Abstract:
A tonneau cover apparatus comprises a frame structure having a pair of laterally spaced apart side rails, an end rail, and a pair of connector assemblies. The connector assemblies are coupled to the end rail, and are movably mounted to an associated side rail to thereby movably interconnect the end rail to the side rails. A pair of springs bias the connector assemblies in a direction outwardly from the side rails such that the end rail applies a force to the flexible cover to maintain the flexible cover in a taut state. Each connector assembly includes a fixed component and a rotatable component. The fixed component includes an aperture and a first plug end secured to an associated side rail. The rotatable component includes a post end and a third plug end removably secured to the end rail. The post end is thus removably secured to the aperture.

Description:
FIELD OF THE INVENTION 
     This invention relates to a tonneau cover and more particularly to a tonneau cover whose tautness is maintained without intervention by the user, and which allows simple access to the cargo area with a rotating rear rail. 
     BACKGROUND OF THE INVENTION 
     Tonneau covers are generally used to cover the cargo box of a vehicle, such as a pick-up truck. A typical tonneau cover includes two primary components: a cover sheet made of fabric or other flexible, preferably waterproof, material; and a frame structure to which the perimeter of the cover sheet is removably attached and which is usually employed to removably position the cover sheet over the bed of a vehicle. The frame generally comprises four rails: a left and a right side rail, which are removably affixed to each respective and opposed sidewall of a pick-up bed, and a front and a rear rail, which are respectively positioned near the passenger cab and the tailgate. Different rail configurations are possible for varying pickup bed configurations. Moreover, the front and rear rails are usually connected to each of the side rails by connector assemblies which are generally manufactured from a material, such as, aluminum or plastic and which allow the rails to cooperatively and removably form a tonneau cover frame. 
     Previous tonneau cover assemblies typically lack an easy and convenient means to remove the tonneau cover from a vehicle to gain access to the enclosed area. Complex user manipulation of the tonneau cover frame and cover was also typically required to place large objects into the cargo area or otherwise remove the rear rail of the tonneau cover frame. 
     Furthermore, the known tonneau cover frame assemblies generally required user intervention to maintain the tonneau cover in a taut state during the lifetime of the tonneau cover. Stretching of the fabric cover due to seasonal temperature changes and daily thermal exposure, for example, causes the tonneau cover to expand and thus sag over the tonneau cover frame. User initiated tensioning of the tonneau cover would re-tension the cover to return it to its original taut state. 
     SUMMARY OF THE INVENTION 
     The above and other objects are provided by a tonneau cover system in accordance with the preferred embodiments of the present invention. In one preferred form, the present invention provides a tonneau cover apparatus having a frame structure, a pair of springs and a flexible cover. The frame structure has a pair of laterally spaced apart side rails, an end rail, and a pair of connector assemblies. Each of the connector assemblies is coupled to the end rail and movably mounted to an associated one of the side rails to moveably interconnect the end rail to the side rails. Each of the springs is coupled to one of the side rails and contacts an associated one of the connector assemblies. The flexible cover is removably attached to at least a portion of the frame structure. The springs bias the connector assemblies in a direction outward from the side rails and cause the end rail to apply a force to the flexible cover to maintain the flexible cover in a taut state. 
     The tonneau cover of another preferred embodiment of the present invention mounts to the cargo box of a vehicle. The tonneau cover includes the frame of the tonneau cover and the cover that is removably attached to the frame. The frame of the tonneau cover includes side rails, a rear rail, and a front rail, all of which are joined by connector assemblies. The frame further includes a spring keeper assembly to maintain tautness of the tonneau cover. The front corner of tonneau cover frame, which is generally located just behind the cab of an open bed vehicle, includes the front rail, the associated side rail, and the front connector assembly, which comprise the front corner. The rear corner of the tonneau cover frame, which is generally located at the rear of the vehicle, includes the rear rail, the associated side rail, and the rear connector assembly. The spring keeper is generally found in the rear portion of the side rail and is connected to the rear connector assembly. The tonneau cover, the front rail, the rear rail, the side rails, associated connector assemblies, and the spring keeper assembly comprise the tonneau cover system. 
