Abstract:
The present invention is directed toward a safety belt web adjuster that incorporates a sliding middle horizontal member around which the lower section of webbing is looped. This allows the webbing section to be trapped between two bars, one sliding and one fixed. The web adjuster of the present invention also allows for relatively easy adjustment of safety belt tension by moving the web adjuster through approximately 90 degrees of motion, thereby removing the bearing force on the webbing previously supplied by the fixed member, allowing the slack in the safety belt to be easily adjusted.

Description:
TECHNICAL FIELD OF THE INVENTION  
       [0001]     The present invention generally relates to safety belts for motor vehicles and, more particularly, to a safety belt web adjuster.  
       BACKGROUND OF THE INVENTION  
       [0002]     As is known in the art, safety belts are commonly used in vehicle interiors in order to limit movement of the belted occupant in the event of sudden vehicle movements, particularly accidents in which the car experiences a violent collision with another stationary or moving object. Because of the generally higher speeds and the competitive nature of the driving, safety belts for racing cars are generally designed for greater protection of the belted occupant than are safety belts for general vehicular use.  
         [0003]     Safety belts of the type generally used in vehicles include a webbing material (such as woven nylon, for example) anchored to the vehicle and formed into a protective harness for the vehicle occupant using various pieces of safety belt hardware. One such common piece of safety belt hardware is the web adjuster, which is used to allow slack in the safety belt to be taken up or added in order to ensure that the safety belt snugly conforms to the size of the current vehicle occupant.  FIG. 1  schematically illustrates a typical prior art safety belt web adjuster, indicated generally at  10 .  
         [0004]     The prior art web adjuster  10  generally comprises a relatively flat member having three horizontal members  12 ,  14  and  16  coupled by two vertical members  18  and  20 , such that the horizontal member  14  is positioned between the horizontal members  12  and  16 . As used herein, the terms “horizontal” and “vertical” are merely indicators of relative positioning between various objects, and are not intended to signify any position with respect to the ground. The web adjuster  10  may be made of any suitably strong material, and is generally formed from metal.  
         [0005]      FIG. 2  illustrates the prior art web adjuster  10  of  FIG. 1  in use with a safety belt.  FIG. 2  assigns the labels “upper,” “lower,” posterior” and “anterior” to four relative directions for ease of discussing the positioning of various portions of  FIG. 2 , but again these directions are not intended to signify any position with respect to the ground. The web adjuster  10  is used to adjustably couple two sections of safety belt webbing, namely a first section  22  and a second section  24 , such that the combined length of the two sections  22  and  24  can be changed in order to fit the safety belt snugly against vehicle occupants of differing sizes. The first section  22  of webbing is looped around the horizontal member  12  and secured thereto by threads  26  sewing the two sections of webbing  22  together, as is known in the art. The other end of webbing section  22  is coupled to a suitable anchor point  27 , typically to the chassis of the vehicle.  
         [0006]     The lower section of webbing  24  is looped around the horizontal member  14 ; however, the two portions  28  and  30  of webbing section  24  are not coupled by any sewn threads, and remain free to move with respect to one another in certain situations, as explained in greater detail hereinbelow. As can be seen from the drawing, both portions  28  and  30  of the webbing section  24  lie on the posterior side of horizontal member  16 . The portion  28  is coupled to a suitable anchor point  31 , typically to the chassis of the vehicle, while the portion  30  remains unattached.  
         [0007]     In use, the safety belt web adjuster  10  allows the section of safety belt webbing into which it is installed to be adjusted to fit vehicle occupants of various sizes. For example, if the vehicle occupant installs the safety belt and determines that it does not fit snugly enough, then slack may be removed therefrom by grasping the portion  30  of the webbing section  24  and pulling the portion  30  towards the lower direction. This will have the effect of lengthening the portion  30  and shortening the portion  28 , thereby removing slack from the combined length of the webbing sections  22  and  24 .  
         [0008]     Once this slack has been removed in sufficient quantity to force the safety belt to lie snugly against the vehicle occupant, the safety belt will be placed in tension, with the safety belt sections  22  and  24  being pulled away from one another. This will cause the safety belt section  22  to bear against the lower side of horizontal member  12 , while the safety belt section  24  bears against the upper side of horizontal member  14 . Furthermore, the portion  30  bears against the upper edge of horizontal member  16  as it passes thereby. The looping of safety belt section  24  through the horizontal members  14  and  16  under tension prevents any further relative motion between the portions  28  and  30 , and therefore prevents any further relative motion between the webbing sections  22  and  24 , thereby maintaining the level of safety belt snugness set by the vehicle occupant. Adding slack to the safety belt may be done by moving the webbing portion  28  toward the lower direction.  
