Abstract:
A tonneau system for a cargo box of a pickup truck having a framework. The framework having a cross bow member for supporting a cover and being positionable generally over the cargo box of the pickup truck. The tonneau system further includes a latch assembly pivotally coupled to the cross bow member. The latch assembly is positionable in a latched position engagable with the cargo box of the pickup truck, an unlatched position disengagable with the cargo box of the pickup truck, and a nested position substantially retracted from the unlatched position and received within the cross bow member. The tonneau system may further include a biasing member that is substantially received within a portion of the latch assembly to improve consistent spring rates across the actuation range.

Description:
FIELD OF THE INVENTION  
       [0001]     The present invention generally relates to coverings for pickup trucks and, more particularly, relates to a latch for use with a foldable tonneau cover system.  
       BACKGROUND OF THE INVENTION  
       [0002]     Tonneau covers have been used for a number of years to cover the cargo box of pickup trucks against dirt, debris, and other environmental contaminants and to improve the aesthetic quality thereof. Originally, tonneau covers were designed by upholstery shops and typically made of vinyl covered fabrics or canvas. The material was often doubled over along its edges for added strength and appearance. Male snaps were then attached to the sides of the cargo box of the pickup truck via fasteners, while female snaps were attached along the edges of the cover. Wooden bows were sometimes used to span the cargo box and ensure that the cover remained high enough to drain water. Unfortunately, these covers were sometimes difficult to handle and/or manufacture, and occasionally failed to protect the cargo box.  
         [0003]     More recently, foldable tonneau covers are often more desirable in that the conveniently cover the bed of the pickup truck for cargo protection. However, when not in use, the foldable tonneau cover may be folded toward the rear of the passenger cabin. Generally, foldable tonneau covers include a frame network of cross bows, a tarp or covering operably coupled to and spanning the frame network, a latching system for coupling the frame network to the pickup truck and a means for stowing the latching system, and a hinge system for hingedly coupled adjacent sections of the foldable tonneau cover. However, the known prior art fails to maximize the ease and effectiveness of foldable tonneau covers and, thus, many foldable tonneau covers suffer from numerous disadvantages.  
         [0004]     By way of example, existing latching systems generally employ an over center cam lock arrangement to fasten the tonneau cover in place relative to the pickup truck. The cam lock hooks onto the downwardly projecting flange of the truck bed. This cam lock is adjustable by rotating a threaded cam pivot to permit attachment of the latching system to pickup trucks with differing length downwardly projecting flanges. However, this adjustment mechanism leads to various problems or failures by users. For instance, if the user adjusts the cam lock too tight, the cam lock may break or fracture the plastic bow(s) in the frame network of the tonneau cover. It should be readily appreciated that such a failure may lead to the tonneau cover becoming loose and blowing off from the vehicle. Alternatively, the cam lock may be fastened loosely, which again may lead to the tonneau cover becoming loose and blowing off. Still further, it is possible that the cam lock may be inadvertently pushed back over center by movement of cargo or the like, which again may lead to the tonneau cover becoming loose. Finally, conventional cam locks and/or clamps often require the clamp to be manipulated to properly align with the truck bed.  
         [0005]     When conventional foldable tonneau covers are stowed, that is when the tonneau cover is folded and positioned generally adjacent the passenger cabin, it is important to ensure that any clamps or latching members are properly stowed to prevent puncture of the cover material. To this end, presently conventional latch systems must be rotated, folded up, clipped to the side and rotated, and then folded flat for no puncture stowage. As should be readily appreciated, this is a complex procedure that often leads to inadvertent damage to the tonneau cover.  
         [0006]     Similarly, conventional foldable tonneau covers often employ an attachment that slides within a receiving groove to retain the tarp or covering to the frame network or bows. Although this technique serves to generally prevent the tarp or covering from becoming disengaged from the frame network, assembly of such is often burdensome due to the sliding nature of the attachment. In fact, these sliding attachments often require the complete disassembly of the tonneau cover to repair the tarp or covering. Additionally, due to the need to gain access to the ends of the frame network or bows to receive the sliding attachment member, alternative assembly sequences are limited.  
         [0007]     Furthermore, it is obvious that in order for a foldable tonneau cover to fold, a hinge system must be provided. However, conventional hinge systems suffer from many disadvantages. For example, when using a single pivot hinge, the tarp or covering may be pinched near the bend area. This may lead to failure, in the form of a tear or rip, of the tarp or covering, thereby exposing the contents of the cargo box to the environment. Accordingly, there exists a need in the relevant art to overcome the disadvantages of the prior art.  
