Abstract:
A height adjuster for a vehicle safety restraint has a web guide ( 38 ) and a track ( 84 ) for the web guide. The web guide ( 38 ) is vertically moveable along the track ( 84 ). A lock ( 76 ) has a lock condition for preventing vertical movement of the web guide ( 38 ) along the track ( 84 ) and an unlocked condition for allowing vertical movement of the web guide ( 38 ) along the track ( 84 ). A release mechanism ( 50, 80 ) is operatively connectable to said lock ( 76 ). The release mechanism ( 50, 80 ) has a release position for placing the lock ( 76 ) in the unlocked condition and an unreleased position from maintaining the lock ( 76 ) in the lock condition. A lift mechanism ( 66 ) at least partially assists vertical movement of the web guide ( 38 ) along the track ( 84 ) and biases the release mechanism ( 50, 80 ) toward the unreleased position.

Description:
[0001]     This non-provisional patent application claims priority to U.S. Provisional Patent Application 60/632,251 filed on Dec. 1, 2004. 
     
    
     BACKGROUND OF THE INVENTION  
       [0002]     This invention relates to a height adjuster for a safety belt system.  
         [0003]     Typically, a safety belt for a vehicle has a lap belt and a shoulder belt. The safety belt is anchored to a vehicle at three different locations around a passenger. Two anchors secure the lap belt while a third anchor, a loop, web guide or D-ring, provides a sliding support for the shoulder belt and is secured to the B-pillar of the vehicle. The web guide or D-ring (or loop) is preferably located just above the shoulder height of the passenger. Due to varying sizes of passengers, manufacturers use a device known as an adjustable turning loop assembly, or height adjuster, to adjust the height of the web guide up or down to permit for the accommodation of these differing sizes.  
         [0004]     The adjustable turning web guide assembly is mounted to a B-pillar of the vehicle. When the assembly is unlocked, say at the touch of a button, the web guide is movable vertically to its desired position. Most of this assembly is covered by a trim panel. The button that unlocks the assembly may be part of the trim panel. Pressing this button to an actuated position such as downward or inward, unlocks a locking mechanism of the height adjuster and permits movement of the web guide from one vertical position to another.  
         [0005]     Due to its location, the height adjuster supports the weight of the shoulder belt. In addition to this load, many safety belt systems have a seat belt retractor that tensions the safety belt to take up slack. Consequently, a passenger wishing to move the position of the web guide upward must overcome the downward force of the seat belt retractor and the weight of the seat belt. It would be desirable to facilitate the lifting of the height adjuster.  
         [0006]     In addition, the button controlling unlocking of the lock mechanism has a spring to bias the button to a rest position, for example, a force (spring) in an upward direction, so that the button returns to its rest position following actuation. The spring is a separate component. It would be desirable to combine this button spring with other components of the height adjuster assembly.  
         [0007]     A need therefore exists for a device that both assists a passenger in the lifting of the height adjuster assembly and returns the button of the assembly to its original position without increasing the number of components.  
       SUMMARY OF THE INVENTION  
       [0008]     A height adjuster for a vehicle restraint has a web guide for receiving a seat belt. The web guide is vertically moveable along a track. A lock prevents vertical movement of the web guide along the track when in a locked condition and allows vertical movement of the web guide along the track when in an unlocked condition. A release mechanism is connected to the lock. The release mechanism has a release position for placing the lock in an unlocked condition and an unreleased position for maintaining the lock in a lock condition. Furthermore, a lift mechanism at least partially assists vertical movement of the web guide along the track and biases the release mechanism toward the unreleased position. In this way, a single lift mechanism, such as a spring, acts to both assist the passenger in raising the web guide and biasing the button that releases the web guide in an unreleased position.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0009]     The various features and advantages of this invention will become apparent to those skilled in the art from the following detailed description of the currently preferred embodiment. The drawings that accompany the detailed description can be briefly described as follows:  
         [0010]      FIG. 1  illustrates a safety restraint system incorporating the inventive height adjuster.  
         [0011]      FIG. 2  illustrates a view of the height adjuster of  FIG. 1 , including web guide.  
