Abstract:
A truck bed cover is adapted to be attached to a toolbox. The cover is hinged to the rearward portion of the toolbox, thereby leaving the toolbox accessible even when the cover is closed over the bed. A single hydraulic cylinder may be used to raise and lower the cover. The hydraulic cylinder is anchored using cross pins in elongated slots. The anchor points are allowed to move so that upon closing the cover the cylinder shifts into a position which does not consume much of the useful space within the bed. A recessed channel on the underside of the cover locks over the pickup bed sides and the tailgate. When closed, the hydraulic cylinder pulls the cover tightly against the pickup truck body—thereby securing the contents of the bed. In addition, certain elements of the invention can be adapted for use in a cover which is not attached to a toolbox.

Description:
CROSS-REFERENCES TO RELATED APPLICATIONS 
     Not Applicable 
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     Not Applicable 
     MICROFICHE APPENDIX 
     Not Applicable 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to truck beds and covers. More specifically, the preferred embodiment of the invention comprises a truck bed cover which attaches to a toolbox so that the contents of the toolbox can be accessed without having to open the cover. 
     2. Description of the Related Art 
     Pickup trucks have been in widespread use for many decades. The advantages of the open pickup bed are well known. However, it is also desirable to cover the bed in order to protect items placed therein. Such a cover must protect the items being hauled while still providing ready access to the bed. U.S. Pat. No. 3,923,334 to Key (1975) discloses a hinged bed cover. It includes a pair of sliding links—appearing to be air cylinders—to control the motion of the cover. A latching mechanism is also provided to secure the cover in its down position. 
     U.S. Pat. No. 4,083,596 to Robertson (1978) shows a hinged bed cover with a supporting link to maintain it in a raised position. A hinged cover having the point of rotation along the side of the truck bed is shown in U.S. Pat. No. 4,142,760 to Dockery et.al. (1979). Like the Robertson device, it uses a swinging link to hold the cover in an elevated position. However, the Key, Robertson, and Dockery et.al. devices all require the user to lift and close the cover. This fact can be a substantial disadvantage, especially since the cover may be quite heavy. 
     An automated bed cover is disclosed in U.S. Pat. No. 5,094,499 to Simone, Jr. (1992). The &#39;499 device employs a cable winch to raise and lower a pair of lift arms. These lift arms, in turn, raise and lower the bed cover. Automated bed covers are also disclosed in U.S. Pat. No. 5,503,450 to Miller (1996) and U.S. Pat. No. 5,909,921 to Nesbeth (1999). 
     While these devices do automate the process of raising and lowering the cover, they incorporate several undesirable features. Simone uses a centrally mounted winch platform. This platform, in combination with the two lift arms, consumes much of the useful space within the pickup truck bed. Nesbeth and Miller disclose the use of two cylinders—one on each side of the bed. This approach adds cost, along with the complexity of simultaneously controlling two cylinders. 
     In addition, most of the prior art covers are adapted to cover the entire pickup truck bed. In recent years, large mounted toolboxes have come into common use. FIG. 1 shows one such device. The reader will observe that toolbox  12  is bolted in place just behind the cab. It consumes a significant amount of bed space and prevents the use of a conventional bed cover. 
     Thus, the prior art devices are limited in that they: 
     1. Require the user to manually open and shut the cover; 
     2. Consume much of the useful space within the pickup truck bed; 
     3. Require the simultaneous operation of two lift cylinders; and 
     4. Cannot be used in conjunction with a large mounted toolbox. 
     BRIEF SUMMARY OF THE INVENTION 
     The present invention is a truck bed cover adapted to be attached to a toolbox. The cover is hinged to the rearward portion of the toolbox, thereby leaving the toolbox accessible even when the cover is closed over the bed. A single hydraulic cylinder may be used to raise and lower the cover. The hydraulic cylinder is anchored using cross pins in elongated slots. The anchor points are allowed to move so that upon closing the cover the cylinder shifts into a position which does not consume much of the useful space within the bed. 
     A recessed channel on the underside of the cover locks over the pickup bed sides and the tailgate. When closed, the hydraulic cylinder pulls the cover tightly against the pickup truck body—thereby securing the contents of the bed. 
     In addition, certain elements of the invention can be adapted for use in a cover which is not attached to a toolbox. 
    
