Abstract:
A portable helmet is disclosed that provides a level of protection at least comparable to conventional non-portable helmets, with the added function of being quickly portable for storage and transport. The helmet includes a series of interlocking curved wedges that can be rotated along pivot-points located on a center support. Wedges to the front of the center support rotate along a front pivot-point, while wedges to the rear of the center support rotate along a rear pivot-point. The curved wedges rotate to nest under the center support when in the closed position and form a wearable helmet when rotated into the extended position.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims the benefit of U.S. Provisional Application No. 61/087,542, filed Aug. 8, 2008, incorporated by reference herein in its entirety. 
     
    
     BACKGROUND 
       [0002]    As construction techniques become ever-more efficient, travel among jobsites by workers from the field-level, as well as the engineering- and management-levels, has become increasing frequent. While most large contractors keep an onsite supply of cheap hard hats to give out to short-term visitors, these hard hats are not always available, leading many workers to enter jobsites without proper head protection. 
         [0003]    Currently, the hard hat industry is largely divided between cheaper “throw away” hard hats that are quickly discarded and seldom moved from site to site, and more expensive “specialty hats” that have more aesthetically appealing designs. These specialty hats are typically well cared for by their owners, but they share the common trait of being bulky and difficult to transport. As such, the specialty hats are often left at a central location and not taken to infrequently-visited jobsites. 
         [0004]    An aesthetically appealing, portable hard hat would solve the problem of easy transport, encourage specialty hat owners to carry their hats with them, and reduce the wasteful use of “throw away” hard hats. 
       SUMMARY 
       [0005]    This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This summary is not intended to identify key features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter. 
         [0006]    In one aspect, a portable helmet is provided, the portable helmet comprising: a center support defining a forward pivot axis and a rearward pivot axis; a plurality of front curved wedges attached to the center support to pivot about the forward pivot axis such that the front curved wedges are pivotable between an extended position wherein the front curved wedges define a front portion of the helmet and a closed position wherein the front curved wedges nest under the central support; a plurality of rear curved wedges attached to the center support to pivot about the rearward pivot axis such that the rear curved wedges are pivotable between an extended position wherein the rear curved wedges define a rear portion of the helmet and a closed position wherein the rear curved wedges nest under the central support; and means for locking the front and rear curved wedges in the extended position. 
         [0007]    In another aspect, a portable helmet is provided, the portable helmet comprising: a center support defining a forward pivot axis and a rearward pivot axis; a plurality of front curved wedges attached to the center support to pivot about the forward pivot axis such that the front curved wedges are pivotable between an extended position wherein the front curved wedges define a front portion of the helmet and a closed position wherein the front curved wedges nest under the central support; a plurality of rear curved wedges attached to the center support to pivot about the rearward pivot axis such that the rear curved wedges are pivotable between an extended position wherein the rear curved wedges define a rear portion of the helmet and a closed position wherein the rear curved wedges nest under the central support; and a clasp for locking the front and rear curved wedges in the extended position, formed between adjacent wedges. 
         [0008]    In another aspect, a portable helmet is provided, the portable helmet comprising: a center support defining a forward pivot axis and a rearward pivot axis; a plurality of front curved wedges attached to the center support to pivot about the forward pivot axis such that the front curved wedges are pivotable between an extended position wherein the front curved wedges define a front portion of the helmet and a closed position wherein the front curved wedges nest under the central support; a plurality of rear curved wedges attached to the center support to pivot about the rearward pivot axis such that the rear curved wedges are pivotable between an extended position wherein the rear curved wedges define a rear portion of the helmet and a closed position wherein the rear curved wedges nest under the central support; and a fastener tab attached to the center support and fastener holes on each individual front and rear curved wedge to accommodate insertion of the fastener tab only when all wedges are fully extended or closed. 
