Abstract:
This invention is a back support system designed to reduce the stress exerted on the back of a wearer when he bends over to lift a load. This back support system comprises a harness and a yoke for distributing the load on the shoulder of the wearer. The back support also comprises a tension system equipped with elastic cables. The back support further comprises leggings including straps designed to wrap around the sole of the wearer and to maintain the force acting on the leg as close as possible to the bone structure of the leg of the wearer, thereby relieving stress on his back and along his legs.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention relates to equipment for supporting, strengthening the back and reducing back strain in circumstances requiring bending at the waist. It also relates to equipment designed to prevent back injuries during bending or lifting activities. 
       BACKGROUND 
       [0002]    Back injuries that result from bending at the waist and lifting heavy loads, besides being painful, difficult and costly to treat, cause the loss of millions of dollars in productivity. These injuries are caused by high twisting forces exerted on the spinal column by the cantilevered action of bending. The vertebras which occupy a few square inches of surface operate as a fulcrum in a lever system. The short segment of the lever system is located on the vertebras themselves. The long segment of the lever system includes the arms, the hands and the load itself. Therefore the force applied to this lever may be located feet away from the backbone. As a result tremendous forces are exerted on the vertebras and may cause injuries. 
         [0003]    Prior art includes U.S. Pat. No. 6,450,131 by Daniel James Broman; U.S. Pat. No. 6,436,065 by Timothy John Mitchell; U.S. Pat. No. 6,129,691 by John F. Ruppert; U.S. Pat. No. 5,957,091 by Kurt D. McDonald and Timothy W. Ecker; U.S. Pat. No. 5,860,944 by Henry R. Hoffman Jr.; U.S. Pat. No. 1,634,621 by Isidoro Martinez; and U.S. Pat. No. 1,409,326 by Ernest S Williamson. The prior art does not address in a methodical, well thought out engineering approach, the problem of how to design a back support system that distributes tensile and compressive forces such as to minimize stress on the spinal column and on soft tissues. This invention solves this problem. 
         [0004]    It is therefore an object of this invention to provide a back support system designed such that forces are mainly applied to the skeleton of the wearers rather than to his soft tissues. 
         [0005]    It is another object of this invention to distribute forces such that compressive forces are mainly applied to the wearer&#39;s skeleton and tensile forces are mainly conveyed to the invention embodiment. 
         [0006]    Further features, aspects, and advantages of the present invention over the prior art will be more fully understood when considered with respect to the following detailed description claims and accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0007]      FIG. 1  illustrates the whole back support system. 
           [0008]      FIG. 2  provides a front view of a person wearing the back support system. 
           [0009]      FIG. 3  provides a back view of a person wearing the back support system. 
           [0010]      FIG. 4  illustrates the harness that wraps around the chest of the wearer. 
           [0011]      FIG. 5  shows how the yoke fits on top of the harness. 
           [0012]      FIG. 6  illustrates how the tension straps fit over the yoke. 
           [0013]      FIG. 7  provides a back view of the invention, showing how the tension straps attach to the elastic tubing. 
           [0014]      FIG. 8  shows the loops of surgical tubing. 
           [0015]      FIG. 8A  shows how the surgical tubing is covered with fabric to protect it. It also shows the carabiners attached to one of the ends of the tubing. 
           [0016]      FIG. 9  illustrates how the ends of the surgical tubing are attached together by means of cable ties to form a loop. 
           [0017]      FIG. 9A  illustrates how the ends of the surgical tubing are attached together by means of nylon cable to form a loop. 
           [0018]      FIG. 9B  shows how the surgical tubing is reinforced at the tips of the loop where it is attached to the tension straps and to the carabiners. 
           [0019]      FIG. 10  illustrates the legging strap system. 
           [0020]      FIG. 11  shows the back support system is used when the wearer bends over. 
           [0021]      FIG. 11A  provides a force diagram illustrating the force vectors acting on the wearer and on the back support system. 
           [0022]      FIG. 12  shows how a yoke system can be shaped out of a single piece. 
           [0023]      FIG. 13  illustrates how the functionality of the D rings can be implemented by shaping the rails in the yoke in the form of tubes slotted along their length. 
       
    
    
     SUMMARY OF THE INVENTION 
       [0024]    This invention is a back support system designed to reduce the stress exerted on the back of a wearer when he bends over to lift a load. This back support system comprises a harness which is secured to the torso of the wearer, by means of breast straps joined at the front of the wearer&#39;s chest. The harness also comprises two shoulder straps wrapped from front to back, over the shoulders of the wearer. 