       SUMMARY OF THE INVENTION  
       [0008]     According to the principles of the present invention, a tonneau system for a cargo box of a pickup truck is provided having advantageous construction. The tonneau system includes a framework having a cross bow member for supporting a cover. The framework being positionable generally over the cargo box of the pickup truck. The tonneau system further includes a latch assembly pivotally coupled to the cross bow member. The latch assembly is positionable in a latched position engagable with the cargo box of the pickup truck, an unlatched position disengagable with the cargo box of the pickup truck, and a nested position substantially retracted from the unlatched position and received within the cross bow member. The tonneau system may further include a biasing member that is substantially received within a portion of the latch assembly to improve consistent spring rates across the actuation range.  
         [0009]     Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0010]     The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein:  
         [0011]      FIG. 1  is a perspective view illustrating a foldable tonneau cover according to the principles of the present invention positioned upon a cargo box of a pickup truck;  
         [0012]      FIG. 2  is a perspective view illustrating the foldable tonneau cover in a folded position;  
         [0013]      FIG. 3  is a perspective view illustrating the foldable tonneau cover with a rear tonneau section folded upon a middle tonneau section;  
         [0014]      FIG. 4  is an enlarged perspective view illustrating the forward clamping system of the front tonneau section of the present invention;  
         [0015]      FIG. 5  is a perspective view illustrating the foldable tonneau cover with the rear tonneau section extended onto the cargo box of the pickup truck;  
         [0016]      FIG. 6  is an enlarged perspective view illustrating the rear clamping system of the rear tonneau section of the present invention being spaced apart from the sidewall of the cargo box;  
         [0017]      FIG. 7  is an enlarged perspective view illustrating the rear clamping system of the rear tonneau section of the present invention positioned adjacent to, yet extended from the sidewall of the cargo box;  
         [0018]      FIG. 8  is a perspective view illustrating the foldable tonneau cover with the rear tonneau section folded upon the middle tonneau section and the rear clamping system nested within a cross bow member;  
         [0019]      FIG. 9  is an enlarged perspective view illustrating the rear clamping system of the rear tonneau section being moved from an extended to the nested position within a cross bow member;  
         [0020]      FIG. 10  is a front perspective view illustrating the foldable tonneau cover in the folded position with retaining clasps fastened;  
         [0021]      FIG. 11  is an enlarged perspective view illustrating the rear clamping system of the rear tonneau section;  
         [0022]      FIG. 12  is an enlarged perspective view illustrating the rear clamping system of the rear tonneau section being moved from an extended to the nested position within a cross bow member;  
         [0023]      FIG. 13  is an exploded perspective view illustrating the rear clamping system of the rear tonneau section;  
         [0024]      FIG. 14  is a side view illustrating a dual linkage hinge assembly coupled between adjacent tonneau sections in a flat position;  
         [0025]      FIG. 15  is a side view illustrating the first hinge link and the second hinge link of  FIG. 14  with additional portions of dual linkage hinge assembly removed for clarity;  
         [0026]      FIG. 16  is a side view illustrating the dual linkage hinge assembly coupled between adjacent tonneau sections in an intermediate position;  
         [0027]      FIG. 17  is a side view illustrating the first hinge link and the second hinge link of  FIG. 16  with additional portions of dual linkage hinge assembly removed for clarity;  
         [0028]      FIG. 18  is a side view illustrating the dual linkage hinge assembly coupled between adjacent tonneau sections in a folded position;  
         [0029]      FIG. 19  is a side view illustrating the first hinge link and the second hinge link of  FIG. 18  with additional portions of dual linkage hinge assembly removed for clarity;  
         [0030]      FIG. 20  is a perspective view illustrating the dual linkage hinge assembly coupled between adjacent tonneau sections in a flat position;  
         [0031]      FIG. 21  is a perspective view illustrating the first hinge link and the second hinge link of  FIG. 20  with additional portions of dual linkage hinge assembly removed for clarity;  
         [0032]      FIG. 22  is a perspective view illustrating the dual linkage hinge assembly coupled between adjacent tonneau sections in an intermediate position;  
         [0033]      FIG. 23  is a perspective view illustrating the first hinge link and the second hinge link of  FIG. 22  with additional portions of dual linkage hinge assembly removed for clarity;  
         [0034]      FIG. 24  is a perspective view illustrating the dual linkage hinge assembly coupled between adjacent tonneau sections in a folded position;  
         [0035]      FIG. 25  is a perspective view illustrating the first hinge link and the second hinge link of  FIG. 24  with additional portions of dual linkage hinge assembly removed for clarity;  
         [0036]      FIG. 26  is a perspective view illustrating a fabric cover attachment assembly to be installed in a side member;  
         [0037]      FIG. 27  is a side view illustrating the fabric cover attachment assembly to be installed in the side member with portions removed for clarity;  
         [0038]      FIG. 28  is a side view illustrating the fabric cover attachment assembly installed in the side member with portions removed for clarity;  
         [0039]      FIG. 29  is a perspective view illustrating an attachment mechanism; and  
         [0040]     FIGS.  30 ( a )-( c ) are progressive side views illustrating assembly of the attachment mechanism. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0041]     The following description of the preferred embodiment is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses.  
