Abstract:
A slidably retainable fastener assembly for securing loads to a track is provided with a retainer adapted to fit at least partly within a track slot and a member operating on the retainer, the member being positionable in at least a first position and a second position. When the member is positioned in the first position, the member causes the retainer to disengage the track slot thereby allowing the fastener to be movable within the track slot, and when the member is positioned in the second position, the member causes the retainer to engage the track slot thereby causing the fastener to remain stationary within the track slot.

Description:
CORRESPONDING RELATED APPLICATIONS  
       [0001]    The present application is related to U.S. application Ser. No. 09/874,979 filed on Jun. 7, 2001, and U.S. application Ser. No. 10/109,051 filed on Mar. 29, 2002 by Mark D. Snyder et al., which are incorporated by reference herein in their entirety. 
     
    
     
       BACKGROUND OF THE INVENTION  
         [0002]    1. Field of the Invention  
           [0003]    The present invention relates generally to fasteners for securing loads to a track, and more particularly, to adjustable fasteners for securing loads to a track mounted in or near a truck bed.  
           [0004]    2. Background of the Invention  
           [0005]    Fasteners for securing loads to framing, tracks, and channels have been commercially available for some time. Some conventional fasteners used in automotive track applications will be briefly described below.  
           [0006]    Conventional track fasteners have been designed to be removable and/or relocateable along a track slot length. Many of these conventional track fasteners employ a rotatable locking base portion that engages locking teeth inside the track slot or on a locking mechanism to securely retain the fastener within the track slot, and to facilitate relocation along the track slot length. These devices, however, can be difficult to install and use, which detracts from their desirability in consumer environments such as original equipment manufactured (OEM) vehicles (e.g., pickup trucks, mini-vans, sport-utility vehicles (SUV) etc.). Often, conventional track fasteners can only be loaded from an end of the track slot (i.e., their design does not facilitate top down loading), and are thus difficult to replace if broken. Also problematic, many of these fasteners have limited load capacities, such as fasteners available on roof racks, and are thus unsuitable for applications such as truck beds and cargo shipping where heavier loads are placed.  
           [0007]    Other conventional track fasteners (e.g., U.S. Pat. Nos. 4,410,298, 4,784,552, and Re. 36,681, which are incorporated by reference herein in their entirety) have been designed with a center through bolt to apply pressure between a top plate mounted above the track slot and a base plate mounted within the track slot. The bolt can be tightened to “clamp” the fastener in place, thereby securely retaining the fastener within the track slot, or loosened to facilitate relocation along the track slot length. Clamp styled fasteners are often used to temporarily attach rails to the top side of a truck bed for tonneau covers and the like, and are generally relocatable along the length of the track slot. These devices, however, often require a user to have a wrench to loosen/tighten the bolt, which detracts from their ease of use.  
           [0008]    Some conventional track fasteners have a track slot with predetermined fastening locations. See, for example, U.S. Pat. No. 4,850,769, which is incorporated by reference herein in its entirety. In one such device, predetermined fastening locations are set at enlarged openings in a top surface of the track in which a movable car “drops into” to retain the movable car in that particular position. The car may include a spring biased vertically movable latch to releasably engage the openings. These devices, however, are limited to the specific predetermined fastening locations, which reduces their utility for many applications. Moreover, as with other conventional track fasteners, these devices typically require the car to be loaded into the track slot from one end of the track slot, making it substantially more difficult to repair or replace a given fastener.  
           [0009]    Thus, a need exists for an improved track slot fastening device.  
         SUMMARY OF THE INVENTION  
         [0010]    The present invention is directed to overcoming or at least reducing the effects of one or more of the problems set forth above and other problems in the prior art.  
