Patent Publication Number: US-11661118-B2

Title: Tailgate for vehicle

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application claims priority to U.S. provisional application Ser. No. 63/132,847, filed Dec. 31, 2020, the entirety of which is incorporated herein by reference. 
    
    
     BACKGROUND 
     Many types of trucks have been built with beds for storage and transportation of materials over the years. Such trucks often have a gate at the rear end of the bed that is commonly referred to as a tailgate. In such trucks, it is common to attach the tailgate using hinges along the bottom edge of the tailgate or at the lower left and right corners of the tailgate. Such hinges permit the tailgate to rotate between a first, vertical position in which the tailgate is substantially perpendicular to the floor of the bed and in which the tailgate may be used to secure items in the bed and a second, horizontal position in which the tailgate is substantially parallel to the floor of the bed and in which items in the bed are more accessible. 
     The hinges of such tailgates may be inundated with particles when the bed of the truck is used to transport particulate matter such as soil, mulch, fertilizer, sand, grain, or other similar items. In some instances, when a truck travels on a dusty road, the road dust alone may inundate the hinges of the tailgate. When inundated with such particles, the hinges may jam or may become difficult to operate. 
     Accordingly, it would be desirable to provide a tailgate in which the hinges are constructed and/or positioned in a manner that will reduce the amount of particulate matter that inundates the hinges of the tailgate. 
     The hinges of common tailgates also restrict the movement of the tailgate such that when the tailgate is in the second, horizontal position, the height of the top side of the tailgate is substantially similar to the height of the truck bed. For many pickup trucks, this height may be between about 26 inches and 36 inches above ground level. Other trucks may have a bed height that is greater than 36 inches. These bed heights are not conducive to climbing into and out of the truck bed to access items stored in the bed. For example, if it is necessary to climb into a truck bed to shovel soil from the bed onto the ground, it will be difficult for most people to step from ground level onto a 36 inch tall bed. 
     For these reasons, various devices to assist with stepping onto a truck bed have been utilized. In some instances, the corners of the truck bumper are provided with stepping surfaces either on top of the bumper or cut into the bumper. In other instances, fold-down steps are provided from the horizontal tailgate. 
     In yet other instances, complex hinge mechanisms are provided, such as those illustrated in U.S. Pat. Nos. 6,966,597; 7,073,837; and U.S. Patent Application Publication No. 2007/007,556. However, such devices introduce additional moving parts and complexity that is less desirable for many owners. 
     For these reasons, it would be desirable to have a tailgate that can be opened to a position suitable for serving as a step between ground level and bed level. It would also be desirable to realize such a tailgate without the need for complex hinges. 
     For these reasons, it would also be desirable to have a tailgate that allows for transfer of particulate matter out of the bed without undue spillage or jamming of hinges. 
     For the avoidance of doubt, the above-described contextual background shall not be considered limiting on any of the below-described embodiments, as described in more detail below. 
     SUMMARY 
     The following presents a simplified summary of the specification in order to provide a basic understanding of some aspects of the specification. This summary is not an extensive overview of the specification. It is intended to neither identify key or critical elements of the specification nor delineate the scope of any particular embodiments of the specification, or any scope of the claims. Its sole purpose is to present some concepts of the specification in a simplified form as a prelude to the more detailed description that is presented in this disclosure. 
     Accordingly, embodiments of the present invention may provide systems, structures, and methods of providing a way to step on a tailgate between ground level and bed level. Such tailgates may be deployed on trucks, trailers, or other suitable vehicles. For purposes of simplicity in discussion, the disclosure herein will reference trucks, but can be applied to trailers and other suitable vehicles. 
     Embodiments of the invention may provide systems, structures, and methods related to such a tailgate without unduly complex hinge structures. 
     Embodiments of the invention may provide systems, structures, and methods related to a tailgate that allows for transfer of small and particulate matter from a truck bed without undue spillage. 
     Embodiments of the invention may provide systems, structures, and methods related to a tailgate that allows for transfer of small and particulate matter from a truck bed without undue jamming of hinges. 
     Embodiments of the invention may provide systems, structures, and methods related to a tailgate having an embedded support rack that may have guard grooves to align cargos and/or tie-down anchors for securing loads. 
     Embodiments of the invention may provide systems, structures, and methods related to a tailgate having an embedded mini-gate that is substantially flush with the bed of the truck when deployed, such that oversized loads may be supported by the mini-gate when the tailgate is deployed in a substantially horizontal position and the mini-gate is raised above the tailgate. 
     One preferred embodiment may provide a tail gate for use with a vehicle having a bed, a front end, and a rear end, comprising an assembly that may be rotated about a substantially horizontal axis from a substantially vertical first position to a substantially horizontal second position, the assembly comprising a gate portion having a surface substantially disposed along a first plane when the assembly is in the first position, wherein the first plane is substantially perpendicular to a first axis, the first axis extending parallel to the bed and from a front center of the vehicle to a rear center of the vehicle; a seal portion attached to the gate portion in proximity to a bottom edge of the gate portion, the seal portion substantially disposed along a second plane parallel to the bed of the vehicle and perpendicular to the first plane when the seal portion is in the first position, the seal portion having a long dimension that is approximately the same as the width of the bed; wherein the seal portion is disposed below a height of the bed and a top edge of the seal portion is arranged in close proximity to the bottom of the bed when the assembly is in the first position; a first pivot structure and a second pivot structure, the first pivot structure located near a first end of the gate portion and mechanically connected to a first end of the gate portion, the second pivot structure located near a second end of the gate portion and mechanically connected to the second end of the gate portion, the first end located opposite the second end; the first pivot structure and the second pivot structure positioned to allow rotation of the assembly about the substantially horizontal axis, the substantially horizontal axis located below the bed and between the first plane and the front end; wherein, when the assembly is in the first position, the gate portion substantially closes the rear end of the bed; and wherein, when the assembly is in the second position, the surface of gate portion is substantially parallel to the bed and below a top level of the bed, and the seal portion is substantially perpendicular to the bed. 
