Abstract:
An improved headband provides adjustment to fit the shape and size of the wearer&#39;s head as well as stand-off from the inner surface of the helmet shell. When the wearer&#39;s head is fitted properly in the headband, the headband desirably resists displacement toward the helmet shell in all directions.

Description:
RELATED APPLICATION  
       [0001]     The present application claims priority to, and the benefits of, U.S. Ser. No. 60/662,063, filed Mar. 15, 2005, the entire disclosure of which is hereby incorporated by reference. 
     
    
     FIELD OF THE INVENTION  
       [0002]     This invention relates to safety helmets, in particular a headband for adjusting and securing the helmet to a wearer&#39;s head.  
       BACKGROUND OF THE INVENTION  
       [0003]     Helmets for head protection are worn in a variety of environments and for various purposes. Protective helmets generally have a spherically shaped rigid outer shell which covers the head and is secured to the user&#39;s head by means of a flexible chin strap. Various approaches have been used to adapt helmets to fit the variety of head shapes and sizes of different users. One such approach is to suspend a flexible headband within the interior of the helmet and provide a way to adjust the girth of the band to fit the user&#39;s head. While this approach adapts easily to different head shapes and sizes, it cannot absorb impact energy and therefore provides little protection against trauma, especially from the side of the helmet. Because of the importance of protecting the head against blunt trauma, recent refinements in helmets have replaced the headband with pads or a liner made of a compressible material, such as foam, situated between the user&#39;s head and the helmet shell. In these designs, however, it is difficult to provide both a comfortable and secure fit because low-density material, which has benefits with respect to comfort, allows the helmet to move too easily and provides less impact protection. Higher-density materials can absorb impact energy but do not adapt well to different head sizes and shapes. There remains a need, therefore, to fit a helmet to the user&#39;s head in a manner that is adjustable, comfortable, secure, stable, yet which provides protection against trauma.  
       SUMMARY OF THE INVENTION  
       [0004]     The present invention improves on conventional approaches to fitting a safety helmet by providing a flexible headband that can be adjusted to fit the shape and size of the wearer&#39;s head and which also provides stand-off from the inner surface of the helmet shell. The stand-off provides space within which impact-absorbing materials may be situated in order to absorb blunt impact energy.  
         [0005]     The headband generally comprises a flexible (e.g., plastic) band that may be fabricated as a thin, flat component which is curved into a circular shape by, for example, joining its ends together. In a preferred embodiment, the band is fabricated by injection molding to create and control the features described below, but alternative fabrication techniques as are well known in the art can also be used. The ends of the band are desirably joined at the back of the wearer&#39;s head in a manner that allows adjustment of the circumference of the headband. This may be accomplished, for example, by providing one or more tabs molded on one end which snap into any of two or more spaced slots in the other end, thereby providing multiple positions for joining the ends, each of which corresponds to a smaller or larger circumference for the headband. Other well-known means for adjusting the circumference of the headband, such as frictional engagement, hook-and-loop fasteners, clasps, etc., may also be used.  
         [0006]     The headband further comprises a plurality of connecting arms to facilitate joining the headband to the helmet shell at multiple positions. For example, in embodiments with four connecting arms, two are positioned on each side, one is in front and the other is in back. In a preferred embodiment the connecting arms are molded with thin bands oriented to provide bending lines, sometimes referred to as “living hinges.” These bending lines allow the arms to flex horizontally and vertically. Each connecting arm has an aperture for engaging a fastener to join the headband to the helmet shell. The connecting arm may, for example, be joined to the helmet using an anchor having an off-round (e.g., square or angular) post that allows the connecting arm to resist rotation. The connecting arm so connected is constrained to flex in a direction approximately perpendicular to the surface of the helmet shell. When at least two of the connecting points are oriented so that the directions of flexure intersect at a point inside the diameter of the circular headband, the headband resists displacement toward the helmet shell.  
