Abstract:
A seat belt height adjuster for anchoring a seat belt is provided in a preferred form with three relatively simple component parts comprising a slider, a rail, and a bent spring. One end of the slider is biased by the bent spring so that a portion of the slider is spaced from the rail and to position locking protrusions on the slider body into at least one opening in the rail to lock the height adjuster at the desired height position. To adjust the location of the slider along the rail, a pushing force on the one end of the slider compresses the spring and removes the locking protrusions from the rail opening thereby allowing sliding of the slider along the rail. The slider pivots about its other end which is engaging the rail. Upon release of the pushing force, the spring expands and biases the locking protrusion into a rail opening. The spring may be a simple V or U-shaped, leaf spring and the slider may be a single, integral piece of metal.

Description:
FIELD OF THE INVENTION  
       [0001]     This invention relates to a shoulder belt height adjuster for a safety belt or seat belt that is attached to a pillar of a vehicle usually in a three-point seat belt system.  
       BACKGROUND OF THE INVENTION  
       [0002]     A large number of prior art shoulder height adjustment mechanisms are available and have been described in various patents for adjusting the incremental height and location of the shoulder belt which is usually mounted to a turning loop or D-ring affixed to the height adjuster to accommodate the various positions that different sizes of occupants of a vehicle desire for the seat belt to be anatomically, correctly positioned for best results. Usually the belt passes through the swivel D-ring which may be freely pivotal about the axis of a bolt which is connected to a slider of the height adjuster. The vehicle passenger will adjust the height of the slider along an internal guide rail which usually has a series of openings spaced at different heights into which a portion of the slider or other mechanism is positioned to lock the slider and thereby the swivel D-ring at the desired height. From a mechanical standpoint the height adjuster must be sufficiently strong to withstand the loads which are encountered during a vehicle accident.  
         [0003]     Many of the prior art height adjusters have had a number of parts or complex parts which are expensive to manufacture and to assemble for use in the height adjuster. Particularly there is a spring which biases the slider to a locking position in which portions such as locking protrusions or lugs on the slider fit into the openings or holes formed in the guide rail until such time as there is a need for height adjustment. For height adjustments, the vehicle occupant typically will operate an actuator button or press the slider or D-ring itself to compress the spring and to remove the locking protrusions from the locking position in the rail so that the slider may be shifted vertically along the rail. When the force compressing the spring is released, the protrusions are again fitted into locking openings in the rail to thereby lock the height adjuster in the newly adjusted position that is desired by the user. From a vehicle occupant standpoint, it is preferred that the height adjuster be easy to use and be readily apparent as to how it is to be used without the user having to consult an owner&#39;s manual or the like. Because of the varying capabilities of the passengers, it is preferred that the height adjuster require only a low force operation and yet still have a good, secure locking condition of the slider relative to the rail. From the manufacturing standpoint, it is particularly desirable to reduce the part count and the complexity of the parts so as to provide a relatively inexpensive height adjuster which is still easy to use and can be operated with a relatively low force.  
         [0004]     There is prior art that purports to disclose height adjusters of relatively simple design such as in U.S. Pat. No. 4,180,023, but in that instance the slider body comprises an upper portion or part and a lower portion or part which are welded together to form the slider. The welding operation and the joining of two separate parts defeats the goal of lowering costs resulting in a high cost part from a manufacturing perspective. U.S. Pat. No. 5,044,666 discloses a height adjust mechanism with a very complex leaf spring element which extends essentially over the length and the width of the slider and is connected with the slider to form a clamping module along the rail. This large leaf spring and slider adjustment element are connected by a protruding portion on the slidable adjustment element extending through a slot in the spring. Further, the guide bar of the &#39;666 patent has a large, central longitudinally extending slot through which portions of the clamping module extend. The large slot can make the flat guide bar weaker than is desired. To this end, the &#39;666 patent also teaches more complexly configured and thus costly guide bars such as with thick, longitudinal upstanding edge walls or a C-shaped channel guide bar.  
