Abstract:
A helmet retention system having a first side strap system configured to connect to a first side of a helmet and a second side strap system configured to connect to an opposite second side of a helmet is provided. A chin cup and a chin cup connecting mechanism are provided. The chin cup connecting mechanism is configured to connect the first and second side strap systems in an area about the user&#39;s chin and to vary the amount of tension in the system between at least two predefined tension states. Strap adjusters provide a cam design for tensioning the straps and retaining the adjustors fixed to the straps at the desired adjustment under external force applied to the straps. Anchors provide secure mounting of the straps to the helmet.

Description:
[0001]    This application claims the benefit of U.S. Provisional Application Ser. No. 61/498,920 filed Jun. 20, 2011. 
     
    
     TECHNICAL FIELD OF THE INVENTION 
       [0002]    The present invention relates to systems for retaining a helmet to a user&#39;s head. 
       BACKGROUND OF THE INVENTION 
       [0003]    A number of protective and military helmets are known, such as the helmet known as the Advanced Combat Helmet (ACH), which was a successor to the Personnel Armor System Ground Troops (PASGT) such as shown in U.S. Pat. No. Des. 242,088. Helmet strap systems for holding a helmet to a user&#39;s head are also known, such as disclosed in U.S. Pat. Nos. 7,600,268, 5,123,121, 4,897,888 and US Patent Application Publication 2006/0179537 A1. 
         [0004]    The present inventors recognize that it would be desirable to provide a strap system with a geometric configuration that reduces the degree of front-to-back helmet rotation that is allowed by the system. 
         [0005]    The present inventors recognize that it would be desirable to provide a strap system with a geometric configuration that reduces the circumstances were a strap could cut up under a user&#39;s earlobe or interfere with a circum-aural ear protection or communication device. 
         [0006]    One solution for fastening a chinstrap requires putting the closure mechanism on top of the side straps of the system which results in bulky hardware on the face, interference with weapons sighting, and the need for left and right eye-dominant configurations. The present inventors recognize that it would be desirable to eliminate the bulky hardware, weapon interference, eye-dominant configuration requirements in a helmet retention system. 
         [0007]    The present inventors recognize that it would be desirable to eliminate the need to adjust the length of straps in the system every time the chin strap is connected rather than at the first fitting. 
         [0008]    The present inventors recognize the need for a low profile chin strap closure mechanism. 
         [0009]    The present inventors recognize a need for a chin strap closure mechanism that is capable of operation by one hand. 
       SUMMARY OF THE INVENTION 
       [0010]    An exemplary embodiment of the invention provides a helmet retention system having a first side strap system configured to connect to a first side of a helmet and a second side strap system configured to connect to an opposite second side of a helmet. A chin cup and a chin cup connecting mechanism are provided. The chin cup connecting mechanism is configured to connect the first and second side strap systems in an area about the user&#39;s chin and to vary the amount of tension in the system between at least two predefined tension states. 
         [0011]    In one embodiment, the chin cup connecting mechanism has at least one loop, a plurality of anchor pins, a key-hole strip having a least two openings each configured to engage one or more anchor pins. The selection of the engagement of one or more openings with one or more anchor pins determines, at least in part, the tension state of the system. 
         [0012]    In one embodiment, the chin cup comprises an upper strap portion, a first lower strap portion, and a second lower strap portion. The upper strap portion and first lower strap portion are configured to encircle a user&#39;s chin in at least one tension state. The key-hole strip is connected to the second lower strap portion. 
         [0013]    In one embodiment, the chin cup connecting mechanism comprising at least two loops for connecting opposite sides of the chin cup to the first and second side strap systems. 
         [0014]    In one embodiment, the first loop is connected between the upper strap portion and the first lower strap portion and the second loop configured to be located between the second lower strap portion and the first lower strap portion for at least one tension state of the system. 
         [0015]    In one embodiment, the first side strap system comprises a first upper front strap portion configured to connect to a front portion of a helmet on a first side and a first lower side strap portion configured to extend to a rear area of a helmet on the first side. The second side strap system comprises a second upper front strap portion configured to connect to a front portion of a helmet on a second side and a second lower side strap portion configured to extend to a rear area of a helmet on the second side. 
