Abstract:
A protective helmet including an outer shell including at least one aperture, an elastomeric diaphragm connected to an inner surface of the outer shell and covering the at least one aperture, an inner shell slidingly connected to the outer shell where the inner shell is spaced apart from the outer shell, and at least one expandable bladder positioned between the outer shell and the inner shell and operatively arranged to displace the elastomeric diaphragm in the at least one aperture of the outer shell.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is filed under 35 U.S.C. §120 as a continuation of U.S. patent application Ser. No. 13/412,782, filed Mar. 6, 2012, which application is hereby incorporated by reference in its entirety. 
     
    
     FIELD 
       [0002]    The invention relates generally to a protective helmet, and, more particularly, to a protective helmet that directs linear and rotational forces away from the braincase, the protective helmet including an expandable bladder. 
       BACKGROUND 
       [0003]    The human brain is an exceedingly delicate structure protected by a series of envelopes to shield it from injury. The innermost layer, the pia mater, covers the surface of the brain. The arachnoid layer, adjacent to the pia mater, is a spidery web-like membrane that acts like a waterproof membrane. Finally, the dura mater, a tough leather-like layer, covers the arachnoid layer and adheres to the bones of the skull. 
         [0004]    While this structure protects against penetrating trauma, the softer inner layers absorb only a small amount of energy before linear forces applied to the head are transmitted to the brain. When an object strikes a human head, both the object and the human head are moving independently and in different angles thus, angular forces, as well as linear forces, are almost always involved in head injuries. While the skull may dampen some linear forces applied to the head, it does not mitigate the effects of angular forces that impart rotational spin to the head. Many surgeons in the field believe the angular or rotational forces applied to the brain are more hazardous than direct linear forces due to the twisting or shear forces they apply to the white matter tracts and the brain stem. 
         [0005]    One type of brain injury that occurs frequently is the mild traumatic brain injury (MTBI), more commonly known as a concussion. Such injury occurs in many settings, such as, construction worksites, manufacturing sites, and athletic endeavors and is particularly problematic in contact sports. While at one time a concussion was viewed as a trivial and reversible brain injury, it has become apparent that repetitive concussions, even without loss of consciousness, are serious deleterious events that contribute to debilitating irreversible diseases, such as, dementia and neuro-degenerative diseases including Parkinson&#39;s disease, chronic traumatic encephalopathy (CTE), and pugilistic dementias. 
         [0006]    U.S. Pat. No. 5,815,846 (Calonge) describes a helmet with fluid filled chambers that dissipate force by squeezing fluid into adjacent equalization pockets when external force is applied. In such a scenario, energy is dissipated only through viscous friction as fluid is restrictively transferred from one pocket to another. Energy dissipation in this scenario is inversely proportional to the size of the hole between the full pocket and the empty pocket. That is to say, the smaller the hole, the greater the energy drop. Unfortunately, as the size of the hole decreases and energy dissipation increases, the time to dissipate the energy also increases. Because fluid filled chambers react hydraulically, energy transfer is in essence instantaneous. Hence, in the Cologne design, substantial energy is transferred to the brain before viscous fluid can be displaced negating a large portion of the protective function provided by the fluid filled chambers. Viscous friction is too slow an energy dissipating modification to adequately mitigate concussive force. If one were to displace water from a squeeze bottle one can get an idea as to the function of time and force required to displace any fluid when the size of the exit hole is varied. The smaller the transit hole, the greater the force required and the longer the time required for any given force to displace fluid. 
         [0007]    U.S. Pat. No. 3,872,511 (Nichols) describes an impact absorbing covering for a helmet including hard inner and outer shells and an intermediate zone between the two shells. The intermediate zone contains fluid-filled bladders that are mounted to the inner surface of the outer shell by means of a valve. When an impact occurs, the outer shell is forced into the intermediate zone squeezing the bladders. The valve closes upon impact causing air to be retained in the bladders to cushion the impact from the user&#39;s head. However, since the bladders are restricted at impact, although the force of an impact is reduced, the force is still directed into the head. In addition, the &#39;511 patent makes no provision for mitigating rotational forces striking the helmet. 