         [0042]     With reference to  FIG. 1 , a pickup truck  100  is shown having a foldable tonneau system  12  for use with pickup truck  100 . Pickup truck  100  generally includes a cargo box  102  and a passenger cabin  104 . Cargo box  102  includes a front wall (not shown), a left sidewall  108 , a right sidewall  110 , and a rear wall or tailgate  112 . It should be understood that right sidewall  110  and left sidewall  108  of pickup truck  100  are identical, yet arranged in mirrored symmetry. Accordingly, in the interest of brevity, only one side will be discussed in detail below in connection with foldable tonneau system  12  unless noted otherwise  
         [0043]     Still referring to  FIG. 1 , foldable tonneau system  12  includes a flexible, stretchable fabric cover  14  that is drawn tightly over a plurality of tonneau sections  16 . It should be understood that the principles of the present invention are equally applicable to foldable tonneau systems having two, three, or more sections, each foldable relative to adjacent sections. However, for purposes of this disclosure, a foldable tonneau system having three tonneau sections  16   a,    16   b,  and  16   n  will be described. This configuration should not be regarded as limiting the claims herein. Tonneau sections  16   a - 16   n  may be referred to herein as front tonneau section  16   a,  middle tonneau section  16   b,  and rear tonneau section  16   n.    
         [0044]     Each of the plurality of tonneau sections  16   a - 16   n  includes an internal framework of support members that are attached to one another to form a rectangular frame. Specifically, front tonneau section  16   a  includes a front rail member  20  fixedly coupled to a pair of side members  22  via a corner insert  24 . Corner insert  24  is preferably rounded along an exterior surface to prevent stress concentrations in fabric cover  14 . Corner insert  24  includes a pair of male portions (not shown) sized to be fixedly received and engaged within front rail member  20  and the pair of side members  22 . A corner brace  26  is fixedly coupled, via conventional threaded fasteners, between front rail member  20  and each side member  22  to provide improved structural integrity. Front tonneau section  16   a  further includes a cross bow member  28  being generally parallel to front rail member  20  and spaced apart therefrom. Cross bow member  28  is generally C-shaped in cross section and is fixedly coupled to the pair of side members  22  via a corner brace  30  disposed on opposing ends thereof. It should be understood that additional or alternative connection features may be employed to couple cross bow member  28  to the pair of side members  22 . The pair of side members  22  is adapted to rest upon a top surface of sidewalls  108  and  110 .  
         [0045]     Similarly, rear tonneau section  16   n  includes a rear rail member  32  fixedly coupled to a pair of side members  34  via a corner insert  36 . Corner insert  36  is preferably rounded along an exterior surface to prevent stress concentrations in fabric cover  14 . Corner insert  36  includes a pair of male portions (not shown) sized to be fixedly received and engaged within rear rail member  32  and the pair of side members  34 . A corner brace  38  is fixedly coupled, via conventional threaded fasteners, between rear rail member  32  and each side member  34  to provide improved structural integrity. Rear tonneau section  16   n  further includes a cross bow member  40  being generally parallel to rear rail member  32  and spaced apart therefrom. For manufacturing simplicity, cross bow member  40  can be identical to cross bow member  28  in cross section and side members  34  can be similar to, but vary in length relative to, side member  22 . However, it should be appreciated that this is not required.  
         [0046]     Cross bow member  40  is fixedly coupled to the pair of side members  34  via a corner brace  42  disposed on opposing ends thereof. Again, it should be understood that additional or alternative connection features may be employed to couple cross bow member  40  to the pair of side members  34 . The pair of side members  34  is adapted to rest upon a top surface of sidewalls  108  and  110 .  