         [0016]    In one embodiment, the system has a nape pad configured to prevent contact of the straps of the system with portions of the back of a user&#39;s neck. 
         [0017]    In one embodiment, the system has at least four strap anchors configured to secure opposite ends of the first and second side strap system to a helmet. 
         [0018]    In one embodiment, the system has a least one tensioner configured to vary the length of a portion of the first or second side strap systems within a predefined range. 
         [0019]    The tensioner has a base and a tension cam. The tension cam is pivotally connected to the base. The base has a crossbar for connecting to a first strap end of the first or second side strap systems; the base has a toothed section ahead of the tension cam opposite the crossbar. The tensioner has an open position and a closed position, the tension cam is configured to create a tortuous path where the strap can engage the teeth under tension when in the closed position. 
         [0020]    Numerous other advantages and features of the present invention will become readily apparent from the following detailed description of the invention and the embodiments thereof, and from the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0021]      FIG. 1  is a rear view of one embodiment of the helmet retention system. 
           [0022]      FIG. 2  is a rear view of a second embodiment of the helmet retention system. 
           [0023]      FIG. 2A  is a view of the connection of segments at a loop. 
           [0024]      FIG. 3  is a front view of the helmet retention system of  FIG. 1  mounted to a helmet with the chin cup released from a first side of the system. 
           [0025]      FIG. 4  is a front view of the helmet retention system of  FIG. 1  mounted to a helmet with the chin cup beginning engagement with the first side of the system. 
           [0026]      FIG. 5  is a front view of the helmet retention system of  FIG. 1  mounted to a helmet with the chin cup further engaged with the first side of the system. 
           [0027]      FIG. 6  is a front view of the helmet retention system of  FIG. 1  mounted to a helmet with the chin cup engaged with the first side of the system. 
           [0028]      FIG. 6A  a right side view a the helmet retention system of  FIG. 1  with certain details not shown. 
           [0029]      FIG. 7  is a front view of the helmet retention system of  FIG. 1  mounted to a helmet with the system in a high stability state. 
           [0030]      FIG. 8  is a front view of the helmet retention system of  FIG. 1  mounted to a helmet with the system in a relaxed stability state. 
           [0031]      FIG. 9  is a bottom perspective view of a key-hole strip of the system of  FIG. 1 . 
           [0032]      FIG. 10  is a top perspective view of the key-hole strip of  FIG. 9 . 
           [0033]      FIG. 11  is a front perspective view of a pin strip of the system of  FIG. 1 . 
           [0034]      FIG. 12  is a perspective view of chin cup connecting loop of the system of  FIG. 1 . 
           [0035]      FIG. 13  is a perspective view D-ring of the system of  FIG. 1 . 
           [0036]      FIG. 14  is a perspective view of a tensioner of the system of  FIG. 1  in a locked position. 
           [0037]      FIG. 14A  is a side view of the tensioner of  FIG. 14  with certain elements not shown. 
           [0038]      FIG. 15  is a perspective view of a tensioner of the system of  FIG. 1  in an open position. 
           [0039]      FIG. 15A  is a side view of the tensioner of  FIG. 15  with certain elements not shown. 
           [0040]      FIG. 16  is a side view of a lever of the tensioner of  FIG. 14 . 
           [0041]      FIG. 17  is a side perspective view of a base of the tensioner of  FIG. 14 . 
           [0042]      FIG. 18  is a perspective view of the lever of  FIG. 16 . 
           [0043]      FIG. 19  is an exploded front perspective view of an anchor system of the system of  FIG. 1 . 
           [0044]      FIG. 20  is an exploded rear perspective view of the anchor system of  FIG. 19 . 
           [0045]      FIG. 21  is an unexploded side view of the anchor system of  FIG. 19 . 
       
    
    
     DETAILED DESCRIPTION 
       [0046]    While this invention is susceptible of embodiment in many different forms, there are shown in the drawings, and will be described herein in detail, specific embodiments thereof with the understanding that the present disclosure is to be considered as an exemplification of the principles of the invention and is not intended to limit the invention to the specific embodiments illustrated. 