     This embodiment may further include a support rack embedded within the surface of the gate portion, the support rack pivotally attached to the gate portion, such that when the assembly is in the second position, the support rack may be pivoted from within the surface of the gate portion to an upright position, to provide a support for items laid in the bed and extending beyond the edge of the bed. The embodiment may further include a pop-up mini gate embedded within the surface of the gate portion and extendable in a direction substantially perpendicular to the surface so as to be arranged at a height that is substantially aligned with the top level of the bed when the assembly is in the second position and the mini gate is extended. The embodiment may further include a support rack embedded within the surface of the gate portion, the support rack pivotally attached to the gate portion, such that when the assembly is in the second position, the support rack may be pivoted from within the surface of the gate portion to an upright position; the support rack arranged about the perimeter of the mini gate when both are positioned within the surface of the gate portion. 
     The embodiment may further be constructed such that the first pivot structure and the second pivot structure are not substantially exposed to solid materials when such materials are in the bed. The embodiment may further include a seal to close gaps between the assembly and the bed to reduce spillage of particulate materials when such materials are in the bed. The embodiment may be included in a vehicle where the vehicle comprises a wheel well for a rear wheel, and a side wall extending upward from the surface of the bed, the side wall arranged substantially perpendicular to the surface of the bed and substantially perpendicular to the first plane, the side wall arranged in proximity to the wheel well; and the first pivot structure is disposed within a compartment between the sidewall and the wheel well; the first pivot structure comprising a thrust bearing. The embodiment may further be constructed so that when the assembly is in the first position, the compartment is substantially closed; and when the assembly is in the second position, the compartment may be accessed for cleaning or lubrication. 
     The embodiment may further be constructed such that the vehicle has a removable, centered, high ball trailer hitch; and the high ball trailer hitch is positioned to support a bottom surface of the gate portion when the assembly is in the second position. The embodiment may further include a tongue and groove alignment structure disposed at an edge of the gate portion, the alignment structure configured to contact a frame of the vehicle below the bed, the alignment structure for reducing lateral deformation of the gate portion when the assembly is in the second position. 
     Another preferred embodiment may be described as a pivoting device for use in a vehicle comprising a bed with a top surface arranged substantially perpendicular to a first axis, the first axis extending in the direction of gravity, the bed having a substantially horizontal first bed edge located at the rear of a vehicle, the first bed edge being substantially linear, the pivoting device comprising: a gate having a first substantially rectangular outline and a gate width approximately equal to the length of the first bed edge, the gate having a lower gate edge extending substantially parallel to the first bed edge, the lower gate edge approximately the same length of the first bed edge; a seal portion having a second substantially rectangular outline, the seal portion having a first seal edge, the first seal edge approximately the same length as the lower gate edge, the first seal edge attached along its length to the lower gate edge such that the ends of the first seal edge are in close proximity to the respective ends of the lower gate edge, the second substantially rectangular outline disposed substantially perpendicular to the first substantially rectangular outline; first and second pivoting structures arranged to pivot about a single pivot axis substantially parallel to the first bed edge, the lower gate edge, and the first seal edge, the first and second pivoting structures mechanically attached to the gate; the pivot axis disposed lower than the top surface of the bed and forward of the first bed edge with respect to a primary direction of travel of the vehicle, such that the gate and seal portion may be rotated about the pivot axis between (a) a first position in which the first substantially rectangular outline is substantially perpendicular to the top surface and substantially parallel to the first axis, and (b) a second position in which the first substantially rectangular outline is substantially parallel to the top surface of the bed; and wherein, when disposed in the second position, a top surface of the gate is lower than the top surface of the bed, such that the top surface of the gate may be used as an intermediate step between a surface on which the vehicle is disposed and the top surface of the bed. 
     The embodiment may be constructed such that when disposed in the second position, the lower gate edge is (a) below the first bed edge and (b) forward or aft of the first bed edge with respect to the primary direction of travel of the vehicle. The embodiment may also include a support rack embedded within the top surface of the gate, the support rack pivotally attached to the gate, such that when the gate is in the second position, the support rack may be pivoted from within the top surface of the gate to an upright position, to provide a support for items laid in the bed and extending beyond the edge of the bed. 
     The embodiment may include a pop-up mini gate embedded within the top surface of the gate and extendable in a direction substantially perpendicular to the top surface of the gate so as to be arranged at a height that is substantially aligned with the top surface of the bed when the gate is in the second position and the mini gate is extended. The embodiment may also include a support rack embedded within the top surface of the gate, the support rack pivotally attached to the gate, such that when the gate is in the second position, the support rack may be pivoted from within the top surface of the gate to an upright position; the support rack arranged about the perimeter of the mini gate when both are positioned within the surface of the gate position. 
     The embodiment may be constructed so that the first pivoting structure and the second pivoting structure are not substantially exposed to solid materials when such materials are in the bed. The embodiment may include a seal to close gaps between the gate and the bed to reduce spillage of particulate materials when such materials are in the bed. 
     The embodiment may be incorporated into a vehicle that comprises a wheel well for a rear wheel, and a side wall extending upward from the top surface of the bed, the side wall arranged substantially perpendicular to the top surface of the bed and substantially perpendicular to the gate, the side wall arranged in proximity to the wheel well; and the first pivoting structure is disposed within a compartment between the sidewall and the wheel well; the first pivoting structure comprises a thrust bearing. 
     The embodiment may be constructed such that when the gate is in the first position, the compartment is substantially closed; and when the gate is in the second position, the compartment may be accessed for cleaning or lubrication. 