       SUMMARY OF THE INVENTION  
       [0005]     In accordance with a preferred aspect, there is provided a new and improved height adjuster for a seat belt which has a reduced part count, and has relatively simple rather than complex parts and which has a simplified operation. This is achieved in the preferred form by having a height adjuster assembly formed of three component parts comprising a slider, a rail and a bent spring. The slider has opposite upper and lower ends spaced longitudinally from each other, and front and back sides that extend between the ends. Preferably, the sides have a larger spacing from each other at the lower end of the slider than at the upper end. The spring is positioned between the rail and the slider biasing the back side of the slider at the lower end of the slider into a locking position while holding the front side of the slider at this lower end at an outward spaced position when the slider is in the locking position. To shift the slider for vertical height adjustment, the seat belt passenger will push on the front side that is spaced from the rail to pivot the slider about the upper end to remove protrusions on the slider from the rail opening so that the slider is in a released position to be moved vertically up or down the rail.  
         [0006]     In accordance with another aspect, the slider is provided with a U-shaped body having integral legs for sliding along the rail and integral protrusions formed on the legs for protruding into openings in the rail in the locking position. In one form, the slider carries a D-ring and a bolt about which the D-ring is mounted for turning about the axis of the bolt which secures the D-ring to the slider. The slider is also provided with an inclined slider body having the locking lugs or protrusions at a larger end at which the leaf spring is positioned to be compressible to shift the slider from its locked position. The smaller end of the slider body rests against the rail and serves as a fulcrum so that there is a mechanical advantage to allow a low amount of force to be used to compress the spring. Usually, the user pushes on the D-ring itself to unlock the height adjuster for movement, although they can also push on the lower, larger end of the slider body.  
         [0007]     In accordance with a further aspect, the spring is a simple U-shaped bent spring that has a first leg engaging the rail and for sliding along the rail and has a second leg which is attached or otherwise secured to the spaced side of the slider body. The leaf spring is very simple with its U or V-shaped configuration and preferably has an inturned end for sliding along the rail surface without catching thereon. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0008]      FIG. 1  is an exploded, perspective view of a height adjuster for a D-ring in accordance with the present invention showing a slider having locking lugs, a guide rail, a bent leaf spring and a trim cover for the height adjuster;  
         [0009]      FIG. 2  is a view of the height adjuster of  FIG. 1  in an assembled condition;  
         [0010]      FIG. 3  is an exploded, perspective view similar to  FIG. 1  showing the slider, spring, rail and trim cover;  
         [0011]      FIG. 4  is a sectional, perspective view taken substantially longitudinally of the rail and showing one of the locking lugs of the slider inserted into an opening in the guide rail for fixing the slider in a locked position along the rail;  
         [0012]      FIG. 5  is a cross-sectional view similar to  FIG. 4  showing the slider biased into the locked position;  
         [0013]      FIG. 6  is an enlarged, sectional view taken longitudinally and centrally along the rail, the spring, and the slider and showing one of the protrusions being pushed out from one of the locking openings in the rail by compressing the leaf spring; and  
         [0014]      FIG. 7  is a cross-sectional view similar to  FIG. 6  with the leaf spring compressed to slide the slider along the rail for adjusting the vertical height of the D-ring. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0015]     In  FIGS. 1-3 , a guide rail  12  and slider  13  are depicted with the guide rail  12  having locking openings  12   a  which are spaced along an interior web  12   b  of the rail at substantially uniformly spaced locations, and the slider  13  having a body  14  that has one or more protrusions  14   a,  each formed on the inner ends of wrap-around leg portions  14   b  of the slider body  14  to be inserted into the openings  12   a  to provide a central, load-bearing, locking position for the slider  14  longitudinally along the rail  12 . In this locking position as shown in  FIGS. 2, 4  and  5 , the inturned leg portions  14   b  are wrapped around the flanged edges  30  and  32  of the rail, the upper end  21  of the slider body  14  is resting on the rail, and the pair of protrusions  14   a  at the backside  14   e  of the slider body  14  are inserted into a locking opening  12   a  from the back or rear side  12   d  of the rail  12 .  