         [0047]    A helmet retention system  100 ,  101  is disclosed. The system has strap segments  150 ,  152 ,  154 ,  156 ,  158 ,  160 ,  162 ,  168 ,  170 ,  172  connected by rings, such as D-rings  130 ,  132 , or strap adjusters or strap tensioners  120 ,  122 ,  124 ,  126 ,  128 . The D-rings  130 ,  132  are connected to a neck or nape pad  102  and connected to each other by strap segments  168 ,  170 , and tensioner  124 . End strap segments  150 ,  152 ,  154 ,  156 , which are a subset of the segments, are connected at one end to an anchor  110 ,  112 ,  114 ,  116  for securing the system to a helmet. The combination of strap segments  168  and  170  may be one continuous piece of strap material. A first end of the combination of segments  168  and  170  has a first loop connected around the crossbar of tensioner  124 , the continuous strap extends around D-ring  130  and through the tensioner and has a second loop at a second end opposite the first end that is connected around a portion of D-ring  132 . By using the tensioner  124 , the overall length of the strap segments  168 ,  170  can be adjusted and the distance between the D-rings  130 ,  132  can be adjusted. 
         [0048]    In one embodiment, the system has a retaining strap  105  to secure the D-rings to the nape pad. A first end of the retaining strap  105  is secured at or adjacent to a first end  102   a  of the nape pad  102 . A second end of the retaining strap opposite the first end is secured at or adjacent a second end  102   b  of the nape pad. The retaining strap extends through each of the D-rings  130 ,  132 . As shown in  FIG. 1 , the retaining strap  105  is secured at the first end  102   a  of the nape pad and extends over a left portion of the D-ring  132  and extends under a right portion of the D-ring  132  and continues under strap segments  170  and  168 , and further it continues extending under a left portion of the D-ring  130  and over a right portion of the D-ring  130  and is secured to the second end  102   b  of the nape pad  102 . 
         [0049]    The system includes a first lower side strap portion  151  and an opposite second lower side strap portion  161 . The system includes a first upper front strap portion  157  and an opposite second upper front strap portion  167 . The first lower side strap portion  151  comprises strap segments  160 ,  162 . The second lower side strap portion  161  comprises strap segments  164 ,  172 . The first upper front strap portion  157  comprises strap segments  156 ,  158 . The second upper front strap portion  167  comprises strap segments  150 ,  166 . The rear strap portion  169  comprises strap segments  168 ,  170 . 
         [0050]    The system comprises a first side strap system  155  and a second side strap system  165 . The first side strap system comprises segments  154 ,  156 ,  158 ,  160 ,  162 . The second side strap system comprises strap segments  150 ,  152 ,  166 ,  164 ,  172 . The system also comprises first and second chin cup-engaging strap portions  153 ,  163 . The first chin cup engaging strap portion  153  comprises strap portions  151 ,  157 . The second chin cup engaging strap portion  163  comprises strap portions  161 ,  167 . In one embodiment, the strap portions  151  and  157  comprise a continuous piece of strap material. A first chin cup connecting loop  142  defines the boundary between strap portion  151  and strap portion  157 . The loop  142  is positionable along the overall length of first chin cup engaging strap portion  153  as the system is adjusted using tensioners  126 ,  128 . Likewise, a second chin cup-connecting loop  140  defines the boundary between strap portion  161  and strap portion  167 . The loop  140  is positionable along the overall length of first chin cup engaging strap portion  153  as the system is adjusted using tensioners  120 ,  122 . 
         [0051]    In one embodiment, each of the first and second chin cup engaging portions comprises one continuous piece of strap material. In this arrangement, a first end of a first continuous piece of material of the first chin cup engaging portion forms a first loop around the cross bar of tensioner  126 . The strap then continues around the D-ring  132 , extends through tensioner  126 , extends through loop  142 , extends through tensioner  128 , loops through anchor  116  and a second end opposite the first end of the first continuous piece of material forms a second loop around the cross bar of tensioner  128 . 
         [0052]    A first end of a second continuous piece of material of the second chin cup engaging portion forms a first loop around the cross bar of tensioner  122  continues around the D-ring  130 , extends through tensioner  122 , extends through loop  140 , extends through tensioner  120 , loops through anchor  110  and a second end opposite the first end of the second continuous piece of material forms a second loop around the cross bar of tensioner  120 . 