     The embodiment may be incorporated into a vehicle that has a removable, centered, high ball trailer hitch; and the high ball trailer hitch is positioned to support a bottom surface of the gate when the gate is in the second position. 
     Various embodiments of the present invention may incorporate one or more of these and the other features described herein. A better understanding of the nature and advantages of the present invention may be gained by reference to the following detailed description and the accompanying drawings. 
     The following description and the drawings set forth certain illustrative aspects of the specification. These aspects are indicative, however, of but a few of the various ways in which the principles of the specification may be employed. Other advantages and novel features of the specification will become apparent from the following detailed description of the specification when considered in conjunction with the drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    illustrates a truck employing a prior art tailgate in an upright position; 
         FIG.  2    illustrates a truck employing a prior art tailgate in a horizontal position; 
         FIG.  3    illustrates a block diagram of a side view of a truck employing a prior art tailgate in an upright position; 
         FIG.  4    illustrates a block diagram of a side view of a truck employing a prior art tailgate in an horizontal position; 
         FIG.  5    illustrates a block diagram of a side view of a truck employing a prior art tailgate in a horizontal position; 
         FIG.  6    illustrates a block diagram of a side view of a truck employing a prior art tailgate in a horizontal position; 
         FIG.  7    illustrates a block diagram of a cutaway side view of a truck along the centerline of the truck employing a prior art tailgate in a horizontal position; 
         FIG.  8    illustrates a block diagram of a cutaway side view of a truck along the centerline of the truck employing a prior art tailgate in an upright position; 
         FIG.  9    illustrates a line diagram of rotation points and paths according to an embodiment of the present invention; 
         FIG.  10    illustrates a block diagram of a cutaway side view of a truck along the centerline of the truck employing an embodiment of the inventive tailgate in an upright position; 
         FIG.  11    illustrates a block diagram of a cutaway side view of a truck employing an embodiment of the inventive tailgate in an upright position; 
         FIG.  12    illustrates a block diagram of a side view of an embodiment of the inventive tailgate in an upright position; 
         FIG.  13    illustrates a block diagram of a side view of an embodiment of the inventive tailgate in a horizontal position; 
         FIG.  14    illustrates a block diagram of a side view of an embodiment of the inventive tailgate in a horizontal position; 
         FIG.  15    illustrates a block diagram of a side view of an embodiment of the inventive tailgate in a horizontal position; 
         FIG.  16    illustrates a block diagram of a thrust bearing according to an embodiment of the invention; 
         FIG.  17    illustrates a block diagram of a side view of an embodiment of the inventive tailgate in a horizontal position; 
         FIG.  18    illustrates a block diagram of an overhead view of an embodiment of the inventive tailgate in a horizontal position; 
         FIG.  19    illustrates a block diagram of an overhead view of an embodiment of the inventive tailgate in a vertical position and a truck bed; 
         FIG.  20    illustrates a perspective view of the passenger side of an embodiment of the inventive tailgate in a horizontal position and a truck bed; 
         FIG.  21    illustrates a perspective view of the rear and passenger side portions of a truck bed and an embodiment of the inventive tailgate in a vertical position; 
         FIG.  22    illustrates a perspective view of the rear and passenger side portions of a truck bed and an embodiment of the inventive tailgate in a horizontal position; 
         FIG.  23    illustrates a perspective view of the rear portions of a truck bed and an embodiment of the inventive tailgate in a horizontal position. 
         FIG.  24    illustrates a perspective view of the rear portions of a truck bed and an embodiment of the inventive tailgate in a vertical position; 
         FIG.  25    illustrates a perspective view of the passenger side of an embodiment of the inventive tailgate in a horizontal position and a truck bed; 
         FIG.  26    illustrates an overhead perspective view of an embodiment of the inventive tailgate in a horizontal position and a truck bed; 
         FIG.  27    illustrates an overhead perspective view of an embodiment of the inventive tailgate in a horizontal position and a truck bed; 
         FIG.  28    illustrates a perspective view of the rear and passenger side portions of a truck bed and an embodiment of the inventive tailgate in a horizontal position; 
         FIG.  29    illustrates a perspective view of the rear and passenger side portions of a truck bed and an embodiment of the inventive tailgate in a vertical position; and 
         FIG.  30    illustrates a block diagram of a thrust bearing according to an embodiment of the invention. 
     
    
    
     DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS 
     The various embodiments are now described with reference to the drawings, wherein like reference numerals are used to refer to like elements throughout. In the following description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the various embodiments. It may be evident, however, that the various embodiments can be practiced without these specific details. In other instances, well-known structures and devices are shown in block diagram form in order to facilitate describing the various embodiments. 
     Referring now to  FIGS.  1  through  8   , an existing version of tailgate is shown in both perspective drawings and block diagrams. 
       FIG.  1    provides a perspective view of a pickup truck  100  having a tailgate  102  deployed in a closed position (which also may be referred to as an upright or substantially vertical position). Tailgate  102  is typically attached in a rotatable manner at the rear of truck  100  and has an attached edge  104  that is the bottom edge when the tailgate is closed. Edge  104  is in close proximity to the rear end of the truck&#39;s bed  110 . Edge  104  may be attached to the truck&#39;s bed  110  or to sidewalls  112  and  114 . Typically, edge  104  will be attached to bed  110  using piano hinges or the like, or edge  104  will be attached to sidewalls  112  and  114  using hinges at the corners that often allow for removal of tailgate  102 . Vertical edges  106  and  108  of tailgate  102  are in close proximity to sidewalls  112  and  114 , respectively, when the tailgate  102  is in a closed position. However, vertical edges  106  and  108  are not typically sealed to sidewalls  112  and  114  with rubber, gaskets, or the like, but instead are often spaced a small distance from the sidewalls. This arrangement may allow particulate or granular matter to enter or exit the truck bed through the gaps adjacent to any of edges  104 ,  106 , and  108 . In a pickup truck, top edge  109  is typically arranged such that it is flush with the tops of sidewalls  112  and  114  when the tailgate is in a closed position. 