         [0009]     One drawback of the prior art web adjuster  10  is that the webbing can bunch to the side within the adjuster  10  when the safety belt is not under proper tension. Furthermore, relatively large pulling forces are required in order to adjust the slack of the safety belt using the prior art web adjuster  10 . There therefore remains a need for improvement in the field of safety belt web adjusters. The present invention is directed toward meeting this need.  
       SUMMARY OF THE INVENTION  
       [0010]     The present invention is directed toward a safety belt web adjuster that incorporates a sliding middle horizontal member around which the lower section of webbing is looped. This allows the webbing section to be trapped between two bars, one sliding and one fixed. The web adjuster of the present invention also allows for relatively easy adjustment of safety belt tension by moving the web adjuster through approximately 90 degrees of motion, thereby removing the bearing force on the webbing previously supplied by the fixed member, allowing the slack in the safety belt to be easily adjusted.  
         [0011]     In one embodiment of the present invention, a safety belt web adjuster is disclosed, comprising a first horizontal member having first and second ends; a second horizontal member having third and fourth ends; a first vertical member extending between the first and third ends; a second vertical member extending between the second and fourth ends; a first ear extending away from the junction between the second horizontal member and the first vertical member; and a second ear extending away from the junction between the second horizontal member and the second vertical member; and a third horizontal member having a first substantially c-shaped end and a second substantially c-shaped end; wherein the first substantially c-shaped end engages the first vertical member; wherein the second substantially c-shaped end engages the second vertical member; and wherein the third horizontal member is free to slide between the first and second horizontal members while engaging the first and second vertical members.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0012]      FIG. 1  is a plan view of a prior art web adjuster.  
         [0013]      FIG. 2  is a partial cross-sectional view of the prior art web adjuster of  FIG. 1  installed on two sections of safety belt webbing.  
         [0014]      FIG. 3  is a plan view of a preferred embodiment web adjuster of the present invention.  
         [0015]      FIG. 4  is a cross-sectional view of the web adjuster of  FIG. 3 .  
         [0016]      FIG. 5  is a partial cross-sectional view of the web adjuster of  FIG. 3  installed on two sections of safety belt webbing.  
         [0017]      FIG. 6  is a partial cross-sectional view of the web adjuster of  FIG. 3  installed on two sections of safety belt webbing, illustrating a preferred adjustment position of the present invention.  
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0018]     For the purposes of promoting an understanding of the principles of the invention, reference will now be made to the embodiment illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended, and alterations and modifications in the illustrated device, and further applications of the principles of the invention as illustrated therein are herein contemplated as would normally occur to one skilled in the art to which the invention relates.  
         [0019]      FIG. 3  illustrates a preferred embodiment web adjuster of the present invention, indicated generally at  100 . The web adjuster  100  generally comprises a relatively flat member having two horizontal members  102  and  104  coupled by two vertical members  106  and  108 . A first ear  110  is formed at the junction between horizontal member  104  and vertical member  106 , while a second ear  112  is formed at the junction between horizontal member  104  and vertical member  108 . The purpose of ears  110  and  112  will be illustrated hereinbelow. An opening  114  is preferably formed in the central portion of horizontal member  104 . The purpose of the opening  114  will also be illustrated hereinbelow.  
         [0020]     As shown in  FIGS. 3 and 4 , a third horizontal member  116  is provided. The horizontal member  116  comprises a relatively flat section  118  joining two relatively c-shaped ends  120  and  122 . The c-shaped ends  120  and  122  allow the horizontal member  116  to slide freely over the vertical members  106  and  108 , as shown in the drawings. When installed in a safety belt as described hereinbelow, the horizontal member  116  is positioned between the horizontal members  102  and  104 . As used herein, the terms “horizontal” and “vertical” are merely indicators of relative positioning between various objects, and are not intended to signify any position with respect to the ground. The web adjuster  100  may be made of any suitably strong material, and is preferably formed from an appropriately high strength material, such as steel or forged aluminum, for example.  
         [0021]      FIGS. 5 and 6  illustrate the web adjuster  100  of the present invention in use with a safety belt.  FIGS. 5 and 6  assign the labels “upper,” “lower,” posterior” and “anterior” to four relative directions for ease of discussing the positioning of various portions of  FIGS. 5 and 6 , but again these directions are not intended to signify any position with respect to the ground. The web adjuster  100  is used to adjustably couple two sections of safety belt webbing, namely a first section  124  and a second section  126 , such that the combined length of the two sections  124  and  126  can be changed in order to fit the safety belt snugly against vehicle occupants of differing sizes. The first section  124  of webbing is looped around the horizontal member  102  and secured thereto by threads  128  sewing the two sections of webbing  124  together, as is known in the art. The webbing section  124  is coupled to a suitable anchor point  130 , typically to the chassis of the vehicle.  