         [0047]     As seen in FIGS.  29 - 30 ( c ), it should be understood that cross bow members  28 ,  40 , and  46  can be coupled to side members  22 ,  34 , and  44 , respectively, via attachment mechanism  700 . Attachment mechanism  700  can include a U-shaped bracket member  702 . U-shaped bracket member  702  can include a pair of generally parallel legs  704  extending from a base portion  706 . The pair of generally parallel legs  704  can each be sized in width and thickness to be slidable received and captured within outboard slots  708  formed in cross bow member  28 ,  40 , and  46 . Outboard slots  708  can be formed separate from upturned slots  314 . Such arrangement permits free movement of rear latch assembly  300  without interference with attachment mechanism  700 .  
         [0048]     Still referring to FIGS.  29 - 30 ( c ), base portion  706  of U-shaped bracket member  702  can further include one or more anti-rotation features  710  preferably formed at opposing ends of base portion  706 . Anti-rotation features  710  can include a reduced width to permit such anti-rotation features  710  to be received within a gap  712  of a slot  714  formed in side members  22 ,  34 , and  44 . When anti-rotation features  710  are received in gap  712 , twisting motion of U-shaped bracket member  702  relative to side members  22 ,  34 , and  44  is minimized, thus minimizing twisting motion of cross bow members  28 ,  40 , and  46 .  
         [0049]     Base portion  706  of U-shaped bracket member  702  further includes an aperture  716  sized to receive a fastener  718  therethrough. Fastener  718  can threadedly engage a sliding washer member  720  slidably received within slot  714 . Sliding washer member  720  is sized to permit sliding movement along slot  714 , yet resist removal therefrom in a direction orthogonal to such sliding movement. During installation, fastener  718  can be fastened to sliding washer member  720  within slot  714  to frictionally retain U-shaped bracket member  702  relative to side member  22 ,  34 , and  44 .  
         [0050]     It should be appreciated that this arrangement permits simple coupling of cross bow members  28 ,  40 , and  46  relative to side members  24 ,  34 , and  44  with a single fastener to simplify manufacturing and assembly. Additionally, such arrangement further permits movement, albeit limited, of cross bow member  28 ,  40 , and  46  relative to side members  22 ,  34 , and  44 , which can reduce material stress in fabric cover  14 .  
         [0051]     Middle tonneau section  16   b  includes a pair of side members  44  and a pair of generally parallel cross bow members  46 . Cross bow members  46  can be identical to cross bow members  28  and  40  and side members  44  can be similar to, but vary in length relative to, side members  22  and  34 . However, again it should be appreciated that this is not required. Cross bow members  46  are each further fixedly coupled to the pair of side members  44  via corner braces  48  disposed on opposing ends thereof. The pair of side members  44  is adapted to rest upon a top surface of sidewalls  108  and  110 .  
         [0052]     Still referring to  FIG. 1 , foldable tonneau system  12  further includes a first pair of dual linkage hinge assemblies  400  and a second pair of dual linkage hinge assemblies  400 ′. The first pair of dual linkage hinge assemblies  400  is sized to pivotally interconnect side members  22  of front tonneau section  16   a  to side members  44  of middle tonneau section  16   b.  Similarly, the second pair of dual linkage hinge assemblies  400 ′ is sized to pivotally interconnect side members  34  of rear tonneau section  16   n  to side members  44  of middle tonneau section  16   b.  The second pair of dual linkage hinge assemblies  400 ′ are preferably shorter than the first pair of dual linkage hinge assemblies  400  to provide the necessary spacing to permit folding of rear tonneau section  16   n  onto middle tonneau section  16   b  and the combination rear and middle tonneau section bundle onto front tonneau section  16   a,  as seen in  FIG. 2 . Dual linkage hinge assemblies  400  and  400 ′ will be described in detail below.  
         [0000]     Front Latch Assembly  
         [0053]     As best seen in  FIG. 4 , front tonneau section  16   a  is fixedly coupled to sidewall  108  of cargo box  100  via a front latch assembly  200 . Front latch assembly  200  includes a front trunnion  202  that is sized to be received within front cross bow member  28 . Front trunnion  202  is captured within the C-shaped cross section of cross bow member  28  as similarly illustrated in  FIG. 11 . As will be discussed below, front trunnion  202  includes the pair of trunnion ends  214  are adapted to slide along C-shaped cross bow member  28  during installation and stowage. More preferably, the pair of trunnion ends  214  is configured to include a flanged end that defines a wheel  216 . As similarly configured as the rear latch assembly illustrated in  FIG. 12 , wheels  216  are captured and retained within upturned slots (identical to upturned slots  314  of  FIG. 12 ) formed in cross bow member  28 .  