         [0012]      FIG. 3  illustrates the height adjuster of  FIG. 2  after adjustment of the location of the web guide.  
         [0013]      FIG. 4  illustrates the height adjuster of  FIG. 2  from a side exposed view.  
         [0014]      FIG. 5  illustrates a behind view of the height adjuster of  FIG. 2 .  
         [0015]      FIG. 6  illustrates the height adjuster of  FIG. 3  after adjustment of the location of the web guide.  
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0016]      FIG. 1  illustrates a safety restraint system  8  for a vehicle. As shown, seat belt  14  is disposed over seat  10 . Seat belt  14  comprises shoulder belt portion  26 , lap belt portion  30  and seat belt buckle  12  and a tongue  12   a  insertable into a locking engagement with the buckle  12 . Seat belt retractor  22  is also provided to take up any slack of shoulder belt portion  26  over a passenger. As shown, shoulder belt portion  26  passes from seat belt retractor  22  through a loop  38 , here a D-ring which is also referred to in the art as a web guide.  
         [0017]     Web guide, (formed as a loop)  38  is a part of a height adjuster assembly  18 , which allows web guide  38  to be moved downward in the direction of arrow A or upward in the direction of arrow B. In this way, web guide  38  may be adjusted in height to accommodate differently sized vehicle occupants. Height adjuster assembly  18 , along with web guide  38 , are mounted to B-pillar  34  of the vehicle (see  FIG. 4  for example). B-pillar trim panel  42  is provided over height adjuster assembly  18  to hide most of its working components. These features of the invention are well known.  
         [0018]      FIG. 2  shows a view of B-pillar trim panel  42  of  FIG. 1 . B-pillar trim panel  42  comprises fixed base  48 , sliding cover  46 , and release actuator cover  50 . Fixed base  48  has trim panel mounting tabs  108  that interlock B-pillar trim panel  42  to other trim panels, which are fixed to B-pillar  34 . Alternatively, the B-pillar trim can be secured directly to the B-pillar. However, sliding cover  46  and release actuator cover  50 , here a button, are free to move relative to fixed base  48  with movement of web guide  38  in the direction of arrow A or arrow B. Furthermore, sliding cover  46  is provided with cover opening  54  through which passes seat belt  14  to web guide  38 .  
         [0019]      FIG. 5  illustrates a back view of B-pillar trim panel  42 . As shown, B-pillar trim panel  42  has sliding cover retaining tabs  116 , which hold sliding cover  46  to fixed base  48  while permitting sliding movement of sliding cover  46  in the direction of arrow A or in the direction of arrow B. In addition, sliding cover stop  92  is provided to prevent further upward travel of sliding cover  46  in the direction of arrow B. Sliding cover  46  in the position shown, however, is free to move in the direction of arrow A, downward, to sliding cover stop  94 . Thus, sliding cover  46  may slide freely between sliding cover stop  92  and sliding cover stop  94 .  
         [0020]     Sliding cover  46  also slideably receives release actuator cover  50 , a button. Here, release actuator cover  50  is retained by release actuator cover retaining tabs  120  that hold release actuator cover  50  to sliding cover  42  while still permitting movement of release actuator cover  50  in the direction of arrow A or in the direction of arrow B. In its highest position, release actuator cover  50  abuts ledge  132  (see  FIG. 4 ) of sliding cover  46 . Release actuator cover stop  104  is provided to prevent release actuator cover  50  from traveling further in the direction of arrow A. Accordingly, release actuator cover  50  may slide freely between release actuator cover stop  104  and ledge  132  of sliding cover  46 .  
         [0021]     The operation of height adjuster assembly  18  will now be explained. Referring to  FIG. 4 , web guide  38  is mounted to bolt  68 . Head  69  of bolt  68  is received within bolt recess  96 , (see also  FIG. 5 ) which is part of sliding cover  46 . Bolt  68  is also mounted to carrier  72  of height adjuster assembly  18 . Further, height adjuster assembly  18  has track  84 , here a rail, which is mounted to B-pillar  34  by mounting bolts  88 . Carrier  72  is slidably received on track  84  so that carrier  72  may move along with web guide  38  and sliding cover  46  in the direction of either arrow A or arrow B.  
