Abstract:
A flexible tonneau cover for trucks that is easily folded for storage or shipping. The tonneau cover has a collapsible peripheral frame, with supporting bows spanning the width of the frame. The bows include separable parts for storage or shipping and can be assembled and expanded to spread the frame.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is a continuation-in-part of U.S. application Ser. No. 10/940,561, filed Sep. 13, 2004, the disclosure of which is herein incorporated by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     This invention relates to a flexible tonneau cover for pick-up trucks. Tonneau covers are to serve the purposes of protecting the contents of a truck bed from the elements, as well as provide a more streamlined surface than just an open truck bed. A drawback to tonneau covers is that shipping them may be difficult due to their size and weight. Such covers can be bulky to ship because a frame is necessary to support the flexible cover and the frame is necessarily large to provide support over a pick-up truck bed. 
     SUMMARY OF THE INVENTION 
     The present invention is a tonneau cover for pick-up trucks. The tonneau cover has a peripheral frame and a flexible cover. The peripheral frame is made from rail sections and has bows that span across the width of the peripheral frame to support the flexible cover. The bows have three main components which are: first and second tubes and a sliding tube. The sliding tube is carried by the first tube and slides over the first tube and onto the second tube to form a bridge across them. This provides continuous support across the width of the cover&#39;s peripheral frame, which prevents the flexible cover from sagging. The sliding tube includes a locking lever or cam tool. The cam tool produces a force that spreads the bow apart and thereby stretches the flexible cover for a smooth appearance. 
     An object of this invention is to provide a tonneau cover with a smooth appearance. 
     Another object of this invention is to provide a tonneau cover that does not sag. 
     Another object of this invention is to provide a tonneau cover that may be folded into a small package for shipping. 
     Other objects of this invention will become apparent upon a reading of the following description. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view showing the tonneau cover folded in its most compact form; 
         FIG. 2  shows the tonneau cover partially un-folded; 
         FIG. 3  shows the tonneau cover unassembled and completely unfolded. 
         FIG. 4  is a fragmentary detailed view taken within broken line circle  4  seen in  FIG. 3 ; 
         FIG. 5  is a fragmentary detailed view taken within broken line oval  5  seen in  FIG. 5 ; 
         FIG. 6  shows the rail sections joined together by the locking member to make a lateral peripheral frame member; 
         FIG. 7  is a sectional view taken along line  7 - 7  of  FIG. 3 ; 
         FIG. 8  is an upper view of the frame members seen in  FIG. 7 ; 
         FIG. 9  shows the sliding tube in locked position; 
         FIG. 10  shows how the cam tool or lever prior to its insertion into the sliding tube; 
         FIG. 11  shows how the cam tool or lever inserted into the sliding tube; and 
         FIG. 12  shows the cam tool or lever in its closed position locking the sliding tube. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The tonneau cover  2  of this invention has a peripheral frame  4  made from rail sections  6 . The rail sections  6  may be made of extruded aluminum or other lightweight, durable material to reduce the overall weight of the tonneau cover  2 . Each rail section  6  has slots  8  as shown in  FIG. 5  that run the entire length of each rail section. End frame members  10 , which span the width of the pick-up bed, are each formed by joining multiple rail sections  6  using a locking member  12  as shown in  FIG. 6 . The locking member has protrusions or keys  14  along its entire length that mate with the slots  8  in the rail sections  6  allowing the locking member  12  to be slid longitudinally into a closed position which spans two adjacent abutting rail sections  6 . Screws  13  secure the locking member to the rail sections in its closed position. When the locking member  12  is slid into its open position onto a rail section  6 , the end frame member can be broken down into smaller pieces, which allows the tonneau cover to be folded in to a smaller package when not in use. In the preferred embodiment two rail sections  6  are used to make one end member  10 , however more could be used. Longitudinal or side frame members  16  run down the sides of the cover and are made from rail sections  6  that are joined by hinges  20 . The hinges  20  allow the tonneau cover  2  to be lifted in parts to access the underlying truck bed, and also allow the tonneau cover  2  to be folded. Side frame members  16  and end frame members  10  are joined to form the peripheral frame  4  by corner pieces  22 . Each corner piece has tabs  24  that are received into the slots  8  in the adjacent rail sections  6  to form a corner of the cover as shown in  FIG. 4 . Once the tabs are inside the rail sections  6 , screws  26  are tightened to secure the corner pieces  22  into the rail sections. 
     Inside the peripheral frame  4  are bows  28 , which span the width of the peripheral frame  4  and support a flexible cover  29 . Clamps  30  used to hold the tonneau cover  2  to the bed of a truck are attached to the bows  28  as shown in  FIG. 3 . Each bow  28  includes a tube  34  which is secured at one end to a frame member  16 , a sliding tube  36 , and a mating tube  38  which is secured at one end to the opposite frame member  16 . The tube  34  and the mating tube  38  have the same cross section. The sliding tube  36  fits telescopically over tube  34 . The sliding tube  36  is slid from tube  34  onto the aligned tube  38  until protrusion  40  formed in tube  36  contacts the end of tube  38 , as shown in  FIG. 9 . At this point, a slot  48  formed in the sliding tube is located at the outer end  47  of tube  34  as seen in  FIG. 10 . A cam tool or lever  46 , normally stored in a clamp  30 , is used to expand the bow. Lever  46  includes a cam part  49  and a notch  50 . Cam part  49  is inserted into the slot  48  in the sliding tube  36  against end  47  of tube  34  and notch  50  is fitted over the edge of the slot. The lever  46  is rotated toward tube  36  as shown in  FIG. 11  into its locked position as shown in  FIG. 12  where it remains until rotated away from the tube. As the lever  46  rotates into its locked position, cam part  49  in contact with tube end  47  cams and urges tube  34  rearwardly relative to tube  36  thereby spreading tubes  34 ,  38  apart. This creates a force that spreads the peripheral frame  4  in a lateral direction. Flexible cover  29  is attached around the perimeter of the peripheral frame, and the force from the bows  28  holds the flexible cover  29  taut to give it a smooth appearance. A taut flexible cover  29  is less likely to sag and collect water, which over time can degrade the appearance of the flexible cover  29 . 
     When the tonneau cover  2  is shipped or stored it can be folded into a relatively small package. The hinges  20  which connect rail sections  6  in the side frame members  16  which run the length of the truck bed allow the tonneau cover  2  to be folded length wise as shown in  FIG. 2 . The tonneau cover  2  may also be folded in half down its width by sliding the locking members  12  along a rail section  6  to a position that allows the rails sections  6  forming the lateral frame members  10  to be separated, as shown in  FIG. 2 . Once one of the rail sections  6  and its corner piece  22  forming each of the end frame members  10  is removed and sliding tubes  36  are withdrawn from tubes  38  with levers  46  removed and stored in clamps  30 , the tonneau cover  2  may be folded along its width to the configuration shown in  FIG. 1 . Mating straps  52  may then be attached to keep the tonneau cover  2  in its fully folded position as shown in  FIG. 1 . This fully folded configuration makes shipping the tonneau cover  2  more affordable since smaller packages are generally cheaper to ship than large awkward packages. 
     To assemble the cover, first the removed rail sections  6  with their corner pieces are reconnected and the peripheral frame  4  assembled with locking members  12  secured in their locked positions. Then sliding tubes  36  are slid over aligned tubes  38  of bows  28  and the tubes  34 ,  38  expanded longitudinally by levers  46 . 
     The above-described invention is not to be limited to the details above, but may be modified in accordance with the following claims.