Abstract:
A rigid bedcover and suspension/access system that provides substantially uniform and stable suspension throughout the angle of travel of the bedcover from the fully closed position to the fully open position. An offset hinge pivotally supports the bedcover and a counterbalanced suspension system suspends the pivoting bedcover with a substantially constant force throughout its path of travel from a fully closed position at 0 degrees to a fully open position at approximately 90 degrees. The counterbalanced suspension system of this invention does not require the hydraulic piston required by the prior art and provides a counterbalancing force and stable opening at every angle.

Description:
BACKGROUND OF THE INVENTION 
     a) Field of the Invention 
     This invention relates to truck bedcovers, and specifically to rigid or hard bedcovers used to cover the cargo bed area of trucks while permitting easy access to the cargo bed area. The bedcover set forth in this application is designed to pivot with respect to the truck bed. 
     b) Description of the Related Art 
     Conventional bedcovers are mounted through a hinge at the forwardmost wall of the truck bed and in operation lift at the tailgate end of the truck bed for access by the operator. The angular position of the bedcover is typically regulated by a hydraulic piston mounted at a mid-point of the truck bed sidewalls. FIG. 1 illustrates the conventional truck bedcover and access system. The angle range of operation is limited by the conventional bedcover suspension system permitting an approximate maximum angle of access of about 30 degrees. The conventional bedcover designs suffer from the following drawbacks: 
     1. Restricted cargo placement and operator access to the truck bed as a result of the limited angle range of displacement of the truck bedcover. 
     2. Danger of physical strain and discomfort for the operator while loading and unloading. As a result of the limited angle of displacement of the bedcover (about 30 degrees), an operator must crawl on hands and knees, or somehow maneuver his/her body under the plane of the bedcover to access the forward cargo area. Alternatively, the operator must grope blindly with his/her hands while standing outside the rails near the cab in order to access contents located in the forward portion of the cargo bed. 
     The conventional bedcover suspension system is designed to counteract the force of gravity with one predetermined force value. Thus, only one counterbalanced angle of suspension is attained. Suspension in angles below the predetermined angle will not occur, and suspension beyond or above the predetermined angle will occur but require the operator to deliver a strong, uncomfortable counteracting force to initiate closure of the bedcover. Most conventional bedcover systems incorporate both features; that is, no suspension near the closed position with suspension designed to occur at a point 40%-70% of the angle of operation and beyond to the fully open position. 
     In recognition of the above prior art design, the operator must lift the bedcover to the predetermined angle before suspension occurs. A short operator may not be able to lift the bedcover to the angle height required to engage suspension, or the bedcover in a suspended position is too high for the short person to close. The operator may not have the physical strength to lift the bedcover to the suspension angle, nor the strength to counteract the suspension force at the fully open position when closing the bedcover. 
     Additionally, the present invention provides a rigid bedcover made from stainless steel or polished aluminum wherein at least the interior surface of the bedcover facing the cargo area is polished to provide a reflective surface. A number 6 or higher grade polish is preferred to achieve the reflective characteristics sought by this invention. 
     In summary, the conventional hard bedcover does not offer a true counterbalance system or provide suspension through most of the angles of operation, but rather a single-force resistance value to ameliorate a portion of the forces for the operator and suspension at an arbitrary angle and above. 
     SUMMARY OF THE INVENTION 
     The present invention seeks to overcome the drawback inherent in the prior art by providing a rigid bedcover and suspension/access system that provides substantially uniform and stable suspension throughout the angle of travel of the bedcover from the fully closed position to the fully open position. 
     The bedcover of this invention is designed with an offset hinge located at a predetermined distance from the forward wall of the truck bed and a counterbalanced system that suspends the pivoting bedcover with a substantially constant force throughout its path of travel from a fully closed position at 0 degrees to a fully open position at approximately 90 degrees. The counterbalanced suspension system of this invention does not require the hydraulic piston provided in the prior art and provides uniform stability at every opening angle. 
     The offset hinge design which C-shaped hinge arm enables the hinge axis to be located inside the cargo bed area permitting integrity of seal operation without drilling or modifying the sheet metal body of the truck, while providing “flush” mounting of the bedcover to the inside of the truck bed rails, thereby providing the finish preferred by style-conscious truck owners. 
     The proposed counterbalanced suspension system gives the operator the ability to choose from a full range of bedcover operation/access angles to provide for the full spectrum of needs. With the suspension system of this invention, a bedcover opening of one degree will provide air ventilation of the cargo area while maintaining privacy of the cargo area and stable positioning of the bedcover. Opening of the bedcover to 30 degrees will provide stability and full access at the tailgate area depending on the operator height and truck suspension design. Opening of the bedcover up to 90 degrees will provide increased access from outside the truck along the rails and increased access from the tailgate with unrestricted head and body clearance for the operator in the 90 degree fully open position while standing in the bed. 