         [0008]    U.S. Pat. No. 6,658,671 (Hoist) describes a helmet with inner and outer shells and a sliding layer. The sliding layer allows for the displacement of the outer shell relative to the inner shell to help dissipate some of the angular force during a collision applied to the helmet. However, the force dissipation is confined to the outer shell of the helmet. In addition, the Holst helmet provides no mechanism for returning the two shells to the resting position relative to each other. A similar shortcoming is seen in the helmet described in U.S. Pat. No. 5,956,777 (Popovich) and European patent publication EP 0048442 (Kalman et al.). 
         [0009]    German Patent DE 19544375 (Zhan) describes a construction helmet that includes apertures in the hard outer shell that allows the expansion of cushion material through the apertures to dispel some of the force of a collision. However, because the inner liner rests against a user&#39;s head, some force is directed toward rather than away from the head. 
         [0010]    U.S. Patent Application Publication No. 2012/0198604 (Weber et al.) describes a safety helmet for protecting the human head against repetitive impacts as well as moderate and severe impacts to reduce the likelihood of brain injury caused by both translational and rotational forces. The helmet includes isolation dampers that act to separate an outer liner from an inner liner. Gaps are provided between the ends of the outer liner and the inner liner to provide space to enable the outer liner to move without contacting the inner liner upon impact. 
         [0011]    Clearly to prevent traumatic brain injury, not only must penetrating objects be stopped, but any force, angular or linear, imparted to the exterior of the helmet must also be prevented from simply being transmitted to the enclosed skull and brain. The helmet must not merely play a passive role in dampening such external forces, but must play an active role in dissipating both linear and angular momentum imparted such that they have little or no deleterious effect on the delicate brain. 
         [0012]    To afford maximal protection from linear and angular forces, the skull and the brain must be capable of movement independent of each other, and to have mechanisms which dissipate imparted kinetic energy, regardless of the vector or vectors by which it is applied. 
         [0013]    To attain these objectives in a helmet design, the inner component (shell) and the outer component (shell or shells) must be capable of appreciable degrees of movement independent of each other. Additionally, the momentum imparted to the outer shell should both be directed away from and/or around the underlying inner shell and brain and sufficiently dissipated so as to negate deleterious effects. 
         [0014]    There is a long-felt need to provide a protective helmet that mitigates the deleterious consequences of repetitive traumatic brain injury. 
       SUMMARY 
       [0015]    According to aspects illustrated herein, there is a provided a protective helmet including an outer shell including at least one aperture, an elastomeric diaphragm connected to an inner surface of the outer shell and covering the at least one aperture, an inner shell slidingly connected to the outer shell where the inner shell is spaced apart from the outer shell, and at least one expandable bladder positioned between the outer shell and the inner shell and operatively arranged to displace the elastomeric diaphragm in the at least one aperture of the outer shell. 
         [0016]    In an example embodiment, the present invention includes a hard outer shell including apertures, a hard inner shell, a padded inner liner functionally attached to the hard inner shell, an intermediate shell contacting the padded inner liner and enclosing cushioning pieces, fluid-filled bladders positioned between the outer shell and the padded inner liner, and, elastomeric cords connecting the outer shell and the inner liner and passing through the intermediate shell. 
         [0017]    One object of the invention is to provide a helmet that directs linear and rotational forces away from the braincase. 
         [0018]    A second object of the invention is to supply a helmet that includes an outer shell that floats or is suspended above the inner shell. 
         [0019]    A third object of the invention is to offer a helmet with a sliding connection between the inner and outer shells. 
         [0020]    An additional object of the invention is to supply a helmet that includes a crumple zone to absorb forces before they reach the braincase of the user. 