         [0054]     Front latch assembly  200  further includes a downwardly extending threaded member  204 . Threaded member  204  may be a bolt extending through an aperture formed in front trunnion  202  or may be integrally formed with front trunnion  202  as a single member. A slidable catch  206 , having an engaging portion  208  and an aperture  210 , is slidably received on threaded member  204  such that threaded member  204  extends through aperture  210 . A corresponding fastener  212  is threadedly engaged with threaded member  204  to retain slidable catch  206 . As seen in phantom in  FIG. 4 , front latch assembly  200  may be slid along front cross bow member  28  to position slidable catch  206  adjacent sidewall  108 . Corresponding fastener  212  is then actuated to draw slidable catch  206  upwardly until engaging portion  208  engages sidewall  108 . Engaging portion  208  is illustrated as being generally U-shaped to provide positive and reliable capture of sidewall  108 . Upon further actuation of corresponding fastener  212 , a compression force is imparted to compress the pair of side members  22  against sidewalls  108  and  110  to retain front tonneau section  16   a  in a desired position.  
         [0055]     In some embodiments, it may be desirable to protect sidewall  108  from contact or abrasion from threaded member  204  positioned adjacent thereto. In this regard, a member  219  may be positioned between threaded member  204  and sidewall  108 . Member  219  may be a deformable sleeve member substantially surrounding threaded member  204  to prevent contact of threaded member  204  directly with sidewall  108 . It should be understood that during installation, member  219  does not impede the upward movement of slidable catch  206 .  
         [0000]     Rear Latch Assembly  
         [0056]     Turning now to  FIGS. 6-9  and  11 - 13 , rear tonneau section  16 n is fixedly coupled to sidewall  108  of cargo box  100  via a rear latch assembly  300 . As best seen in  FIG. 13 , rear latch assembly  300  includes a rear trunnion assembly  302  that is sized to be received within rear cross bow member  40 . Specifically, rear trunnion assembly  302  includes a pair of trunnion ends  304  extending from a trunnion main body  306  and a pair of parallel slide members  308 . The pair of parallel slide members  308  each extends orthogonally from trunnion main body  306 . Rear trunnion assembly  302  further includes an aperture  310  extending through trunnion main body  306 . A longitudinal axis of aperture  310  is generally parallel to the pair of parallel slide members  308 .  
         [0057]     As seen in  FIGS. 11 and 12 , the pair of trunnion ends  304  is sized to be slidably captured within the C-shaped cross section of cross bow member  40 . The pair of trunnion ends  304  is adapted to slide along C-shaped cross bow member  40  during installation and stowage. More preferably, the pair of trunnion ends  304  is configured to include a flanged end that defines a wheel  312 . As seen in  FIG. 12 , wheel  312  is captured and retained within upturned slots  314  formed in cross bow member  40 .  
         [0058]     Referring again to  FIG. 13 , rear latch assembly  300  further includes a downwardly extending threaded member  316  received within aperture  310  of trunnion main body  306 . In the present embodiment, threaded member  316  is a carriage bolt. It should be understood, however, that threaded member  316  may be integrally formed with trunnion main body  306  as a single member.  
         [0059]      59  A slidable handle assembly  318  is slidably coupled to trunnion main body  306  and threaded member  316 . Specifically, slidable handle assembly  318  includes a handle portion  320 , a biasing member  322 , and a retaining nut  324 . Handle portion  320  includes a central bore  326  extending partly through handle portion  320 . Central bore  326  is sized to receive biasing member  322  therein such that an end of biasing member  322  engages a surface within handle portion  320  to resist movement of biasing member  322  during compression. Retaining nut  324  includes a threaded opening  327  and a flange  328  sized to engage an opposing end of biasing member  322  and fit within central bore  326  to exert a compression force upon biasing member  322 . Handle portion  320  further includes an aperture (not shown) formed within a shank portion  330  ( FIG. 11 ) that is sized to receive threaded member  316  there through, yet smaller than a diameter of biasing member  322 . Accordingly, threaded member  316  extends through shank portion  330  and at least partly through central bore  326 . Biasing member  322  is positioned within central bore  326  and about threaded member  316 . Biasing member  322  is captured within central bore  326  by retaining nut  324  that threadedly engages threaded member  316  to define an assembled state.  
         [0060]     As best seen in  FIG. 11 , in this assembled state, the pair of parallel slide members  308  is received within a corresponding pair of slots  329  formed in handle portion  320 . The pair of slots  329  is sized to permit the pair of slide members  308  to slide in response to relative movement between rear trunnion assembly  302  and handle assembly  318  but constrain relative axial rotation. This lack of axial rotation ensures that slidable handle assembly  318  is properly orientated for attachment to cargo box  102  and also for nesting within cross bow member  40 , as will be discussed below.  