         [0025]    The back support also comprises a yoke system which includes two curved rails made of rigid material. The curved rails are attached to the shoulder strap, and are wrapped in their longitudinal directions over the shoulders of the wearer from front to back. In addition, both curved rails have their top surface configured in a concave shape in their perpendicular directions. 
         [0026]    The back support also comprises a tension system which includes tension straps extending from front to back inside the concave surface of the curved rails. Both tension straps are attached at their top ends to the breast straps at points located at the front of the wearer&#39;s chest. The tension system also includes two elastic cables, each cable attached at its top end to one of the straps. 
         [0027]    The back support system also includes a legging system comprised of a right legging net and a left legging net. The legging nets are worn on the legs of the wearer. Each legging net comprises a vertical strap attached at its two ends to the bottom of one of the elastic cable, in such a fashion as to form a vertical loop that wraps around the respective right or left sole of the wearer. In addition, the legging nets include at least one horizontal strap that fastens the vertical strap against the leg of the wearer essentially following the bone structure of his leg. Another foot strap fastens the vertical strap against the foot of the wearer. 
         [0028]    The back support system generates a tension force when said wearer bends over to lift a load. This tension force counterbalances the force generated on the back of the wearer by the load, thereby relieving stress on his back. In addition, the tension system, maintains the tensile force essentially aligned along the bone structure of the leg of the wearer thereby relieving stress along his legs. 
         [0029]    This invention includes several variations such as fastening and adjusting buckles to fit wearer&#39;s of different sizes. The curved rails can be made with an upper surface concave in the perpendicular direction of the rail. The concavity could be obtuse or extreme such as to form a tube slotted along the length of the rail. The elastic cable could be made of surgical tubing configured such that the ends of the tubing are joined together to form a loop. The surgical tubing may be reinforced at their point of contact with the tension straps and with the legging nets by rigid u-shaped tubing. Carabiners could be used to join the elastic cable to the legging nets. Fastening and adjusting buckles may be replaced by VELCRO™ fasteners. D-shaped rings can be used to keep the tension straps firmly inside the rails. A horizontal strap can be used to join together the tension straps to prevent them for sliding off the rails. 
       DETAILED DESCRIPTION 
       [0030]    This invention is illustrated in  FIG. 1 .  FIGS. 2 and 3  illustrate the device as it is worn by a person. It comprises the following parts 
         [0031]    a) The harness  1   
         [0032]    b) The yoke system  2   
         [0033]    c) The tension system  3   
         [0034]    d) The legging strap system  4   
         [0035]    Harness 
         [0036]    This component is shown in  FIG. 4 . It resembles to a certain extent, a back-pack harness. It is made of a flexible, breathable mesh material attached to the chest of the wearer. Two padded shoulder straps  11  wrap over the shoulder of the wearer. These straps are equipped with adjusting buckles  12 . Two additional straps  13  and  34  wrap around the chest of the wearer and are attached to the shoulder straps approximately at the breast location on the chest. These straps are equipped with adjusting and fastening buckles  14  and  41 . 
         [0037]    Yoke System 
         [0038]    The yoke system  2  is shown in  FIG. 5 . It consists of two rigid curved rails  15  attached to the shoulder straps  11  and wrapping around the shoulders of the wearer. The two curved rails  15  fit on the top of the shoulder straps  11 . They are designed to apply the load mainly to the skeleton of the wearer instead of onto his soft tissues. These rails are attached to the shoulder straps  11  by means of snap-on bands  16 . Alternatively, the rails  15  can also be sewn to the shoulder straps  11 . Sewing the rails  15  to the shoulder straps can be done, for example, by pre-drilling or pre-forming holes  43  in rows, each row oriented longitudinally along the rails  15 , with each hole  43  separated approximately ¾″ from each others. Thread  44  can then be passed through the holes  43  to sew the shoulder straps  11  securely to the rails  15 . The rails  15  can be made of light plastic such as PVC. They can be detached as shown in  FIG. 1 . 
         [0039]    Tension System 
         [0040]    The tension system  3  is shown in  FIGS. 6 ,  7  and  8 . It is designed to provide an elastic tension that counterbalances the weight carried by the wearer of the device. It comprises the following components: 
         [0041]    a) Two tension straps  17  shown in  FIGS. 6 and 7 , equipped with adjustable buckles  18 . The straps are attached (for example sewn) at their top ends to the front of the harness  1 . At their bottom ends, the straps form loops  19 . D-shaped rings  39  may be used to hold the tension straps  17  in place inside the curved rails  15 . In addition, the tension straps  17  can be joined together by means of a horizontal strap  40 . 