     
    
     
       DESCRIPTION OF THE DRAWINGS 
         [0009]    The foregoing aspects and many of the attendant advantages of this invention will become more readily appreciated as the same become better understood by reference to the following detailed description, when taken in conjunction with the accompanying drawings, wherein: 
           [0010]      FIG. 1  shows a perspective side-view of a helmet in accordance with the present invention in its deployed form, ready to be worn; 
           [0011]      FIG. 2  shows a fragmentary side-view of the helmet shown in  FIG. 1 , including a representative tab-based fastening system with the hat in its deployed form and the fasteners open; 
           [0012]      FIG. 3  shows a perspective side-view of the tab-based fastening system of the helmet shown in  FIG. 1 , with the helmet in its closed form and tabs open; 
           [0013]      FIG. 4  shows a fragmentary interior-view of the tab-based fastening system of the helmet shown in  FIG. 1 , with the fasteners closed; 
           [0014]      FIG. 5  shows an inverted view of the helmet shown in  FIG. 1 , in its closed form; 
           [0015]      FIG. 6  shows a perspective side-view of an embodiment of the helmet in accordance with the present invention that includes fully-exposed alignment ridges; 
           [0016]      FIG. 7  shows a perspective side-view of the helmet in one embodiment which includes semi-recessed ridges, and includes a ventilation gap between wedges; 
           [0017]      FIG. 8  shows an interior view of a representative fastening system that includes a Z clasp that locks adjacent wedges to one another; 
           [0018]      FIG. 9  shows cross-sectional view of the Z clasp mechanism illustrated in  FIG. 8 ; 
           [0019]      FIG. 10  shows a side-view of the inner headgear, or lining; 
           [0020]      FIG. 11  shows a perspective view of the inner headgear as seen from above; 
           [0021]      FIG. 12  shows a side-view of the inner headgear with the helmet superimposed over it; 
           [0022]      FIG. 13  shows a side-view of the inner headgear with arrows showing the direction of collapse, with the helmet superimposed over it; 
           [0023]      FIG. 14  shows a side view of the inner headgear in its closed form, with the helmet superimposed over it; and 
           [0024]      FIG. 15  shows the inner headgear installed into the helmet, as seen from above. 
           [0025]      FIG. 16  is a side view of one embodiment of the provided helmet that does not have tabs as a fastening system but instead employs interlocking clasps or friction to immobilize the wedges in the fully-deployed position; 
           [0026]      FIG. 17  is an underside view of the helmet of  FIG. 17 ; 
           [0027]      FIG. 18  is a transparent side view of a helmet similar to that illustrated in  FIG. 17  when in a fully-stowed position; 
           [0028]      FIG. 19  is a detail perspective view of an interlocking clasp, prior to clasping, useful in the embodiments described herein; 
           [0029]      FIG. 20  is a detail perspective view of the interlocking clasp shown in  FIG. 19 , yet advanced further towards clasping; and 
           [0030]      FIG. 21  is a detail perspective view of the interlocking clasp shown in  FIGS. 19 and 20 , advanced to a clasped position. 
       
    
    
     DETAILED DESCRIPTION 
       [0031]    In one aspect, a portable helmet is provided, the portable helmet comprising: a center support defining a forward pivot axis and a rearward pivot axis; a plurality of front curved wedges attached to the center support to pivot about the forward pivot axis such that the front curved wedges are pivotable between an extended position wherein the front curved wedges define a front portion of the helmet and a closed position wherein the front curved wedges nest under the central support; a plurality of rear curved wedges attached to the center support to pivot about the rearward pivot axis such that the rear curved wedges are pivotable between an extended position wherein the rear curved wedges define a rear portion of the helmet and a closed position wherein the rear curved wedges nest under the central support; and means for locking the front and rear curved wedges in the extended position. 
         [0032]    The present invention is a helmet (also referred to herein as a “hard hat”), comprising a series of curved wedges, as shown in the multiple views of an embodiment illustrated in  FIGS. 1-6 . The wedges extend laterally across the width of the helmet and attach at a pair of oppositely-disposed pivot points on the central support  102  ( FIG. 4  illustrates two pivot points  132  and  134 , as will be described below). The wedges rotationally stow under, or extend and deploy from beneath, the center support  102  (also referred to herein as a “central wedge”). 