     
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
         [0021]    The nature and mode of the operation of the present invention will now be more fully described in the following detailed description of the invention taken with the accompanying drawing Figures, in which: 
           [0022]      FIG. 1  is a front view of a double shell helmet (“helmet”) of the present invention; 
           [0023]      FIG. 2  is a side view of the helmet of  FIG. 1  including two face protection device attachments on one side of the helmet; 
           [0024]      FIG. 3A  is a cross-sectional view of the helmet of  FIG. 1  showing the inner shell and the elastomeric cords connecting the two shells; 
           [0025]      FIG. 3B  is a cross-sectional view of the helmet of  FIG. 1  including an intermediate shell enclosing cushioning pieces; 
           [0026]      FIG. 4A  is a fragmentary exploded view of the helmet of  FIG. 1  including part of a liftable lid that protects a diaphragm covering an aperture; 
           [0027]      FIG. 4B  is a fragmentary exploded view of the helmet of  FIG. 1  depicting a liftable lid protecting a bulging fluid-filled bladder; 
           [0028]      FIG. 5  is a fragmentary exploded view of a cord connecting the inner shell and outer shells of the helmet of  FIG. 1 ; and, 
           [0029]      FIG. 5A  is a cross-sectional view of a cord and plugs between the inner and outer shells of the helmet of  FIG. 1 . 
       
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
       [0030]    At the outset, it should be appreciated that like drawing numbers on different drawing views identify identical structural elements of the invention. It also should be appreciated that figure proportions and angles are not always to scale in order to clearly portray the attributes of the present invention. 
         [0031]    While the present invention is described with respect to what is presently considered to be the preferred embodiments, it is understood that the invention is not limited to the disclosed embodiments. The present invention is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. 
         [0032]    Furthermore, it is understood that this invention is not limited to the particular methodology, materials and modifications described and as such may, of course, vary. It is also understood that the terminology used herein is for the purpose of describing particular aspects only, and is not intended to limit the scope of the present invention, which is limited only by the appended claims. 
         [0033]    Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood to one of ordinary skill in the art to which this invention belongs. It should be appreciated that the term “substantially” is synonymous with terms such as “nearly”, “very nearly”, “about”, “approximately”, “around”, “bordering on”, “close to”, “essentially”, “in the neighborhood of”, “in the vicinity of”, etc., and such terms may be used interchangeably as appearing in the specification and claims. Although any methods, devices or materials similar or equivalent to those described herein can be used in the practice or testing of the invention, the preferred methods, devices, and materials are now described. It should be appreciated that the term “proximate” is synonymous with terms such as “nearby”, “close”, “adjacent”, “neighboring”, “immediate”, “adjoining”, etc., and such terms may be used interchangeably as appearing in the specification and claims. 
         [0034]    Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood to one of ordinary skill in the art to which this invention belongs. Although any methods, devices or materials similar or equivalent to those described herein can be used in the practice or testing of the invention, the preferred methods, devices, and materials are now described. 
         [0035]    In the present invention, a helmet is presented that includes multiple protective zones formed in layers over the user&#39;s skull or braincase. The outer protective zone is formed by an outer shell that “floats” or is suspended on the inner shell such that rotational force applied to the outer shell cause it to rotate, or translate around the inner shell rather than immediately transfer such rotational or translational force to the skull and brain. 
         [0036]    The inner shell and outer shell are connected to each other by elastomeric cords that serve to limit the rotation of the outer shell on the inner shell and to dissipate energy by virtue of elastic deformation rather than passively transferring rotational force to the brain as with existing helmets. In effect, these elastomeric cords function like mini bungee cords that dissipate both angular and linear forces through a mechanism known as hysteretic damping, i.e., when elastomeric cords are deformed, internal friction causes high energy losses to occur. These elastomeric cords are of particular value in preventing so called contrecoup brain injury. 