           [0011]    According to one embodiment of the present invention, a fastener assembly for securing loads to a track is provided, the fastener assembly being slidably retainable within a track slot of the track. The fastener assembly comprises a retainer adapted to fit at least partly within the track slot, a cam member operating on the retainer, the cam member being positionable in at least a first position and a second position, and a pressure plate positioned above the track and below the cam member, the pressure plate applying a pressure on a top surface of the track in response to the position of the cam member. When the cam member is positioned in the first position, the cam member causes the retainer to disengage the track slot thereby allowing the fastener to be movable within the track slot, and when the cam member is positioned in the second position, the cam member causes the retainer to engage the track slot thereby causing the fastener to remain stationary within the track slot.  
           [0012]    According to another embodiment of the present invention, a slidable fastening device for securing an object to a track is provided, the fastening device being slidable along a track slot of the track. The slidable fastening device comprises a base portion positionable at least partly within the track slot, the base portion being horizontally displaceable along the track slot and vertically displaceable in a direction substantially perpendicular to a top surface of the track slot, a pressure plate positioned above the base portion for applying a pressure to the top surface of the track slot, and a pivotable actuator for selectably applying a force on the pressure plate thereby vertically displacing the base portion between an engagement position and a released position, the engagement position fixing the position of the fastening device within the track slot, and the released position allowing slidable displacement along the track slot.  
           [0013]    According to another embodiment of the present invention, a method of securing an object to a track including a track slot is provided, comprising pivoting a cam member to a retain position, vertically displacing a retainer positioned within the track slot in response to motion of the cam member, applying a substantially uniform force across a top surface of the track slot opposite to the retainer, and engaging the retainer with an inner surface of the track slot.  
           [0014]    According to another embodiment of the present invention, a fastener assembly for securing loads to a track is provided, the fastener assembly being slidably retainable within a track slot of the track. The fastener assembly comprises a retainer including a base portion adapted to fit at least partly within the track slot, and a ratchet lock for locking the retainer to the track slot.  
           [0015]    According to another embodiment of the present invention, a method of securing an object to a track including a track slot is provided, comprising rotating a ratchet lock, vertically displacing a member positioned within the track slot in response to rotating the ratchet lock, and locking a retainer to the track slot via the vertically displaced member.  
           [0016]    According to another embodiment of the present invention, a fastener assembly for securing loads to a track is provided, the fastener assembly being slidably retainable within a track slot of the track. The fastener assembly comprises a retainer adapted to fit at least partly within the track slot, and a pin lock operating on the retainer, the pin lock being positionable in at least a first position and a second position. When the pin lock is positioned in the first position, the pin lock causes the retainer to disengage the track slot thereby allowing the fastener assembly to be movable within the track slot, and when the pin lock is positioned in the second position, the pin lock causes the retainer to engage the track slot thereby causing the fastener assembly to remain stationary within the track slot.  
           [0017]    According to another embodiment of the present invention, a fastener assembly for securing loads to a track is provided, the fastener assembly being slidably retainable within a track slot of the track. The fastener assembly comprises means for locking a retainer to the track slot in a locked position, means for selectably releasing the retainer from the locked position, and means for securing the load to the retainer.  
           [0018]    According to another embodiment of the present invention, a fastener assembly for securing loads to a track is provided, the fastener assembly being slidably retainable within a track slot of the track. The fastener assembly comprises a retainer adapted to fit at least partly within the track slot, a rotatable handle operating on the retainer, the rotatable handle being rotatable between at least an engagement position and a release position, and a pressure applicator positioned above the track and below the rotatable handle, the pressure applicator applying a pressure on a top surface of the track in response to the position of the rotatable handle.  
           [0019]    According to another embodiment of the present invention, a method of securing an object to a track including a track slot is provided, comprising rotating a rotatable handle thereby vertically displacing the rotatable handle relative to a pressure applicator positioned above the track, and vertically displacing a retainer positioned within the track slot between an engagement position and a release position relative to the vertical displacement of the pressure applicator.  
