Abstract:
An improved design for a helmet to reduce injuries caused by helmet-to-helmet collisions. The helmet has a thin layer of padding added onto the hard shell of the helmet. The padding may be textured to add “crumple zones.” A thin, rugged, low-friction exterior cover is affixed to the padding. In one embodiment of the helmet, the cover is separated slightly from the padding to provide air space. The air space, combined with the textured padding, provides a substantial reduction in peak acceleration resulting from a helmet-to-helmet collision.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims priority under 35 U.S.C. §119(e) to provisional patent application Ser. No. 61/457,739, which is hereby incorporated by reference. 
     
    
     THE NAMES OF THE PARTIES TO A JOINT RESEARCH AGREEMENT 
       [0002]    Not Applicable 
       INCORPORATION-BY-REFERENCE OF MATERIAL SUBMITTED ON A COMPACT DISC 
       [0003]    Not Applicable 
       BACKGROUND OF THE INVENTION 
       [0004]    1. Field of the Invention 
         [0005]    The present invention is for a protective helmet. This helmet could be used in sports activities, like football. 
         [0006]    2. Description of Related Art 
         [0007]    The collision between hard helmets is an elastic collision, with little energy lost like when billiard balls collide. Previous attempts by football leagues to put padding on helmet exteriors have failed because of cost and the fact that modified helmets were bulky and strange-looking. In addition, helmets that are too soft on the outside carry the risk of neck injury because of the friction that is generated during collisions. 
         [0008]    There is a need for a safer helmet. This helmet should be able to be manufactured cost-effectively, whether by retrofitting existing helmets or by manufacturing new helmets. The new safety features of this helmet should be integrated into the exterior of the helmet in an aesthetically pleasing way, in order to encourage its adoption. 
       BRIEF SUMMARY OF THE INVENTION 
       [0009]    The present invention uses a thin, low-friction, and inexpensive padding on the outside of a helmet. Testing of this padding demonstrates significant reduction in peak acceleration to the brain in helmet collisions. 
         [0010]    An existing helmet can be retrofitted with exterior padding using by vacuum thermoforming of cheap PETG plastic onto moleskin. Although there is some benefit to a smooth padding surface, there are substantial benefits to molding shapes into the exterior. One embodiment uses textured spirals. Another uses textured Celtic knots. Other shapes are also possible as well as other cushioning materials and shielding materials (instead of moleskin and PETG plastic, respectively), as would be evident to one of ordinary skill in the art. 
     
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
         [0011]      FIG. 1  shows a front perspective view of one embodiment of the present invention. 
           [0012]      FIG. 2  shows a front view of one embodiment of the present invention. 
           [0013]      FIG. 3  shows a side view of one embodiment of the present invention. 
           [0014]      FIG. 4  shows a back perspective view of one embodiment of the present invention. 
           [0015]      FIG. 5  shows experimental results demonstrating the effectiveness of the present invention at reducing peak acceleration resulting from helmet-to-helmet collisions. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0016]      FIGS. 1-4  illustrate an embodiment of the present invention. The present invention comprises a standard helmet  1 , such as a football helmet, that has outside the hard shell  2  a thin layer of padding  3 . The padding  3  may have no design or may be in the shape of 3-dimensional decorative adhesive stickers that, in addition to providing a certain amount of cushion, may take on a decorative or informational quality (such as a team insignia or a player number, code, or unique image). In addition, the illustrated helmet has an exterior cover  4  that goes outside the layer of cushions. 
         [0017]    The cover  4  may bow outwardly to form a protective casing or bubble to provide additional resistance and cushioning from collision. This void space around the hard shell  2  also increases the overall surface area of the outer cover  4  to distribute the pressure of collisions over a greater surface area. Using an outer cover  4  around the padding  3  also provides a low-friction surface to the helmet  1  in order to lower the risk of neck injuries by deflecting the force from collisions and allowing glancing blows to occur instead of the helmets locking together. 
         [0018]    The exterior cover  4  may be see-through or opaque. Indicia such as the team insignia may be placed on the outer shell, especially if the outer shell is opaque so that people could see the insignia. The padding  3  between the outer hard shell  2  of the helmet and the exterior cover  4  can be adhered with glue, affixed mechanically or otherwise attached to either the hard shell  2 , or to the cover  4 , or both the hard shell  2  and the cover  4 . One way to attach the cover  4  is to adhere the padding  3  to the shell  2  and maintain an air space between the padding  3  and the cover  4 . In another embodiment, the padding  3  is adhered both to the exterior of the hard shell  2  and the interior of the cover  4 . Another variation may be to texture the padding  3  with ridges, bumps, or other shapes such that the force from a collision is distributed over a greater surface area and increase the amount of air pockets and crumple zones. The use of textures to increase surface areas bearing the force of collisions could also be applied to the inside and outside of the thin plastic cover and the inside and outside of the hard shell  2  of the helmet  1 . In the illustrated embodiment, padding  3  has molded spirals  5 . 
         [0019]    The padding  3  may be made from moleskin, polyethylene foam, or other suitable material. The cover  4  can be made of any material that provides a sufficiently rugged, but low-friction surface. For example, a thin plastic would be suitable, provided that it has the desired properties. In some embodiments, the cover  4  and hard shell  2  incorporate cooperating holes for ventilation or other climate control. In some embodiments, the padding  3  is inflatable. In such embodiments, the cover  4  has a hole at the top for the pump needle to inflate the padding  3 . The padding  3  and outer cover  4  may be replaceable when damaged or for other reasons. 
         [0020]    To test the present invention, a hole was drilled in the back of one helmet and a rope was attached to it to ensure consistency in the dropping of the helmet. A second helmet was placed on the floor, stabilized between two bags of playground sand. An accelerometer was mounted on a piece of wood and that wood was mounted inside the helmet such that it would measure acceleration changes in a direct, downward direction. The helmets were aligned so that with the top helmet was released the front of both helmets collided. Drop test data was collected in sets of  10  for each of the experimental variations from a height of 70 cm. The data were collected on a computer and were analyzed to isolate the shock of the initial impact from the subsequent bouncing or other “noise.” 
         [0021]    Data from testing supports the hypothesis that shock attenuation can be improved through the use of designs that maximize mechanical resistance and surface area of the semi-rigid plastic shield. Parts of the plastic shield showed signs of stress after hard collisions, which suggests that the proposed design could also be useful to help detect when and where players&#39; brains have been exposed to stresses. 
         [0022]    The graph in  FIG. 5  shows the results of testing. The following table compares the mean and range peak acceleration (m/seĉ2) in helmet collisions with varying configuration of padding: 
         [0000]    
       