         [0053]    As shown in  FIG. 2A , segments  164  and  166  are one continuous piece of strap material. The segments are secured to each other by stitching rows  166   a ,  166   b  to form a loop portion  166   c  around the loop  140  so as to secure the loop in a position along the lengths of segments  164  and  166 . The segments  164  and  166  overlap each other in a V-fashion so that there is a V-shaped overlap portion  166   d . The stitching rows  166   a  and  166   b  extend through the V-shaped portion onto each of the segments  164 ,  166 . This overlap arrangement is also provided on segments  160 ,  158  at loop  142 . The segments  182 ,  186  are secured by one or more stitching rows  182   a  at loop  140  of the chin cup in an arrangement similar to that described regarding segments  164 ,  166  at loop  140 . 
         [0054]    The system  100  has a chin cup  181  for engaging on or about a user&#39;s chin as shown in  FIGS. 3-7 . The chin cup  181  has an upper chin strap portion  186 , a first lower chin strap portion  182 , and a second lower chin strap portion  188 . The first lower chin strap portion  182  has an anchor pin strip  180 . The second lower chin strap portion  188  connects with a keyhole strip  190 . In one embodiment, the second lower chin strap portion  188 , the upper chin strap portion  186 , and the first lower chin strap portion  182  comprise one continuous piece of strap material where a first end  187  of the first lower chin strap portion is attached at a predefined position along the strap comprising portions  186  and  188  as is shown in  FIG. 1 . The attachment at the first end edge  184  at the connection of the first end  187  to the upper chin strap portion  186  may be by means known in the art such as gluing, stitching, or the like. The stitching arrangement may be the same as the stitching  182   a  across segments  182  and  186 . In one embodiment, the chin cup  181  is one continuous piece of webbing. The chin cup  181  comprises a second end  185  opposite a first end  187  which is defined by where the loop  140  engages to continuous strap that comprises strap portions  186  and  182 . Therefore, the loop  140  is positionable along the strap that comprises strap portions  186  and  182  to define the boundaries of the upper chin strap portion  186  and the first lower chin strap portion  182  respectively. The second lower chin strap portion  188  is configured to be threaded through the first chin cup connecting loop  142 . 
         [0055]    Referring to  FIGS. 1 and 2 , the second end  185  of the chin cup  181  may be attached to either side of the system. For example in  FIG. 1 , the second end  185  of the chin cup  181  is threaded through the second chin cup connecting loop  140 . In the configuration shown in  FIG. 2 , the second end of the chin cup  181  is threaded through the first chin cup connecting loop  142 . This connecting point may decided at the place of manufacture or, in one embodiment, the first end  187  of the first lower chin strap portion  182  may be releasably connected to the upper chin strap portion  186  and the second lower chin strap portion  188 . The pin strip may be removed and the chin cup may be taken out of the second chin cup connecting loop  140  and placed in the first chin connecting loop  142  or vice versa. 
         [0056]    Referring to  FIGS. 9 and 10 , the keyhole strip  190  is shown in more detail. The keyhole strip  190  is configured to engage the pin strip  180 . The strip  190  has a first raised portion  210  connected to a recess portion  246  by a sloping section  212 . The recess portion  246  adjoins a second raised portion  240  at a step edge  242  opposite the first raised portion  210 . The recess portion  246  has a first keyhole opening  220  and a second keyhole opening  230  located along the length of the recess portion  246 . Each keyhole opening has large openings  224 ,  234  contiguous with small openings  222 ,  232  respectively. The large openings  224 ,  234  are larger than the pinheads  252 ,  258  so that the pin heads may be received through large openings. 
