Abstract:
A head-protective helmet comprising a geodesic dome. A further feature is the geodesic dome in combination with other elements providing a head-protective helmet.

Description:
BACKGROUND OF THE INVENTION 
     This invention relates to a head-protective helmet including a geodesic dome. Further, this invention relates to a geodesic dome in combination with other elements comprising a head-protective helmet. 
     Numerous head-protective helmets are known to the art, such as, by way of example and not by way of limitation, firefighters, helmets, industrial helmets (sometimes referred to as hard hats), fighter pilot helmets, and other military helmets. 
     An example of a firefighter&#39;s head-protective helmet is disclosed in U.S. Pat. No. 5,044,016 entitled PROTECTIVE HELMET ASSEMBLY INCLUDING RELEASABLE HEAD RETAINING ASSEMBLY, patented Sep. 3, 1991, Christopher E. Coombs, inventor. This patent is assigned to the same assignee as the present application, and this patent is hereby incorporated herein by reference as if fully reproduced herein. FIGS. 1 and 2 of this incorporated patent are reproduced herein as FIGS. 1 and 2. Referring to FIG. 1, the head-protective helmet is indicated by general numerical designation  10  and includes an outer shell  12 , sometimes referred to as the hard shell, an attenuation liner assembly  14 , a brim  16  circumscribing the outer shell  12 , a pivotally mounted transparent visor  18 , a chin strap  22  including a chin cup  24 . The attenuation liner assembly  14 , FIG. 2, includes a non-resilient foam liner  26 , sometimes referred to as an inner impact cap, frictionally fitted within the outer shell  12 , with the exterior of the foam liner  26  corresponding to the interior surface of the outer shell  12 . The foam liner or inner impact cap  26  is retained frictionally within the outer shell  12  with such frictional retention being augmented by the cooperating patches of hook and loop fastener material generally indicated as  40  in FIG.  1 . The non-resilient foam liner  26 , or inner impact cap, is for absorbing force or energy applied to the helmet  10  by being compressed which attenuates force or energy that would otherwise be transferred to the head of the wearer of the helmet upon, for example, a falling object striking the head-protective helmet  10 . The outer shell  12  typically is made of a hard plastic such as a suitable high temperature thermoset which may be filled with glass or other fibers for increased strength, and the inner impact cap  26  typically is made of a suitable non-resilient or compressible material such as, for example, rigid polyurethane foam. 
     While the head-protective helmets known to the art, such as the firefighter&#39;s helmet disclosed in the incorporated patent and shown in FIG. 1, have worked well for their intended purpose, there still exists a need in the head-protective helmet art for a head-protective helmet providing increased protection against force or energy that would be applied to the head of the helmet wearer, such as by falling objects. Also there is a further need in the head-protective helmet art for a head-protective helmet providing increased resistance against a falling object penetrating the helmet and striking the head of a wearer of the helmet. 
     SUMMARY OF THE INVENTION 
     It is the object of the present invention to satisfy the foregoing need in the art. 
     A head-protective helmet satisfying such need and embodying the present invention is a head-protective helmet comprising a geodesic dome. A further feature of the present invention is the geodesic dome in combination with other elements comprising a head-protective helmet. 