         
               
               
               
             
               
               
               
             
           
               
                   
               
               
                 Padding on exterior 
                 Mean 
                 Range 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 None(control) 
                 146.83 
                 93.5 
               
               
                 Moleskin 
                 77.14 
                 43.5 
               
               
                 Moleskin with smooth PETG shield 
                 51.93 
                 36.5 
               
               
                 Moleskin with Celtic knot design PETG shield 
                 26.93 
                 25.9 
               
               
                 Moleskin with spiral design PETG shield 
                 26.63 
                 24.7 
               
               
                   
               
             
          
         
       
     
         [0023]    The present invention reduces peak acceleration when such helmets  1  are collided. The reduction in peak acceleration is at least partially dependent on the padding configuration on the exterior. In testing, average peak acceleration of a control football helmet was 146.83 m/seĉ2. The average peak acceleration of the standard football helmet was 146.83 m/seĉ2. The average peak acceleration of the helmet with moleskin was 77.14 m/seĉ2. This is a 47% improvement over the control. The average peak acceleration of the helmet with plain plastic and moleskin was 51.93 m/seĉ2. This is almost a 65% improvement over the control. Second best was the helmet with the Celtic knot design with an average peak acceleration of 26.93 m/seĉ2. This is almost an 82% improvement over the control. The helmet with spirals preformed the best, with an average peak acceleration of 26.63 m/seĉ2, just three tenths of a m/seĉ2 better than the Celtic knot design. This is almost an 82% improvement over the control. The helmets with designs (Celtic knot and spiral) most successfully reduced the peak acceleration because the surface area was greater and could therefore better distribute the force over a greater area and spread the collision over a greater interval of time. This is similar to the design approach used in making “crumple zones” for automobiles. 
         [0024]    It is also envisioned that as football helmets will have increased numbers of sensors and that the sensors will be able to do a number of things. First of all, they will be able to calculate the peak acceleration of any helmet collisions. If the hit is greater than 80 G&#39;s, the medics will pull the player over. If the hit is below 80 G&#39;s, the player may be able to continue playing (unless the player shows TBI symptoms, of course). The sensors will also be able to calculate the players&#39; speed in real time and project it onto the Jumbotron®, Internet, or TV. Lastly, the sensors will be able to calculate the peak acceleration of any collision. 
         [0025]    The described embodiments could be applied by one of ordinary skill in the art to other types of protective gear, such as shoulder, knee, or elbow protectors as well as protectors for any equipment subject to damage due to dropping or other shock, such as a cell phone, tablet or laptop computer, or sensitive components in cars or airplanes. 
         [0026]    The described embodiments are not intended to be exhaustive descriptions of the present invention. Other variations are also possible, as would be understood by one of ordinary skill in the art.