     These and other objectives of the present invention will become more apparent with reference to the following drawings and associated detailed description thereof. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is an illustration embodying the prior art wherein a bedcover is hinged at the forward wall of the truck bed and the bedcover is suspended by a piston member. 
     FIG. 2 is a perspective view of a truck employing the bedcover assembly of this invention. 
     FIG. 3 is a modified design of the embodiment shown in FIG. 2 wherein a latch mechanism is employed for added security and interacts with the tailgate. 
     FIG. 4 is a cross sectional view of the suspension system as viewed in the direction of cross sectional lines IV—IV of FIG.  2 . 
     FIG. 5 is a cross sectional view of the suspension system as viewed in the direction of cross section lines V—V of FIG.  4 . 
     FIG. 6 illustrates the mounting structure securing the suspension system to the sidewall and stake pockets formed in the truck bed sidewalls. 
     FIG. 7 is a perspective view of the split bearing member of the present invention. 
     FIG. 8 is a second embodiment of the hinge member and suspension system of the present invention employing a piston and cylinder arrangement. 
     FIG. 9 is a cross sectional view of the second embodiment of FIG. 8 as taken along section line IX—IX of FIG.  8 . 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     FIG. 2 shows a truck  2  employing the rigid bedcover  10  of this invention in a partial opened position. As clear from FIG. 2, the rigid bedcover  10  is fixed to the truck bed via a suspension system comprising an offset hinge disposed at a distance ‘X’ from the forward wall  5  of the truck bed or cargo area. In the preferred embodiment, the axis of the offset hinge is located about 4-6 inches from the forward sidewall of the truck bed of a typical truck bed. 
     The offset hinge design described below enables the hinge axis to be located inside the cargo bed area permitting integrity of seal operation without drilling or modifying the sheet metal body of the truck, while providing “flush” mounting of the bedcover to the inside of the truck bed rails, thereby providing the “flush” finish position of the cover preferred by style-conscious truck owners. 
     It should be noted that the bedcover  10  of this invention has a rigid design and is formed with a peripheral edge  12  having a perimeter that matches the inner periphery of the truck bed walls  4 ,  5 ,  6 . Truck cargo areas and shapes vary greatly with each vehicle, therefore, the bedcover  10  of this invention is adapted to be reconfigured to match any conceivable design. 
     To enhance security, a latch mechanism  16  may be provided at the tailgate  7  which interacts with the bedcover  10  to prevent access to the cargo area. In the preferred embodiment, the latch  16  comprises a non-compressive shock absorbing cylinder stock  17  mounted to the tailgate  7  which is disengaged from a hook  18  mounted to the underside of the bedcover  10  when the tailgate  7  is pivoted to a lowered position (see FIG.  3 ). Thus, disengagement of the latch mechanism  16  first requires the tailgate to be lowered. 
     FIG. 2 generally shows the hinge and suspension mechanism  30  of this invention which enables the bedcover  10  to be opened and retained at an infinite number of positions throughout the path of travel of the bedcover. That is, the suspension system  30  of the present invention utilizes a counterbalancing arrangement to apply a uniform force to the bedcover to retain the same at a variety of opened positions. With the suspension system of this invention, a bedcover opened to a small angle (for example, one to five degrees) will provide air ventilation of the cargo area while maintaining privacy of the cargo area. More importantly, the suspension system will maintain a stable position of the bedcover when slightly ajar. Opening the bedcover to a greater angle of inclination will still provide stability while enabling full access at the tailgate area. Fully opening the bedcover to an angle of approximately 90 degrees will provide increased access from outside the truck along the rails and increased access from the tailgate with unrestricted head and body clearance for the operator in the 90 degree fully open position while standing in the bed. 
     The suspension system  30  of the present invention will now be described with reference to FIGS. 4-6. FIG. 4 is a cutaway view of the suspension system  30  as viewed in the direction of cross sectional lines IV—IV of FIG.  2 . The offset hinge of the invention comprises a C-shaped hinge arm  32  fastened to the bedcover  10  in a suitable manner, i.e., screws  32 ′ (see FIG.  5 ). The suspension system  30  further comprises a first gear member  34  fixed to hinge arm  32 ; the first gear member comprises gear teeth  34   a  spanning an arc ‘θ’ of at least 90 degrees. Matingly engaging the first gear member  34  is second gear member  36  pivotally supported with respect to the truck bed. The second gear member  36  transmits torque from the first gear member  34  to a power spring  38  which is fixed at one end  38   a  to the truck bed and fixed at the other end  38   b  to the second gear member  36 . In the preferred design, the power spring  38  is recessed within the second gear member  36  to provide a compact yet durable arrangement to counterbalance the torque generated by the pivoted bedcover  10 . 