         [0057]    As shown in  FIG. 10 , the first raised portion has a corresponding lower portion  211  on the back face of the keyhole strip. A rising slope section  213  corresponds to be sloping section  212  and connects the recess portion on the backside with the lower portion  211 . Unlike the first raised portion  210  the second raised portion does not have a corresponding lowered portion. Instead the raised back surface  244  comprises the length of the recess portion  246  and the second raised portion  240 . As a result the thickness in the second raised portion is greater than that of the thickness in the recess portion  246  and the first raised portion  210 . Each of the large openings  224 ,  234  of the key hole openings  220 ,  230  have a dish or angled portion  225 ,  235  which provides a recess from the back surface  244  to accommodate the pin heads  252 ,  258  of the pin strip  180 . One skilled in the art will recognize that while two keyhole openings are provided, any number of keyhole openings may be provided in the keyhole strip to correspond to the number of pinheads provided in the pin strip. The strap portion  188  may be connected on the lower portion  211  so that the strap portion  188  is in line with the recess portion  246 . A slot (not shown) may be formed through the lower portion  211  and thread can be used to secure the strap portion  188  to the lower portion  211 . Other means of attachment may also be used. 
         [0058]      FIG. 11  provides a detailed view of the pin strip  180 . The pin strip  180  comprises a strip body  261 . The strip body  261  has four elongated slot openings  260 ,  262 ,  264 ,  266 , a first pin  250 , and a second pin  256 . Two of the four elongated slot openings are center elongated slot openings  262 ,  264  and are located along the strip body  261  between the two pins  250 ,  256 . The other two of the four elongated slot openings are outside elongated slot openings  260 ,  266 . Outside elongated slot opening  260  is located opposite center elongated slot openings  262  with pin  250  located therebetween. The outside elongated slot opening  266  is located opposite center elongated slot opening  264  with pin  256  located therebetween. Each pin  250 ,  256  comprises a pin shaft  259  (not shown for pin  250 ) and a pin head  252 ,  258 . The pin shaft spaces the pin head from the strip body  261 . 
         [0059]    The strip body  261  comprises an upper arched area  253 ,  257  and a corresponding lower arched area  251  (not shown for pin  250 ). The arched areas have a common center with the center of the pin heads  252 ,  256 . The pin heads  252 ,  256  have a greater radius than the radius of the arched areas. The pin strip may be secured to the first lower chin strap portion  182  via stitching, adhesive, or by securing fasteners through the elongated slot openings  260 ,  262 ,  264 ,  266 , or other means known in the fastening art. 
         [0060]    In one configuration, the first pin  250  is configured to engage with the first keyhole opening  220  of the keyhole strip, and the second pin  256  is configured to engage with the second keyhole opening  230  of the keyhole strip. In one embodiment, the strip body  261  has an arc that is configured to approximate the under chin contact of a user and provide a comfortable contact therebetween. The keyhole strip has an arch that is substantially similar to the arch of the strip body  261  to provide a conforming contact between the keyhole strip and the strip body when the pins  250 ,  256  are engaged in the keyhole openings  220 ,  230  respectively. 
         [0061]    Referring to  FIG. 10 , to secure the keyhole strip  190  to the pin strip  180  each of the large openings  224 ,  234  are positioned under the pin heads  252 ,  258 . A keyhole strip  190  is raised in that direction A shown in  FIG. 10  and the pins pass through the large openings  224 ,  234  until the pin heads clear at least the lowest portion of the dished areas  225 ,  235 . To lock the keyhole strip and the second lower strap in place, the keyhole strip is then moved so that pin shafts  259  (not shown for pin  250 ) engage the small opening  222 ,  232  respectively, shown as the direction B in  FIG. 10 . To remove key hole strip from the pin strip  180  the keyhole strip is moved in the direction opposite of direction B shown in  FIG. 10  so that the pin heads  252 ,  258  align over the large openings  224 ,  234 . 
         [0062]      FIGS. 3-8  shows the system in various stages of use. In  FIG. 3 , the chin cup  181  is shown disconnected from the first chin cup engaging strap portion  153 . The chin cup  181  is attached to the second chin cup engaging strap portion  163  by second chin cup connecting loop  140 . The anchors  110 ,  112 ,  114 ,  116  are attached to the helmet  50  to hold the system to the helmet.  FIG. 6A  shows a right side view, with details not shown, of the system as it is attached to a helmet  50  at a front side attachment location  55  and a rear side attachment location  54 . The anchor  110  connects at attachment location  55  and anchor  112  connects at attachment location  54 . 