     In accordance with the preferred embodiment of the present invention, the front connector assemblies are a single rigid perpendicular unit, while the rear connector assemblies are a two piece perpendicular unit that interlocks in such a way to provide a rotating corner. The front connector assemblies of the tonneau cover frame tie the front rail to the associated side rails to form the front corners of the tonneau cover frame. The front connector assemblies when connected provide a rigid corner of the frame, but are easily removed by one person and without the use of tools. The rear connector assemblies are comprised of two pieces, one of which joins with the rear rail and the other with the associated side rail. The two piece design enables the user to conveniently detach the rear rail from the tonneau cover frame without having to disassemble and reassemble the rear connector assemblies. 
     The rotating rear connector assemblies provide for easy access to the cargo box, while providing a convenient means to open and close the tonneau cover. The two-piece connector assemblies unlock and detach from each other, allowing the user to roll the rear rail inside the tonneau cover toward the front of the vehicle. The user is able to detach the rear rail by use of the locking tabs and detents on the rear connector assemblies but needs to neither disassemble nor remove the rear connector assemblies to remove the rear rail. Closure of the tonneau cover is accomplished by inserting the rear rail and the associated rotating components of the rear connector assemblies back into the associated fixed components of the rear connector assemblies attached to the associated side rails. Closure causes the two piece rear connector assembly to latch and hold the rear rail in place, thereby returning the tonneau cover frame to its closed configuration. 
     In accordance with the preferred embodiment of the present invention, the spring keeper assembly resides in the rear portion of the side rail and in direct engagement with the rear connector assembly. The spring keeper is comprised of housing, a spring, and a spring retaining device. The housing is secured in the rear rail in close proximity to the rear connector assembly, whereby the spring contained in the fixed housing can exert a force on the rear connector assembly. The force applied by the spring forces the rear connector assembly to translate in a direction opposite the front connector assembly. The translation of the rear connector assembly results in the increase of the distance between the front rail and the rear rail thereby maintaining the tonneau cover in a taut state. The spring keeper assembly maintains tautness of the tonneau cover without intervention by the user. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The various advantages of the present invention will become apparent to one skilled in the art by reading the following specification and claims and by referencing the following drawings in which: 
     FIG. 1 is an environmental perspective view of a tonneau cover system constructed in accordance with the teachings of the present invention, with the tonneau cover shown in the closed position and attached to the cargo box of a vehicle; 
     FIG. 2 is an environmental perspective view of the tonneau cover system of FIG. 1 illustrating the tonneau cover in a partially rolled up condition; 
     FIG. 3 is a top plan view of a portion of the tonneau cover system in FIG. 1 illustrating the rear connector assembly components in a detached condition; 
     FIG. 4 is a top plan view similar to that of FIG. 3 but illustrating the rear connector assembly in an assembled condition; 
     FIG. 5 is an exploded perspective view of a portion of the rear connector assembly of the tonneau cover system in FIG. 1; 
     FIG. 6 is a partial sectional view of a portion of the tonneau cover system of FIG. 1 illustrating the rear rail in rotated condition preparatory to engaging the rotatable component to the fixed component of the rear connector assembly; 
     FIG. 7 is a partial section view similar to FIG. 6 but illustrating the rotatable component partially engaged to fixed component; 
     FIG. 8 is a partial section view similar to FIG. 6 but illustrating the rotatable component fully engaged to fixed component; 
     FIG. 9 is a an exploded perspective view of a portion of the tonneau cover system of FIG. 1, but illustrating the spring keeper assembly in greater detail; and 
     FIG. 10 is partial sectional view of a portion of the tonneau cover system of FIG. 1 illustrating the spring keeper assembly in an assembled condition in a side rail, similar to that of FIG.  1 . 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     With reference to FIGS. 1 and 2 of the drawings, a tonneau apparatus or system constructed in accordance with the teachings of the present invention is generally indicated by reference numeral  8 . The tonneau cover system  8  includes a frame structure  10  and a flexible tonneau cover  12 . The tonneau cover  12  is closed and attached to the frame structure  10 . 