    
    
     DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a side view of a prior art firefighter&#39;s head-protective helmet; 
     FIG. 2 is an enlarged cross-sectional view taken generally along the line II—II in FIG. 1 in the direction of the arrows; 
     FIG. 3 is a side view of a head-protective helmet of the present invention embodying a geodesic dome; 
     FIG. 3A is an enlarged cross-sectional view taken generally along the line  3 — 3  in FIG. 3 in the direction of the arrows; 
     FIG. 4 is a perspective view of an octagonal geodesic dome having a frequency of 4; 
     FIG. 5 is a perspective view of an octagonal geodesic dome having a frequency of 6; 
     FIG. 6 is a perspective view of an octagonal geodesic dome having a frequency of 8; 
     FIG. 7 is an enlarged view of a portion of FIG. 6; 
     FIG. 8 is a perspective view of the geodesic dome of FIG. 5 showing its length and width; 
     FIG. 9 is a cross-sectional view of the geodesic dome shown in FIGS. 5 and 8 showing its height; 
     FIG. 10 is a diagrammatical illustration of the three planes of symmetry of the geodesic dome shown in FIGS. 5 and 8; 
     FIG. 11 is a perspective view of the geodesic dome shown in FIGS. 5 and 8 and illustrating the symmetry of the hemispherical quadrants or sectors; 
     FIG. 12 is a perspective diagrammatical illustration of an alternate embodiment of the geodesic dome of the present invention; 
     FIGS. 13-16 are diagrammatical, generally transverse cross-sectional views, of further alternate embodiments of the head-protective helmet of the present invention embodying one or more geodesic domes; 
     FIG. 17 is a diagrammatical illustration of an alternate embodiment of the head-protective helmet of the present invention embodying vertically stacked geodesic domes; 
     FIG. 18 is an enlarged partial diagrammatical view showing detailed structure of the stacked geodesic domes shown in FIG. 17; 
     FIGS. 19-21 are diagrammatical illustrations of still further alternate embodiments of the head-protective helmet of the present invention embodying one or more geodesic domes; and 
     FIG. 22 is a cross-sectional view showing a geodesic dome molded interiorly of an inner impact cap of a head-protective helmet embodying the present invention. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The present invention will be described in the context of a firefighter&#39;s head-protective helmet, but it will be understood that such is merely by way of illustration and not by way of limitation and that the present invention is capable of being embodied in other head-protective helmets known to the art. 
     Referring to FIG. 3, there is shown a firefighter&#39;s head-protective helmet embodying the present invention which is indicated by general numerical designation  50 . The firefighter&#39;s helmet  50  includes a geodesic dome  52  and may include the brim  16 , visor  18 , and chin strap and chin cup  24  shown in FIG.  1  and described in the Background of the Invention. 
     Geodesic domes, such as geodesic dome  52  in FIG. 3, are one-half, or hemispheres, of geodesic spheres. Geodesic spheres are three dimensional polyhedrons having repeating geodesic patterns. For example, an octagonal geodesic sphere has eight repeating sectors or quadrants. A hemisphere, or one-half, of a geodesic sphere is referred to or defined in the context of the geodesic sphere of which it comprises a half or a hemisphere, and hence a hemisphere, or one-half, of an octagonal geodesic sphere is referred to as an octagonal geodesic dome even though it only comprises four, not eight, of the repeating sectors or quadrants. In addition to being defined geometrically, geodesic domes are also defined in terms of a frequency. Frequency refers to the number of pieces that each edge of the base figure, of the geodesic pattern, is divided into in the process of triangulating its sides. Triangulation means the process of subdividing a triangle into smaller triangles. 
     Referring to FIG. 4, there is shown an octagonal geodesic dome indicated by general numerical designation  54  which has a frequency of 4, with the 4 edges defining the frequency being identified in FIG. 4 by numerical designations 1-4. Shown in FIG. 5 is an octagonal geodesic dome indicated by general numerical designation  56  and which dome has a frequency of 6 with the 6 edges of the dome defining such frequency being identified by numerical designations  1 - 6 . FIG. 6 illustrates an octagonal geodesic dome identified by general numerical designation  58  and which dome has a frequency of 8 with its 8 edges defining such frequency being identified in FIG. 6 by numerical designations 1-8. The geodesic dome  52  shown in FIG. 3 comprising the firefighter&#39;s head-protective helmet  50  is an octagonal geodesic dome having a frequency of 6 the same as the geodesic dome  56  shown in FIG.  5 . As will be understood from FIG. 7, an enlarged portion of FIG. 5, the geodesic patterns are defined by a vertex  60 , edges  61 - 66  and faces or facets  67 - 72 . The geodesic domes of the present invention may be made of polycarbonate, and may be made by suitable molding techniques known to the art. 