           [0020]    According to another embodiment of the present invention, a slidably retainable fastener assembly for securing loads to a track is provided, comprising a retainer adapted to fit at least partly within a track slot of the track, and a cam member operating on the retainer, the cam member being positionable in at least a first position and a second position. When the cam member is positioned in the first position, the cam member causes the retainer to disengage the track slot thereby allowing the fastener to be movable within the track slot, and when the cam member is positioned in the second position, the cam member causes the retainer to engage the track slot thereby causing the fastener to remain stationary within the track slot. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0021]    The foregoing advantages and features of the invention will become apparent upon reference to the following detailed description and the accompanying drawings, of which:  
         [0022]    [0022]FIG. 1 is a sectional view of a fastener assembly according to an embodiment of the present invention.  
         [0023]    [0023]FIG. 2 is an exploded view of the fastener assembly of FIG. 1.  
         [0024]    [0024]FIG. 3 is a sectional view of a fastener assembly according to another embodiment of the present invention.  
         [0025]    [0025]FIG. 4 is a perspective view of a retainer with a threaded shaft according to an embodiment of the present invention.  
         [0026]    FIGS.  5 A- 5 G are views of a ratchet lock according to an embodiment of the present invention.  
         [0027]    [0027]FIG. 6 is a sectional view of another fastener assembly according to an embodiment of the present invention.  
         [0028]    [0028]FIG. 7 is a sectional view of the fastener assembly of FIG. 6 in a locked position according to an embodiment of the present invention.  
         [0029]    [0029]FIG. 8 is a sectional view of the fastener assembly of FIG. 6 in a released position according to an embodiment of the present invention.  
         [0030]    [0030]FIG. 9 is a drawing of a pin lock configuration according to an embodiment of the present invention.  
         [0031]    [0031]FIG. 10 is a perspective view of the fastener assembly of FIG. 6 in a released position according to an embodiment of the present invention.  
         [0032]    [0032]FIG. 11 is a perspective view of the fastener assembly of FIG. 6 in an engagement position according to an embodiment of the present invention.  
         [0033]    [0033]FIG. 12 is a perspective view of a variation on the fastener assembly of FIG. 6 in a released position according to an embodiment of the present invention.  
         [0034]    [0034]FIG. 13 is a sectional view of a fastener assembly with ramped or angled portions according to an embodiment of the present invention.  
         [0035]    [0035]FIG. 14 is a partial sectional view of the fastener assembly of FIG. 13 along plane XIV-XIV according to an embodiment of the present invention. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0036]    Reference will now be made in detail to presently preferred embodiments of the invention. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts.  
         [0037]    The following description of the present invention will describe implementations of the present invention in reference to a track slot used in a truck bed. One such implementation is described in copending U.S. patent application Ser. No. 09/874,979 filed Jun. 7, 2001, by Michael D. Anderson et al., which is incorporated by reference herein in its entirety. Additional improvements and variations are described in the aforementioned corresponding related applications. Other implementations are also contemplated, as would be readily apparent to one of ordinary skill in the art after reading this disclosure.  
         [0038]    It should be appreciated that the term “track slot” as used in the present application refers to the entire internal volume of the track. Hence, “track slot” includes the space substantially between two upper inwardly protruding portions at the top of the track, and the volume underneath the protruding portions to a bottom surface of the track. It should also be appreciated that the term “load” as used in the present application refers to a force applied to a fastener assembly by an object secured thereto. This “load” may include, for example, a horizontal force acting substantially along a plane of a vehicle body, a vertical force acting upwards and away from the aforementioned plane of the vehicle body, or a combination of the two.  
         [0039]    A fastener assembly  100  retainable within a track slot according to an embodiment of the present invention is shown in the sectional view of FIG. 1, and the exploded view of FIG. 2. As shown, track  110  is substantially C shaped, with two inward projecting extensions  112 . The two extensions  112  include abscesses  114  which are preferably smooth, but can be serrated if desired.  