     In the particular embodiment illustrated, the frame structure  10  includes a pair of side rails  14 , a front rail  16 , a rear rail  18 , front connector assemblies  20 , and rear connector assemblies  22 . The frame structure  10  is attached to the cargo box  23  of a vehicle  24 . Although the particular vehicle illustrated is a pick-up truck, those skilled in the art will appreciate that the tonneau cover system  8  may be used with other vehicles types and as such, the exemplary vehicle illustrated is not intended to limit the scope of the disclosure in any manner. Those skilled in the art will also appreciate that the front rail  16  may be optionally omitted from the frame structure  10  in an appropriate situation, as when the tonneau cover  12  is permanently affixed to the cargo box  23 . 
     The tonneau cover  12  is coupled to the frame structure  10  such that the frame structure  10  is positionable between a closed condition, which is illustrated in FIG. 1, and an open position, which is illustrated in FIG.  2 . The means by which the tonneau cover  12  is coupled to the frame structure  10  is conventional, with one such means being described in U.S. Pat. No. 5,934,735 to Wheatley, which is incorporated by reference as if fully set forth herein. 
     With specific reference to FIG. 2, the tonneau cover  12  is illustrated as being wrapped around the rear rail  18 . The tonneau cover  12  detaches in a conventional manner from the associated side rail  14  as it is rolled, with one such means being described in U.S. Pat. No. 5,934,735 to Wheatley. As the tonneau cover  12  is rolled, it is wrapped about the rear rail  18 . The tonneau cover  12  remains attached to the rear rail  18  while it is rolled. Additional use of VELCRO® 27, or similar hook and loop type fasteners, prevents further axial movement of the rear rail  18  along its longitudinal axis. 
     The rear rail  18  is kept close to the fabric of tonneau cover  12  to ensure a small moment arm against which the fabric can pull while the user locks the rear rail  18  into the closed position. 
     With reference to FIG. 2, the rear connector assemblies  22  are illustrated to include a fixed component  26  and a rotatable component  28 . Each fixed component  26  is attached to an associated side rail  14  and remains fixed to the vehicle  24 . Each rotatable component  28  is attached to the rear rail  18  and rotates when the tonneau cover  12  is opened. The rear connector assemblies  22  are shown in greater detail in FIGS. 3 and 4. 
     In FIG. 3, the fixed component  26  and the rotatable component  28  of the rear connector assembly  22  are shown aligned but detached from one another. The fixed component  26  includes a first plug end  44 , which includes a clip  33  and a detent  42  that accepts the locking tab  38 . The fixed component  26  also includes a second end  29  that defines an aperture  30 , within which is formed a mating slot  32 . 
     The first plug end  44  and the aperture  30  are generally orthogonal to each other. 
     The first plug end  44  removably secures to the associated side rail  14  as shown in greater detail in FIG.  9 . First plug end  44  is inserted into the associated side rail  14  and a clip  33  removably secures the fixed component  26  to the associated side rail  14  as in a manner that is disclosed in U.S. Pat. No. 5,934,735. 
     The rotatable component  28  includes a post end  34 , which includes a pawl  36 , a third plug end  46  and a clip  33 . The third plug end  46  and the post end  34  are generally colinear. 
     The rotatable component  28  further includes a locking tab  38 . The locking tab  38  is thin at its base  39 , or first end, to allow for easy flexing but thicker at the tip  41 , or second end, to aide in use. In the particular example provided, the locking tab  38  has a rectangular cross-section where the base measures about 0.5 inches by about 0.06 inches, and the tip measures about 0.25 inches by about 0.12 inches. 
     Reinforcement  40  is assembled in locking engagement with the indentation  43  of the locking tab  38  to provide a constant force. The force upon the locking tab  38  results in greater resiliency, thereby counteracting the possible loss in resiliency when the tonneau cover system components expand due to changes in ambient temperatures. 
