Abstract:
A lightweight ballistic protection backpack and other useful items are realized utilizing one or more panels of ultra high molecular weight polyethylene (or UHMWPE) unidirectional laminate.

Description:
CROSS-REFERENCE TO CORRESPONDING APPLICATIONS 
       [0001]    This application takes priority from provisional patent application Ser. No. 60/790,638 filed on Apr. 10, 2006. 
     
    
     TECHNICAL FIELD 
       [0002]    The present invention relates generally to ballistic protection devices and more specifically to lightweight ballistic protection devices that also function as useful articles such as backpacks, bags, briefcases, seat cushions, etc. 
       BACKGROUND OF THE INVENTION 
     Background Art 
       [0003]    The most common ballistic protection device is the bulletproof vest. These vests have saved the lives of many law enforcement officers and military personnel in recent years. Most modern day ballistic vests include one or more protective panels having overlying layers of a fabric made from woven high tensile strength ballistic resistant polymeric fibers. Woven fabrics made from an aramid fiber known as KEVLAR, for example, have been used successfully in ballistic vests because of the high-energy absorption properties of the fabric material. 
         [0004]    Resistance to projectile penetration is a principal factor in designing a ballistic panel. Thicker panels comprising added protective layers can offer greater protection against projectiles having higher threat levels, but added protective layers also add undesired weight and inflexibility. In addition to woven KEVLAR fabric layers, ballistic panels have been made from other high performance synthetic fibers and composites to reduce weight and improve flexibility. 
         [0005]    Ballistic panels are regularly certified by ballistics testing to measure their ability to protect against different projectiles fired from different types of weapons at various angles. One ballistic test commonly used in the industry is the National Institute of Justice (NIJ) Standards 0101.03 which, in general terms, is a high performance standard requiring that a ballistic panel prevent penetration of specified rounds fired at velocities up to 1450 ft/sec. In addition to preventing such projectile penetration, “backface deformation” also is a required test factor in the NIJ Standard 0101.03 certification test. Backface deformation indirectly measures the trauma level experienced by a user from a projectile that does not penetrate the test ballistic panel. 
         [0006]    In addition to the need for bulletproof vests used by the military and police, with the seeming proliferation of school, office and other random shootings, there is a need for ballistic protection devices that can be used on an everyday basis by students, office workers and other civilians. These devices should be concealable and lightweight enough to be used on a regular basis, even by small children. 
         [0007]    Therefore, there is a need to provide bullet resistant devices that use ballistic panels that are reasonably thin and light in weight as compared to ballistic panels currently employed in bulletproof devices. Also, although thinner and lighter than most existing ballistic panels, these ballistic panels must also still be capable of meeting the NIJ high performance projectile test specifications. 
         [0008]    The following issued U.S. Patents appear to constitute relevant prior art: 
         [0000]    
       
         
               
               
               
             
           
               
                   
               
               
                 U.S. PATENT NO. 
                 PATENT DATE 
                 INVENTOR 
               
               
                   
               
             
             
               
                 4,830,245 
                 May 16, 1980 
                 Arakaki 
               
               
                 6,161,738 
                 Dec. 19, 2000 
                 Norris 
               
               
                   
               
             
          
         
       
     