         [0037]    The outer shell, in turn, floats on the inner shell by virtue of one or more fluid filled bladders located between the inner shell and the outer shell. To maximize the instantaneous reduction or dissipation of a linear and/or angular force applied to the outer shell, the fluid filled bladders interposed between the hard inner and outer shells may be intimately associated with, that is, located under, one or more apertures in the outer shell with the apertures preferably being covered with elastomeric diaphragms and serving to dissipate energy by bulging outward against the elastomeric diaphragm whenever the outer shell is accelerated, by any force vector, toward the inner shell. Alternatively, the diaphragms are located internally between inner and outer shells, or at the inferior border of the inner and outer shells, if it is imperative to preserve surface continuity in the outer shell. This iteration would necessitate separation between adjacent bladders to allow adequate movement of associated diaphragms. 
         [0038]    In existing fluid filled designs, when the outer shell of a helmet receives a linear force that accelerates it toward the inner shell, the interposed gas or fluid is compressed and displaced. Because gas and especially fluid is not readily compressible, it passes the force passively to the inner shell and hence to the skull and the brain. This is indeed the very mechanism by which existing fluid filled helmets fail. The transfer of force is hydraulic and essentially instantaneous, negating the effectiveness of viscous fluid transfers as a means of dissipating concussive force. 
         [0039]    Because of the elastomeric diaphragms in the present invention, any force imparted to the outer shell will transfer to the gas or liquid in the bladders, which, in turn, instantaneously transfers the force to the external elastomeric diaphragms covering the apertures in the outer shell. The elastomeric diaphragms, in turn, bulge out through apertures in the outer shell, or at the inferior junction between inner and outer shells thereby dissipating the applied force through elastic deformation at the site of the diaphragm rather than passively transferring it to the padded lining of the inner shell. This process directs energy away from the brain and dissipates it via a combination of elastic deformation and tympanic resonance or oscillation. By oscillating, an elastic diaphragm employs the principle of hysteretic damping over and over, thereby maximizing the conversion of kinetic energy to low level heat, which, in turn, is dissipated harmlessly to the surrounding air. 
         [0040]    Furthermore, the elastomeric springs or cords that bridge the space holding the fluid filled bladders (like the arachnoid membrane in the brain) serve to stabilize the spatial relationship of the inner and outer shells and provide additional dissipation of concussive force via the same principle of elastic deformation via the mechanism of stretching, torsion, and even compression of the elastic cords. 
         [0041]    By combining the bridging effects of the elastic springs or cords as well as the elastomeric diaphragms strategically placed at external apertures, both linear and rotational forces can be effectively dissipated. 
         [0042]    Henceforth, my design, by employing elastomeric cords and diaphragms can protect against concussion as well as so-called coup and contrecoup brain injury and torsional brain injury which can cause subdural hematoma by tearing of bridging veins or injury to the brain stem through twisting of the stem about its central axis. 
         [0043]    Adverting to the drawings,  FIG. 1  is a front view of helmet  10  (“helmet  10 ”) including outer shell  12  and inner shell  20 . Outer shell  12  and is preferably manufactured from rigid, impact resistant materials such as metals, plastics, such as, polycarbonates, ceramics, composites and similar materials well known to those having ordinary skill in the art. Outer shell  12  defines at least one and preferably a plurality of apertures  14 . Apertures  14  may be open but, are preferably covered by a flexible elastomeric material in the form of diaphragm  16 . In a preferred embodiment, helmet  10  also includes several face protection device attachments  18   a,    18   b.  In a more preferred embodiment, face protection device attachments  18   a,    18   b  are fabricated from a flexible elastomeric material to provide flexibility to the attachment. The elastomeric material reduces the rotational pull on helmet  10  if the attached face protection device (not shown in  FIG. 1 ) is pulled. The term “elastomeric” means made of any substance resembling rubber in properties, such as resilience and flexibility. Such elastomeric materials are well known to those having ordinary skill in the art. 
