foot while using the treadmill. 
         [0014]    The spacing between the elevated areas is preferably large enough as compared to the size of the heel of most adults, so that the heel gets tilted as it lands on the inclined part of the elevated region, causing tilting of the ankle either laterally, forwardly or rearwardly. The non-elevated or valley region of the belt can be flat or can have many small size raised areas to impart a massage like action to the bottom sole if the person walking on the belt is bare footed. The elevated regions can also be made up of many small size raised areas as well. 
         [0015]    Said elevated regions can be integral with the belt, having been produced during the manufacture thereof as by a molding operation. Alternatively, pads of varied thickness, compressibility and shape can be bonded in varied spacings to said exterior surface. The belt can be of uniform thickness, having a flat surface wherein the valley areas are filled with material having lower hardness than the hardness of the elevated regions. Such construction simulates the effect of traversing upon uneven ground, and strengthens the involved ankle muscles. 
         [0016]    In a still further embodiment, the sought variability in the effective thickness of the belt can be achieved by a separate sheet-like structure removably attachable to the belt. In order to reduce the extension of the material closer to the outer surface as the belt goes around the rollers, the belt can be slitted across the width every short distance along the length of the belt. The slits may be as deep as the thickness of the belt or may be shorter. 
         [0017]    In yet another embodiment of the present invention, the aforesaid regions of variable effective thickness of the belt may be formed on-demand by the inflation of a pillow-like structure underneath or above the upper reach of the belt. 
     
     
       BRIEF DESCRIPTION OF THE DRAWING 
         [0018]    For a fuller understanding of the nature and objects of the invention, reference should be had to the following detailed description taken in connection with the accompanying drawing forming a part of this specification and in which similar numerals of reference indicate corresponding parts in all the figures of the drawing: 
           [0019]      FIG. 1  is a side view of an embodiment of the treadmill of the present invention with portions broken away to reveal interior details. 
           [0020]      FIG. 2  is a left end view of  FIG. 1  with portions broken away. 
           [0021]      FIG. 3  is a top plan view of  FIG. 1 . 
           [0022]      FIG. 4  is an enlarged sectional view taken in the direction of the arrows upon the line  4 - 4  of  FIG. 3 . 
           [0023]      FIG. 5  is an enlarged fragmentary side view of an embodiment of the treadmill belt of the present invention having identical rounded pads. 
           [0024]      FIG. 6  is a fragmentary top view of the belt of  FIG. 5 . 
           [0025]      FIG. 7  is a fragmentary side view of a belt embodiment having pads of high hardness and a valley area having small raised elements. 
           [0026]      FIG. 8  is a fragmentary side view of a belt embodiment having a checkerboard pattern of alternating soft and hard rectangular pads. 
           [0027]      FIG. 9  is a fragmentary top view of the belt of  FIG. 8 . 
           [0028]      FIG. 10  is a fragmentary sectional side view of a belt having pads of high hardness embedded in a valley of lesser hardness. 
           [0029]      FIG. 11  is a fragmentary sectional side view of a belt having inflatable pads. 
           [0030]      FIG. 12  is a schematic side view of a belt embodiment with pads having vertical slits. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0031]    Referring now to  FIGS. 1-12 , an embodiment of the exercise treadmill  10  of the present invention is shown having a frame  11  including a pair of laterally spaced apart parallel side channels  12   a  and  12   b  extending lengthwise of the frame. A front roller  13  and a rear roller  14  are journaled between said side channels adjacent the front and rear ends thereof, respectively. An endless flexible belt  15  is entrained around the front and rear rollers, with the belt having horizontally elongated upper and lower reaches  16  and  17 , respectively. Belt  15  is bounded by interior and exterior surfaces  18  and  19 , respectively, and parallel side edges  20   a  and  20   b . The distance between said rollers, and consequently the length of said upper and lower reaches is typically between about 4 and 8 feet. The width of the belt, namely the distance of separation of said side edges is typically between about 18 and 30 inches. As commonly constructed, the belt contains at least one layer of a reinforcing fabric embedded in a synthetic elastomer such as neoprene by way of a compression molding operation similar to the production of automobile tires. The belt is fabricated from a single length of belt material having a thickness of about 0.125 inch, the end edges of which are joined by metal fasteners. The material of construction of the belt must be durable, resilient to repeated impact load, abrasion resistance, may be composite, multi-layered, open cell foam, closed cell foam, hybrid of open and closed cell foam, impregnated with binders, woven, made up of discrete or continuous fibers using various manufacturing process commonly used in manufacturing belt like articles in various combinations therein, can contain additives like antimicrobial, antifungal, deodorizing compounds, moisture absorbing, hydrophobic, and hydrophilic compounds. 
