Abstract:
A tonneau cover for a pick-up truck cargo box in which a flexible cover of sheet-like material is attached to a frame with snap fasteners. The snap portions carried by the frame are slidable there along to change the position of the snap fastener. The snap fasteners include a protrusion, which engages the frame and creates sufficient force to prevent the snap fastener from sliding freely along the rail and losing their longitudinal location when the tonneau cover is not attached.

Description:
BACKGROUND AND SUMMARY OF THE INVENTION 
     The present invention relates to tonneau covers for covering a pickup truck cargo box and in particular to a nib on one half of the snap fasteners for retaining the position of that half of the snap fastener on the rail of the tonneau cover frame. 
     Soft tonneau covers for pick-up trucks typically have two major components. The first component is a flexible sheet cover such as vinyl coated fabric. The second component is a frame attached to the pick-up truck cargo box. The frame and cover include a fastening mechanism for attaching the cover to the frame, thus covering the cargo box. One commonly employed means for fastening the cover to the frame is the use of a plurality of snap fasteners about the periphery of the cover. One portion of each snap fastener is attached to the flexible sheet while the other portion of each fastener is carried by the tonneau cover frame. 
     Preferably, that portion of the snap fasteners on the frame (hereinafter “male portion” or “snap portion”) are slidable along the length of the frame rails. This enables the male portion to be positioned anywhere along the length of the rail to accommodate variations in the snap location on the cover. This prevents wrinkling or excessive pulling in the cover that would occur if the male portions were fixed in location on the rail. The male portions are slidable along the rails and are prevented form sliding off the ends of the rails by the corner blocks. The male portions mounted to the rails include a generally C-shaped base that engages and slides along the snap mounting wall of the rail. 
     When large objects are being carried in the cargo box which extend above the cargo box walls, it is necessary to remove the tonneau cover at least partially from the cargo box. This is accomplished by rolling the cover forward and tying it at the front end of the cargo box. When this is done, however, the male portions are free to slide longitudinally along the side rails as a result of wind, vibration and other forces during movement of the truck. The male portions must be relocated back into position before the tonneau cover is remounted over the bed. 
     One approach to maintaining the male portions on the rail is to use a flexible steel for the base of the male portions so that the male can be crimped or otherwise formed into a C-shape which firmly grips the rail and does not easily slide unless intentionally forced. Over time, these base portions may loosen and begin to slide. However, to provide a low-cost fastener, it is preferred to form the male portion in a single injection molded part. This is less expensive and stronger than an assembled male portion having a collar member riveted to a C-shaped steel base. Unfortunately, the injection molded male portion does not have the ability to be crimped. 
     Accordingly, an object of the present invention is to provide a means for retaining the portions of snap fasteners in position on the tonneau rail when the tonneau cover is not attached. Another object is to provide the above while maintaining the ability to remove those snap portions and, when desired, to change the location of those snap portions. 
     The present invention provides a nib protruding from the snap portion&#39;s inside surface, the surface facing the tonneau rail. The nib creates a frictional interference with the rail sufficient to retain the snap portion in its location on the tonneau rail while the vehicle is moving, yet which may still be easily overcome by a person who wishes to relocate the snap portion longitudinally on the tonneau rail to accommodate variations in the location of the female snap portion on the cover, either as manufactured or as it may vary with seasonal temperatures. The nib may be centered behind a recess in the male portion or in a different location on the inside of the snap fastener. The nib may also be on a cantilevered arm. 
     Further objects, features and advantages of the invention will become apparent from consideration of the following description and the appended claims when taken in connection with the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of a pick-up truck with a tonneau cover employing the snap fasteners of the present invention; 
     FIG. 2 is an enlarged perspective view of the left rear corner of the cargo box shown in FIG. 1 illustrating the corner of the tonneau frame; 
     FIG. 3 is a sectional view of a portion of a snap fastener according to the present invention and mounted to the side rail; 
     FIG. 4 is a top view of the snap portion of the present invention; 
     FIG. 5 is a side view of the snap portion shown in FIG. 4; 
     FIG. 6 is an end view of the snap portion shown in FIG. 4; 
     FIG. 7 is a side view of another embodiment of a snap portion of the present invention containing a nib protruding therefrom. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     With reference to FIG. 1, a pick-up truck  10  is shown having two side bed walls  12  and a rear wall  14  or tailgate surrounding the cargo box  16 . While not shown, it will be understood that a front wall defines the forward extent of the cargo box. Each of the side bed walls  12  has a top surface  18  and the rear wall  14  also has a top surface  20 . 