         [0044]      FIG. 2  is a side view of helmet  10  showing two face protection device attachments  18   a  and  18   b  on one side of the helmet. Examples of face protection devices are visors and face masks. Such attachments can also be used for chin straps releasably attached to the helmet in a known manner. 
         [0045]      FIG. 3A  is a cross-sectional view of helmet  10  showing hard outer shell  12 , hard inner shell  20 , and elastomeric springs or cords  30  (“cords  30 ”) that extend through an elastomeric zone connecting the two shells. Inner shell  20  forms an anchor zone and is preferably manufactured from rigid, impact resistant materials such as metals, plastics, such as, polycarbonates, ceramics, composites and similar materials well known to those having ordinary skill in the art. Inner shell  20  and outer shell  12  are slidingly connected at sliding connection  22 . 
         [0046]    The term “slidingly connected” means that the edges of inner shell  20  and outer shell  12 , respectively, slide against or over each other at connection  22 . In an alternate embodiment, outer shell  12  and inner shell  20  are connected by an elastomeric element, for example, a u-shaped elastomeric connector  22   a  (“connector  22   a ”). Sliding connection  22  and connector  22   a  each serve to both dissipate energy and maintain the spatial relationship between outer shell  12  and inner shell  20 . 
         [0047]    Cords  30  are flexible cords, such as, bungee cords or elastic “hold down” cords or their equivalents used to hold articles on car or bike carriers. This flexibility allows outer shell  12  to move or “float” relative to inner shell  20  and still remain connected to inner shell  20 . This floating capability is also enabled by the sliding connection  22  between outer shell  12  and inner shell  20 . In an alternate embodiment, sliding connection  22  may also include elastomeric connection  22   a  between outer shell  12  and inner shell  20 . Padding  24  forms an inner zone and lines the inner surface of inner shell  20  to provide a comfortable material to support helmet  10  on the user&#39;s head. In one embodiment, padding  24  may enclose loose cushioning pieces, such as, STYROFOAM® brand beads  24   a  or “peanuts” or loose oatmeal. 
         [0048]      FIG. 3A  is also a cross-sectional view of bladders  40  situated in the elastomeric zone between outer shell  12  and inner shell  20 . Helmet  10  includes at least one and preferably a plurality of bladders  40 . Bladders  40  are filled with fluid, either a liquid such as water or a gas such as helium or air. In one preferred embodiment, the fluid is helium as it is light and its use would reduce the total weight of helmet  10 . In an alternate embodiment, bladders  40  may also include compressible beads or pieces such as STYROFOAM® brand beads. Bladders  40  are preferably located under apertures  14  of outer shell  12  and are in contact with both inner shell  20  and outer shell  12 . Thus, if outer shell  12  is pressed in toward inner shell  20  and the user&#39;s skull during a collision, the fluid in one or more of bladders  40  compresses and squeezes bladder  40 , similar to squeezing a balloon. Bladder  40  bulges toward aperture  14  and displaces elastomeric diaphragm  16 . This bulging-displacement action diverts the force of the blow from the user&#39;s skull and brain up toward the aperture providing a new direction for the force vector. Bladders  40  may also be divided internally into compartments  40   a  by bladder wall  41  such that if the integrity of one compartment is breached, the other compartment still functions to dissipate linear and rotational forces. Valve(s)  42  may also be included between the compartments to control the fluid movement. 