     Geodesic dome  52  from FIG. 3 is shown separately in FIGS. 8 and 9 and is illustrated diagrammatically in FIG.  10 . From FIGS. 8 and 9, it will be understood that the geodesic dome  52  has a length L and a width W. From FIG. 9, it will be understood that the geodesic dome  52  has a height H. It will be further understood from FIGS. 8 and 9 that the length L is greater than the width W and the width W is greater than the height H. Accordingly, it will be understood from these FIGS. that the geodesic dome  52  is an oblate hemispherical geodesic dome. 
     From FIG. 10, it will be understood that the geodesic dome  52  has a major axis  75  along its maximum length, a first minor or secondary axis  77  along its maximum width, and a second minor or tertiary axis  79  along its maximum height. 
     Referring to FIG. 11, it will be understood that the geodesic dome  52  is comprised of four spherically shaped, or hemispherical, quadrants or sectors S1, S2, S3 and S4. The dome  52  has three planes of symmetry. The first plane of symmetry, indicated in FIG. 11 by general designation P1 extends along the length of the dome and is indicated by the lines  81 ,  82  and  83 . The second plane of symmetry, indicated in FIG. 11 by general designation P2, extends through the maximum width of the dome  52  as indicated by lines  84 ,  85  and  86 , and the third plane of symmetry, indicated in FIG. 11 by general designation  13 , extends through or is coincident with the bottom edge of the dome  52  and is illustrated in FIG. 11 by lines  87 ,  88  and  89 . It will be noted from FIG. 11 that the sectors S1 and S4 are symmetrical with respect to sectors S2 and S3 and with respect to the plane of symmetry indicated by lines  81 ,  82  and  83 . Sectors S1 and S2 are symmetrical with respect to sectors S3 and S4 and with respect to the plane of symmetry indicated by lines  84 ,  85  and  86 . The sectors S1, S2, S3 and S4 are symmetrical with respect to each other and with respect to the planes indicated by lines  87 ,  88  and  89 . Accordingly, from FIG. 10 it will be understood that the geodesic dome  52  is an oblate hemispherical geodesic dome having respective unequal major, minor and tertiary axes  74 ,  77  and  79 , and from FIG. 11 it will be understood that the oblate hemispherical geodesic dome  52  has three planes of symmetry P1, P2 and P3. 
     Another embodiment of the geodesic dome which may comprise the head-protective helmet of the present invention is illustrated in FIG.  12  and identified by general numerical designation  90 . Geodesic dome  90  includes a central portion  92 , a first annular portion  93  generally concentric with and surrounding the central portion  92 , and a second annular portion  94  formed generally concentrically with and surrounding the first annular portion  93 ; the portions  92 ,  93  and  94  are formed integrally such as by molding. In this embodiment, the central portion  92  and the annular portions  93  and  94  may each be of a different geodesic dome pattern and frequency. For example, the central portion  92  may be comprised of the central portion of the octagonal geodesic dome  54  shown in FIG. 4 having a frequency of 4, the first annular portion  93  may be comprised of an annular portion of the octagonal geodesic dome  56  shown in FIG. 5 having a frequency of 6 and the second annular portion  94  may be comprised of an annular portion of the octagonal geodesic dome  58  shown in FIG. 6 having a frequency of 8. 
     Further alternate embodiments of the head-protective helmet of the present invention, which may be embodied as a firefighter&#39;s head-protective helmet, are shown respectively in FIGS. 13-16. In these FIGS., the outer shell  12  and inner impact cap  26  shown respectively in FIGS. 1 and 2 are illustrated diagrammatically and given the same numerical designations. The head-protective helmet shown in FIG. 13 is indicated by general numerical designation  100  and in addition to the outer shell  12  and inner impact cap  26 , this head-protective helmet includes a geodesic dome which may be the geodesic dome  56  shown in FIG.  5  and described above. The geodesic dome  56  is indicated diagrammatically by the irregular line in FIG.  13  and is identified by numerical designation  56 ; the geodesic dome  56  resides interiorly of the inner impact cap  26 . Geodesic dome  56  may be mounted releasably to the inner impact cap  26  by cooperating pairs of patches of hook and loop material illustrated diagrammatically in FIG.  13  and identified by pairs of numerical designations  101  and  102  and  104  and  105 . 
