Abstract:
A truck bed assembly within which the width dimension of the bed&#39;s cargo space can be selectively adjusted, the assembly including laterally movable sidewalls that are constructed so as to widen the bed floor surface as they are moved outward as well as a laterally expandable tailgate that lengthens and shortens as the sidewalls are laterally expanded and retracted.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    The present invention generally relates to an expandable truck bed, and it specifically relates to a truck bed assembly in which the bed sidewalls may be moved laterally outward, to increase bed carrying capacity, while retaining their vertical posture. 
         [0002]    Pickup trucks are characterized by having cargo beds configured to carry items that could not be fitted inside the passenger compartments of most other vehicles, or that would risk damaging upholstery if placed within the passenger cabin. Typically, a truck bed will comprise a rectangular floor, a front wall joined to the frontward end of the floor, a pair of opposing sidewalls joined to the side ends of the floor and a tailgate hinged to the rearward end of the floor. Conventional tailgates are downwardly openable to permit cargo to be loaded onto and unloaded from the bed without having to lift the cargo over an upright tailgate or the sidewalls. However, sometimes the dimensions of cargo to be placed onto a truck are such that that truck&#39;s bed simply cannot accommodate the cargo without somehow enlarging the cargo carrying space. 
         [0003]    Consequently, adjustable truck bed assemblies and bed add-on devices have been developed in the prior art. Some of these truck bed assemblies are length-adjustable. For example, U.S. Pat. No. 6,367,858 to Bradford discloses a truck bed extension assembly featuring slide panels that can be slid between a closed position in which the panels are entirely disposed within the bed sidewalls and an open position in which the panels are extended out from within the sidewalls to effectively lengthen the bed. This assembly also includes a second tailgate that provides bed closure when the first tailgate is open and the slide panels are extended the length of the horizontal lying first tailgate. As another example, U.S. Pat. No 5,938,262 to Mills discloses a truck bed assembly which includes a horizontal plate that is slidable relative to the bed floor by way of a rail and roller assembly which operatively connects the plate and the floor. When the truck&#39;s tailgate is open, the plate can be slid rearward and locked into position to provide an elongated bed floor. The prior art is also replete with various truck bed attachment devices that can be affixed to the end of the bed to provide rear closure for a longitudinally expanded cargo space when the tailgate is open. 
         [0004]    Additionally, there is a plethora of prior art truck bed assemblies in which the bed carrying capacity can be effectively expanded laterally. For instance, U.S. Pat. No. 7,059,666 to Harrison teaches a cargo bed in which the sidewalls are pivotally connected to the bed floor such that they can be selectively moved between vertical closed positions and horizontal open positions. U.S. Pat. No. 6,644,708 to Grzegorzewski et al. discloses an operatively similar assembly in which the sidewalls can be laid down. However, a common aesthetic, if not functional, disadvantage of the width-adjustable prior art truck beds of which the present inventor is aware is that, when laterally expanded, they either convert to flatbed configurations that lack side retaining walls, or they require erection of secondary sidewalls or sidewall attachments that adversely affect the truck&#39;s appearance. 
         [0005]    Therefore, there exists a need for a truck bed that can be expanded widthwise to increase its cargo capacity, but that substantially maintains its appearance and retaining structure throughout expansion. The present invention substantially fulfills this need. 
       SUMMARY 
       [0006]    The present invention is directed to a truck bed which can be selectively expanded widthwise to increase its cargo carrying capacity in a manner that does not alter the vertical disposition of the bed sidewalls. A minimal embodiment of the inventive truck bed comprises: a bed floor; a front wall coupled perpendicularly to the frontward end of the floor; sidewalls which are substantially perpendicular to the floor and which span the length of the floor; a tailgate pivotally attached to the rearward end of the floor; and at least one slide mechanism which connect the sidewalls to the bed floor and permit the sidewalls to expand and contract laterally. Preferably, the truck bed further includes at least a pair of vertically oriented hydraulic jacks which move the sidewalls between a retracted position in which they are spaced from one another by the width of the bed floor panel to an expanded position in which they are spaced further apart; and a user controller for allowing push button actuation of the jacks. 