         [0040]    A pressure plate  140  (e.g., a pressure applicator) is shown positioned above the track  110 , applying a substantially uniform pressure on a top surface of the track  110 . Preferably, pressure plate  140  is flanged at opposite lateral ends, such that the flanged portions properly seat the pressure plate  140  on the top surface of the track  110 .  
         [0041]    A belleville washer  190  (i.e., one type of spring) positioned adjacent to pressure plate  140  is shown in a decompressed configuration in FIG. 2, and a compressed configuration in FIG. 1. A washer  150  is shown positioned between belleville washer  190  and a handle  170 . Preferably, washer  150  has a diameter substantially equal to the compressed diameter of belleville washer  190 . Handle  170  is coupled with a retainer  130  at end A (represented by separable bolt  120 ) of shaft B; the shaft B including at one end C at least one of an eyelet  180 , a hook, a ring, a carabiner, a clamp, a clasp, or other suitable tie down or attachment connection. As shown, the shaft B may comprise a bolt  120  or other suitable coupler.  
         [0042]    Positioned within the track slot is retainer  130 . Preferably, retainer  130  has a width substantially equal to the inner width of the track slot such that retainer  130  substantially conforms to an inner width of the track slot. Also, retainer  130  is preferably configured so as to have a size and shape that allows for top down loading (i.e., in a direction substantially perpendicular to the top surface of track  110 ) into the track  110 . More specifically, retainer  130  is configured to have angled/cut corners on diagonally opposite edges such that the retainer  130  can be rotated about 90° once it is placed within the track  110 .  
         [0043]    As shown best in FIG. 2, retainer  130  preferably includes channel portions  134  for engaging ribs  116  of abscesses  114 . Furthermore, retainer  130  also may include serrated edges  132  outside of the channel portions  134  for engaging abscesses  114  of the track  110 . Preferably, the retainer  130  is made of aluminum or steel, preferably cold headed or forged. Such a material is selected such that the retainer  130  has a high strength and durability, and is resistant to corrosion. The operation of the fitting assembly will now be described in detail below.  
         [0044]    As shown in FIG. 1, the fitting assembly is configured in an engagement position, where serrated edges  132  of retainer  130  engage abscesses  114  of track  110 . A slight gap is present between the bottom of bolt  120  and the bottom surface of track  110 . Serrated edges  132  help to fix the fitting assembly securely in place along the track  110  when engaging abscesses  114  of track  110 .  
         [0045]    To release the fitting assembly, the handle  170  is pivoted about a pin  160  to a disengagement position, preferably about 180° with respect to the engagement position shown in FIG. 1. During pivoting, an integrated cam surface  172  of handle  170  releases the force on washer  150  which decompresses belleville washer  190  from pressure plate  140 , thereby vertically displacing retainer  130 . Serrated edges  132  of retainer  130  then disengage abscesses  114  of track  110 , allowing the fitting assembly to slide freely along the track  110 .  
         [0046]    It should be appreciated that the holes in handle  170  (see FIG. 2) are preferably off center (i.e., closer to the top), such that when the handle  170  is pressed down, the retainer  130  is lifted and tightened into the engagement position, and when the handle  170  is lifted, the retainer  130  loosens. Hence, this configuration causes the above described engagement and disengagement operation.  
         [0047]    The above described fastener assembly is particularly advantageous over conventional approaches, as it is relatively easy to use and inexpensive to manufacture. Belleville washer  190  and the shape of cam surface  172  also provide for automatic locking of the handle  170  in a given position, which improves the ease of use. Moreover, the above described fastener assembly requires no tools to relocate it along the track, and can be relocated to any position along the track (i.e., not just at predetermined fastening locations). Also, the invention eliminates any uncertainty as to whether the fastener is tightened too much or too little. Thus, the present invention provides substantial improvements over conventional fasteners.  