         [0016]     In preferred and illustrated from as can be seen in  FIG. 1 , the height adjuster  10  has three operating components: the elongated rail  12  on which is slidably mounted the slider  13  for sliding along the rail to adjust the height of the seat belt and D-ring assembly, and a biasing spring  16  for urging the slider  13  to a locked position. As best seen in  FIGS. 4 and 5 , the slider  13  is biased to the locked position in which locking protrusions or lugs  14   a  on the slider body  14  are engaged in one of the openings  12   a  formed in the rail by means of the leaf spring  16  shown in its uncompressed state. In order to shift the slider body to the release position, as best seen in  FIGS. 6 and 7 , the operator will push on the D-ring or on a first or lower end  20  of the slider body  14 . This push force indicated by the arrow P compresses a leg  16   a  of the spring  16  toward the other leg  16   b  so that as the front side  14   c  at the end  20  of the slider body  14  is brought closer to front side  12   e  of the rail  12 , the protrusions  14   a  leave the opening  12   a  in the rail.  
         [0017]     As illustrated, the spring  16  is a very simple part to make. The spring  16  is relatively a small part which can be positioned within a large space therefor defined at the lower end  20  of the slider body  14 . More specifically, the body  14  has a web wall  14   d  at its front side  14   e  that substantially spans the transverse width of the relatively flat web  12   b  of the rail and to the slightly raised side flanges  30  and  32  thereof. At the lower end  20  of the slider body  14 , the front web  14   d  has its lower end  17  spaced further from the rear side  14   e  of the body  14  than at the upper end  19  of the web  14   d  which provides the spring  16  sufficient space for being mounted toward the lower end  20  of the slider body  14 . The spring  16  is secured to the slider body  14  for travel therewith as by means of a fastener  25  such as the rivet shown in  FIG. 6  which secures the leg  16   a  to and against the underside of the slider body  14 . The other leg  16   b  is preferably situated against the interior side  12   e  of the rail web  12   b  to slide therealong and is preferably formed with an inturned end  16   c  as best seen in  FIGS. 1 and 6 . The end  16   c  is turned up to extend toward the front web wall  14   d  near the lower end  17  thereof and thus provides a curved or rounded surface which can slide along the front  12   e  of the web wall portion  12   b  of the rail. Because the spring  16  is wider than the openings  12   a  in the rail, it will freely slide thereover. The curved surface of the end portion  16   c  will not catch on the edges of the openings  12   a  when the spring slides across any opening  12   a  in either direction. The spring  16  is a simple U or V-shaped leaf spring-type member and has an intermediate curved portion  16   d  between the legs  16   a  and  16   b  to provide an inexpensive and reliable part for biasing the locking protrusions  14   a  into the locking position in an opening  12   a  in the rail  12 .  
         [0018]     Turning now in greater detail to the illustrated embodiment, the rail  12  is of metal material such as steel, and has a one-piece construction with a pair of slightly raised, side flanges  30  and  32  that extend laterally from the central web portion  12   b.  The central web  12   b  has the spaced rectangular holes or openings  12   a  therein. In other instances the rail could be formed with a different shape having spaced rows of openings in the central web  12   b  such as two rows of openings in the central web portion  12   b.  In still other instances, the openings  12   a  may be formed in the respective side flanges  30  and  32  rather than in the central web. The illustrated construction is preferred in that it provides a relatively strong, inexpensive rail. At the ends of the rail are circular holes or openings  12   c  to bolt the rail to a pillar or other portion of a vehicle.  
         [0019]     Turning now to the slider  13 , it is seen that the body  14  has a generally C-shaped cross-section formed by a stamping of metal material, preferably without any welding or other connected portions, so that the slide body  14  is one integral piece. The integral body  14  of the slider  13  is formed with the pair of inturned side-walls or legs  14   b  which extend downwardly from either lateral side of the slider front web  14   d  and include a pair of underside portions  46  (one of which is shown in  FIGS. 5 and 6 ) integrally formed on the ends of the legs  14   b  and extending laterally inward toward each other so as to slide along the back side  12   d  of the rail  12 . These underside portions  42  also extend longitudinally along the rear side  14   e  of the slider body  14 . The slider front web  14   d  and rear portions  42  extend at an incline relative to each other so that they are closer at the upper end  21  of the slider body  14  than at the lower end  27  thereof.  