         [0007]    Therefore, it is an object of the present invention to provide a truck bed that is capable of being adapted to accommodate larger cargo. 
         [0008]    It is another object of the invention to allow for lateral expansion of the bed capacity without requiring that the bed sidewalls be folded down or otherwise manipulated such that they cease providing side retention when the sidewalls are laterally expanded. Accordingly, it is also an object of the invention to allow the bed to substantially maintain its appearance when expanded. 
         [0009]    It is a further object of the present invention to provide for powered lateral expansion and retraction of the truck bed. By incorporating remotely controlled hydraulic jacks or electric motors that drive the bed sidewalls, a user can effortlessly adjust the bed size as needed. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]      FIG. 1  is a top plan view of a pickup truck that is equipped with the expandable truck bed of the present invention. In this view, lateral expandability of the bed sidewalls is demonstrated with phantom lines. 
           [0011]      FIG. 2  is a top and right perspective view of the left sidewall of the bed, shown in isolation. 
           [0012]      FIG. 3  is a top and right perspective view of the floor panel of the bed, shown in isolation. 
           [0013]      FIG. 4  is a rear and elevational view of an alternative embodiment of a slide mechanism for the present invention—an embodiment in which linear movement of a sidewall is motor driven. In this view, the bed floor and the floor extension portion of the left sidewall are shown in cross-section. 
           [0014]      FIG. 5  is a rear and elevational view of a portion of the preferred embodiment of a slide mechanism for the present invention—an embodiment in which linear movement of a sidewall is hydraulically driven. In this view, the bed floor and the floor extension portion of the left sidewall are shown in cross-section. 
           [0015]      FIG. 6  is a rear and elevational view of the tailgate of the present invention. In this view, the tailgate is in a retracted state. 
           [0016]      FIG. 7  is a rear and elevational view of the tailgate in an extended state. 
           [0017]      FIG. 8  is a diagrammatic illustration of the entire hydraulic slide mechanism. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0018]    A preferred embodiment of the expandable truck bed of the present invention employs several integrated elements including: a bed floor  140 , a front wall  120 , left and right sidewalls  110  and a rear tailgate  130 . 
         [0019]    As shown in  FIG. 3 , the front wall  120  is a hollow steel panel with open left and right ends  126 . It is vertically positioned adjacent the truck cabin  10 . Secured to the bottom of the front wall  120  is the bed floor  140 . The bed floor  140  is a generally horizontal, hollow steel panel formed by a top sheet  142  that directly supports cargo and a bottom sheet  144 , both of which are joined by a bend at their longitudinal rearward ends such that openings  146  remain along the left and right sides of the floor panel  140 . The top  142  and bottom  144  sheets of the floor panel are secured to the bottoms of counterpart metal sheets of the front wall panel  120  to form continuous space within the perpendicularly joined floor  140  and front wall  120 . Finally, the tailgate  130  is comprised of two extension panels  136  retractably disposed within a hollow central panel  134  as illustrated in  FIG. 6 . The tailgate  130  is hinged to the rearward end of the bed floor  140  and may be pivoted 90 degrees between an open horizontal position and a closed vertical position. As with conventional tailgates and as will be discussed later, the present tailgate  130  releasably engages the sidewalls  110 . 
         [0020]    From viewing  FIG. 2 , it can be understood that each sidewall  110  is a single unit comprising the following three distinct sections: (1) a side retaining wall  118  which is vertically disposed and functions as a traditional truck bed sidewall; (2) a front extension  116  which is vertically disposed, perpendicularly meets the frontward end of the side retaining wall  118  and inserts into an end opening  126  within the front wall  120 ; and (3) a floor extension  114  which is horizontally disposed, perpendicularly meets the side retaining wall  118  and inserts into a lateral side opening  146  within the floor  140 . Therefore, when the two sidewalls  110  are fully contracted, their front extensions  116  and their floor extensions  114  are fully enveloped by the front wall  120  and bed floor  140 , respectively, such that the opposing side retaining walls  118 , the front wall  120 , the tailgate  130  and the floor  140  define the truck bed enclosure. As the sidewalls  110  are laterally extended, their respective front extension portions  116  slide out from within the front wall  120 , and their floor extension portions  114  emerge from within the bed floor  140 . Thus, when the bed enclosure is extended, both the bed floor part  140  and the sidewall floor extensions  114  provide cargo floor support, while the front wall  120  and sidewall front extensions  116  jointly provide frontal retention. 