     A tonneau cover system  21 , including a tonneau cover  22  sits atop the cargo area  16 . Side frame rails  24  are mounted to the side bed wall top surfaces  18  by clamp (not shown) or other means. A rear frame rail  26  is mounted to extend across the rear wall top surface  18 . Corner blocks  27  connect the side rails  24  to the end rails  26 . As further described below, the tonneau cover  22  is attached to the side frame rails  24  and rear frame rail  26  (collectively, the frame  28 ) and covers the cargo box  16 . 
     With reference to FIG. 2, it can be seen that the tonneau cover  22  is a sheet of flexible material, such as vinyl, and has female engagement portions  32  attached about its periphery. These female engagement portions  32  match and engage with corresponding male engagement portions  30 , slidably carried on the frame  28 , and hold the tonneau cover  22  to the frame  28 . 
     The shape of the frame rails  24 ,  26  is best shown in FIG.  3 . Each frame rail  24 ,  26  has a closed section shape with an inner wall  40 , an upper wall  42  and a lower wall  44 . An outer wall  48  slopes generally downwardly and outwardly from the upper wall  42  to the lower wall  44 . The outer wall  48  is interrupted by the snap mounting wall  50 . The snap mounting wall  50  is coupled to the outer wall  48  by an upper connecting wall  52  and a lower connecting wall  54 . 
     The snap mounting wall  50  further includes upper and lower side edges that extend beyond the connecting walls  52  and  54  forming over hanging flanges  58  and  60 . It is about the overhanging flanges  58  and  60  that the male engagement portions  30  are retained on the frame  28 . 
     Each male engagement portion  30  includes a C-shaped base  62  with a raised collar  72  protruding upward from the base  62 . The collar  72  interferingly fits with the female engagement portions  32  on the tonneau cover  22 . As thus described, it can be seen that the male and female engagement portions  30 ,  32  are parts of a snap fastener, with the female engagement portion  32  and the collar  72  of the male engagement member  30  being of conventional construction. Accordingly, these components are not discussed in further detail herein. Furthermore, it will be understood that a wide range of other fastening mechanisms can be employed in place of snap fasteners as specifically described and illustrated. 
     The C-shaped base  62  of the male engagement portion  30 , as seen in FIGS. 3 and 5, is formed with two reversely bent ends  63 . These ends  63 , when mounted to snap mounting wall  50 , extend about the overhanging flanges  58  and  60 , capturing the male engagement portion  30  thereon. The ends  63  therefore define a gap  65  approximately the thickness of the flanges  58  and  60 . At a maximum, this gap  65  is greater than the thickness of the flanges  58  and  60  and, at a minimum, is less than that thickness, but flexible and separable to allow the flanges  58  and  60  to be inserted therein. 
     Also formed on the base  62  is a projection or nib  70 . The nib  70  may be one of a number of shapes (round, elongated, semispherical or other) and is formed on bottom surface  82  of the base  62  such that it projects toward the snap mounting wall  50 . The height of the nib  70  is such that it causes the reversely bent ends  63  to be forced or pulled against the edges  58  and  60 , securely retaining the male engagement portion  30  thereon. 
     In the preferred embodiment, the nib  70  is formed on a cantilevered arm  80  formed in the base  62  and defined therein by a slot or groove  84 . By providing the arm  80 , the amount of force exerted by the nib  70  can be relieved such that only one to ten pounds of force, and more preferably, about two to five pounds of force, is exerted through the nib  70 . In this manner the force exerted by the nib  70  will retain the male engagement portion  30  in position on the rail  24 ,  26  when the tonneau cover  22  is not attached thereto and the vehicle  10  is moving. The force exerted by the nib  70  is also such that the male engagement portion  30  can be intentionally moved by an operator to relocate them along the rail  24 ,  26  and thereafter retained in position. 
     In another preferred embodiment, shown in FIG. 7, the nib  70 ′ is formed centrally beneath the collar  72 ′ on what is referred to as a flexible diaphragm  90 ′. The diaphragm  90 ′ is formed by thinning that portion of the base  62 ′ centrally within the collar  72 ′. In all other respects, the male engagement portion  30 ′ operates and behaves as the prior embodiment. For this reason, like elements between the two embodiments bear like reference numbers with a prime (′) designation. 
     In the preferred embodiment, the male engagement member  30  is formed of glass filled nylon, plastic or similar materials through an injection molding process. Other processes and materials, however, could alternatively be utilized. Further, the collar  72  may be formed on the base  62  off-center and toward one end thereof, as illustrated, to allow for adjustments in tension of the cover  22  based on seasonal temperature or other changes. Alternatively, the collar  72  may be centered on the base  62 . 
     It is to be understood that the invention is not limited to the exact construction illustrated and described above, but that various changes and modifications may be made without departing from the spirit and scope of the invention as defined in the following claims.