         [0033]    The wedges rotate about pivot points (e.g.,  120  and  126 ) that come in pairs (the paired pivot points to  132  and  134  are not illustrated) that are typically transversely located on the latitudinal sides of the center support  102 . In the embodiment illustrated in  FIG. 1 , two pairs of pivot points are illustrated: wedges  104 ,  106 ,  108 , and  110  pivot around a front pivot point  132  and wedges  112 ,  114 , and  116  pivot around a rear pivot point  134  (e.g.,  FIG. 3 ). The wedges can expand to form a protective helmet (e.g.,  FIG. 1 ), or collapse into a folded configuration.  FIG. 1  shows the helmet in its fully expanded (“deployed”) form, ready to wear by a user. The center support  102  provides the housing into which all of the other wedges can collapse and nest. 
         [0034]    As each wedge locks during expansion, or mates, with the wedge(s) next to it, the wedge immediately tangential to a given wedge is considered its “mating wedge.” As described herein, wedges  104 ,  106 ,  108 , and  110  comprise the front wedges, while wedges  112 ,  114 , and  116  comprise the rear wedges. As the center support  102  is located in the center of the helmet  100 , all front and rear wedges are progressively lower in profile than the center support  102 , creating downward connections and preventing liquid from above from leaking into the helmet. 
         [0035]    The front wedges  104 ,  106 ,  108 , and  110  rotate about a forward pivot axis created by the pair of pivot points (e.g.,  132  and its paired, oppositely-disposed pivot point). Similarly, the rear wedges  112 ,  114 , and  116  rotate about a rear pivot axis created by a pair of pivot points (e.g., rear pivot point  134  and its paired, oppositely-disposed pivot point). 
         [0036]    The front pivot point is shown as  132  and the rear pivot point is shown as  134 .  FIG. 4  has been illustrated to make these pivot points highly visible for illustrative purposes. In one embodiment of the invention, the lynchpins (not illustrated) upon which the wedges rotate at said pivot points are ultrasonically welded in place, making them nearly invisible. 
         [0037]    Means for locking the front and rear curved wedges are provided. Such means are also referred to as a “fastening system” herein. Representative locking means include friction between wedges, a fastener tab system, a clasp system between wedges, and combinations thereof. 
         [0038]    A representative fastening system is the fastener tab system  118  that includes fastener tabs  122  and  124 , housed in a molded housing, that are sized and configured to insert into holes  120  and  126  that pass through openings in each wedge when the wedges are fully stowed or fully deployed so as to secure the helmet  100  in the desired position. Parts  120  and  122  comprise a front fastening system, while  124  and  126  comprise a rear fastening system. In one embodiment the space between the front tab  122 , and the rear tab  124 , in the housing  118  contains an insert tab for accepting a visor or face protection accessory (not illustrated). 
         [0039]    To prevent any possibility of improper use, the tab fastening system  118 , is designed so that locking the fasteners is only achievable when all of the wedges are in their properly expanded (or, optionally, contracted) form.  FIG. 2  shows the helmet in its expanded form, ready to be locked. Accordingly,  120  and  126  show fastener-holes that properly align to allow the fastening tabs,  122  and  124 , to push into place. Conversely,  FIG. 3  shows the helmet in its closed form, where the fastener-holes  120  and  126  do not align, preventing insertion of the fastener tabs  122  and  124 . In one embodiment, each fastener-hole (e.g.,  120 ) is progressively sized, with the center support  102 , containing the largest fastener-hole. In this embodiment, wedges  110  and  112  have fastener-holes of equal size, slightly smaller than the fastener-hole in the center support  102 . Wedges  108  and  114  again have faster-holes of equal size, slightly smaller than the fastener holes in  110  and  112 . This continues progressively so that  104  and  116  have the smallest fastener-holes, again of equal size. Accordingly, the fasteners  122  and  124  are tapered so that when inserted into the properly aligned fastener-holes the tapered stalk of the fastener fits snugly against each hole in each progressive wedge. In this embodiment, both  122  and  124 , the tapered fastener-tabs, have a split-squeeze design with an ellipse-head at the end. The head is squeezed together during insertion, temporarily making a transverse dimension of the head smaller and allowing the tab to slide into place through all of the wedges. After passing through the final front wedge and back wedge,  104  and  116 , respectively, the tabs are free to expand, locking themselves into place, as shown in  FIG. 4 . The tabs can therefore only be released by removing the helmet from the head and squeezing while simultaneously pushing the tabs outward from the interior. The considerable gap between the outer shell and the inner headgear prevents any chance of accidentally bumping the fasteners during use. 