         [0021]    A plethora of linear motion systems, both manual and automated, could conceivably be used to facilitate lateral sidewall movement. Nevertheless, a couple of suitable alternative slide mechanisms are illustrated and described herein. One is a motor driven mechanism and the other, and preferred, mechanism is hydraulically driven. Nevertheless, both such slide mechanisms incorporate two identical, synchronously actuated subassemblies which each operate on one sidewall  110  to achieve inward and outward lateral movement of the sidewalls  110 . For simplicity, the configuration of merely one subassembly of each alternative slide mechanism will be described in succession immediately following. However, it should be again emphasized that still other mechanisms for facilitating lateral movement of the sidewall elements could be employed without departing from the present overall inventive concept. 
         [0022]    As shown in  FIG. 4 , embedded within the bed floor&#39;s top and bottom sheets  142 ,  144  are arrangements of rollers  148  that are in contact with the sidewall floor extension  114 . These rollers  148  permit the floor extension  114  to slide laterally within the floor panel  140  while encountering minimal friction. Also sandwiched within the floor panel  140 —inward of the sidewall extension  114 —is a nut  240  having a threaded bore. The nut  240  is affixed to the floor panel sheets  142 ,  144  to prevent it from sliding or rotating. Finally, in threaded engagement with the nut  240  is a screw-threaded shaft  220  that is rotated by an electric drive motor  210 . From the motor  220 , the shaft  220  projects laterally outward through the fixed nut  240  and then through a hole  112  within the sidewall floor extension  114 . Coupling the shaft  220  to the floor extension  114  are a pair of circular flanges  226 ,  224  that are shortly spaced apart along the shaft  220  about opposite sides of the hole  114 . 
         [0023]    As the drive motor  210  rotates the shaft  220  clockwise, threaded engagement of the shaft  220  and fixed nut  240  causes the rotating shaft  220  to advance linearly outward through the nut  240 . In turn, the shaft&#39;s inner flange  224  pushes against the abutting metal of the sidewall extension  114  and, aided by the bed floor rollers  148 , the sidewall  110  slides laterally outward to expand the width of the cargo bed. Conversely, when the shaft  220  is rotated counterclockwise, the shaft  220  is drawn inward through the nut  240 , and the pressing force of the outer flange  226  pulls the sidewall extension  114  deeper within the bed floor  140  to retract the sidewall  110 . 
         [0024]    The electric motor  210  is selectively controlled by a user interface module  300  disposed within the cabin area of the vehicle. The user module  300  may be wired (not shown) to the motor  210  may operate it wirelessly. Regardless, the number of revolutions in which the motor  210  is permitted to rotate the attached shaft  220  in either rotational direction should be electronically limited so as to prevent the shaft  220  from advancing too far inward or outward and encountering undesirable resistance (caused by motor  210  running into the nut  240 , for example). 
         [0025]    However, because of the nut and shaft assembly&#39;s susceptibility to mechanical wear, it is preferable to push and pull the sidewalls  110  by way of hydraulic or pneumatic means. Therefore, the preferred embodiment of the present invention employs a hydraulic push/pull device or jack  260  as illustrated in  FIG. 5 . This horizontally disposed jack  260  comprises a cylindrical rod  262  in telescopic engagement with a larger diametered cylinder  264 . The rod  262  is selectively extendable from and retractable into the cylinder  264  by conventional hydraulic operation. At one end of the jack  260 , its rod  262  is coupled to the sidewall floor extension  114  via a bolted attachment plate  268  or other suitable securing means. At the jack&#39;s opposite end, its cylinder  264  is similarly secured to a vertical mounting wall  150  which resides within the bed floor panel  140 . 