         [0049]      FIG. 3B  is a cross-sectional view similar to  FIG. 3A  discussed above depicting an alternate embodiment of helmet  10 . Helmet  10  in  FIG. 3B  includes a crumple zone formed by intermediate shell  50  located between outer shell  12  and inner shell  20 . In the embodiment shown, intermediate shell  50  is close to or adjacent to inner shell  20 . As seen in  FIG. 3B , intermediate shell  50  encloses filler  52 . Preferably, filler  52  is a compressible material that is packed to deflect the energy of a blow to protect the skull, similar to a “crumple zone” in a car. The filler is designed to crumple or deform, thereby absorbing the force of the collision before it reaches padding  24  and the brain case. In this embodiment, cords  30  extend from inner shell  20  to outer shell  12  through intermediate shell  50 . One suitable filler  52  is STYROFOAM® brand beads or “peanuts” or equivalent material, such as, any suitable material that is used in packing objects. Because of its “crumpling” function, intermediate shell  50  is preferably constructed with softer or more deformable materials than outer shell  12  or inner shell  20 . Typical fabrication material for intermediate shell  50  is a stretchable material such as latex or spandex or other similar elastomeric fabric that preferably encloses filler  52 . 
         [0050]      FIG. 4A  is a fragmentary exploded view of one section of outer shell  12  of helmet  10  including liftable lids  60  (“lid  60 ”) used to cover aperture  14  to shield diaphragm  16  and/or bladder  40  from punctures, rips, or similar incidents that may destroy their integrity. 
         [0051]      FIG. 4B  is a fragmentary exploded view of one section of outer shell  12  of helmet  10  including lid  60  covering aperture  14  and bladder  40 . Lids  60  are attached to outer shell  12  by lid connector  62  (“connector  62 ”) in such a way that they lift or raise up if a particular diaphragm  16  bulges outside of aperture  14  due to the expansion of one or more bladders  40 , exposing it to additional collisions. Because it is liftable, lid  60  allows diaphragm  16  to freely elastically bulge through aperture  14  above the surface of outer shell  12  to absorb the force of a collision, but still be protected from damage caused by external forces. In an alternate embodiment, diaphragm  16  is not used and lid  60  directly shields and protects bladder  40 . In one embodiment, lids  60  are attached to outer shell  12  using hinges. In an alternate embodiment, lids  60  are attached using flexible plastic. Elastomeric cords  30 , crumple zone  51 , and intermediate shell  50  are also shown. 
         [0052]      FIG. 5  is a fragmentary exploded view of cord  30  connecting inner and outer shells  12 ,  20  of helmet  10 . Cord  30  is attached to helmet  10  to enable outer shell  12  to float over inner shell  20 . Cavities  36 , preferably with concave sides  36   a,  are drilled or otherwise placed in outer shell  12  and inner shell  20  so that the holes are aligned. Each end of cord  30  is attached to plugs  32  which are then placed in the aligned holes. In one embodiment, plugs  32  are held in cavities  36  using suitable adhesives known to those having ordinary skill in the art. In an alternate embodiment, plugs  32  are held in cavities  36  with a friction fit or a snap fit. 
         [0053]      FIG. 5A  is a cross-sectional view of cord  30  and plugs  32  between inner and outer shells  12 ,  20  of helmet  10  in  FIG. 1 . Cord  30  is attached to two plugs  32 ,  32  and extends between outer shell  12  and inner shell  20 . Filler  52  of intermediate shell  50  is shown proximate inner shell  20 . Bladders  40  are not shown. In an embodiment including bladders  40 , the bladders would be disposed between intermediate shell  50  (or inner shell  20 ) and outer shell  12 . 
         [0054]    Thus it is seen that the objects of the invention are efficiently obtained, although changes and modifications to the invention should be readily apparent to those having ordinary skill in the art, which changes would not depart from the spirit and scope of the invention as claimed. 
       LIST OF REFERENCE NUMBERS 
       [0000]    
       
           10  Helmet 
           12  Outer shell 
           14  Aperture 
           16  Diaphragm 
           18  Attachment 
           20  Inner shell 
           22  Sliding connection 
           24  Padding 
           22   a  Connector 
           30  Cord 
           32  Plug 
           36  Cavity 
           36   a  Concave sides 
           40  Bladder 
           40   a  Compartments 
           41  Bladder wall 
           42  Valve 
           50  Intermediate shell 
           52  Filler 
           60  Lid 
           62  Lid connector