         [0032]    As shown in  FIG. 3 , the upper reach  16  of the belt moves from front to rear so that a user standing on the upper reach has to walk or run at a predetermined speed in the forward direction (to the right as shown in  FIGS. 1 and 3 ) to remain stationary relative to frame  11 . Front roller  13  is generally rotatably driven by a variable speed DC electric motor housed within the frame, with the motor connected to the roller by means of a belt and pulley drive. A plurality of shock absorbing support feet  22  comprised of rubber pads, springs or the like are provided on the bottom faces of said side channels at the forward and rear ends thereof for the purpose of minimizing vibration of the treadmill. A front frame member  23  is secured to and extends between the forward ends of the side channels. 
         [0033]    As generally indicated at  25 , a control panel is provided at the front end of the treadmill in position so that the panel&#39;s display may be readily viewed by a user of the treadmill when walking or running on upper reach  16 . Control panel  25  includes a plurality of switches for controlling the operation of the drive motor. Also, certain display readouts  26  may be provided for showing the speed of the belt and hence the velocity at which the user is walking or running. Control panel  25  is supported by a pair of support arms  27   a  and  27   b  secured to respective side channels  12   a  and  12   b  and extending upwardly and rearwardly from the front ends thereof. Paired handlebars  29   a  and  29   b  extend upwardly from side channels  12   a  and  12   b , respectively, and provide a grip for the user while walking or running on upper reach  16  of the belt. A slider panel  31  fabricated of heat-conductive metal is secured by said side channels in the intervening space  32  between said upper and lower reaches, and slidingly supports said upper reach along its entire length. 
         [0034]    In a first embodiment of the treadmill of this invention, as best shown in  FIGS. 3 and 4 , the elevated regions or protrusions are in the form of a series of resilient pads  35  of varied thickness, size, shape and compressive modulus adhered in varied spacing and patterns to exterior surface  19  of the belt. The laterally extending shape of the pad is defined by a perimeter  39  of preferably irregular configuration. The pads are typically fabricated of resilient polymers, and have a flat bottom surface  36 . The upper surfaces of the pads may be flat, rounded or otherwise contoured. In preferred embodiments, the upper surface has a central region of maximum elevation or apogee  40  which is downwardly tapered toward said perimeter, causing the pad to have a hill-shaped profile with a maximum height or thickness corresponding to said region of maximum elevation. Such construction provides lessened impact, and provides comfort to the soles of the exerciser&#39;s feet. 
         [0035]    The pads may have a height or thickness, measured between said bottom surface and region of maximum elevation in the range of 0.1 to 1.50 inch, and may be of foam structure, having closed and/or open cells. The pads may be adhered to the belt by conventional adhesives, and may be emplaced either in a factory operation or by the treadmill user. In fact, one aspect of the present invention is a kit comprised of pads and/or pad material along with a supply of a suitable adhesive. Alternatively, the bottom surfaces  36  of the pads of the kit may contain a layer of contact adhesive covered by a protective release paper. Such kits will contain between about 25 and 100 pads. 
         [0036]    The nature of the selection and arrangement of pads on the belt provides a texture which can simulate the effects of walking or running upon different types of natural terrain. Such effect serves to strengthen the ankle muscles of the exerciser. 
         [0037]      FIGS. 5 and 6  illustrate a belt embodiment having identical rounded pads  60  upon flat exterior surface  19 . The spaces between the pads are considered as valleys  61 . 
         [0038]      FIG. 7  illustrates a belt embodiment having pads  62  of high hardness surrounded by a valley area  63  having small raised elements  64 . 
         [0039]      FIGS. 8 and 9  illustrate a belt embodiment having a checkerboard pattern of alternating soft pads  65  and hard pads  66 . 
         [0040]      FIG. 10  shows a belt embodiment having pads  67  of high hardness embedded in a valley layer  68  of lesser hardness. 
         [0041]      FIG. 11  illustrates a belt embodiment having inflatable pads  69  connected to underlying air supply means  70 . 
         [0042]      FIG. 12  shows a belt embodiment with pads  71  having vertical slits  72  oriented transversely to the direction of belt travel. 
         [0043]    While particular examples of the present invention have been shown and described, it is apparent that changes and modifications may be made therein without departing from the invention in its broadest aspects. The aim of the appended claims, therefore, is to cover all such changes and modifications as fall within the true spirit and scope of the invention.