         [0040]    As shown in  FIG. 1  the tab fastening system  118 , allows the fasteners  122  and  124  to insert into the holes and fit flush against the side of the helmet  100  when fully expanded, avoiding any chance for protrusions to snag on debris, disproportionately absorb impact, or otherwise compromise the structural integrity or safety of the helmet. 
         [0041]    In closed form (e.g.,  FIG. 3 ), the wedges abut against each other and are immobilized by a fastening system. Representative fastening systems, as previously mentioned, include friction between the wedges, the above-described tab mechanism  118 , or a tab stop  420 , illustrated in  FIG. 18 . 
         [0042]    In one embodiment, the fastening system is a Z clasp  170  locking mechanism, as shown in  FIGS. 8 and 9 . Z clasps are known to those of skill in the art and will not be described in further detail. 
         [0043]    In one embodiment, the locking system is an interlocking clasp  510 , as illustrated in  FIGS. 19-21 . The interlocking clasp  510  includes an upper clasp portion comprising an upper tab  512  and an upper notch  516  formed on an upper ridge  518  of an upper wedge  502  of a helmet  500 . The interlocking clasp  510  also includes a lower clasp portion comprising a lower tab  514  and a lower ridge  520 . The interlocking clasp  510  is shown in a closed position in  FIG. 21  such that the lower wedge  504  is prevented from extending further because the lower tab  514  will be impeded by the upper tab  512 . Additionally, when clasped, the lower wedge  504  is prevented from collapsing into the upper wedge  502  because the lower ridge  520 , disposed within the upper notch  516  will be impeded by the upper ridge  518 . The illustrated interlocking clasp  510  is released with upward pressure on the upper wedge  502  such that the upper wedge  502  and lower wedge  504  are sufficiently separated such that the interlocking clasp  510  is disabled. 
         [0044]      FIG. 5  shows an inverted interior view of an embodiment of the helmet in its closed form. 
         [0045]    In one embodiment, the wedges are formed with overhead interlocking ridgelines  142  to mitigate lateral torque and add overall structural stability, as shown in  FIG. 6 . The ridge design instills additional structural strength in the event of an overhead or side impact, and also aids in aligning the wedges during collapsing and expanding of the helmet  100 . 
         [0046]    In one embodiment the ridges are fully exposed, as shown in  FIG. 6 . In another embodiment the ridges  162  are semi-recessed, as shown in  FIG. 7 . Recessing the ridges  162  in this embodiment is possible because the rotational access of each individual wedge is tighter then the curve of the overall fully-expanded helmet  100 . Thus, each wedge begins to pull away from its mating wedge(s) during collapse towards the stowed position. The recess angle for the ridges follows the curve of each individual wedge as it pivots towards the closed form. 
         [0047]    The helmet  100  of  FIG. 7  includes a ventilation gap  164 . 
         [0048]    In one embodiment, the center support can be split such that the helmet includes a first center support, and a second center support, each with at least one pair of pivot points. 
         [0049]    In one embodiment, the helmet further comprises a portable inner headgear  200  attached to the helmet  100 , the inner headgear  200  being sized and configured to directly engage a user&#39;s head. The inner headgear  200 , or lining, is designed to collapse and expand along with the outer shell. Attaching and detaching the inner headgear  200  on traditional hard hats is time-consuming, and it can be reasonably assumed that extra setup time to affix the lining would prove inconvenient enough to discourage users from collapsing and expanding after each use, thus functionally negating the primary utility of a portable hard hat.  FIG. 10  shows a side view of the inner headgear  200  in its expanded form. Pivot points  185  and  187  on the inner headgear align with the pivot points  132  and  134  in the outer shell of the helmet. During use, the rear portion of the inner headgear  184  and  186 , will protrude slightly beyond the outer shell to aid stability and effectively keep the helmet  100  on the user&#39;s head. Part  184  is the ratcheting section, while  188  is the ratcheting handle. Turning the handle  188  clockwise will pull the rear section  186  to tighten, while turning the handle  188  counter-clockwise will cause it to loosen. Users may adjust the hat in this way to fit the exact size of their heads. Unlike traditional hard hat inner headgear, the angle of the rear portion  186  and  188 , can be adjusted by the user for comfort. Additionally, the rear portion  184  and  188 , can be pivoted  180  degrees inward during collapse to avoid protrusion. 