     As illustrated in  FIGS.  1  and  2   , a typical pickup truck has two rear wheels  190  (only one shown) and two front wheels  192  (only one shown). The box of the truck comprises the bed  110 , sidewalls  112  and  114 , the front wall  116  that is adjacent to a cab  180 , and the tailgate  102  opposite wall  116  and at the rear of the truck  100 . The cab  180  contains the passenger and driving control areas. Two or more doors  182  (only one shown) allow passenger and driver access to the cab  180 . 
     Referring to  FIG.  2   , a pickup truck  100  is illustrated with the tailgate  102  in an open position (which also may be referred to as a lowered or substantially horizontal position). The upper side of tailgate  102  is at substantially the same height above the ground as the bed  110 , and the upper side of tailgate  102  is substantially parallel to the bed  110 . The four edges  104 ,  106 ,  108 , and  109  are all at substantially the same height above the ground and form a substantially rectangular shape that is substantially parallel to the bed  110 . In some versions, restraining devices (not shown) such as chains, cables, or other mechanisms attach the upper portion of sidewalls  112  and  114  to the tailgate  102  at or near the corners. The upper portion of sidewall  112  may be attached to a restraining device that is also attached to the corner of tailgate  102  formed by edges  106  and  109 . And the upper portion of sidewall  114  may be attached to a restraining device that is also attached to the corner of tailgate  102  formed by edges  108  and  109 . Such restraining devices may be used to provide support to the tailgate to prevent edge  109  from sagging or being otherwise deformed such that it may be closer to the ground than edge  104 . While such restraining devices may be used with the inventions described further herein, they may not be necessary due to features of certain embodiments of the invention that prevent sagging without restraints. As illustrated, edge  104  remains closely adjacent to the rear edge of bed  110  when the tailgate  102  is in an open position. 
     When deployed as shown in  FIG.  2    in a typical pickup truck  100 , tailgate  102  is likely to be at a height between 26 and 36 inches above ground level. Such a height is above the height that a typical human can step. The inventive tailgate provides for a reduction in the height of an open tailgate such that it more easily permits a human to step or climb on the tailgate. 
       FIG.  3    provides a cutaway block diagram of the passenger (right) side of the box of a pickup truck  100  with the tailgate  102  in a closed position. Zig-zag line  370  indicates that the right-most (i.e., forward) portion of the truck has been omitted to simplify the image. The upper surface of the bed  110  is indicated with a dashed line. As shown in  FIG.  3   , edge  109  is substantially directly above edge  104  when the tailgate  102  is closed. The block diagram of  FIG.  3    corresponds closely to the perspective image of  FIG.  1   . 
     Referring to  FIG.  4   , the block diagram shows tailgate  102  pivoted to an open/horizontal position. In this position, edge  104  remains closely adjacent to the rear edge of bed  110 . Edge  109  has pivoted away from the truck  100  such that edge  109  is at substantially the same height above the ground as is edge  104 . The block diagram of  FIG.  4    corresponds closely to the perspective image of  FIG.  2   . 
       FIGS.  5  and  6    provide block diagrams of a device that some have used to attempt to overcome the problems posed in climbing onto the tailgate  102  or bed  110 . Such devices include structures that may be unfolded from or attached to tailgate  102 . Support structure  588  is a substantially vertical structure attached to and extending below tailgate  102 . Step  686  is a substantially horizontal structure that may serve as a step between the ground level and the height of tailgate  102 . As shown, step  686  may be folded into structure  585 , and the structure  585  may be folded or inserted into a depression or cavity in tailgate  102 . Alternatively, structure  585  and step  686  may be detached from tailgate  102  when not in use. Such steps  686  are intended to solve the problem of stepping onto tailgate  102  but are themselves problematic due to the additional complexity of the structure and the inherently less-stable nature of a step that is smaller than the entirety of the tailgate  102 . Such steps  686  may also prove problematic if inundated with particulate or granular matter and prevented from fully opening, closing, or attaching based on such matter. 
       FIGS.  7  and  8    show cutaway block diagrams of a cross section of the box of a pickup truck taken at or near the midpoint of the bed along a vertical plane that is parallel to the primary direction of travel of the truck  100 . Because the diagrams are at the midpoint, sidewall  114  and wheel  190  are indicated with dashed lines while bed  110  and gate  102  are indicated with solid lines. As indicated, edge  104  is substantially adjacent to the rear edge of bed  110  when tailgate  102  is in an open position. And edge  109  arcs between a closed position in which edge  109  is substantially vertically above edge  104  and an open position in which edge  109  is disposed substantially horizontal to and rearward (with respect to the primary direction of travel of truck  100 ) to edge  104 . Arc  772  illustrates the path taken by edge  109  when the tailgate  102  is rotated about a hinge at edge  104  between open/horizontal and closed/vertical positions. 
       FIG.  9    represents a cartesian graph having the same orientation as the block diagram of  FIGS.  10  and  11   . The notation U represents the top of a tailgate. The notation G represents the ground below a truck. The notation T represents that point at which the bottom edge of a closed gate (such as tailgate  102 ) touches the rear edge of the bed (such as bed  110 ) of the truck  100 . The line segment TD represents the upper surface of the bed  110 . The line segment TA is disposed at a 45-degree angle from TD and a 45 degree angle from line segment TG. 
     Points  902 ,  904 ,  906 ,  908  represent approximations of potential pivot points for an inventive tailgate. Arcs  903 ,  905 ,  907 ,  909  represent arcs of circles corresponding to points  902 ,  904 ,  906 ,  908 . Notably, for purposes of clarity in  FIG.  9    and to reduce overlapping portions, arcs  903 ,  905 ,  907 ,  909  are not drawn as perfect arcs, but instead are intended to represent arcs. Rotation of the portion of a tailgate that contacts the edge of the bed by ninety degrees from closed/vertical position to open/horizontal position may be represented by these points and arcs. 
