Abstract:
A helmet having an outer shell and an inner shell placed within the outer shell. The inner shell attached to the outer shell by a plurality of elastomeric elements to isolate the inner shell from impacts and rotational forces applied to the outer shell.

Description:
BACKGROUND 
       [0001]    1. Field of the Invention 
         [0002]    The present invention relates generally to helmets used as protective gear. 
         [0003]    2. Description of Related Art 
         [0004]    Helmets are well known in the art to be securely fashioned to a head and provide padding in an attempt to absorb impact. Most helmets are designed to prevent skull injury and most testing systems test for this ability. Recently the concept of brain injury separate from skull injury has come to light and helmets are not typically designed to prevent such injuries well. Current helmets may dampen high crushing forces, but they do nothing to reduce against rotational forces that can damage the brain and the upper spine. 
         [0005]    A need exists, therefore, for a helmet that protects the brain and upper spine as well as the skull. 
         [0006]    All references cited herein are incorporated by reference to the maximum extent allowable by law. To the extent a reference may not be fully incorporated herein, it is incorporated by reference for background purposes and indicative of the knowledge of one of ordinary skill in the art. 
       BRIEF SUMMARY OF THE INVENTION 
       [0007]    The problems presented in typical helmets are solved by providing a helmet with two shells connected by a plurality of discrete elastomeric elements. 
         [0008]    Other objects, features, and advantages of the present invention will become apparent with reference to the drawings and detailed description that follow. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]      FIG. 1  is a perspective view of a helmet; 
           [0010]      FIG. 2  is a side view of the helmet of  FIG. 1 ; 
           [0011]      FIG. 3  is a front view of the helmet of  FIG. 1  showing the sectional line for  FIG. 4 ; 
           [0012]      FIG. 4  is a sectional view of the helmet of  FIG. 3 ; and 
           [0013]      FIG. 5  is a close up sectional view of the helmet of  FIG. 4 . 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0014]    All references cited herein are incorporated by reference to the maximum extent allowable by law. To the extent a reference may not be fully incorporated herein, it is incorporated by reference for background purposes and indicative of the knowledge of one of ordinary skill in the art. 
         [0015]    In the following detailed description of the preferred embodiments, reference is made to the accompanying drawings that form a part hereof, and in which is shown by way of illustration specific preferred embodiments in which the invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention, and it is understood that other embodiments may be utilized and that logical mechanical and electrical changes may be made without departing from the spirit or scope of the invention. To avoid detail not necessary to enable those skilled in the art to practice the invention, the description may omit certain information known to those skilled in the art. The following detailed description is, therefore, not to be taken in a limiting sense, and the scope of the present invention is defined only by the appended claims. 
         [0016]      FIG. 1  is a perspective view of a helmet  10  having an outer shell  12  and an inner shell  14  connected to each other by a plurality of discrete elastomeric elements  16 . The elastomeric elements  16  are only partially viewable in this view as they extend through the outer shell  12 . Outer shell  12  and inner shell  14  are both made of relatively stiff plastics such as polycarbonates or other materials with similar stiffness and toughness, including mixtures of different materials and layers of different materials combined into a single shell. If a helmet  10  has a chinstrap  18  then chinstrap  18  will be secured to inner shell  14 , not outer shell  12 . 
         [0017]      FIG. 2  is a side view of the helmet  10  of  FIG. 1  showing the profile of outer shell  12  and a layout of elastomeric elements  16 . If a helmet  10  has a facemask  20  or visor  22  then facemask  20  or visor  22  will be attached to outer shell  12 . Other optional equipment attached to the helmet will be attached to the outer shell  12  unless the optional equipment is intended to touch a head, such as the chinstrap  18  or pads  24 , shown in  FIG. 3   
         [0018]      FIG. 3  is a front view of the helmet of  FIG. 1  showing the sectional line for  FIG. 4 . Various optional aspects of the helmet are shown from this view such as those attached to the inner shell  14  like the pads  24  and chinstrap  18 . 
         [0019]      FIG. 4  is a sectional view of the helmet  10  of  FIG. 3  more clearly showing an inside view of helmet  10  and inner shell  14  in particular. Elastomeric elements  16  are shown extending through inner shell  14 . 
         [0020]      FIG. 5  is a close up sectional view of the helmet  10  of  FIG. 4  to show the relationship between elastomeric elements  16  and inner shell  14  and outer shell  12 . Both inner shell  14  and outer shell  12  have bore holes  26  placed in a pattern such that when inner shell  14  is placed within outer shell  12  the bore holes substantially align. Each borehole  26  has a recess  28 . For outer shell  12  the recess  28  is on an outer surface  36  while for inner shell  14  the recess  28  is on an inner surface  38 . 
         [0021]    Elastomeric elements  16  are comprised of a body  30 , shanks  32  extending from the body  30 , and heads  34  attached to shanks  32 . Body  30  sits between outer shell  12  and inner shell  14 , while shanks  32  extend through boreholes  26  in inner shell  14  and outer shell  12 . Heads  34  are shaped to fit recesses  28  in the outer surface  36  of outer shell  12  and inner surface  38  of inner shell  14 . Elements  16  are made of elastomeric materials such as urethane, silicone, or other material with similar elastomeric properties, including mixtures of materials or combinations of materials within the same elastomeric element. The elements  16  are placed in aligning boreholes  26  to secure inner shell  14  within outer shell  12  and provide an elastic connection between inner shell  14  and outer shell  12  that allows outer shell  12  to rotate relative to inner shell  14  as well as absorb shocks applied to outer shell  12  so that they are not fully transmitted to inner shell  14 . 
         [0022]    As shown on one element  16  in both  FIG. 4  and  FIG. 5  an element  16  may have placement strands  40 . Placement strands  40  may be cast into elastomeric element  16  when element  16  is formed. Placement strands  40  may be made of suitable wire, chord, string or twine. If the placement strands  40  are cast in the elastomeric elements  16  when they are formed, the strands  40  should be made of a material with a higher melting temperature than the material used in the elastomeric elements  16 . Placements strands  40  are used to align the elastomeric elements  16  with bore holes  26  when locating the inner shell  14  within the outer shell  12 . For example, elastomeric elements  16  may have one end fitted to bore holes  26  in the inner shell  14  and then placement strands  40  would be threaded through the corresponding bore holes  26  in outer shell  12 . As inner shell  14  is moved into place near outer shell  12  the placement strands  40  may be pulled to align each elastomeric element  16  with its corresponding bore hole in outer shell  12 . Once the elastomeric elements  16  are aligned with bore holes  26  in outer shell  12  the placement strands may be used to pull each elastomeric element  16  into engagement with its corresponding bore hole in outer shell  12 , by pulling the heads  34  through the bore hole  26  to rest in the recess  28 . Placement strands may extend from just one end of the elastomeric elements or from both ends to allow for adjustment if an elastomeric element  16  is pulled too hard during placement. After placement the placement strands  40  may be removed from the elastomeric elements  16 , typically by trimming them off with scissors or a razor blade. 
         [0023]    Other methods for placement may be used for elastomeric elements  16 , but placement strands  40  are one placement method that can be done by hand. 
         [0024]    Even thought he embodiment shown in this application is in a sports helmet with several optional features the basic concept is easily applicable to military helmets, construction helmets, safety helmets, and other helmet applications. Also, the basic concept may be used in helmets with less of the optional features, such as a football helmet with no visor. 
         [0025]    It should be apparent from the foregoing that an invention having significant advantages has been provided. While the invention is shown in only a few of its forms, it is not just limited but is susceptible to various changes and modifications without departing from the spirit thereof.