         [0048]    A fastener assembly retainable within a track slot according to another embodiment of the present invention is shown in FIG. 3, with parts thereof depicted in greater detail in FIGS. 4 and 5A- 5 G. The fastener assembly  200  according to this second embodiment comprises a cleat  210  including a base portion  220  adapted to fit within the track slot  110  (preferably in such a way as to provide for top-down loading). The cleat  210  is locked to the track slot  110  (i.e., in an engagement position) via ratchet lock  240 . It should be appreciated that the cleat  210  refers to any slidable member adapted to fit within the track slot  110 . It should also be appreciated that the term “ratchet” refers to a device that is tightened as it rotates until a predetermined amount of torque is attained, and then spins freely, re-releases, locks, or indicates in some manner that the required fastening torque has been attained.  
         [0049]    Hence, the ratchet lock  240  is preferably configured to limit the maximum fastening torque applied to the ratchet lock  240  to prevent damage to the track  110  and/or the fastener assembly  200  from over tightening. Furthermore, the ratchet lock  240  is also configured to set a minimum fastening torque applied to the ratchet lock  240  to prevent undertightening of the fastener assembly  200 . In operation, the ratchet lock will “click” when an appropriate torque is attained, similar to a gas cap being screwed on after refueling. As will be set forth in greater detail below, one such ratchet lock  240  is shown in the views of FIGS.  5 A- 5 G.  
         [0050]    The ratchet lock  240  preferably comprises a rotatable base portion  242  (e.g., a header) coupled to a retainer  250  via a threaded shaft  260  (see FIG. 4). The rotatable base portion  242  is configured to thread onto the shaft  260  to raise/lower the retainer  250 . According to one aspect of the present invention, the rotatable base portion  242  includes a hex nut (not shown) placed in the center portion of the rotatable base portion  242 . Alternatively, the rotatable base portion  242  may be drilled and threaded to directly thread onto the shaft  260 .  
         [0051]    As shown in FIGS.  5 A- 5 G, the base portion  242  can be formed with one or more torque cantilevers  244 , preferably a plurality of torque cantilevers  244  extending all the way around a vertical surface of the rotatable base portion  242 . As shown best in FIG. 5E, the torque cantilevers  244  engage corresponding notched portions  233  formed on an inner surface of rotatable top  243 . The torque cantilevers  244  “spin” when a fastening torque greater than a predetermined maximum is applied to the ratchet lock  240 , or when the rotatable top  243  is rotated in a counterclockwise direction. When the rotatable top  243  is rotated in a clockwise direction, the torque cantilevers  244  ratchet engage the notched portions  233  formed on the inner surface of rotatable top  243 , thereby rotating the rotatable base portion  242  on the shaft  260 , thereby vertically displacing the retainer  250  within the track slot  110 . The vertical displacement of retainer  250  locks the cleat  210  to the track slot  110  (i.e., an engagement position), or releases the cleat  210  from the track slot  110  (i.e., a disengagement position).  
         [0052]    As shown best in FIG. 5F (an enlargement of the bottom left corner of FIG. 5G), the rotatable base portion  242  is preferably rotatably fixed relative to the rotatable top  243  by a protrusion  259  extending within the groove  257  formed along an exterior surface of the rotatable top  243 . As shown in FIG. 5B, preferably four protrusions  259  are formed, though the number and spacing along rotatable base portion  242  may vary. Other attachment schemes are also within the scope of this invention, as would be readily apparent to one of ordinary skill in the art after reading this disclosure.  
         [0053]    As shown in FIG. 3, the fastener assembly  200  also includes a tie down  230  for securing loads to the fastener assembly  200 . portion  220  of cleat  210 .  