     The alternate embodiment of the head-protective helmet of the present invention illustrated in FIG. 14 is identified by general numerical designation  108  and includes the outer shell  12 , inner impact cap  26  which includes an outer surface  109  to which a geodesic dome, such as the geodesic dome  56  of FIG. 5, is suitably mounted; geodesic dome  56  is illustrated diagrammatically in FIG. 14 by the irregular line identified by numerical designation  56 . Upon, for example, the inner impact cap  26  being made of a high temperature polyurethane foam, and upon the geodesic dome  56  being made of polycarbonate, geodesic dome  56  may be bonded to the outer surface of the inner impact cap  26  by a suitable adhesive known to the art for bonding plastic parts together. 
     A still further alternate embodiment of the head-protective helmet of the present invention is illustrated diagrammatically in FIG.  15  and is indicated by general numerical designation  110 . The helmet  110  includes the outer shell  12 , inner impact cap  26 , and a geodesic dome which may be the geodesic dome  56  shown in FIG. 5 which is illustrated diagrammatically in FIG. 15 by the irregular line identified by numerical designation  56 . Geodesic dome  56  is suitably mounted to the inner surface  112  of the inner impact cap  26 . Upon the inner impact cap  14  being made of high temperature polyurethane foam and upon the geodesic dome  56  being made of polycarbonate, the geodesic dome  56  may be bonded to the inner impact cap  26  by a suitable adhesive known to the art for bonding plastic parts together. 
     A still further alternate embodiment of the head-protective helmet of the present invention is illustrated in FIG.  16  and indicated by general numerical designation  116 . Helmet  116  includes the outer shell  12 , inner impact cap  26  having an outer surface  116  to which a geodesic dome  56  is suitably mounted and an inner surface  118  to which a second geodesic dome  56  is suitably mounted; the geodesic domes  56  are indicated diagrammatically in FIG. 16 by the irregular lines and each may be, for example, the geodesic dome  56  shown in FIG.  5 . As with regard to the helmet embodiments  108  and  110  illustrated respectively in FIGS. 14 and 15, upon the inner impact cap  26  being made of high temperature polyurethane foam and the geodesic domes  56  being made of polycarbonate, the domes may be bonded to the inner impact cap  26  by a suitable adhesive known to the art for bonding plastic parts together. 
     A further embodiment of a geodesic dome, a composite geodesic dome, which may comprise a head-protective helmet of the present invention is illustrated diagrammatically in FIG.  17  and indicated by general numerical designation  120 . Composite geodesic dome  120  includes a first or innermost geodesic dome  121 , an outermost geodesic dome  122 , and an intermediate geodesic dome  123 ; although only one intermediate geodesic dome  123  is shown in FIG. 17, it will be understood that in accordance with the teachings of the present invention a plurality of intermediate geodesic domes may be utilized. It will be understood from FIG. 18 that the geodesic domes  121 ,  122  and  123  comprising the composite geodesic dome  120  are stacked and spaced apart and that such geodesic domes increase in size outwardly from the innermost geodesic dome to the outermost geodesic dome. These geodesic domes may be each a geodesic dome, but of different size, of the types disclosed in FIGS. 5,  6  and  6  and described above. The bottom edges of the geodesic domes  121 ,  122  and  123  reside generally in a common plane and are bonded together and upon such geodesic domes being made of polycarbonate, it will be understood that their bottom edges are bonded together with a common bonding material of the type known to the art for bonding plastic parts together. Portions of the geodesic domes  121 ,  122  and  123  shown in FIG. 18 are shown in FIG.  19 . It will be understood that in accordance with the further teachings of the present invention these stacked geodesic domes may be stacked such that the vertices of each geodesic dome are aligned with the faces of the next adjacent geodesic dome. This provides the composite geodesic dome  120  with further force and penetration resistance. More particularly, it will be noted from FIG. 18 that the vertices V1, V2 and V3 of geodesic dome  123  are aligned or oppose the faces F1, F2 and F3 of adjacent geodesic dome  122  and that the vertices V6, V7 and V8 of geodesic dome  121  are opposite the faces F6, F7 and F8 of adjacent geodesic dome  123 . 