     The third plug end  46  is fixedly but removably coupled to the rear rail  18 . Third plug end  46  is inserted into rear rail  18  and clip  33  removably secures the rotatable component  28  to the rear rail  18  as in a manner disclosed in U.S. Pat. No. 5,934,735. 
     Referring to FIGS. 3 and 4, the post end  34  is removably disposed within aperture  30 ; as such, pawl  36  inserts into mating slot  32  as shown in greater detail in FIG.  5 . The rotatable component  28  is rotated into locking engagement with the fixed component  26 , the progression of which is shown in greater detail in FIGS. 6,  7 , and  8 . 
     With specific reference to FIG. 4, the rear connector assembly  22  is shown assembled such that the rotatable component  28  is secured to the fixed component  26 . Locking tab  38  is shown in the open position and shown in phantom in a closed position, wherein the detent  42  has captured the locking tab  38 . 
     Referring to FIG. 5, the rear connector assembly  22  is shown in a disassembled condition. The fixed component  26  is shown with the mating slot  32  exposed along with the detent  42 . The detent  42  accepts the locking tab  38 , and the mating slot  32  accepts the pawl  36 . The post end  34  of the rotatable component  28  is inserted into the aperture  30  of the fixed component  26 , according to the progression shown in FIGS. 6,  7 , and  8 . 
     In FIGS. 6,  7 , and  8 , the progression of the rotatable component  28  is illustrated as it is locked into the fixed component  26 . As the fixed component  26  progresses into the locked position as shown in FIGS. 4 and 8, the locking tab  38  travels down a ramp  41  into the detent  42 . Once the locking tab  38  is in the detent  42 , the depth of the detent  42  is deep enough to capture the locking tab  38 , so that the rotatable component  28  is prevented from moving unless the locking tab  38  is released by the user. 
     The front connector assemblies  20  are conventional; as such, one example of their material and construction is described in U.S. Pat. No. 5,934,735. The rear connector assemblies  22  are constructed of a plastic, but also could be constructed of metal or any other appropriate material. In the preferred embodiment of the present invention, the rear connector assemblies  22  are constructed of NYLON® or other similar polyamides. The front rail  16 , the rear rail  18 , and the pair of side rails  14  are constructed of a metal, but also could be constructed of plastic, or any other appropriate material. In the preferred embodiment of the present invention, the front, rear, and pair of side rails  16 ,  18 ,  14  are constructed of extruded aluminum. The reinforcement  40  for locking tab  38  is constructed of metal, but could be constructed of plastic or any other appropriate material according to one skilled in the art. In the particular example provided, the reinforcement  40  is constructed of stainless steel with the thickness of about 0.02 inches and is in side-by-side locking engagement with the locking tab  38 . 
     Referring to FIG. 9, the spring keeper assembly  48  is illustrated in association with a side rail  14  and a fixed component  26 . Side rail  14  includes an opening  59  to accept the spring keeper assembly  48  and the fixed component  26 . Side rail  14  also includes an elongated groove  56 , weather stripping  58 , and a bight  62 . Fixed component  26  includes a first plug end  44  and a clip  33 . The spring keeper  48  includes a spring  50  with coils  49 , a housing  52  with a threaded opening  53  and a spring retaining device  54 . 
     The spring  50  is contained within the housing  52  and held in place by the spring retaining device  54 , which in the particular embodiment illustrated, is a conventional threaded fastener that is threadably engaged to the housing  52  through the threaded opening  53  and disposed through the coils  49  of the spring  50 , as illustrated in FIG.  10 . 
     The coils  49  of the spring  50  are contained within the housing  52 . As such, housing  52  is inserted in the opening  59  of the associated side rail  14 , such that the threaded opening  53  aligns with the groove  56 . After the housing  52  is inserted and aligned the spring retaining device  54  is inserted through an elongated groove  56  and then through the threaded opening  53 . 
     The spring retaining device  54  is inserted into and held by the threaded opening  53  of housing  52 , thereby securing the housing  52  to the inside of the side rail  14 . Spring retaining device  54  can be loosened to allow the spring keeper  48  to translate longitudinally in the associated side rail  14 . 