         [0054]    In addition to the aforementioned benefits of previously described embodiment(s) of the present invention, the fastener assembly  200  of the present invention provides for a cosmetically appealing fastener by partially hiding the ratchet lock  240  via the arc shaped tie down  230 . Furthermore, the “spin” torque cantilevers  244  help prevent over tightening of the ratchet lock  240  and indicate to the user that the fastener assembly  200  is fully tightened (e.g., by generating audible clicking sounds when the fastener assembly  200  is sufficiently tight), thereby reducing any chance of damaging the fastener assembly  200  or track  110  due to over tightening. Hence, the fastener assembly  200  provides for substantial improvements over existing fasteners.  
         [0055]    A fastener assembly retainable within a track slot according to another embodiment of the present invention is shown in FIGS.  6 - 12 . The fastener assembly  300  according to this third embodiment comprises a retainer  330  adapted to fit within the track  110 . Similar to the first embodiment, the retainer  330  is vertically displaceable within the track  110 , such that it engages abscesses of the track  110  to secure the fastener assembly  300  to the track  110 . Retainer  330  is preferably configured so as to have a size and shape that allows for top down loading (i.e., in a direction substantially perpendicular to the top surface of track  110 ) into the track slot.  
         [0056]    According to this third embodiment, the fastener assembly  300  includes a pin lock  305  operating on the retainer  330 , the pin lock  305  being operable in a released/disengagement position (FIGS. 6, 8,  10 ,  12 ), and in a locked/engagement position (FIGS. 7, 11). The pin lock  305  includes a first pin  360  coupled to the retainer  330  via shaft  320  and linked to a second pin  370  via a first locking arm  390 . A welded base portion  350  (e.g., a lockplate) or the like may be used to couple the shaft  320  to the retainer  330  depending on the particular implementation. The pin lock  305  further includes a third pin  380  coupled to the handle operating on the pin lock  305  and linked to the second pin  370  via a second locking arm  395 . Second locking arm  395  is preferably an integral part of the handle  312  (FIGS. 10, 11) but is described as a separate arm for illustration purposes.  
         [0057]    The operation of the pin lock  305  will now be described in reference to FIG. 9. For purposes of explanation, both the “released” position (i.e., Φ about 40°) and the “locked” position (i.e., θ about 10°) are depicted in FIG. 9. Preferably, first locking arm  390  has a length L 1  of about 14 mm, and second locking arm has a length L 2  of about 9 mm. It should be appreciated that L 1 +L 2 ≅M 1 , the maximum length of the locking arms  390  and  395  in combination.  
         [0058]    Assuming the third pin  380  remains substantially in the same location in the released position and in the locked position, the first pin  360  is located at a distance M 3  from one end of the maximum length M 1  when in the locked position. The first pin  360  is vertically displaceable within the fastener assembly  300  to displace the retainer  330  between the locked position and the released position Similarly, in the released position, the first pin  360  is located at a distance M 2  from one end of the maximum length M 1 . In operation, the first pin  360  and the third pin  380  are aligned along a locking axis  302  substantially bisecting the first pin  360  and the third pin  380  when the pin lock  305  is positioned in the locked position. Furthermore, the first pin  360  and the third pin  380  are aligned along a released axis  304  substantially bisecting the first pin  360  and the third pin  380  when the pin lock  305  is positioned in the released position.  
         [0059]    This configuration provides for vertical displacement of the retainer  330  coupled to the vertically displaced first pin  360 , and a secure “lock” of the retainer  330  to the track  110  when the pin lock  305  is in the locked position. It should be appreciated that Φ must be large enough to provide sufficient travel to take up the entire release clearance. This provides for a simple locking mechanism to lock the fastener assembly  300  to the track  110 , and also provides for an easy release to allow the fastener assembly  300  to be slid along track  110  to another position. Hence, in addition to various advantages of the aforementioned embodiments of the present invention, this configuration also provides for many improvements over conventional fasteners.  
         [0060]    For loading purposes, the fastener assembly  300  may be provided with spring  321 , first loading projection  322 , second loading projection  333 , and running surface  334  as shown best in FIG. 12. To load the fastener assembly  300 , the fastener assembly  300  is placed on top of a track  110  rotated 90° about a vertical axis therefrom with respect to the operational position shown in FIGS. 10 and 11. The second loading projection  333  is configured to have a length greater than a width of the slot of the track  110 , such that the second loading projection  333  rests on a top surface of the track  110  in a loading position.  