     Point  906  falls on line segment TA. Assume a rotation of ninety degrees from vertical to horizontal. A ninety-degree arc drawn around rotation point  906  with a radius equal in length to the distance between T and point  906  is represented by arc  907 . One end of arc  907  is at point T and the opposite end falls on the line segment TG based on the position of rotation point  906 , indicating that the lower portion of the tailgate will end directly beneath the edge of the bed. 
     Point  904  also falls on line segment TA, between point  906  and T. A ninety-degree arc drawn around rotation point  904  with a radius equal in length to the distance between T and point  904  is represented by arc  905 . The end points of this arc are similar to those of the arc drawn around point  906 . The upper endpoint is point T. The lower endpoint is on the line segment TA. 
     A point  902  is placed in the area bounded by line segments TD, TA, and AD (not shown). A ninety-degree arc  903  drawn about point  902  with radius equal to the distance between T and  902  will have a starting point at T and an endpoint in the area bounded by TG, TA, and AG (not shown). With this endpoint, it is apparent that the lower portion of the tailgate will be between the ground G and the bed (labeled TD) and will be forward of point T with respect to the ordinary direction of travel of truck  100 . 
     Point  908  is placed in the area bounded by line segments TG, TA, and AG (not shown). A ninety-degree arc  909  drawn about point  908  with radius equal to the distance between T and  908  will have a starting point at T and an endpoint to the left of line segment UG, or aft of the edge of the bed with respect to the primary direction of travel of the truck  100 . 
     These rotation points and the corresponding arcs inform the placement of the bearings or hinges on which the inventive tailgate rotates. With respect to point  903 , while it may be desirable for the edge of the opened tailgate to be slightly under the edge of the truck bed TD, if point  903  is moved to far (for example to the right), then the rotating tailgate may interfere with or be interfered with by other parts of the truck  100 . Similarly, while rotation about point  908  moves the tailgate into a position that would be more likely to avoid interference or problems, if the position is moved too far, such move might negate the usefulness of certain features of the inventive tailgate, depending on the embodiment to be used. In the preferred embodiments of the invention as used in a pickup truck, it is preferable to place the rotation point approximately six inches forward of the rear edge (line segment UG) of the bed and approximately six inches below the top of the bed (line segment TD), by using lever arms outside of the bed and preferably isolated from the wheel wells. This rotation point would be along line segment TA, and would result in the top of the tailgate being approximately one foot lower than the top of the bed when the tailgate is in the open/horizontal position. 
       FIGS.  10 - 15    are a series of block diagrams of preferred embodiments of the inventive tailgate, all from same viewing perspective as  FIGS.  3 - 8   . 
       FIG.  10    corresponds closely with  FIG.  8    and shows a cutaway block diagram of a cross section of the box of a pickup truck taken at or near the midpoint of the bed along a vertical plane that is parallel to the primary direction of travel of the truck  100 . Tailgate  1002  has a top edge  1009  and a lever arm  1003  that may also serve as an additional seal or may be fitted with a seal beneath the truck bed if the lever arm  1003  is extended across the width of the bed such that it is in proximity to the lower side of the bed  1010  when the tailgate  1002  is in the closed/vertical position as in this FIG. Such a feature may be used to reduce the loss of particulate or granular matter being transported in the truck and may also serve to reduce the loss of granular matter under the truck when opened and the truck is being loaded or unloaded over the tailgate. When the tailgate  1002  is open/horizontal, the portion of lever arm  1003  that extends across the bed can serve similar to a stair riser insofar as it may help to prevent a human foot from slipping into the gap between the bottom of the bed  1010  and the tailgate  1002 , and may also serve to reduce the loss of granular or particulate matter that may otherwise spill into the gap between the bottom of the bed  1010  and the tailgate  1002  and drop beneath the truck. Point  1095  represents the foremost portion of the lever arm and the approximate location of the axis of rotation of tailgate  1002 , although it will be recognized by those of skill in the art that the axis of rotation preferably not on the edge of the lever arm. 
       FIG.  11    corresponds closely with  FIG.  3    and shows a portion of the truck  100  that is closer to the viewer to illustrate the preferred lever arm more fully. This view may correspond to  FIG.  21    wherein lever arm  1003  is visible from outside the truck while the gate  1002  is closed or  FIG.  29    wherein lever arm  1003  is largely blocked from view from outside the truck while the gate  1002  is closed. As shown in  FIG.  11   , lever arm  1003 , which is preferably a metal similar to the metal used for formation of the tailgate  1002 , has a trapezoidal shape that extends roughly from point  1095  to point  1099 , and from each of those points to tailgate  1002 . Lever arm  1003  and tailgate  1002  may be rotated about a point at or near point  1095 . Lever arm  1003  is arranged substantially perpendicularly to tailgate  1002  and attached together so as to provide additional resistances to stress, deformation, and the forces that may otherwise tend to distort the shape of tailgate  1002 . For this reason, it preferable to deploy tailgate  1002  and lever arm  1003  without the use of the restraining devices used in the prior art tailgates to prevent sagging or deformation. Use of tailgate  1002  without such restraining devices can decrease mechanical complexity and potential failure points while also increasing the ability to work in and around tailgate  1002  without interference by such restraining devices. 