    
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
     FIG. 1 is a perspective view, showing the proposed invention mounted on a pickup truck. 
     FIG. 2 is a perspective view, showing the position of the hydraulic cylinder. 
     FIG. 3 is an isometric view, showing how the cover mates to the truck side. 
     FIG. 4 is an isometric view, showing how the cover mates to the truck tailgate. 
     FIG. 5 is an isometric view, showing the details of how the hydraulic cylinder attaches to the cover. 
     FIG. 6 is an isometric view, showing the details of how the hydraulic cylinder attaches to the toolbox. 
     FIG. 7 is an elevation view, showing the cover in its open position. 
     FIG. 8 is an elevation view, showing the cover in the process of closing. 
     FIG. 9 is an elevation view, showing the cover in its fully closed position. 
     FIG. 10 is a perspective view, showing the toolbox and attached cover as a separate unit. 
     FIG. 11 is an elevation view, showing the attachment of the cover to the toolbox. 
     FIG. 12 is a perspective view, showing how the hydraulic cylinder attaches to the truck. 
     
       
         
               
             
               
               
               
               
             
           
               
                   
               
               
                 REFERENCE NUMERALS IN THE DRAWINGS 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 10 
                 pickup truck 
                 12 
                 toolbox 
               
               
                 14 
                 cover 
                 16 
                 hinge 
               
               
                 18 
                 hydraulic cylinder 
                 20 
                 bed 
               
               
                 22 
                 tailgate 
                 24 
                 truck side 
               
               
                 26 
                 recessed channel 
                 28 
                 side wall 
               
               
                 30 
                 rod 
                 32 
                 cover bracket 
               
               
                 34 
                 rod pin 
                 36 
                 spring anchor 
               
               
                 38 
                 spring 
                 40 
                 rod slot 
               
               
                 42 
                 air cylinder 
                 44 
                 cylinder pin 
               
               
                 46 
                 cylinder slot 
                 48 
                 cylinder mount 
               
               
                 50 
                 toolbox lid 
                 52 
                 gutter 
               
               
                 54 
                 cab 
                 56 
                 toolbox bracket 
               
               
                 58 
                 side wall 
               
               
                   
               
             
          
         
       
     
    
    