         [0009]    Arakaki discloses a backpack carrier comprising lightweight metal frame wrapped by a plurality of layers of KEVLAR, which produces a bullet resistant shield. 
         [0010]    Norris discloses a container for transporting articles that includes a ballistic shield attached to one or more walls of the container. Norris discloses using a flexible textile material such as KEVLAR or one of a group of rigid materials. 
         [0011]    Neither of these patents disclose using a ballistic panel comprising an ultra high molecular weight polyethylene (or UHMWPE) unidirectional laminate. 
       SUMMARY OF THE INVENTION 
       [0012]    A lightweight ballistic protection backpack is realized utilizing one or more panels of ultra high molecular weight polyethylene (or UHMWPE) unidirectional laminate. UHMWPE, also known as high modulus polyethylene (HMPE) or high performance polyethylene (HPPE) is a thermoplastic. It has extremely long chains, with molecular weight numbering in the millions, usually between 2 and 6 million. The longer chain serves to transfer load more effectively to the polymer backbone by strengthening intermolecular interactions. This results in a very tough material, with the highest impact strength of any thermoplastic presently made. 
         [0013]    UHMWPE fibers are made using a DSM patented (1979) method called gel spinning. A precisely heated gel of UHMWPE is processed by an extruder through a spinneret. The extrudate is drawn through the air and then cooled in a water bath. The end result is a fiber with a high degree of molecular orientation, and therefore exceptional tensile strength. To fabricate a UHMWPE ballistic panel, the fibers are generally aligned and bonded into sheets, which are then layered at various angles to give the resulting composite material strength in all directions. 
         [0014]    There are several direct advantages of UHMWPE unidirectional panels over a KEVLAR weave/woven design. For example, UHMWPE unidirectional panels, on a pound for pound comparison, are better &amp; stronger in terms of ballistic performance than panels made with KEVLAR type materials. A panel of UHMWPE is 15 times stronger than Steel versus a panel of KEVLAR of the same weight, which is only 5 times stronger than Steel. In addition, UHMWPE unidirectional panels are also more resistant to corrosive chemicals, have extremely low moisture absorption, have very low coefficients of friction, are self-lubricating and are highly resistant to abrasion. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0015]    The aforementioned objects and advantages of the present invention, as well as additional objects and advantages thereof, will be more fully understood herein after as a result of a detailed description of a preferred embodiment when taken in conjunction with the following drawings in which: 
           [0016]      FIG. 1  is a side view of a preferred embodiment of the present invention; 
           [0017]      FIG. 2  is a side view of a ballistic resistant panel as incorporated in the invention of  FIG. 1 ; 
           [0018]      FIG. 3  is a front view of the ballistic resistant panel of  FIG. 2 ; 
           [0019]      FIG. 4  is a rear view of the invention of  FIG. 1 ; 
           [0020]      FIG. 5  is a rear view of the invention of  FIG. 1  further illustrating the ballistic resistant panel of  FIG. 2 ; 
           [0021]      FIG. 6  illustrates an alternative embodiment of the present invention; and 
           [0022]      FIG. 7  illustrates a second alternative embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
       [0023]    Referring to the accompanying figures and initially  FIGS. 1 through 5  in particular, a bullet resistant backpack  10  is shown. As illustrated, the bullet resistant backpack  10  includes at least one bullet resistant panel  20 . In certain respects the bullet resistant backpack  10  is similar to most backpacks in that it includes an interior section  28  for transporting objects. The interior section  28  is formed by a front panel  30 , a pair of side panels  32 ,  34 , a top panel  36 , a bottom panel  38  and a back panel  40 . 
         [0024]    In the present embodiment, the bullet resistant backpack further includes a zipper  50 , which allows the top panel  36  to open and provide access to the interior section  28 . Straps  52 ,  54  and handle  56  allow the user to either carry or wear the backpack. Optional side pouches  60 ,  62  and front mesh pouch  66  are shown for purposes of example; however, it should be appreciated that any backpack configuration may be used. 
         [0025]    In a preferred embodiment, the bullet resistant panel  20  comprises a plurality of layers of lightweight composite material such as ultra high molecular weight polyethylene unidirectional (“UHMWPE”) laminations. The bullet resistant panel  20  as shown is either removably or permanently incorporated into a sleeve  70 , which is operatively connected to the back panel  40 . Other embodiments for securing the bullet resistant panel  20  within or on the outside of the backpack  10  are contemplated such as Velcro, snaps, glue, etc. 
         [0026]    In certain embodiments additional bullet resistant panels may be incorporated in or attached to the front panel  30 , side panels  32 ,  34  and or top and bottom panels  36 ,  38 . In preferred embodiments the bullet resistant panel  20  should be sufficient by itself to stop most types of ammunition used in random shootings yet light enough that even the youngest of students that typically carry a backpack to school could carry a bag employing bullet resistant panel  20  without much additional effort. 
         [0027]    Referring now to  FIGS. 4 and 5 , the back panel  40  is shown wherein the bullet resistant panel  20  incorporated therein. It should be noted that in a preferred embodiment of the present invention the bullet resistant panel  20  covers as much of the cross sectional surface of the back panel  40  as is practicable, which provides for a larger ballistic shield, however, smaller profiles are contemplated. 
         [0028]    Referring now to  FIGS. 6 and 7 , other everyday carryable items are shown that include bullet resistant panels similar to the bullet resistant panel  20 . As shown in  FIG. 6 , a seat cushion  100  includes a bullet resistant panel  110 . The bullet resistant panel  110  preferably comprises the same characteristic properties as those of the bullet resistant panel  20  and is therefore thin and lightweight. Because of the lightweight and thin properties of the bullet resistant panel  110 , the seat cushion  100  can comfortably be carried to sporting events and other outings while concealing the presence of the bullet resistant panel. In addition, the seat cushion  100  can be used in a car, on a boat or in an office environment. 
         [0029]    A briefcase  120  includes at least one bullet resistant panel  122  operatively positioned within a top panel  130 . The bullet resistant panel could also be incorporated within a bottom panel  132 . Again, because of the lightweight and thin properties of the bullet resistant panel  122  the briefcase  120  can be utilized just like any other briefcase without adding significant fatigue to the user. 
         [0030]    Various aspects of the disclosed embodiments have been omitted to avoid obfuscation of the more salient features. By way of example, it will be understood that the bullet resistant panel  20  may be incorporated into other everyday items, which may be employed as a ballistic barrier wherein weight and size is an important factor. 
         [0031]    Having thus described various embodiments of the present invention, it will now be evident that many modifications and additions are contemplated. Accordingly, the scope hereof is limited only by the appended claims and their equivalents.