         [0050]    The front section of the inner headgear  200  is shown as  180 , the middle section as  182 , and the upper-rear is shown as  184 . These pieces have mirror duplicates on the opposite side of the inner headgear. Each of these pieces will attach individually to the inside wall of the outer shall through insert tabs. 
         [0051]    A fully inserted inner headgear system with the outer shell of the helmet superimposed on top is shown in  FIG. 12 .  FIG. 13  further illustrates the collapse motion through arrows and shading. Lightly shaded pieces are in the closed position, while arrows show the pivot direction, starting from the expanded position.  FIG. 14  shows the inner headgear in the fully closed position with the helmet superimposed on the top. The ratchet handle  188  is protruding. 
         [0052]    A flexible strap system  189  is attached to insert tabs (one of which is shown as  202 ) so that the straps bisect the helmet and intersect at the crown. In one embodiment this flexible strap system is VERSAFLEX®, or a similar rubber-based substance, which is a substitute for traditional nylon straps that does not tend to retain odor, does not tend to discolor from sweat, and is gentler to the touch. In another embodiment this strap system is nylon. 
         [0053]      FIG. 11  shows the complete inner headgear  200 , as seen from above. Insert tabs, such as  202 , are placed at the endpoints of the flexible strap system  189 . In  FIG. 10 , part  183  is a location for attaching the flexible strap system  189  to the inner headgear  200 . The corresponding insertion slot is part of the molded design of the inside wall of the outer shell in each wedge that accepts inner headgear insertion tabs. 
         [0054]      FIG. 15  shows the inner headgear inserted into the helmet, as seen from below. Insert slots are molded into the inner side of the outer shell at the endpoint of each strap in the flexible strap system, and insert tabs are attached to each end of the corresponding strap to fit into the insert slots. 
         [0055]    When in the closed position (e.g.,  FIGS. 3 and 18 ), the helmet is at its most compact, and the dimensions of the helmet substantially match those of the center support (e.g.,  102 ). The compact dimensions facilitate the portability of the helmet. 
         [0056]      FIGS. 16-18  illustrate various views of an embodiment of the invention that does not use a tab-based fastening system, but instead relies on friction between the wedges or an interlocking clasp system for immobilization of the helmet in a closed or expanded position. Referring to  FIG. 16 , a side view of a helmet  300  is illustrated in an expanded position. The helmet  300  includes a center support  302 , front wedges  311  (individually,  304 ,  306 ,  308 , and  310 ), and rear wedges  317  (individually,  312 ,  314 , and  316 ). Referring to  FIG. 17 , a bottom view of the helmet  300  is illustrated, with the bottom side of the front and rear wedges shown. Additionally, ridges  330  on the underside of the wedges and center support  302  are illustrated. As described previously, ridges can be included to provide torsional, longitudinal, and lateral stability to the helmet  300 . Additionally, illustrated in  FIG. 17  are the attachment points between the wedges and the center support  302 . The attachment assembly  320  includes, in this illustrated representative embodiment, a pin  322  passing through (at a pivot point) the three wedges  312 ,  314 ,  316  (the combination of the three at the pivot point being labeled as part  324 ). 
         [0057]      FIGS. 16 and 17  additionally illustrate the interface between the center support  302  and front wedge  310  at an interface location marked  318 . At the interface between the center support  302  and a wedge (e.g.,  310 ) or between wedges (e.g.,  310  and  308 ), a means for locking the mating pieces together is provided. Representative examples of this locking means include friction, or an interlocking clasp system, as described above. In the embodiment illustrated in  FIGS. 16-18 , friction is used as the locking means, as no interlocking clasp system is illustrated. 