         [0026]      FIG. 8  illustrates an example of an overall hydraulic system  20  used to operate the jack  260 . In addition to the jack  260  itself, system components include a fluid reservoir  270 , a pump  280  and a pair of solenoids  274  that are positioned about the vehicle as may be desired. The solenoids  274  are continually connected to the jack  260  via fluid lines  288 . However, they are selectively connected to either the pump  280  or the reservoir  270  directly. A pressure line  284  connects the solenoids  274  to the pump  280 , while a drain line  286  connects the solenoids  274  directly to the reservoir  270 . When a solenoid  274  connects to the pressure line  284 , the pump  280  is able to deliver pressurized fluid through the pressure line  284  and then through a fluid line  288  to the jack  260 . Conversely, when a solenoid is connected to the drain line  286 , fluid exits the jack  260  through a fluid line  288  and then through the drain line  286 , depositing into the reservoir  270 . 
         [0027]    When the rate of fluid flow into the jack  260  is greater than that exiting it, fluid pressure projects the rod  262  out of the cylinder  264  and, in turn, pushes the coupled sidewall  110  outward. Conversely, when the net fluid flow is out of the jack  260 , the rod  262  withdraws back into the cylinder  264  and pulls the sidewall  110  inward. Solenoid connectivity, which dictates the balance of hydraulic fluid flow between the jack  260  and the reservoir  270  and thus effects extension and retraction of the jack  260 , is selectively controlled through a user module  300  that is wired to the solenoids  274 . 
         [0028]    Residing at the outer ends of the two tailgate extension panels  136  are spring loaded latches  430  which secure to corresponding posts within the side retaining walls  118  to maintain tailgate  130  closure. Furthermore, if the tailgate  130  is closed while the sidewalls  110  are being extended, engagement of the latches  430  and the side retaining walls  118  will cause the tailgate extension panels  136  to be pulled out from within the tailgate central panel  134 . An extended tailgate  130  is illustrated in  FIG. 7 . Of course, the opposite effect occurs to the closed tailgate  130  as the sidewalls  100  are retracted. Therefore, without any manual manipulation of the tailgate  130  itself and without the use of any separate attachments, the truck bed&#39;s rear retaining wall automatically adjusts to correspond to the changing distance between the left and right side retaining walls  118 . Sets of rollers  138  within the tailgate  130  allow its two extension panels  136  to slide back and forth against its central panel  134 . 
         [0029]    A handle  160  disposed on the tailgate central panel  134  is operatively linked to the left and right latches  430 . More specifically, as shown in  FIG. 6 , parallel pairs of rods  164 ,  164 ′ connect the handle  160  to each latch  430 , and a clip  168  binds the two rods  164 ,  164 ′ together. A first rod  164  is attached to the handle  160  and has the clip  168  rigidly affixed to it. A second rod  164 ′ is attached to the latch  430 , and it is slidable through the clip  168 . The second rod  164 ′ features successive stop grooves  166  along its length, and within the clip  168  is a retracting pin element (not shown) that projects into each groove  166 . As the latch  430  advances inward or outward (by virtue of sidewall lateral movement), the second rod  164 ′ progresses through the stationary clip  168 . The force applied to the second rod  164 ′ by a moving sidewall  110  will not allow the clip  168  to rest a stop groove  166  along the rod  164 ′. However, the magnitude of the pull force applied to the first rod  164  as the tailgate handle  160  is being pulled is insufficient to dislodge the clip  168  from a stop groove  166  at which the clip  168  is resting. Therefore, when the handle  420  is pulled while the tailgate  130  is closed, an opening force is transferred, via the clip  168 , from the first rod  164  to the second rod  164 ′ and is delivered to the latch  430 . This opening force releases the latch  430  from the retaining wall  118  so that the tailgate  130  is free to pivot open. 
         [0030]    It is understood that substitutions and equivalents for various elements set forth above may be obvious to those skilled in the art. Therefore, the full scope and definition of the present invention is to be set forth by the claims that follow.