       FIGS.  12  and  13    are block diagrams that focus more fully upon a preferred embodiment of the inventive tailgate  1002 , wherein the cargo box of the truck including sidewall  114  is partially shown using dashed lines. As illustrated, tailgate  1002  may be configured to rotate about thrust bearings  1096  that are attached to lever arm  1003  in a position that is below the lower side  1010  of the truck bed. Such attachment position will permit rotation of the tailgate  1002  in the manner described with respect to  FIG.  9   . In  FIG.  12   , tailgate  1002  is depicted in a closed/vertical position. In  FIG.  13   , the same tailgate  1002  is depicted in an open/horizontal position, and dashed lines on tailgate  1002  and lever arm  1003  show the difference in profile of the mid-section of the tailgate  1002  as opposed to the ends of the tailgate where the lever arm  1003  is more substantial. 
       FIG.  14    depicts a preferred embodiment of the invention that is very similar to that shown in  FIG.  13   , but with the addition of a trailer hitch. The trailer hitch is depicted as ball  1420 , ball mount  1430 , and receiver  1440 . These parts are arranged in such a manner that when the tailgate  1002  is in the open/horizontal position, the top of ball  1420  is in contact with tailgate  1002  so as to provide additional support to tailgate  1002  against sagging or deformation. It is recognized that such metal to metal contact may result in damage to the paint of tailgate  1002 . Thus, it may be desirable to provide a bumper or other protective device on tailgate  1002  so that damage from contacting ball  1420  may be minimized, while still gaining the advantage of the extra support provided by ball  1420 . 
       FIG.  15    depicts yet another preferred embodiment of the invention that is very similar to that shown in  FIG.  13   , but with the addition of a rudimentary bumper. The bumper  1550  is arranged so as to be in contact with the lower side of tailgate  1002  when tailgate  1002  is deployed in an open/horizontal position. As with the embodiment described with respect to  FIG.  14   , it is expected that contact between bumper  1550  and tailgate  1002  may cause damage if a protective device is not present. Thus it may be desirable to provide a protective device between bumper  1550  and tailgate  1002 . One of ordinary skill will recognize that the configuration of the tailgate  1002  may result in blockage or scraping against bumper  1550  at the point marked  1560 . Thus, if the embodiment depicted in  FIG.  15    is deployed, it may be desirable or necessary to provide a beveled, radiused, or similarly modified tailgate that will eliminate contact that would otherwise occur at point  1560  during rotation of tailgate  1002 . 
       FIG.  16    is a block diagram of a thrust bearing  1600  suitable for use as thrust bearing  1096  in the inventive tailgate  1002 . Substantially conical portion  1610  may be attached to the tailgate  1002 . Substantially conical receiver  1620  may be attached to the truck frame, body, or other suitable mounting point. Rotation axis  1630  is represented by a dashed line. Axis  1630  is substantially perpendicular to the primary direction of travel of the truck and substantially parallel to the rear edge of the truck bed and flat ground. Axis  1630  is also substantially perpendicular to a vertical axis when in use. Thrust bearing  1600  may include balls or rollers between portion  1610  and receiver  1620 . A thrust bearing is desirable for the inventive tailgate  1002  because it will allow particulate and/or granular debris to fall out rather than becoming trapped within the bearing. It is preferable that the thrust bearing have an approximately fifteen degree horizontal taper. 
       FIG.  17    depicts a block diagram of an alternative embodiment of the inventive tailgate  1002  in which a pop-up mini-deck  1718  is housed within a recessed portion  1720  of tailgate  1002 . Mini-deck  1718  may be optionally raised to approximate the height of the truck bed  110  so that when the tailgate  1002  is in the open/horizontal position, the mini-deck  1718  functionally serves as an extension of the truck bed  110  for purposes of supporting cargo that is longer than the bed  110  of the truck  100 , for example, pipes, lumber, or other lengthy cargo. Mini-deck  1718  may be optionally configured so that it can be deployed when the tailgate  1002  is in the closed/vertical position, so that mini-deck  1718  may serve to reduce the length of the bed  110  to put pressure on cargo when a small amount of such pressure may help to secure the cargo. 
     Mini-deck  1718  may be sealed at its edges with a gasket or other appropriate seal to prevent excess debris or particulate matter from entering recess  1720  when the mini-deck is not raised. Mini-deck  1718  may be raised and supported by a dual scissor support  1730 ,  1740 . The beams  1730  and  1740  of the scissor support may be attached to the tailgate  1002  at points  1702  and  1708 , and attached to the mini-deck  1718  at points  1706  and  1704 . The beams  1730  and  1740  may be attached together at point  1710 . As one of skill will recognize,  FIG.  17    illustrates one side of the tailgate  1002  and mini-deck  1718 . As such, a mirror-image structure corresponding to scissor support  1730 ,  1740  is preferably attached to the opposite side of tailgate  1002  and mini-deck  1718 . It is also preferable that some or all of points  1702 ,  1704 ,  1706 ,  1708 ,  1710  are attached to a sturdy axle (not shown) that extends from the near side of mini-deck  1718  to the far side of mini-deck  1718  and that the axle attaches to corresponding point  1702 ,  1704 ,  1706 ,  1708 ,  1710  on the opposite end of mini-deck  1718 . Such axle(s) greatly increase the probability that the near and far scissor structures operate in a coordinated manner and prevent the mini-deck  1718  from tilting forward or backward while raised above the tailgate  1002 . Each of attachments  1702 ,  1704 ,  1706 ,  1708 ,  1710  may be made with a bearing or other suitable attachment that allows for rotation about an axis. For example, points  1702 ,  1704 ,  1706 ,  1708  are preferably attached in raceways using shoes to constrain the ends of the beams  1730  and  1740  to the raceways while permitting movement therein. Such attachments will reduce shearing movement against the gate surface during cargo loading and unloading. Beams  1730  and  1740  may optionally be attached together by a dampener  1712  that is depicted as a line to avoid complicating the FIG., but which may be a hydraulic or other suitable dampener. A tension spring (not shown) may attach beams  1730  and  1740  together at or near points  1702  and  1708 , to provide mechanical assistance with raising or lowering mini-deck  1718  from and into recess  1720 . Alternatively the locations of spring (not shown) and dampener  1712  may be reversed. Alternatively, if the mini-deck  1718  is constructed such that it may rise to a height of approximately 12 inches above the deck, it may be desirable to use compressive springs (not shown) located between the tailgate  1002  and mini-deck  1718  in place of the tension spring. Due to the presence of the spring, it might be necessary for a person to stand on the mini-deck to compress it into recess  1720  for stowage. Alternatively, a mechanical crank or other suitable mechanism (not shown) may be provided for compressing mini-deck  1718  into recess  1720  for stowage without relying upon the weight of a person. 