         [0061]     Turning now to  FIGS. 6, 7 , and  11 - 13 , slidable handle assembly  318  further includes an integrally formed engaging portion  331 . As seen in phantom in  FIGS. 6 and 7 , rear latch assembly  300  may be slid along rear cross bow member  40  to position slidable handle assembly  318  adjacent sidewall  108 . Slidable handle assembly  318  can then be pulled downwardly, against the biasing force of biasing member  322  until engaging portion  331  engages sidewall  108 . Engaging portion  331  is illustrated as being generally U-shaped to provide positive and reliable capture of sidewall  108 . Handle portion  320  includes a gripping portion  333  to facilitate such gripping operation. Upon release, the biasing force of biasing member  322 , acting between the internal wall of central bore  326  and retaining nut  324 , imparts a compression force upon the pair of side members  34  and sidewalls  108  and  110  to retain rear tonneau section  16 n in a desired position concealing cargo box  102 . It has been found that this biasing force of biasing member  322  is sufficient to reliably retain rear tonneau section  16   n  to cargo box  102 . It should be appreciated that this biasing force is adjustable by varying the extension spring size and/or adjusting retaining nut  324  to achieve the desired level of compression. Also, it should be appreciated that biasing member  322  may be an extension spring, an elastomeric member, a bushing, a hydraulic or pneumatic cylinder, a bushing, or any other known system for biasing a member.  
         [0062]     Briefly, it should be appreciated that by positioning biasing member  322  within central bore  326  of handle portion  320 , a number of advantages are realized. For example, known hook latches often employ a short spring positioned between the latch base and the latch hook/latching point. This dictates a longer bodied latch than is desirable for a tonneau and also dictates a short stroke spring. These short stroke springs have a spring rate that varies quickly. However, with such a wide variety of sidewall flange thicknesses/lengths of today&#39;s pickup truck, a short stroke spring would either prevent any attachment whatsoever or would fail to provide enough compression force to reliably retain the tonneau system.  
         [0063]     These disadvantages are overcome in the present invention by positioning a longer biasing member  322  within handle portion  320 , which protrudes past engaging portion  331  (i.e. the latching point). This long extension spring arrangement provides a more constant spring rate over a longer range of sidewall flange thicknesses/lengths. Additionally, by positioning engaging portion  331  (i.e. the latching point) near the top of rear latch assembly  300 , rear latch assembly  300  is able to better accommodate short sidewall flange thicknesses/lengths.  
         [0064]     Additionally, a considerable feature of rear latch assembly  300  is its ability to be stowed substantially within the cross-sectional perimeter of rear cross bow member  40 . As best seen in  FIGS. 9 and 12 , this is a substantial advantage in that by nesting rear latch assembly  300  generally within the confines of rear cross bow member  40 , fabric cover  14  of foldable tonneau system  12  is substantially less likely of being damaged by contact with rear latch assembly  300 , thereby improving the durability of fabric cover  14 . During a nesting operation, rear latch assembly  300  is pivoted from a latching position to a nested position. Specifically, once rear latch assembly  300  is unlatched from sidewalls  108 , it may be slid longitudinally inboard from its latching position. Rear latch assembly  300  may then be pivoted about an axis extending through trunnion ends  304  toward rear cross bow member  40  until handle portion  320  is received within a space generally defined by the periphery of rear cross bow member  40 .  
         [0065]     To retain rear latch assembly  300  in this nested position, handle portion  320  includes a pair of integrally-molded locking clips  332  ( FIGS. 11 and 12 ). The pair of integrally molded locking clips  332  is each molded to define a flexible cantilever portion  334  and a locking feature  336  extending therefrom. Locking clips  332  are operable to flex inwardly as handle portion  320  is pushed within rear cross bow member  40 . Specifically, locking feature  336  engages an inwardly turned flange  338 , which is part of slot  314  of rear cross bow member  40  ( FIG. 12 ), and causes cantilever portion  334  to flex inwardly until locking feature  336  passes flanges  338 . Once cantilever portion  334  passes flange  338  it expands slightly to reliably lock handle portion  320  in the nested position. To remove handle portion  320  from the nested position, the ends of cantilever portions  334  may be collapsed by a user to disengage locking features  336  from flange  338 , thereby permitting handle portion  320  to be pivoted into the latching position orthogonal to rear cross bow member  40 .  