     The end of the spring retaining device  54  traps the coils  49  of spring  50  in the housing  52 , such that spring retaining device  54  is inserted through the elongated groove  56 , through the threaded opening  53 , and then through the coils  49  of the spring  50 . Alternatively, the housing  52  has a closed end that traps the coils  49  of the spring  50 , such that the spring retaining device  54  does not protrude into the housing  52  and interfere in between the coils  49  of spring  50 . 
     Weather stripping  58  provides a seal between the tonneau cover and the lip of the cargo box (not shown). Bight  62  cooperates with the cylindrical fastening system of the tonneau cover (not shown), in a manner disclosed in U.S. Pat. No. 5,934,735. 
     Referring to FIG. 10 there is shown a sectional top view of the spring keeper assembly  48  assembled, an associated side rail  14 , and a fixed component  26  in accordance with the preferred embodiment of the present invention. The coils  49  of spring  50  are shown in housing  52 . Spring retaining device  54  is shown interdisposed between the coils  49  of the spring  50 . Fixed component  26  includes the first plug end  44  inserted into the associated side rail  14 . The elongated groove  56  is shown with the spring retaining device  54  inserted therein. 
     Spring retaining device  54  is shown inserted through the elongated groove  56 , wherein the spring retaining device  54  is in a full forward position within the elongated groove  56 . The full forward position of the housing  52  and spring retaining device  54  correspond to the farthest position from the fixed component  26 . Different positions of the spring retaining device  54  and housing  52  in the elongated groove  56  provide differing levels of force on the fixed component  26 . 
     As explained above, setting the spring retaining device  54  full rearward in the elongated groove  56  positions the housing  52  closest to the fixed component  26 . The shorter the distance between the housing  52  and the fixed component  26  the more force the coils  49  of the spring  50  apply against the first plug end  44  of the fixed component  26 . Ultimately, the distance the spring retaining device  54  can travel is limited by the length of the elongated groove  56 . 
     Referring to FIG.  1  and FIG. 10, the force of the spring  50  applied to the first plug end  44  pushes the fixed the component  26  outward from the associated side rail  14 , such that the distance will increase between the fixed component  26  and the associated side rail  14 . When the tonneau cover system  8  is in the closed position as shown in FIG. 1, the rear rail  18  is locked into the rear connector assembly  22 . As such, the spring keeper assembly  48  exerts a force on the first plug end  44 , thereby exerting a force on the rear connector assembly  22 . With the rear rail  18  locked into the rear connector assembly  22 , the rear rail  18  and rear connector assembly  22  translate in a direction opposite the front rail  16 . The increase in distance between the rear rail  18  and the front rail  16  increase the tautness on the tonneau cover  12 . 
     To that end, the different positions of the spring keeper assembly  48  within the associated side rail  14  are determined by the position of the spring retaining device  54  in the elongated groove  56 . As such, differing positions of the spring retaining device  54  will apply differing amounts of force on the first plug end  44 . Advancing the spring retaining device  54  full rearward in the elongated groove  56 , such that it is closer to the rear rail  18 , will apply the most force to the first plug end  44 . Conversely, positioning the spring retaining device  54  in the full foreword position in the elongated groove  56 , such that the spring retaining device  54  is farthest from the rear rail  18 , will apply the least amount of force on the rear rail  18 . 
     Proper positioning of the spring retaining device  54  within the elongated groove  56  may be dictated by the age of the tonneau cover  12  (the tonneau cover may stretch) or, the ambient temperature to which the tonneau cover  12  is exposed. (Elevated ambient temperatures may cause the tonneau cover  12  to expand.) Positioning the spring retaining device  54  in the full rearward position for the greatest amount of force or the full foreword position for the least amount of force will maintain the tautness of the tonneau cover  12  depending on the amount of tautness control required. 
     Those skilled in the art can now appreciate from the foregoing description that the broad teachings of the present invention can be implemented in a variety of forms. Therefore, while this invention has been described in connection with particular examples thereof, the true scope of the invention should not be so limited since other modifications will become apparent to the skilled practitioner upon a study of the drawings, specification, and following claims.