         [0061]    The first loading projection  322  operates with the spring  321  to force a gap between a top surface of the retainer  330  and a bottom surface of the second loading projection  333 . This gap is designed to be large enough such that the retainer  330  can be rotated 90° within the track  110  once the fastener assembly  300  is placed in the loading position. The entire fastener assembly  300  is then rotated 90° to the operation position shown in FIGS. 10 and 11. The second loading projection  333  is thus configured to have a width smaller than a width of the slot of the track  110 , such that the second loading projection  333  rests within the track  110  in the operational position, and the running surface  334  is configured to rest on a top surface of the track  110  in the operational position as shown in FIGS. 10 and 11. Once in the operational position, the fastener assembly  300  can be used as indicated above.  
         [0062]    A fastener assembly retainable within a track slot according to another embodiment of the present invention is shown in FIGS. 13 and 14, with a portion cut along plane XIV-XIV shown in greater detail in FIG. 14. The fastener assembly  400  according to this embodiment includes a rotatable handle  410  (e.g., a thumb-wheel) within an outer tie down  411  for securing loads to the fastener assembly  400 . The rotatable handle  410  operates retainer  450  via shaft  420 . A spring  430  is provided in a space between the rotatable handle  410  and pressure plate  440 , such that the spring  430  applies a vertical force on the pin  443  with respect to the pressure plate  440 .  
         [0063]    To operate the fastener assembly  400 , the rotatable handle  410  includes an angled running surface  445  interfacing pin  443 . As the rotatable handle  410  is rotated between a locked position and a released position, the angled running surface  445  vertically displaces the pin  443  coupled to the retainer  450  with respect to the pressure plate  440 . The rotatable handle  410  cannot be vertically displaced beyond a maximum amount due to intersecting the outer tie down  411 , thus the rotatable handle  410  vertically displaces the pin  443  via the angled surface  445 , which similarly displaces retainer  450  via shaft  420 , thereby locking or unlocking the fastener assembly  400  from the track slot  110 .  
         [0064]    The interface between the angled running surface  445  and the pin  443  can be designed to prevent overtightening of the fastener assembly  400  and to default to a tightened condition when “partial” tightening occurs. By way of example, the angled running surface may include a notch (not shown) for receiving the pin  443  at a loosened state near a “top” of the angled running surface  445 . If an operator only partially loosens the fastener assembly  400 , thereby not reaching the notch, the spring  430  forces the pin  443  to slide down the angled running surface  445  back into a tightened/engaged position. To prevent overtightening, the spring  430  is configured to apply the maximum retention force on the retainer  450  when the pin  443  is at the “bottom” of the angled running surface  445 . Hence, both overtightening prevention and default engagement can be achieved.  
         [0065]    It should be appreciated that various aspects of the aforementioned embodiments may be combined and/or modified amongst the various embodiments of the present invention. Thus, for example, the second and/or third embodiments may be provided with channel portions  134  for engaging ribs  116  of abscesses  114 , and/or serrated edges  132  outside of the channel portions  134  for engaging abscesses  114  of the track  110 . Furthermore, the second and/or third embodiments may be configured to allow for top down loading into the track  110 , to make it easier to replace or add fasteners. Other variations are also possible, as would be readily apparent to one of ordinary skill in the art after reading this disclosure.  
         [0066]    The foregoing description of preferred embodiments of the invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed, and modifications and variations are possible in light of the above teachings or may be acquired from practice of the invention. The embodiments were chosen and described in order to explain the principles of the invention and its practical application to enable one skilled in the art to utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated. It is intended that the scope of the invention be defined with reference to the claims appended hereto, and their equivalents.