Abstract:
An improved protective helmet having an outer impact receiving shell, and inner protective shell and an intermediate piston interposed between the outer and inner shells which allows the inner shell to decelerate gradually when the outer shell is subjected to a sudden impact, and which, therefore, permits the brain to decelerate safely.

Description:
FIELD OF INVENTION 
       [0001]    This invention relates to helmets and is particularly directed to improved protective helmets for absorbing concussive forces encountered during sports events, motor ear racing, construction work and the like. 
       PRIOR ART 
       [0002]    It is well known that serious and sometimes fatal head injuries are often sustained by persons engaged in activities, such as sports events, motor car racing, construction work and the like. Accordingly, it is common practice to require protective helmets for persons engaging in such activities. The prior art protective helmets seek to negate impact forces by absorbing or deflecting the majority of the impact. However, the prior art protective helmets miss the critical mechanism for brain injury. It is not the impact, but the sudden deceleration which causes brain injuries. This is the difference between laying your head on a pillow and laying it on a brick. The brick causes instant deceleration, whereas the pillow allows gradual deceleration. Unfortunately, none of the prior art protective helmets provide for gradual deceleration. Thus, none of the prior art protective helmets have been entirety satisfactory. 
       BRIEF SUMMARY AND OBJECTS OF INVENTION 
       [0003]    These disadvantages of the prior art are overcome with the present invention and an improved protective helmet is provided which allows gradual deceleration of the head in response to a sudden impact, thereby allowing the brain to decelerate safely. 
         [0004]    These advantages of the present invention are preferably attained by providing an improved protective helmet having an outer impact receiving shell, and inner protective shell and an intermediate piston interposed between the outer and inner shells which allows the inner shell to decelerate gradually when the outer shell is subjected to a sudden impact, and which, therefore, permits the brain to decelerate safely. 
         [0005]    Accordingly it is an object of the present invention to provide an improved protective helmet. 
         [0006]    Another object of the present invention is to provide an improved protective helmet allows gradual deceleration of the head in response to a sudden impact. 
         [0007]    An additional object of the present invention is to provide an improved protective helmet is provided which allows gradual deceleration of the head in response to a sudden impact, thereby allowing the brain to decelerate safely. 
         [0008]    A specific object of the present invention is to provide an improved protective helmet having in outer impact receiving shell, and inner protective shell and an intermediate piston interposed between the outer and inner shells which allows the inner shell to decelerate gradually when the outer shell is subjected to a sudden impact, and which, therefore, permits the brain to decelerate safely. 
         [0009]    These and other objects and features of the present invention will be apparent from the following detailed description, taken with reference to the accompanying drawing. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWING 
         [0010]      FIG. 1  is a side view of a protective helmet embodying the present invention; 
           [0011]      FIG. 2  is a vertical section through the protective helmet of  FIG. 1 ; and 
           [0012]      FIG. 3  is a diagrammatic representation showing how the helmet of  FIG. 1  reacts to a sudden impulse. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0013]    In that form of the present invention chosen for purposes of illustration,  FIGS. 1 and 2  show a protective helmet, indicated generally at  10 , having a generally spherical outer shell  12  formed of rigid material and having an opening  14  to permit entry and removal of a wearer&#39;s head and to provide visibility when the helmet is worn. A generally spherical inner shell  16  formed of rigid or semi-rigid material and a generally spherical piston  18  are located within the outer shell  12  and are freely and independently movable in any direction within the outer shell  12 . Resilient means, such as springs  20  and  22 , serve to maintain the inner shell  16  and piston  18  in generally centered positions within the outer shell  12 . Motion-retarding means, such as brake pads  24  and  26  are mounted between the outer shell  12  and the piston  18  to retard relative movement between the outer shell  12  and piston  18 , while additional motion-retarding means, such as brake pads  28  and  30 , are mounted between the piston  18  and the inner shell  16  and serve to retard relative movement between the piston  18  and the inner shell  16 . The pads of braking material  24 ,  26 ,  28  and  30  may be formed of material similar to the pads used in automotive brake systems. Also, preferably, the motion-retarding means  28  and  30  are off-set from the motion-retarding means  24  and  26  to cause shocks to the outer shell  12  to be delivered indirectly to the inner shell  16 . The outer shell  12  is provided with generally L-shaped end pieces  32 , which serve to retain the piston  18  and inner shell  16  within the outer shell  12 . Finally, padding  34  is provided on the inner shell  16  to provide additional cushioning and to comfortably lit the helmet  10  to the wearer&#39;s head. 
         [0014]    In use, when a sudden impact is delivered to the protective helmet  10 , it tends to drive the outer shell  12  in the direction of the impact, as indicated by arrow  36  in  FIG. 3 . Initially, inertia will cause the piston  18  to remain stationary, as indicated by the dashed portion of arrow  38  in  FIG. 3  However, shortly after the impact, the force of the impact will be transmitted through the brake pads  24  and  26  to cause the piston  18  to also move in the direction of the impact, as seen by the solid portion of arrow  38 . However since the brake pads  24  and  26  allow some movement therebetween, the force of the impact which is delivered to the piston  18  will be significantly diminished. Also, the force from the outer shell  12  must travel some distance through the piston  18  in order to reach brake pads  28  and, hence, to be delivered through brake pads  28  and  30  to the inner shell  16 . This further diminishes the force which is delivered to the inner shell  16 . Similarly, when the piston begins to move, the inner shell  16  will, initially, remain stationary, as indicated by the dashed portion of arrow  40  in  FIG. 3 , until the force of the impact is delivered through brake pads  28  and  30  to cause the inner shell  16  to also move in the direction of the impact, as seen by the solid portion of arrow  40 . Again, since the brake pads  28  and  30  allow some movement therebetween, the force of the impact which is delivered from the piston  18  to the inner shell  16  will be further diminished. Finally, the padding  34  will further reduce the force of the initial impact which is delivered to the wearer&#39;s head. Thus, the force of the initial impact is retarded and reduced between the outer shell  12  and tie piston  18  and is further retarded and reduced between the piston  18  and the inner shell  16  and is still further reduced by the padding  34  before being delivered to the wearer&#39;s head. This greatly reduces the effect of the impact and serves to protect the wearer&#39;s head from concussion and other such injuries. 
         [0015]    If desired, radio earphones or the like may be mounted within the inner shell  18 . Moreover, numerous variations other variations and modification can obviously be made without departing from the spirit of the present invention. Therefore, it should be dearly understood that the forms of the present invention described above and shown in the figures of the accompanying drawing are illustrative only and are not intended to limit the scope of the present invention.