         [0022]     Holding carrier  72  in place is locking mechanism  76 , here shown schematically, which locks carrier  72  to track  84  as known. One such carrier, rail and lock mechanism is shown in U.S. Pat. No. 6,733,041 B2 to Arnold, et al., which is incorporated herein by reference. Actuator  80  is linked by actuator link  112  to locking mechanism  76  and unlocks locking mechanism  72  to permit movement of carrier  72 . Additionally, actuator  80  is in contact with release actuator cover  50  at button ledge  134  (see also  FIG. 5 ). Thus, movement of release actuator cover  50  in the direction of arrow A causes movement of actuator  80  in the same direction to unlock locking mechanism  76  and to permit carrier  72  to move up or down. Locking mechanism  76  may have a spring (not shown, however, see the above patent) that biases actuator  80  in the direction of arrow B to return to its locked condition so that release of release actuator cover  50  will lock carrier  72  in place.  
         [0023]     Because of a downward tensioning force from seat belt retractor  22  and from the weight of the shoulder belt portion  26 , web guide  38  is subject to a downward force in the direction of arrow A. Accordingly, an individual wishing to move loop  38  upwardly in the direction of arrow B must overcome the combined load of the weight of shoulder belt portion  26  and the downward force from seat belt retractor  22 . This load may make adjustment of height adjuster assembly  18  inconvenient. The prior art shows the use of assist springs acting directly upon the carrier of a height adjuster.  
         [0024]     To facilitate the lifting of sliding cover  46  and web guide  38 , a lift assist spring  66  is provided as shown in  FIG. 4 . Lift assist spring  66  is attached at one end portion  67  to fixed base  48 . Another end portion  71  of lift assist spring  66  is attached to release actuator cover  50 , which abuts ledge  132  of sliding cover  46 .  
         [0025]     Hence, as shown in  FIG. 6 , following actuation of actuator  80 , carrier  72  along with web guide  38  and sliding cover  46 , may be dropped downward in the direction of arrow A to position  62  shown in  FIG. 6 . In this position, lift assist spring  66  is extended creating additional lifting force on release actuator cover  50 , which is linked to sliding cover  46  and web guide  38  by ledge  132 . Thus, when release actuator cover  50  is pressed in the direction of arrow A to release locking mechanism  76 , lift assist spring  66  causes an upward force in the direction of arrow B on release actuator cover  50 .  
         [0026]     To couple this upward force to sliding cover  46  and web guide  38 , one need only place a digit, such as a thumb, at thumb spot  128  while holding release actuator cover  50  down. Typically, when a passenger adjusts height adjuster assembly  18 , he or she will place a digit, such as a finger, at finger spot  124  and a digit, such as a thumb, at thumb spot  128 . The finger presses downward in the direction of arrow A to unlock locking mechanism  76  while the thumb at thumb spot  128  permits the lifting of sliding cover  46 . The link between finger and thumb allows the upward force on the release actuator cover  50  to be transferred to the thumb and thus the sliding cover  50 . In this way, a finger at finger spot  124  squeezes in the direction of arrow A to release locking mechanism  72  while a thumb at thumb spot  128  receives lift in the direction of arrow B from lift assist spring  66  to assist in the lifting of loop  38 .  
         [0027]     As further shown in  FIG. 4 , lift assist spring  66  also biases release actuator cover  50  in the direction of arrow B so that when release actuator cover  50  is pressed in the direction of arrow A, lift assist spring  66  will return release actuator cover  50  upwardly in the direction of arrow B. Thus, lift assist spring  66  works to return release actuator cover  50  to its unactuated position. In this way, a single spring performs both the function of assisting in the lifting of loop  38  and in the returning of release actuator cover  50  to its original position.  
         [0028]     The aforementioned description is exemplary rather that limiting. Many modifications and variations of the present invention are possible in light of the above teachings. The preferred embodiments of this invention have been disclosed. However, one of ordinary skill in the art would recognize that certain modifications would come within the scope of this invention. Hence, within the scope of the appended claims, the invention may be practiced otherwise than as specifically described. For this reason the following claims should be studied to determine the true scope and content of this invention.