     FIG. 5 shows the suspension system  30  as viewed in the direction of cross section lines V—V of FIG. 4 when the bedcover  10  is in the closed position. As shown in FIG. 5, the hinge arm  32  is design to be well-balanced and compact to thereby enable a 90 degree pivoting motion without interfering or penetrating with the truck bed sidewalls. The C-shaped hinge arm  32  comprises first fastening leg  32   a  having a means for affixing the hinge arm  32  to the bedcover  10 . The hinge arm further comprises second and third legs  32   b ,  32   c  which wrap around the flange  9  defining the top surface of the truck sidewall. The first gear member  34  is fixed in a suitable manner to the second and third legs  32   b ,  32   c  in order to transmit torque from the bedcover  10  to the second gear member  36 . In the preferred design, the first gear member  34  is formed as part of the third leg  32   c  to provide gear teeth  34   a  at the lower face of the third leg  32   c  of the hinge arm  32 . In FIG. 6, the fourth leg  32   d  is shown to be wider than the lower second leg  32   b.    
     A fourth leg  32   d  of the hinge arm  32  engages a split bearing  33  mounted under the flange  9  of the sidewall. The two-piece shape of the split bearing member  33  is shown more clearly in FIG.  7 . The design of the split bearing  33  (i.e., two-pieces  33   a,    33   b ) enables accurate setting and adjustment of a fixing force that aids to retain the bedcover  10  in any one of an infinite number of fixed positions throughout its path of travel. Thus, when the bedcover  10  is pivoted to a desired position, the frictional resistance of the bearing  33  aids to retain the bedcover at a fixed position to compensate for external forces incidental on occasion, i.e. parking on grade, light wind, vibration from cargo area during loading and unloading, incidental bumping, etc., while permitting easy adjustment of the angle of inclination of the bedcover  10 . 
     The offset hinge design having a C-shaped hinge arm  32  enables the hinge axis to be located inside the cargo bed area permitting integrity of seal operation without drilling or modifying the sheet metal body of the truck, while providing a flush positioning of the bedcover to the inside of the truck bed rails, thereby maintaining the “flush” finish position of the cover preferred by style-conscious truck owners. 
     The power spring  38  provides a resiliency force to the second gear member  36  in order to supply a constant force of resistance to the torque transmitted from the bedcover  10  when pivoted from the closed position to the opened position regardless of the angle of inclination of the bedcover  10 . 
     The suspension mechanism  30  described above is housed within a casing  40  that is securely mounted to the cargo bed sidewall through conventional stake pockets  44  formed in the sidewalls of most trucks (see FIG.  6 ). The casing  40  consists primarily of a main base plate  40   a  having metal flanges  41 ,  42 ,  43  projecting from the stake pocket to which the hinge member, i.e. hinge arm  32  and bearing  33 ) are securely mounted. The second gear member  36  and associated spring  38  are likewise mounted on an arbor  39  provided on the flange members of the casing  40  (see FIG.  5 ). Thus, the casing  40  is easily mounted via bolts  45  to the existing structure of the cargo area sidewall without invading the storage area of the cargo space. It should be noted that the mechanism of this invention can likewise be mounted directly to the side rail of the truck bed independent of the stake pockets described above. 
     It must be understood that the counterbalancing suspension mechanism of this invention may be accomplished through a number of equivalent designs that are apparent to those of skill in the art. For example, a second embodiment of the suspension system of the present invention is shown in FIGS. 8 and 9. The second embodiment replaces the first and second gears  34 ,  36  and the power spring  38  of the first embodiment with a piston arrangement intended to accomplish the same objective, that is, to provide a uniform force of resistance or counterbalancing effect against the torque generated by the bedcover in an inclined, opened position. 
     Similar to the first embodiment, the hinge member of the second embodiment comprises a hinge arm  132  having first attachment leg  132   a  affixed to the bedcover  10 , second and third legs  132   b ,  132   c  wrapping around the flange  9  of the truck bed sidewall, and a fourth leg  132   d  which engages a split bearing  133  mounted to the truck sidewall. In a structural deviation from the first embodiment, a piston and cylinder device is mounted between the first leg  132   a  of the hinge arm  132  and the truck sidewall to provide a suspension system during inclination of the bedcover  10 . More specifically, a piston arm  134  is fixed to the hinge arm  132  in a pivoting manner at a point adjacent the bedcover  10 . A cylinder  136  is fixed to the truck bed sidewall in the manner shown in FIG.  9 . 
     From the foregoing description, it is clear that the present invention amounts to a substantial improvement over the prior art because the novel design set forth herein enables easy access to the cargo area of a truck bed without the limitation inherent in the prior art. The offset hinge and suspension system of this invention permits the bedcover to be pivoted to an angle of 90 degrees, and more importantly, enables stable positioning of the bedcover at an infinite number of positions along the path of travel of the bedcover without undue stress on the operator. The counterbalancing arrangement of the suspension system provides a uniform force acting against the weight of the bedcover  10  thus enable stability, convenience and versatility during use. 
     While the foregoing objects and advantages of the invention have been shown and described with respect to preferred embodiments, it will be understood by those of skill in the art that various changes in form and detail may be made without departing from the spirit and scope of the present invention.