         [0063]    In  FIG. 4 , the keyhole strip  190  has been inserted through the first chin cup connecting loop  142  so that the first chin connecting loop  142  is located between the first keyhole opening  220  in the second keyhole opening  230 . In  FIG. 5 , the keyhole strip  190  has been pulled through the first chin cup connecting loop  142  and along the second lower chin strap portion  188  until the loop  142  reached the first end edge  184  which is where the upper chin strap portion  186  meets the first lower chin strap portion  182 . 
         [0064]    Each connecting loop  140 ,  142  has parallel arm portions  140   a ,  140   b  connected at each end to end segments to form the loop, as shown in  FIG. 12 . To secure the chin cup in position the second lower chin strap portion  188  is folded over one of the two arm portions  140   a ,  140   b  of the first chin cup connecting loop  142 . As the second lower chin strap portion  188  is folded over the first chin cup connecting loop  142 , the first and second keyhole openings  220 ,  230  of the keyhole strip  190  are aligned with the first pin  250  and the second pin  256  of the pin strip. The keyhole strip is then engaged with the pin strip as explained above to secure the chin cup in position between the first and second chin cup connecting loops  140 ,  142 . 
         [0065]    The system has at least two tension settings as shown in  FIGS. 7 and 8 . A high stability tension setting is shown in  FIG. 7 . In the high stability tension setting the first and second keyhole openings  220 ,  230  are engaged with the first and second pins  250 ,  256  to cause the upper chin strap portion  186  of the chin cup to be located between the lower edge of the chin of a user and the user&#39;s lips as shown in  FIG. 7 . In the high stability tension setting, both the upper strap portion  186  and the first lower strap portion  182  are more fully engaged with the user&#39;s face about the user&#39;s chin. 
         [0066]    A relaxed tension setting is shown in  FIG. 8 . In this configuration, less than all the keyhole openings are engaged with less than all of the pins. In the relaxed tension setting shown, only one keyhole opening is engaged with one of the pins. In the example shown in  FIG. 8 , the second keyhole opening  230  is engaged with the first pin  250 . In this configuration, the first end edge  184  is not necessarily in contact with the first chin cup connecting loop  142 . The second pin  256  is not engaged with the keyhole opening. In the relaxed tension setting, more slack is provided in the chin cup  181  between the chin cup connecting loops  140 , 142  so that the upper chin strap portion is located at a lower position relative to the user&#39;s chin than in the case of the high stability tension setting. In the example shown in  FIG. 8 , the upper chin strap portion  186  is located below the user&#39;s chin  52  along a least a portion of the upper chin strap portion&#39;s length. The relaxed tension setting also allows compatibility with CBRN masks. 
         [0067]    The system provides a strap link adjustability mechanism where the length of any one of the strap portions  151 ,  157 ,  161 ,  167 ,  169  may vary within a predefined range by the use of tensioners  120 ,  122 ,  124 ,  126 ,  128 . Each of tensioners  120 ,  122 ,  124 ,  126 ,  128  is identical to the others, therefore only one tensioner will be described in detail. Each tensioner has an open position in a locked position. The open position as shown in  FIGS. 15 and 15A ; the locked position is shown in  FIGS. 14 and 14A . Component parts of the tensioner are shown in  FIGS. 16 ,  17 , and  18 . 
         [0068]    Each tensioner has a base  300 . The base has opposing base side walls  304 ,  306  joined by a crossbar  302  and a front bar such as a tooth bar  308 . The outward facing surface of the side walls each have a series of parallel vertical grip bars  316  to aid a user&#39;s grip for sliding or adjusting the location of the tensioner. Adjacent to the grip bars  316  are pivot lever mounting holes  320 ,  322  for connecting with a pivot lever  330 . The tooth bar  308  is located at the front of the base  300 . The tooth bar  308  has a front surface  309  opposite a back surface. The back surface of the tooth bar has a plurality of teeth  310  extending rearward towards the crossbar  302 . The tooth bar has an upper surface that is recessed below the highest surface of the side walls as shown in  FIG. 17 . On the inside surface of the side walls between the tooth bar and a crossbar is a lever pin channel  324 ,  326  that extends from the top edge of the side wall down to the pivot lever mounting holes  320 ,  322 . 