         [0007]     As noted above, impact liner materials may be to be placed in the top of the helmet and optionally in the space between the headband and the helmet shell. Softer “comfort” pads may be positioned between the impact liner and the wearer&#39;s head to provide a cushioned surface in contact with the wearer&#39;s head. The positional security provided by the improved headband of the present invention means that the impact liner and comfort pads need not play a significant role in the fit or retention of the helmet. This allows greater choice of materials and shapes than is the case with helmets that rely on the energy absorbing materials to also provide positional security.  
         [0008]     Accordingly, in a first aspect, the invention comprises an interior head-retention element for use in connection with a safety helmet. The retention element comprises an adjustable-size headband for engaging a wearer&#39;s head, and a plurality of stand-off attachment elements, disposed about the headband, for facilitating spaced-apart attachment of the headband to the helmet. The stand-off elements yieldably resist movement of the helmet toward the wearer&#39;s head. The resistance is yieldable in the sense that impact energy is at least partially absorbed rather than transmitting the energy, through excessive resistance, to the wearer.  
         [0009]     In preferred embodiments, the stand-off attachment elements each comprise a generally U-shaped member. For example, as described above, each U-shaped member may be folded over a plurality of bending lines that accommodate at least horizontal, and desirably some vertical flexure. The stand-off attachment elements desirably have directions of horizontal flexure that intersect within the headband.  
         [0010]     In another aspect, the invention comprises a helmet incorporating the head-retention element described above. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0011]     In the drawings, like reference characters generally refer to the same parts throughout the different views. Also, the drawings are not necessarily to scale, emphasis instead generally being placed upon illustrating the principles of the invention. In the following description, various embodiments of the present invention are described with reference to the following drawings, in which:  
         [0012]      FIG. 1  is a front elevational view of a user with safety helmet in place;  
         [0013]      FIG. 2  is a cross-section of the safety helmet shown in  FIG. 1 , taken along the line  2 - 2 ;  
         [0014]      FIG. 3  is a cross-section of the safety helmet shown in  FIG. 1 , taken along the line  3 - 3 ;  
         [0015]      FIG. 4  is a perspective view of the headband of the present invention removed from the helmet; and  
         [0016]      FIG. 5  is an exploded view of a portion of the headband and other components of a helmet retention system. 
     
    
     DETAILED DESCRIPTION  
       [0017]     With reference to  FIGS. 1 and 2 , a helmet  10  is shown secured to the wearer&#39;s head by a pair of flexible straps  13   a ,  13   b  secured to the helmet  10  by respective screws  15   a ,  15   b . The flexible straps  13   a ,  13   b  at the front of the helmet join with straps  13   c ,  13   d  from the back of the helmet and are secured at the chin by means of a flexible strap  16 , which scoops beneath and may cup the chin. A detachable buckle comprising a male component  19   a  and a female component  19   b  may be used to secure the straps. When the buckle is detached, separating the components  19   a ,  19   b , the chin strap  13  is released, allowing the wearer to remove the helmet  10 .  
         [0018]     With reference to  FIG. 2 , which shows the helmet from the right side of the wearer (including an outline of the wearer&#39;s head for reference), the left half of the headband  22  of the present invention is shown secured at the front left side of the helmet  10  by a screw  15   b , and at the back left side by another screw  15   c . An impact-absorbing liner  28  may be positioned between the wearer&#39;s head and the helmet shell  10 . The impact liner can be formed from conventional materials such as expanded polypropylene (EPP), expanded polyethylene (EPE), expanded polystyrene (EPS), or visco-elastic foam. Other impact-absorbing structures taught in U.S. Pat. Nos. 6,777,062 and 6,032,300 may also be used to advantage.  
         [0019]     Softer pads (representatively shown at  31   a ,  31   b ,  31   c ) may be positioned between the wearer&#39;s head and the impact material  28  to provide a cushioned surface in contact with the wearer&#39;s head. By way of example, such comfort pads may be made from urethane foam or EVA foam.  
         [0020]      FIG. 3  shows the headband  22  of present invention attached to the helmet shell  10  by a pair of screws  15   a ,  15   b  in front and another pair of screws  15   c ,  15   d  in back. The impact liner  28  and the comfort pads  31   a - 31   e  are positioned at the top of the helmet.  