         [0022]     The lower section of webbing  126  is looped around the horizontal member  116 ; however, the two portions  132  and  134  of webbing section  126  are not coupled by any sewn threads, and remain free to move with respect to one another in certain situations, as explained in greater detail hereinbelow. As can be seen from the drawing, both portions  132  and  134  of the webbing section  126  lie on the posterior side of horizontal member  104 . The portion  132  is coupled to a suitable anchor point  136 , typically to the chassis of the vehicle, while the portion  134  remains unattached. Preferably, a material tab  138  is looped through the opening  114  and its two ends are sewn together with thread  140 . The provision of the tab  138  facilitates grasping of the web adjuster  100  during safety belt adjustment procedures, as described in greater detail hereinbelow.  
         [0023]     In use, the safety belt web adjuster  100  allows the section of safety belt webbing into which it is installed to be adjusted to fit vehicle occupants of various sizes. For example, if the vehicle occupant installs the safety belt and determines that it does not fit snugly enough, then slack may be removed therefrom by grasping the portion  134  of the webbing section  126  and pulling the portion  134  towards the lower direction. This will have the effect of lengthening the portion  134  and shortening the portion  132 , thereby removing slack from the combined length of the webbing sections  124  and  126 . The adjustment of the safety belt using the web adjuster  100  of the present invention is described in greater detail hereinbelow with respect to  FIG. 6 .  
         [0024]     Once this slack has been removed in sufficient quantity to force the safety belt to lie snugly against the vehicle occupant, the safety belt will be placed in tension, with the safety belt sections  124  and  126  being pulled away from one another. This will cause the safety belt section  124  to bear against the lower side of horizontal member  102 , while the safety belt section  126  bears against the upper side of horizontal member  116 . Furthermore, because the horizontal member  116  is free to slide over the length of the vertical members  106  and  108 , placing the safety belt in tension causes the horizontal member  116  to slide toward the lower direction, entrapping the portion  134  of the webbing section  126  between the horizontal member  116  and the horizontal member  104 . Therefore, the portion  134  is sandwiched under tension between the horizontal members  116  and  104 , and also bears against the upper posterior edge of horizontal member  104  as it passes thereby. The looping of safety belt section  126  through the horizontal members  116  and  104  under tension, and the sliding of the horizontal member  116  toward horizontal member  104 , prevents any further relative motion between the portions  132  and  134 , and therefore prevents any further relative motion between the webbing sections  124  and  126 , thereby maintaining the level of safety belt snugness set by the vehicle occupant. It will be appreciated that the ears  110  and  112  facilitate retention of the sliding horizontal member  116  while the web adjuster  100  is first being installed upon the safety belt (i.e. before the webbing section  126  has been looped therethough.  
         [0025]     Adding slack to the safety belt may be done by moving the webbing portion  134  toward the lower direction; however, this may be difficult to do when the safety belt is under tension, as the sliding horizontal member  116  is exerting a force toward the horizontal member  104 , thereby sandwiching the webbing portion  134  therebetween. As illustrated in  FIG. 6 , adjustment of the web adjuster  100  is facilitated by rotating the web adjuster  100  through approximately 45° to 135°, and preferably through 90°, from the upper/lower plane to lie in the posterior/anterior plane. Provision of the tab  138  facilitates grasping of the web adjuster  100  by the vehicle occupant, particularly when the vehicle occupant is wearing gloves as would normally be the case in a racing application.  
         [0026]     As shown in  FIG. 6 , the user has grasped the tab  138  and pulled the web adjuster  100  toward the upper direction, thereby rotating the web adjuster  100  through approximately 90° and into the posterior/anterior plane. In this position, there is no longer a tension force acting on the sliding horizontal member  116  tending to force it toward the horizontal member  104 . Without this force acting on horizontal member  116 , horizontal member  116  is free to slide in the posterior direction away from horizontal member  104 . Now that the webbing section  126  is no longer sandwiched between horizontal members  116  and  104 , it is much easier to adjust the slack of the safety belt by moving the webbing portion  134  with respect to the webbing portion  132 . It will be appreciated that the ability of horizontal member  116  to slide freely along vertical members  106  and  108  is critical to the ability of web adjuster  100  to be easily adjusted when in the position illustrated in  FIG. 6 . Once the slack has been adjusted as desired, the vehicle occupant simply releases his grip on the tab  138  and the web adjuster will automatically return to the position illustrated in  FIG. 5 .  
         [0027]     While the invention has been illustrated and described in detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character, it being understood that only the preferred embodiment has been shown and described and that all changes and modifications that come within the spirit of the invention are desired to be protected.