         [0000]     Dual Linkage Hinge Assembly  
         [0066]     As discussed above, with reference to  FIGS. 1 and 14 - 25 , foldable tonneau system  12  further includes the first pair of dual linkage hinge assemblies  400  and the second pair of dual linkage hinge assemblies  400 ′. The first pair of dual linkage hinge assemblies  400  is sized to pivotally interconnect side members  22  of front tonneau section  16   a  to side members  44  of middle tonneau section  16   b.  Similarly, the second pair of dual linkage hinge assemblies  400 ′ is sized to pivotally interconnect side members  34  of rear tonneau section  16   n  to side members  44  of middle tonneau section  16   b.  The second pair of dual linkage hinge assemblies  400 ′ are preferably shorter than the first pair of dual linkage hinge assemblies  400  to provide the necessary spacing to permit folding of rear tonneau section  16   n  onto middle tonneau section  16   b  and the combination rear and middle tonneau section bundle onto front tonneau section  16   a,  as seen in  FIG. 2 . However, despite this difference in size, the first pair of dual linkage hinge assemblies  400  and the second pair of dual linkage hinge assemblies  400 ′ are identical in construction. Therefore, in the interest of brevity, only one of the dual linkage hinge assemblies  400  will be described in detail.  
         [0067]     With particular reference to  FIGS. 14 and 15 , dual linkage hinge assembly  400  includes a first hinge body  402 , a second hinge body  404 , a first hinge link  406 , and a second hinge link  408 . First hinge body  402  is fixedly coupled to one of side members  22 ,  34 ,  44  (hereinafter, side member A) and second hinge body  404  is fixedly coupled to adjacent one of side members  22 ,  34 ,  44  (hereinafter, side member B).  
         [0068]     First hinge link  406  and second hinge link  408  are each generally L-shaped having a first pivot aperture  410 ,  412  and a second pivot aperture  414 ,  416 , respectively. Each pivot aperture  410 ,  412 ,  414 ,  416  defines a pivot axis. It should be noted that first pivot aperture  410 ,  412  is positioned at an end of a base section  418 ,  420  of the L-shape and are offset inwardly such that first pivot aperture  410 ,  412  is generally tangent to base section  418 ,  420 . Likewise, second pivot aperture  414 ,  416  is positioned at an end of a long section  422 ,  424  of the L-shape and are offset inwardly such that second pivot aperture  414 ,  416  is generally tangent to long section  422 ,  424 . This offset positioning serves to define a smooth face surface generally planar with side members A and B (see  FIG. 20 ) to ensure a smooth bottom surface of the side members and a proper sealing engagement along the top of sidewalls  108 ,  110 . Furthermore, this arrangement serves to cause engagement of a stopper corner portion  426 ,  428  of the L-shape with a face  430 ,  432  (see  FIGS. 20 and 22 ) to prevent undesired hyper- or over-rotation (i.e. greater than about 180 degrees between tonneau sections) of one tonneau section relative to an adjacent tonneau section. Similarly, extension leg  427 ,  429  are further provided to prevent undesired relative rotations beyond parallel in a collapsing movement (see  FIGS. 18,19 ,  24 , and  25 ) in that extension legs  427 ,  429  engage faces  430 ,  432  to prevent such movement.  
         [0069]     First hinge link  406  and second hinge link  408  are each pivotally coupled between first hinge body  402  and second hinge body  404  in a mirrored relationship via coupling pins (not shown) extending through hinge link apertures  434  and pivot apertures  410 ,  412 ,  414 ,  416 .  
         [0070]     Each pair of hinge link apertures  434  are generally arranged to define a rectangular box configuration, generally referenced at Z ( FIG. 14 ). The particular arrangement of first hinge link  406  and second hinge link  408  of dual linkage hinge assembly  400  further serves to define an “instant center” hinge. As seen in  FIG. 15 , this instant center hinge defines an overall effective pivot axis at the point where a first line  436  interconnecting first pivot aperture  410  to second pivot aperture  414  of first hinge link  406  intersects a second line  438  interconnecting first pivot aperture  412  to second pivot aperture  416  of second hinge link  408  (generally referenced as EPA). As can be seen in  FIGS. 14-19 , as one tonneau section pivots relative to the other tonneau section, the effective pivot axis prevents the tonneau sections from contact each other until the folding motion is complete, thereby minimizing the potential of damaging fabric cover  14  and ensuring repeatable opening and closing motions.  