         [0021]      FIG. 4  shows the headband  22  removed from the helmet. The headband is preferably fabricated from a flexible plastic such as nylon or polypropylene and molded as a flat band that may be curved into a circular shape with the narrowed end  34   a  passing through a slot  35  in the other end  34   b  to join the two ends of the headband at the back of the wearer&#39;s head. Headband end  34   a  is molded with tabs (not shown) sized and spaced appropriately to match a series of slots  36  formed in headband end  34   b . Providing more slots  36  than tabs in the headband allows the wearer to select from multiple positions for joining the ends  34   a ,  34   b , each position corresponding to a smaller or larger circumference for the headband, thus allowing the wearer to select a position that is comfortable yet secure.  
         [0022]     The headband  22  further has a pair of front connecting arms  37   a ,  37   b  and a pair of rear connecting arms  40   a ,  40   b . The connecting arms  37  may be shaped to have preferred bending lines or “living hinges” (as indicated, for example, at  43   a ,  43   b ), which allow the corresponding arm  37  to be bent approximately 90 degrees (e.g., from vertical to horizontal), and another set of bending lines (as indicated, for example, at  46   a ,  46   b ) which allow the corresponding arm  37  to be bent approximately a further 90 degrees (e.g., from horizontal to vertical) to join the headband  22  to the helmet shell.  
         [0023]     As best seen in  FIG. 5 , the connecting arm  37   b  is joined through a hole  49  to the helmet shell  10  in the manner explained below, thereby allowing the connecting arm  37   b  to resist rotation. The headband  22  so connected is able to flex a small amount vertically, which brings the wearer&#39;s head into contact with the comfort pads  31  (see  FIG. 3 ). In the horizontal plane, the headband  22  flexes only in the direction shown by the arrows in  FIG. 4 , i.e., approximately perpendicular to the shell at the points where the headband is joined to the shell. It is desirable that no two connecting arms have directions of flexure that are substantially parallel; in a headband configuration with four connecting arms, for example, the opposing arms are oriented so that the directions of flexure are not aligned with one another. In the preferred embodiment, at least two such connecting points are oriented so that the directions of flexure intersect at a point within the contour defined by the headband. This helps the headband resist displacement toward the helmet shell, keeping the wearer&#39;s head centered and therefore providing space for impact absorption.  
         [0024]      FIG. 5  illustrates details of an exemplary mode of attaching connecting arm  37   b  to the helmet shell  10 ; connecting arms  37   a ,  40   a  and  40   b  have the same assembly components. The headband  22  is mounted to the shell  10  by passing the post  52  of an anchor  55  through hole  49  in the connecting arm  37   b , and also through the hole  58  in the helmet shell  10 , then securing it using the screw  15   b . The off-round (e.g., polygonal—square, for exmaple—or angular) shape of the post  52  and the matching shape of the hole  49  allow the connecting arm to resist rotation within the hole  49 . The anchor  55  may also include a contour  61  formed to match a complementary recession  64  molded into the connecting arm  37   b  to further aid in resisting rotation.  
         [0025]     The attachment of the energy absorbing liner  28  to the helmet shell  10  may be accomplished by providing a tab  67  having a hole  70  therethrough. The tab  67  may be formed directly as part of the liner  28  if a material such as polypropylene is used for the liner  28 , or co-molded if a softer material such as EPE is used. The attachment is made by passing the anchor post  52  through hole  70 , thereby capturing the tab  67  between the connecting arm  37   b  and the helmet shell  10 . A chin-strap component may be attached to the anchor  55  by passing the strap  13   b  through slot  73 . A comfort band  76  made of a soft material, such as compressible urethane or EVA foam, may be added on the side of the headband  22  facing the wearer&#39;s head and secured using, for example, hook-and-loop fasteners to improve comfort.  
         [0026]     Having described certain embodiments of the invention, it will be apparent to those of ordinary skill in the art that other embodiments incorporating the concepts disclosed herein may be used without departing from the spirit and scope of the invention. The described embodiments are to be considered in all respects as only illustrative and not restrictive.