         [0069]    The pivot lever  330  is shown in  FIGS. 16 and 18 . The lever has a front edge  351 , a first sloping upper front surface  348  continuing on the top side to a second upper sloping surface  346  continuing on the top to a rear tail surface  356  and connecting with a tail tooth  360 . On the underside of the lever from the front edge  351  is a first bottom sloping section  350  connecting to a concave second bottom sloping section  352  further connecting to a third bottom portion  354  connecting with the tail tooth  360 . The lever has opposite lateral lever sidewalls  341 ,  343 . Each side has a base-engaging pin  336 ,  338 . Since the pins  336 , 338  are mirror image identical across a longitudinal, vertical center plane of the lever (which center plane contains the curved line L in  FIG. 18 ), only the pin  336  need be described. The pin  336  extends outward from the side wall. The pin  336  joins the side wall at a dish portion  342 . The dish portion  342  provides a smooth concave transition between the sidewall  341  and the shaft  345 . The outer face of the pin provides a vertical section  340  and an angled section  339 . The vertical section  340  comprises half of the outer face of the pin and the angled section  339  comprises the second half. The angled section of the surface of the pin is designed smooth the connection between the base and is the first component of the pin to contact the channels  326 ,  324  when the lever is attached to the base. In one embodiment, the pins  336 ,  338  are aligned over the channels  326 ,  324  so that the angled portions  339  (not labeled or shown for pin  338 ) are closest to the channels. Downward force is then applied to the upper surface  348 ,  346  of the lever to force the pins down through the channels to a snapped engagement in the pivot lever mounting holes  322 ,  320 . 
         [0070]    Each of the lever sidewalls  341 ,  343  of the lever include locking nubs  332 ,  337 . Each of the inside surfaces of the sidewalls  306 ,  304  of the base  300  have locking nub recesses  303  (not shown for sidewall  306 ). The locking nub recess  303  may be located so that when the lever is in a closed position, the top surface of the lever is parallel with the top surface of the sidewalls of the base portion. In another embodiment, locking recess may be located so that when the lever is in a closed position, the top surface of the lever is above or below the top surface of the side walls of the base portion. The locking nub has a snapped engagement with the locking recess to ensure proper closure and prevent accidental release. 
         [0071]    The location of the base engaging pins  336 ,  338  and the shape of the front of the lever, including the first bottom sloping section  350 , a front edge  351  in the first sloping upper front surface portion  348 , forms a cam end  353 . As shown in  FIGS. 14 and 15  the lever pins are received in the lever pinholes of the base and the lever is pivotable about the lever pinholes between an open and a locked position. Strap segment  160  has a loop end  160   a  secured around the crossbar  302 . The loop end is formed by the strap being folded over on itself and is secured to itself. Strap  162  is threaded over the tooth bar  308  under the cam end of the lever and over the crossbar to extend out the rear end of the tensioner. 
         [0072]    As shown in  FIGS. 14 and 14A , when the lever is moved to the locked or closed position that cam end of the lever pivots about the lever pins forwardly towards the teeth  310 . Therefore, the strap  162  is secured between the teeth and the cam end of the lever including the front edge  351 . In one embodiment, the lever does not provide pressure between the strap  162  and the crossbar  302 . In one embodiment, the pressure provided between the strap  162  and the crossbar is negligible and the holding force is provided between the cam end of the lever and the teeth  310  of the tooth bar  308 . 
         [0073]    Referring to  FIG. 14A , in one embodiment, when the tensioner is in a locked position the lever  330  including the cam end  353 , the tooth bar  308 , and the crossbar  302  create a tortuous path where the strap  162  will engage the teeth  310  under tension. The tortuous path, beginning at the left in  FIG. 14A , has a downward segment which encounters the teeth  310  between the tooth bar  208  and the front of the cam end  353  and an upward extending segment that follows along the bottom of the lever over the crossbar  302  and out the rear of the tensioner. In one embodiment, shown in  FIG. 14A , the teeth come in close proximity to the cam but the teeth do not touch the cam. While the teeth may contact or come in close proximity to the cam, because of the tortuous path, it is not necessary for the cam end  353  to put excessive pressure on the strap between the teeth to secure the strap in position. This may reduce wear on the teeth and other components and extend the working life of the tensioner. In  FIG. 15A , the tensioner is in the open position. When the tensioner is in the open position, the strap is relieved from the tortuous path in that the strap is not forced in contact with the teeth  310  and the strap extends along a top portion of the lever including along the first sloping upper front surface  348 . 