     DESCRIPTION OF THE INVENTION 
     FIG. 1 shows a typical pickup truck  10  having a toolbox  12  installed in the forward portion of the bed  20 , near cab  54 . Toolbox  12  is covered by toolbox lid  50 . Items which the truck&#39;s owner commonly needs are stored within toolbox  12 . Thus, it is important for these items to remain accessible. 
     Bed  20  is used for the storage of larger items. Many prior art bed covers have been employed for pickup trucks. However, as those skilled in the art will know, these covers extend over the full length of bed  20 . They are thus incompatible with the installation of a toolbox such as the one shown. The present invention eliminates this disadvantage by combining toolbox  12  and cover  14  into one integrated unit. As illustrated, cover  14  is linked to toolbox  12  by hinges  16 . Cover  14  is just long enough to cover the portion of bed  20  lying behind toolbox  12 . 
     FIG. 2 is a perspective view looking into bed  20  from the rear of the truck. Bed  20  is bounded by a left truck side  24 , toolbox  12 , and a right truck side  24 . Tailgate  22 —shown in the open position—selectively closes the rear of bed  20 . Cover  14  is shown in the open position. The lower surface of cover  14  opens into recessed channel  26 . When cover  14  is closed, recessed channel  26  fits snugly over the two truck sides  24  and tailgate  22 . 
     FIGS. 3 and 4 show the design of recessed channel  26  in greater detail. FIG. 3 shows a sectional view of cover  14  closed over truck side  24 . The reader will observe that recessed channel  26  is shaped to fit snugly over the upper portion of truck side  24 . FIG. 4 shows a sectional view of cover  14  closed over tailgate  22  (with tailgate  22  in the closed position). The portion of recessed channel  26  lying over tailgate  22  is shaped differently. Again, however, it fits snugly over the upper portion so as to engage tailgate  22 . 
     Returning now to FIG. 2, those skilled in the art will appreciate that cover  14 —depending on the materials selected for its construction—can be quite heavy. It may therefore be difficult for some users to lift into the open position. Accordingly, a pair of air cylinders  42  can be provided to assist in raising the cover. These types of cylinders are quite common in the prior art. They compress as cover  14  is closed, thereby acting as a sort of counterbalance to the weight. 
     It is also desirable to automate the opening and closing of cover  14 . An extendable lift cylinder can be provided to accomplish this goal. FIG. 2 shows hydraulic cylinder  18  attached between toolbox  12  and cover  14 . When rod  30  extends from hydraulic cylinder  18 , it will push cover  14  to the open position—as shown. When it retracts, it will pull cover  14  closed. Hydraulic cylinder  18  can also be used to establish considerable closing force on cover  14  after cover  14  has seated over the two truck sides  24  and tailgate  22 . It therefore secures the contents of bed  20  without the need for a lock. 
     Those skilled in the art will realize that hydraulic cylinders such as the one shown in FIG. 2 can exert considerable force—up to several thousand pounds. Particular attention must therefore be paid to how hydraulic cylinder  18  is anchored to toolbox  12  and cover  14 . Cover  14  is preferably made of fiberglass, which can crack if too much stress is placed on it. Thus, if rod  30  is retracted too far into hydraulic cylinder  18 , it could actually damage cover  14  or rip loose the mountings. 
     Electrical limit switches are typically used to control the extension and retraction of rod  30 . However, these have limited accuracy. It is therefore preferable to mount hydraulic cylinder  18  in such a manner that some inconsistency in the fully extended and fully retracted positions for rod  30  can be accommodated. FIG. 5 shows the provision for mounting rod  30  to the underside of cover  14 . Cover bracket  32  is attached to the underside of cover  14  by conventional means—such as adhesives, rivets, or bolts. It has two descending side walls  28 . Both of these open into rod slot  40 , which passes transversely through both side walls  28 . 
     The upper end of rod  30  is joined to a transverse rod pin  34 . Rod pin  34  rests within the two rod slots  40 . The reader will therefore appreciate that the extension and retraction of rod  30  will cause rod pin  34  to move within rod slot  40 . Sets of springs  38  are provided to impede this movement. On the side visible in FIG. 5, two springs  38  are attached to spring anchors  36  and the exposed end of rod  34 . The identical arrangement is found on the opposite side of cover bracket  32 . These sets of springs are configured to bias rod pin  34  toward the middle of rod slot  40 . However, they do allow some relative motion between rod  30  and cover  14 , in order to allow for variations in the fully extended and filly retracted positions of rod  30 . 
     Hydraulic cylinder  18  is preferably powered by a DC hydraulic pump using a small integral reservoir. Such a pump, which is quite common in the prior art, can be mounted within toolbox  12 . The controls for actuating the pump can likewise be mounted within toolbox  12 . This fact is important, since toolbox lid  50  can be locked in the closed position. This feature prevents unauthorized persons from accessing the hydraulic controls, thereby allowing them to open cover  14  and gain access to the bed. Obviously, the controls could also be mounted in the cab of the truck, although this would typically be a more difficult installation. 
     The aforementioned allowance for variations in the shut-off point for the closed position on hydraulic cylinder  18  is particularly important when cover  14  is brought to the closed position. Returning to FIG. 2, the reader will observe that cover  14 —along with the associated recessed channel  26 —is configured to close tightly over and secure the pickup truck bed (typically with tailgate  22  in the closed position). In order to secure the contents of the bed without the need for an additional locking mechanism, the control mechanism for hydraulic cylinder  18  must be set to exert considerable downward force on cover  14  before the hydraulic pump is switched off (with the associated hydraulic valves closing, thereby locking hydraulic cylinder  18  in position). Those skilled in the art will understand—by inspecting the geometry of the device—that if the electrical limit switch used to halt the retraction of rod  30  is slow to actuate, considerable extra force could be placed on cover  14 , possibly damaging it. The use of springs  38  prevents this possibility. 