         [0042]    b) Elastic cables  20  shown in  FIGS. 7 and 8  pass through the loops  19  formed by the straps  17 . The cables  20  can be made from a diversity of elastic material. For example, it has been found convenient to use cables consisting of loops of surgical tubing made of latex. The tubing is formed into a loop by joining two ends of a tube segment. The joining of the ends can be done in many possible ways. For example as shown in  FIG. 9 , one can use for this purpose a cylinder  21  made of hard plastic and with a diameter slightly larger than the inner diameter of the tubing  20 . The cylinder  21  would be threaded at both ends, with a clockwise screw at one end and a counterclockwise screw at the other end. The cylinder  21  would then be screwed inside the ends of the tubing  20  thus joining the two ends together. To provide additional binding, each tubing end could be clamped against the cylinder by means of at least one zip tie or cable tie  33 . At their top ends, the loops of surgical tubing pass through the loops  19  located at the bottom of the straps  17 . Alternatively, as illustrated in  FIG. 9B , high tension nylon string  42  can be wound over and over the length of the coupling. 
         [0043]    As illustrated in  FIG. 9B , the elastic cables  29  are reinforced at the point of contact with the loops  19  by U-shaped rigid tubing  32  formed, for example, by assembling together two L-shaped copper tube elbows. The surgical tubing loop  20  is covered by a fabric sheath  22  to protect it and allow it to easily move during use. The bottom of the loops of surgical tubing  20  holds a carabiner  23  (as it is known in the trade) or a functionally equivalent device. It is a metal loop with a sprung or screwed gate which can quickly and reversibly connect components. The surgical tubing  20  is also reinforced at the point of contact with the carabiners  23  by U-shaped rigid tubing  32 . 
         [0044]    Optionally, as shown in  FIG. 7  the tension straps  17  can be joined together by means of a horizontal strap  37 . 
         [0045]    Legging 
         [0046]    Each carabiner  23  connects one of the surgical tubing loops  20  in the tension system  3  to a side of the legging strap system  4 . A detailed view of the legging strap system  24  is shown in  FIG. 10 . It comprises a vertical strap  25  attached at both of its ends to a carabiner  23 . This vertical strap  25  extends from the carabiner  23  and wraps around the wearer&#39;s shoe. The vertical strap  25  is held in place against the wearer&#39;s leg by means of several horizontal straps  26 ,  27  and  28 . These straps comprise adjustable buckles  29  and are wrapped around the foot, the ankle and just below the knee of the wearer. 
         [0047]    Transfer of Forces 
         [0048]    An important aspect of this invention is how the forces are distributed. This feature can be illustrated by means of  FIGS. 11 and 11A . One must note how the tension system  3  and the legging  4  follow the wearer&#39;s skeleton. As the wearer of the device bends over, the tension system  3  takes over tensile forces  35  allowing the skeleton of the wearer to experience mainly compressive forces  30 . This configuration results in the least effort and stress on the wearer&#39;s part. 
         [0049]    In addition, the yoke system  2  ensures that forces are applied to the wearer&#39;s skeleton rather than to his soft tissues. 
         [0050]    Variations 
         [0051]    As is evident to someone versed in the arts, many embodiments of this invention are possible. The straps  11 ,  13 ,  34 ,  17 ,  25 ,  26 ,  27  and  28  can be made of material such as nylon, Kevlar, leather or such similar material. 
         [0052]    According to another variation, fastening buckles  14  and  41  can be replaced by VELCRO™ fasteners. 
         [0053]    According to yet another variation, the surgical tubing loops  20  can be replaced by springs. 
         [0054]    In a further variation illustrated in  FIG. 12 , the yoke system can be a single piece  37  instead of being two different pieces  15  as shown in  FIG. 5 . 
         [0055]    In yet a further variation, the functionality of the D rings can be implemented by shaping the rails  15  in the yoke  37 , in the form of tubes. The tubes may incorporate longitudinal slots  38  as shown in  FIG. 13  or may be closed. 
         [0056]    While the above description contains many specificities, the reader should not construe these as limitations on the scope of the invention, but merely as exemplifications of preferred embodiments thereof. Those skilled in the art will envision many other possible variations within its scope. Accordingly, the reader is requested to determine the scope of the invention by the appended claims and their legal equivalents, and not by the examples which have been given.