         [0074]    The cam end has an over-center design such that the cam end  353  is urged to rotate when subjected to strap tension. Strap  162  extends around the cam end  353  that is radially spaced from the pivot axis at the base engaging pins  336 , 338  wherein pivoting of the lever from an open position to the locked or tensioning position pulls the strap about the cam tending to shorten the effective length of strap via the tortuous path that has a longer length, as compared to the open path when in the open position, and produces a tension in the strap. If the strap  162  is further drawn in the direction D shown in  FIG. 14A  when the tensioner is in the locked position, the additional drawing force will urge the lever to rotate with respect to the base  300  toward the closed position as the strap draws upward on the front bottom sloping section  350  and the front edge  351  about the pivot axis, which creates a rotational force or moment on the cam end  353  and increases the griping force of the tensioner on the strap. 
         [0075]    In operation, to extend the strap&#39;s effective length, strap  162  is moved in the direction C shown in  FIG. 14  so that more of strap  162  is located in front of the cam end of the lever. To reduce the strap&#39;s effective length, strap  162  is moved in the direction opposite of the directions C shown in  FIG. 14  so that more of the strap  162  is located to the rear of the crossbar  302 . 
         [0076]    As is shown in  FIG. 14 , tail tooth  360  is recessed from the plane defined by rear surfaces  301 ,  305  of the sidewalls  304 ,  306  of the base  300  to avoid the tail tooth snagging unintentionally on other elements that may be close to the system. However, the tail tooth  360  provides a grip or contact point that allows the tensioner to be operated while the user is wearing gloves. 
         [0077]    The D-ring  130 ,  132  is shown in  FIG. 13 . The D-ring has strap engaging links  133 ,  134 ,  135  joined together by intervening shorter links  136 ,  137 ,  138  respectively. 
         [0078]    Each of the anchors  110 ,  112 ,  114 ,  116  is identical. An anchor system  400  is shown in  FIGS. 19 ,  20 , and  21 . The anchors system includes an anchor  110 ,  112 ,  114 ,  116 , a screw receiver such as a t-nut  410 , and a screw  440 . The anchor includes a helmet mounting portion  428  and a strap connecting portion  452 . The helmet mounting portion  428  includes a mounting hole  426 . The back surface of the helmet mounting portion  428  includes a diamond recess  430 . The t-nut  410  includes a shaft portion  412  and a diamond shaped plate portion  414 . The t-nut includes a threaded bore  416  that extends through the shaft portion  412  and the diamond shaped plate portion  414 . The diamond shaped plate portion  414  is sized to fit in the diamond recess  430  so as to prevent substantial rotation of the T-nut  410 . The screw  440  has a threaded shaft portion  442  connected to a non-threaded shaft portion  446 , which is connected to the head  444 . 
         [0079]    The strap connecting portion  452  includes a strap opening  422  adjacent to a strap bar  420 . The strap connecting portion  452  is angled away from or setoff from the plane defined by the helmet mounting portion  428  to prevent the strap from pinching against a helmet mounting surface. In one embodiment, the set off is 3 mm. The anchor may include an oblong center opening  424  for reducing the weight of anchor. 
         [0080]    As shown in  FIG. 21 , the shaft portion  412  of the t-nut is received in the mounting hole  426  of the anchor and the diamond recess  430  is receives the diamond shaped plate portion  414  of the t-nut that so that shaft portion  412  extends beyond the surface of the anchor opposite the diamond shaped recess. The screw may be threaded into the bore  416  until the non-threaded shaft portion  446  contacts the shaft portion  412  or is in close proximity thereto, or until sufficient resistance is created between the screw head and the helmet. Therefore, the anchor is secured to a helmet between the screw thread and a helmet engaging portion  428  in a helmet engaging area  450 . 
         [0081]    From the foregoing, it will be observed that numerous variations and modifications may be effected without departing from the spirit and scope of the invention. It is to be understood that no limitation with respect to the specific apparatus illustrated herein is intended or should be inferred.