         [0058]    Referring to  FIG. 18 , the helmet  400  is illustrated in closed form (e.g., the helmet  300  of  FIGS. 16 and 17  closed) such that the center wedge  402  has nested within it the front and rear wedges  404 ,  406 ,  408 ,  410 ,  412 ,  414 , and  416 . The width of the center wedge  402  is approximately equal to the width of the entire helmet  400  in the closed position. Additionally illustrated in  FIG. 18  is a lock tab  420  that provides a rotational stopping point for the front and rear wedges. In the embodiment illustrated in  FIG. 18 , the front wedges  406 ,  408 , and  410  rotate on front pivot point  425  and each wedge includes a notch  422  (numbered collectively for all wedges) and the rear wedges rotate on a rear pivot point  425  and include a rear notch  424  (collectively labeled for wedges  312 ,  314 , and  316 ). When the wedges rotate toward the closed position, the notches  422  and  424  on the wedges prevent the wedges from traveling further toward the closed position when they abut the locking tab  420 . The locking tab  420  may additionally provide friction at the notches  422  and  424  that prevents the wedges from opening unless force is applied by the user. In one embodiment, the interface between the locking tab  420  and the notches  422  and  424  is a Z clasp. 
         [0059]    In one embodiment, the front and rear curved wedges are sufficiently hard to protect a wearer from above impacts. 
         [0060]    In one embodiment, the front and rear curved wedges are not electrically conductive. 
         [0061]    In one embodiment, the front and rear curved wedges are sufficiently hard to protect a wearer from above impacts. 
         [0062]    In one embodiment, wherein the front and rear curved wedges are not electrically conductive. 
         [0063]    In one embodiment, the front and rear curved wedges are plastic. 
         [0064]    In one embodiment, the helmet is made primarily out of ABS plastic (acrylonitrile butadiene styrene) which is hard enough to resist side or overhead impact. For head-protection purposes, the most important mechanical properties of ABS are resistance and toughness. A variety of modifications can be made to improve impact resistance, toughness, and heat resistance. The impact resistance can be amplified by increasing the proportions of polybutadiene in relation to styrene and acrylonitrile. Impact resistance does not fall off rapidly at lower temperatures, making it ideal for the hard hat application. Stability under load is excellent with limited loads. ABS is not an electrical conduit. 
         [0065]    In one embodiment, the plastic comprises a polycarbonate. Polycarbonate plastic is derived from bisphenol A. Polycarbonate is a very durable material, and can be laminated to make bullet-resistant glass or other material. Polycarbonate plastic is electrically non-conductive. 
         [0066]    In one embodiment, the front and rear curved wedges are fiberglass. Fiberglass is comprised of glass fibers which are useful because of their high ratio of surface area to weight. Fiberglass is electrically non-conductive. 
         [0067]    In another aspect, a portable helmet is provided having a clasp locking system, the portable helmet comprising: a center support defining a forward pivot axis and a rearward pivot axis; a plurality of front curved wedges attached to the center support to pivot about the forward pivot axis such that the front curved wedges are pivotable between an extended position wherein the front curved wedges define a front portion of the helmet and a closed position wherein the front curved wedges nest under the central support; a plurality of rear curved wedges attached to the center support to pivot about the rearward pivot axis such that the rear curved wedges are pivotable between an extended position wherein the rear curved wedges define a rear portion of the helmet and a closed position wherein the rear curved wedges nest under the central support; and a clasp for locking the front and rear curved wedges in the extended position, formed between adjacent wedges. 
         [0068]    In another aspect, a portable helmet is provided having a tab-based locking system, the portable helmet comprising: a center support defining a forward pivot axis and a rearward pivot axis; a plurality of front curved wedges attached to the center support to pivot about the forward pivot axis such that the front curved wedges are pivotable between an extended position wherein the front curved wedges define a front portion of the helmet and a closed position wherein the front curved wedges nest under the central support; a plurality of rear curved wedges attached to the center support to pivot about the rearward pivot axis such that the rear curved wedges are pivotable between an extended position wherein the rear curved wedges define a rear portion of the helmet and a closed position wherein the rear curved wedges nest under the central support; and a fastener tab attached to the center support and fastener holes on each individual front and rear curved wedge to accommodate insertion of the fastener tab only when all wedges are fully extended or closed. 
         [0069]    While illustrative embodiments have been illustrated and described, it will be appreciated that various changes can be made therein without departing from the spirit and scope of the invention.