     Those skilled in the art will also realize that numerous spring configurations could be substituted for the one shown in FIG.  5 . Other energy storage devices—such as air cylinders, elastic polymers, or leaf springs, could be substituted. The reader should also appreciate that many devices could be substituted for hydraulic cylinder  18 . As one example, a screw drive device—often found in gate openers and aircraft control surface actuators—could be substituted. Any device which provides extension and retraction would work. 
     Returning again to FIG. 2, the reader should be aware that air cylinders  42  can be used in conjunction with hydraulic cylinder  18  in order to dampen any oscillating motions when cover  14  is opened or closed. However, they are not required for the operation of the invention. Likewise, the use of the hydraulic cylinder is entirely optional to the present invention. 
     The method of anchoring the lower part of hydraulic cylinder  18  to toolbox  12  incorporates another novel feature. FIG. 6 shows toolbox bracket  56 , which is typically attached to a rearward facing portion of toolbox  12 . Toolbox bracket  56  includes two rearward extending side walls  58 . These two side walls open into a transverse cylinder slot  46 . The reader will observe that cylinder slot  46  is angled; i.e., its lower extremity is closer to the cab of the pickup than its upper extremity. The bottom of cylinder  18  is provided with cylinder mount  48 . Cylinder pin  44  is rotationally attached to cylinder mount  48 . It also rests within cylinder slot  46 . 
     The motivation underlying the angled nature of cylinder slot  46  is shown in FIGS. 7 through 9. FIG. 7 shows cover  14  in its open position. Hydraulic cylinder  18  is at this point under a compressive load. This fact causes cylinder pin  44  to move to the bottom of cylinder slot  46 . FIG. 8 shows the invention at the point where cover  14  has just closed over the bed, but before hydraulic cylinder  18  has applied additional closing force. FIG. 9 shows the invention in the closed and locked state—just after the limit switches or other control device has caused rod  30  to cease retracting. At this point, two actions have occurred. First, as described previously, rod pin  34  has moved forward—toward the pickup truck cab—in rod slot  40 . Second, cylinder pin  44  has moved up to the upper extreme of cylinder slot  46 . This has resulted in hydraulic cylinder  18  tucking up against the underside of cover  14 . This fact means that hydraulic cylinder  18  does not consume valuable bed space when cover  14  is in the closed position. 
     At this point, the reader may naturally wonder why the fact that the hydraulic cylinder does not consume bed space in the closed position is relevant, since the hydraulic cylinder most certainly does consume that space in the opening and closing operations. The answer lies in the fact that in some embodiments, tailgate  22  can be configured to open and close even though cover  14  is in the closed position. Looking at FIG. 4, those embodiments eliminate the portion of recessed channel  26  that lies over tailgate  22 . Thus, tailgate  22  may be opened without disturbing cover  14 . It is therefore important—for these embodiments—that a central portion of the bed not be obstructed by hydraulic cylinder  18 . 
     FIG. 10 shows toolbox  12  and cover  14 —along with other associated elements—detached from the pickup truck. The reader will by this point understand that in the embodiment shown in FIG. 10, the hydraulic pump, hydraulic cylinder, and control circuits can all be housed within this one unit. In order to install it on a truck, one needs only to provide electrical power and physically attach the unit. 
     It is important to prevent the entry of water into the bed when cover  14  is in the closed position. A water tight seal as to the truck sides and tailgate is provided via the arrangements shown in FIGS. 3 and 4. However, it is also important to seal the interface between toolbox  12  and cover  14 . FIG. 11 shows an elevation view of the interface found at hinge  16 . Rain gutter  52  is placed beneath hinge  16 , so that any water leaking past will be contained within gutter  52 . Gutter  52  runs transversely across the toolbox, exiting on either side past the outer extremes of cover  14 . Thus, any water leaking past hinge  16  will be trapped by gutter  52  and drained away. 
     Having read the preceding disclosure, the reader will appreciate that many devices could be substituted for hydraulic cylinder  18 . These would include, without limitation: screw drive devices, four bar linkage devices, pneumatic lift systems, gear drives driving a rotary pinion located at hinge  16 , etc. Likewise, the reader will appreciate that the invention includes embodiments having no lifting device at all. In its simplest form, the invention would comprise only a cover  14  as attached to a toolbox  12  (the embodiment shown in FIG. 10, with the exclusion of the hydraulic cylinder and mounting hardware). 
     Likewise, it is certainly not essential that the hydraulic cylinder be mounted to the toolbox. It could just as easily be mounted to the pickup truck itself. This could be true where there is a toolbox, or for instances where no toolbox is used (Although, as explained previously, the novel aspects for those embodiments not incorporating a toolbox are limited to the mounting systems for the lift cyder). 
     FIG. 12 shows such an embodiment. The reader will observe that hydraulic cylinder  18  is attached to pickup truck  10  via the placement of toolbox bracket  56  directly on the bed of the truck. Toolbox bracket  56  can be attached to the truck via bolts, welding, or other common prior art techniques. 
     Although the preceding description contains significant detail, it should not be construed as limiting the scope of the invention but rather as providing illustrations of the preferred embodiment of the invention. Thus, the scope of the invention should be fixed by the following claims, rather than by the examples given.