     Mini-deck  1718  may be locked into place with a key or other suitable locking mechanism (not shown). Mini-deck  1718  may be released by a dedicated handle (not shown) or other suitable release mechanism. It is further desirable to provide a mechanism to secure the mini-deck  1718  in a stable position when raised. This may be accomplished in many ways. One such method of securing the mini-deck  1718  in the raised position may be the use of an adjustable hinged pipe with a spring-loaded ball (not shown) attached to the pipe. The ball may be seated in a recess in the bottom of the mini-deck  1718 , preferably near the middle, such that it depresses minimally when laden. 
       FIG.  18    depicts an overhead block view of an embodiment of tailgate  1002  in an open/horizontal position. This embodiment incorporates both mini-deck  1718  and a hinged embedded support rack indicated by beams  1810 ,  1820 ,  1830 . Beam  1810  may be rotatably attached to tailgate  1002  at point  1802 . Beam  1820  may be rotatably attached to tailgate  1002  at point  1804 . Beam  1830  may be attached at its ends to beams  1810  and  1820 , with the attachment at the ends opposite points  1802  and  1804 . If the rack is suitably stiff, rotation about points  1804  and  1802  will allow beam  1830  to raise above the level of the tailgate  1002  to provide a support rack for lengthy cargo. It is preferable that both beams  1810  and  1820  rotate about an axis that passes through points  1802  and  1804 . If beams  1810  and  1820  are permitted to rotate approximately 135 degrees from their resting position, then beam  1830  may be disposed at approximately the height of the bed  110  and at a point that extends beyond edge  1009  of the tailgate  1002 , to allow for support for very lengthy items that extend beyond mini-deck  1718 . The exact angle at which rotation of beams  1810  and  1820  should be stopped is dependent on the length of beams  1810  and  1820  and the height of the bed  110  above the tailgate  1002 . In some embodiments, a mechanical clamp or other suitable tightening or locking device may be provided at one or both of points  1802  and  1804  to permit locking the rack at different angles. Such device may include holes and a pin for locking or it may include a lever to tighten a clamp or other suitable mechanisms. 
     In a preferred embodiment, beams  1810 ,  1820 , and  1830  are stowed in a recess in tailgate  1002  when not deployed, to avoid interference with other uses. It is also preferable to include one or more locks or latches to secure beam  1830  to tailgate  1002  when not deployed as a rack. Beam  1830  may incorporate guard grooves to align long thin cargoes and may further incorporate tie-down anchors for securing loads. 
       FIG.  19    depicts an overhead view of block diagram of an embodiment of the inventive tailgate  1002  as attached to the cargo box of a pickup truck  100 . In this FIG., tailgate  1002  is in a closed/vertical position. Tailgate  1002  preferably extends across the entire width of bed  110  and lever arms  1003  are attached beyond part or all of sidewalls  114  and  112 . Lever arms  1003  may be sealed with a gasket or other suitable seal along all three mating edges of gate  1002  to reduce loss of particulate or granular loads such as sand, sawdust, fertilizer, or the like. 
       FIG.  20    depicts a perspective view of the passenger side of pickup truck  100  that is constructed with an embodiment of the inventive tailgate  1002 . In this depiction, tailgate  1002  is in an open/horizontal position. It can be seen that rotation about thrust bearing  1096  results in the lower edge of the tailgate being below and forward (relative to the primary direction of travel of the truck) of the rearmost edge of bed  110 . In this depiction, lever arms  1003  are constructed with a significant body to reduce deformation of tailgate  1002 . 
       FIG.  21    depicts a perspective view of the rear and passenger side of a pickup truck cargo box constructed with an embodiment of the inventive tailgate. In this depiction, a platform  2110  is provided for supporting tailgate  1002  when tailgate  1002  is in the open/horizontal position. Platform  2110  reduces the deformation and strain on tailgate  1002  when weight is placed on tailgate  1002  in the open/horizontal position. As can be seen, in this embodiment, the lower edge of tailgate  1002  is higher than the lower edges of lever arms  1003  to allow for clearance when rotating between open and closed positions. Notably, platform  2110  is depicted as a small platform, possibly comprising a trailer hitch receiver in the middle of bed  110 . However, platform  2110  may be of various widths, and may extend across the width of bed  110  and be incorporated into a bumper or other suitable structure. 
       FIG.  22    depicts the same view as  FIG.  21   , with the exception that the tailgate  1002  is depicted in an open/horizontal position. In  FIG.  22   , a dashed line represents the lower edge of tailgate  1002  and shows that it is in contact with supporting platform  2110 . A protective bumper or other suitable device may be provided on platform  2110  to reduce scratching of tailgate  1002 . 
       FIG.  23    is a rear perspective view of the embodiment shown in  FIGS.  21  and  22    with the tailgate  1002  disposed in an open/horizontal position. As can be seen, tailgate  1002  is substantially closer to the ground level than the top of bed  110 . 
       FIG.  24    is a perspective view from the same angle as  FIG.  23   , except that in  FIG.  24   , the tailgate  1002  is disposed in a closed/vertical position. In  FIG.  24   , the position of the open tailgate  1002  is depicted with dashed lines. 