     Still further alternate embodiments of the head-protective helmets of the present invention which may be embodied as a firefighter&#39;s head-protective helmet are illustrated diagrammatically in FIGS. 19,  20  and  21  and identified, respectively, by general numerical designations  130 ,  140  and  150 . The head-protective helmets illustrated in these FIGS. comprise the shell  12  from FIG. 1 with the shell  12  being shown in these FIGS. diagrammatically and identified by numerical designation  12 . In FIG. 19, the shell  12  of the head-protective helmet  130  includes an outer surface  132  to which a geodesic dome  56  is bonded. The geodesic dome is illustrated diagrammatically by the irregular line in FIG.  20  and may be, for example, the geodesic dome  56  shown in FIG.  5  and described above. The shell  12  of the head-protective helmet  140  of FIG. 20 includes an inner surface  142  to which a geodesic dome, such as geodesic dome  56  of FIG. 5, is suitably mounted. In the head-protective helmet  150  illustrated in FIG. 22, includes the shell  12  includes an outer surface  152  and an inner surface  154  and geodesic domes  56  are bonded to both the outer surface  152  and the inner surface  154 . These geodesic domes may be the geodesic dome  56  illustrated in FIG.  5  and are so identified in FIG.  21 . Upon the shell  12  shown in FIGS. 20-22 being made of a high temperature polycarbonate and upon the geodesic domes  56  being made of polycarbonate, the geodesic domes  56  may be bonded to the respective inner and outer surfaces of the shell  12  by suitable bonding agents known to the art for bonding plastic parts together. The shells  12  shown in FIGS. 18-20 may be provided with a visor and chin strap such as the visor  18  and chin strap  22  shown in FIGS. 1 and 2. 
     Referring now to FIG. 22, a further embodiment of the head-protective helmet of the present invention is illustrated including the outer shell  12  and an inner impact cap  26  which is molded around a geodesic dome such as the geodesic dome  56  shown in FIG.  5 . The inner impact cap  26 , as noted above, may be molded from high temperature polyurethane foam and in accordance with the teachings of the present invention such impact cap  26  may be molded around the geodesic dome  52  to provide the inner impact cap with increased resistance to force and penetration. 
     Referring to FIG. 3A, it will be understood that the geodesic dome  52  of the invention embodiment illustrated in FIG. 3 may include an outer surface  160  having a geodesic dome pattern indicated by general numerical designation  161  molded thereon and an inner surface  162  having the same geodesic dome pattern molded therein and indicated by general numerical designation  163 . The geodesic dome  52 , as noted above, may be made of molded high temperature polycarbonate, and the geodesic dome pattern  161  molded in the outer surface  160  may be molded thereon by embossing providing a raised geodesic dome pattern  163  and the geodesic dome pattern molded into the inner surface  162  may be molded therein by intaglio to provide the inner surface  162  with the geodesic dome pattern in relief or indentation. 
     Referring again to the head-protective helmet embodiment of the present invention illustrated in FIGS. 3,  17 , and  19 - 21 , it will be understood that such head-protective helmet embodiments may include an inner impact cap such as the inner impact cap  26  shown in FIG.  2  and suitable head mounting components for mounting such helmets to the head of the helmet wearer and which head mounting components may be, for example, the cradle  28  of a plurality of web straps  30  and an adjustable head band  32  including the sweat band  34  shown in FIG.  2 . It will be still further understood that the head-protective helmet embodiments of the present invention illustrated in FIGS. 13-16 and  22  may be provided with suitable components for mounting such helmets to the head of a helmet wearer such as, for example, the cradle  28  of the plurality of web straps  30  and the adjustable head band  32  including the sweat band  34  shown in FIG.  2 . 
     It will be understood that the head-protective helmet of the present invention embodying a geodesic dome provides improved protection to the head of a wearer of the helmet against force or energy applied to the helmet, such as by a falling object striking the helmet, and provides improved protection against such falling object penetrating the helmet. 
     It will be understood by those skilled in the art that many modifications and variations may be made in the present invention without departing from the spirit and the scope thereof.