         [0000]     Fabric Cover Attachment  
         [0071]     Referring now to  FIGS. 26-28 , a fabric cover attachment assembly  500  is illustrated. Fabric cover attachment assembly  500  includes an attachment plate  502  having an attachment feature  504  formed therein for engagement with a corresponding receiving feature  506  formed in side member  22 ,  34 ,  44 , front rail member  20 , rear rail member  32 , and/or cross bow member  28 ,  40 ,  46 . As seen in  FIG. 26 , fabric cover  14  is connectable to attachment plate  502  through any conventional process; however, it is preferably that fabric cover  14  includes a molded U-shaped runner member  508  engagable with an edge  510  of attachment plate  502 . Runner member  508  may be sewn to attachment plate  502  or fastened according to other conventional methods.  
         [0072]     As seen in  FIGS. 27 and 28 , attachment feature  504  is preferably formed to substantially resist disengagement from side member A. To this end, attachment feature  504  includes a central pin  512  extending generally orthogonally from an underside surface  514  of attachment plate  502  at a proximal end  516  thereof. A pair of elastic legs  518  are convergently connected to a distal end  520  of central pin  512  and are each angled upwardly to form a pointed tip  522 . The pair of elastic legs  518  are sized to permit insertion of attachment feature  504  into receiving feature  506  while permitting some flexural movement of the pair of elastic legs  518  relative to gripping flanges  524  extending from a channel  526  of receiving feature  506 . Once inserted, as seen in  FIG. 28 , elastic legs  518  expand to reliably engage gripping flanges  524  and retain attachment plate  502  and fabric cover  14  relative to side member A (or other rail member). It should be noted that attachment feature  504  can comprise a plurality of elastic legs  518  extending along central pin  512  to permit varying engagement locations and loading forces.  
         [0073]     With particular reference to  FIGS. 1 and 5 , fabric cover attachment assembly  500  is preferably formed substantially about the periphery of the internal framework of foldable tonneau system  12  and along each cross bow member  28 ,  40 ,  46 . It should be appreciated that attachment feature  504  may be an elongated continuous member that extends substantial portions of the aforementioned segments or may be a series of individual fasteners depending upon the desired configuration. Either way, fabric cover attachment assembly  500  provides a substantial advantage over current attachment designs that require a rigid member to be slid within the side members from an end to capture the fabric cover—namely, fabric cover attachment assembly  500  enables the entire foldable tonneau system framework to be assembled and tested before fabric cover  14  is installed, thereby permitting much less cumbersome manufacturing.  
       Installation  
       [0074]     With particular reference to  FIGS. 1-10 , the installation of foldable tonneau system  12  on cargo box  102  of pickup truck  100  will now be described. As best seen in  FIG. 2 , a folded tonneau system  12  is first placed upon sidewalls  108 ,  110  of cargo box  102  such that side members  22  of front tonneau section  16   a  are equally positioned upon a top surface of sidewalls  108 ,  110 . Restraining straps  602  ( FIG. 10 ) are unlatched to permit the bundled group of middle tonneau section  16   b  and rear tonneau section  16   n  to be pivoted about the pair of dual linkage hinge assemblies  400  relative to front tonneau section  16   a.  As seen in  FIG. 3 , foldable tonneau system  12  is then adjusted to ensure proper positioning of foldable tonneau system  12  on cargo box  102 . As seen in  FIG. 4 , front latch assemblies  200  are them slid to outboard positions adjacent a flange of sidewalls  108 ,  110  by sliding front trunnion  202  along cross bow member  28 . Fastener  212  is then tightened such that engaging portion  208  of slidable catch  206  engages the flange of sidewalls  108 ,  110  to affect a reliable coupling.  
         [0075]     As seen in  FIG. 5 , rear tonneau section  16   n  is then pivoted about the pair of dual linkage hinge assemblies  400 ′ relative to middle tonneau section  16   b  to conceal cargo box  102 . Rear latch assemblies  300  are them slid to outboard positions adjacent the flange of sidewalls  108 , 110  by sliding trunnion main body  306  along cross bow member  40 . Slidable handle assembly  318  is then slid downwardly, against the biasing force of biasing member  322 , and positioned to engage the flange of sidewalls  108 ,  110  and released such that biasing member  322  drives engaging portion  323  against the flange of sidewalls  108 ,  110  to affect a reliable coupling.  
         [0076]     Briefly, as illustrated in  FIGS. 8-10 , to fold foldable tonneau system  12 , rear latch assemblies  300  are disengaged from sidewalls  108 ,  110  and slid inboard by sliding trunnion main body  306  along cross bow member  40 . Slidable handle assembly  318  is then pivoted about trunnion main body  306  and into the nested position.  
         [0077]     The description of the invention is merely exemplary in nature and, thus, variations that do not depart from the gist of the invention are intended to be within the scope of the invention. Such variations are not to be regarded as a departure from the spirit and scope of the invention.