       FIG.  25    is a perspective view from the same angle as  FIG.  20   . In  FIG.  25   , a support rack  1810 ,  1820 ,  1830  is depicted in a deployed position wherein it is at an angle of approximately 135 degrees from the rack&#39;s angle of rest in the tailgate  1002 . Lengthy cargo  2501  is depicted using a dot-dot-dash line. Cargo  2501  extends from near the front wall  116  to beyond the length of the tailgate  1002  and even beyond rack  1810 ,  1820 ,  1830 . 
       FIG.  26    provides an overhead perspective view of a cargo box employing an embodiment of the inventive tailgate  1002  in which a rack  2661  takes the form of a plate that may be hinged from the tailgate  1002 . Tailgate  1002  is depicted in the open/horizontal position. Lengthy items  2651 ,  2652 ,  2653 , and  2654  (denoted with dot-dot-dash lines) may be rested on the bed  110  and the edge  2664  of the rack  2661 . The rack may also include guide features  2662 ,  2663  that allow for placement of such lengthy items in a more secure manner. As illustrated, items  2651  and  2652  are placed in guide feature  2662 . Also as illustrated, item  2654  is placed in guide feature  2663 . When rack  2661  is deployed, it is preferable that the height of edge  2664  above the ground be approximately the same as the height of bed  110  to reduce stress on the items being supported by the rack. While the guide features in  FIG.  26    are illustrated as concave features  2662 ,  2663 , one of ordinary skill will appreciate that such guide features may take many forms to accommodate various types of cargo. In one embodiment, it is possible to have an interchangeable set of guide features that may be attached to or removed from edge  2664  as desired. For example, a guide feature having small arcuate resting positions may be used for small diameter pipes, while a guide feature having large arcuate resting positions may be used for large diameter pipes, and a guide feature having rectangular cutouts may be used for lumber such as 2×4 boards. Tie downs (not illustrated) may also be present on rack  2661 . 
       FIG.  27    provides the same perspective as  FIG.  26   , except that in  FIG.  27    the rack  2661  is not deployed. Rack  2661  is depicted as folded closed against tailgate  1002 . Rack  2661  may lay flush against the top of tailgate  1002 , or rack  2661  may fit into a recess (not shown) in tailgate  1002 . It is preferable to provide an attachment mechanism whereby rack  2661  may be secured to tailgate  1002  when not deployed. Further, the perimeter of rack  2661  may be sealed using an appropriate sealing mechanism to prevent the intrusion of particulate or granular matter between rack  2661  and tailgate  1002  while the rack  2661  is not in use. 
       FIG.  28    depicts the same view as  FIG.  22    and shows rack  2661  deployed and supporting cargo items  2851  and  2852 . Cargo items  2851  and  2852  are depicted using dot-dot-dash lines. Cargo items  2851  and  2852  may rest on bed  110  and edge  2664  of rack  2661  when tailgate  1002  is open/horizontal and rack  2661  is deployed for use. 
       FIG.  29    depicts the same view as  FIG.  21    and presents an alternative embodiment wherein, when tailgate  1002  is in the closed/vertical position, lever arm  1003  rests between sidewall  114  and sidewall protrusion  2914  on the passenger/right side and between sidewall  112  and sidewall protrusion  2912  on the driver/left side of the truck  100 . The alternative embodiment may be used for both aesthetic and aerodynamic purposes rather than the embodiment shown in  FIG.  21   . 
       FIG.  30    provides another block diagram of a thrust bearing  1600  suitable for use as thrust bearing  1096  in the inventive tailgate  1002 , from an overhead perspective. In a reverse of the installation depicted in  FIG.  16   , in  FIG.  30    conical portion  1610  is depicted as attached to a truck sidewall  114  and substantially conical portion  1620  is depicted as attached to lever arm  1003  of tailgate  1002 . The entire assembly is enclosed between a wheel fairing, e.g., protrusion  2914  and sidewall  114 . Arrow A is depicted above axis  1630  showing particles (depicted as circles) entering the thrust bearing  1600  between  1610  and  1620 . Arrow B is depicted below axis  1630  showing that particles (depicted as circles) later exit the bearing  1600  due to gravitational forces and rotational forces. In this manner, the use of a thrust bearing  1600  permits continued operation of the tailgate  1002  with reduced possibility of clogging the bearing. 
     The above description of embodiments of the invention has been presented for the purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form described, and many modifications and variations are possible in light of the teaching above. The embodiments were chosen and described in order to best explain the principles of the invention and its practical applications to thereby enable others skilled in the art to best utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated. Thus, it will be appreciated that the invention is intended to cover all modifications and equivalents within the scope of the following claims. 
     What has been described above includes examples of the implementations of the present invention. It is, of course, not possible to describe every conceivable combination of components or methods for purposes of describing the claimed subject matter, but many further combinations and permutations of the subject embodiments are possible. Accordingly, the claimed subject matter is intended to embrace all such alterations, modifications, and variations that fall within the spirit and scope of the appended claims. Moreover, the above description of illustrated implementations of this disclosure, including what is described in the Abstract, is not intended to be exhaustive or to limit the disclosed implementations to the precise forms disclosed. While specific implementations and examples are described herein for illustrative purposes, various modifications are possible that are considered within the scope of such implementations and examples, as those skilled in the relevant art can recognize. 
     In particular and in regard to the various functions performed by the above described components, devices, systems and the like, the terms used to describe such components are intended to correspond, unless otherwise indicated, to any component which performs the specified function of the described component (e.g., a functional equivalent), even though not structurally equivalent to the disclosed structure, which performs the function in the herein illustrated exemplary aspects of the claimed subject matter. In this regard, it will also be recognized that the various embodiments include a system as well as the various methods of the claimed subject matter.