         [0020]     The protrusions  14   a  are in the form of lugs or tabs formed integrally with and projecting upwardly from the inner ends  46   a  of the underside portions  46 . The ends  46   a  of the underside portions  46  are generally parallel edges  46   a  ( FIG. 3 ) which define an elongated slot  47  therebetween. This slot  47  is formed on the back or underside  14   e  of the slider body. The inturned legs  14   b  including portions  46  thereof on the slider body  14  wrap around, as best seen in  FIG. 2 , the lateral edges of the respective side flanges  30  and  32  of the rail. The upper web  14   d  of the slider body is located to slide along the top of the rail flanges  30  and  32  at the rail front side  12   e  when the spring  16  is compressed ( FIG. 7 ) against its bias force and the protrusions  14   a  are removed from a rail opening  12   a.  When the spring  16  is not compressed ( FIG. 4 ) or spaced from the bias force of the spring  16  pushes the front web wall  14   d  at the lower end  20  of the slider  14  to be substantially above or spaced from the flanges  32  and  30  of the rail  12  when the slider is in its locking position. The slider web  14   d  at its upper end  19  engages the side edges of the flanges  30  and  32  when the slider body is in the locking position, as shown in  FIG. 4 . The upper web  14   d  thus is inclined relative to the rail  12  as it extends between the upper and lower ends of the slider body  14  with the underside portions  46  extending generally parallel to the rail  12  along the bottom or rear side  12   d  thereof, as best seen in  FIGS. 4 and 5 .  
         [0021]     For the purpose of mounting the bolt, to which the D-ring is attached, the slider body  14  is formed with an upturned aperture  50  punched out and formed out of the metal of the web  14   d  the slider body. The upturned aperture  50  includes integrally upwardly or outwardly extending annular wall  52  which defines a central opening  54  therein into which the bolt for the slider assembly is received. The D-ring is mounted to swivel about the axis of the bolt in a well-known manner.  
         [0022]     For adjusting the height of the D-ring, the push force P exerted on the front web  14   d,  either directly or via the connected D-ring, compresses the spring  16  and pivots the slider body  14  about its upper end  21 . When the slider  13  is pushed by the vehicle occupant at the lower end  20 , the mechanical advantage provided by the lever arm formed by the slider body  14  via the upper fulcrum end  21  allows for easy unlocking of the slider  13  from the rail  12  for sliding therealong. This pivoting of the slider body  14  causes the underside portions  46  to shift away from back side  12   d  of the rail  12  particularly at the body lower end  20  at which the locking lugs  14   a  are formed. The spacing of the web wall  14   d  from the underside portions  46  along with the size of the lugs  14   a  is such that the pivoting action of the slider body  14  will shift the lights  14   a  out from the corresponding locking openings  12   a  in the rail  12 . Accordingly, in the unlocked position, the underside portions  46  of the slider body  14  are inclined relative to the rail  12  as they extend between the upper and lower ends of the slider body  14  with the slider web  14   d  extending in more of a parallel orientation along the front side  12   e  of the rail  12 , as best seen in  FIGS. 6 and 7 .  
         [0023]     Referring to  FIG. 1  there may also be provided a piece of trim cover  60  for the rail  12 . The illustrated trim cover  60  has a one-piece integral body, usually of molded plastic with a pair of opposed slide channels  60   a  and  60   b  which are sized and spaced to receive therein the respective side flanges  30  and  32  of the rail  12 . That is, the trim cover is slid over the rail flanges  30  and  32  to bring a set of openings  60   d  in the trim cover  60  into alignment with the openings  12   a  in the rail. Also, a pair of circular openings  60   d  are formed at the opposite ends of the trim cover for alignment with bolt receiving openings  12   c  in the rail to receive bolts to secure the rail  12  together with the trim cover  60  to the vehicle.  
         [0024]     While there have been illustrated and described particular embodiments of the present invention, it will be appreciated that numerous changes and modifications will occur to those skilled in the art, and it is intended in the appended claims to cover all those changes and modifications which fall within the true spirit and scope of the present invention.