Abstract:
A vehicle tailgate side mounted step assist mechanism attachable to a vehicle including a vehicle bed coupled to a pillar and a tailgate pivotally attached to the vehicle bed for providing access to the vehicle bed in a tailgate open position and securing contents of the vehicle bed in a tailgate closed position. The mechanism may include generally parallel supports rotatably mountable to a side of the tailgate, the supports capable of being deployed when the tailgate is in the tailgate open position and stowed when the tailgate is in the tailgate closed position. A tailgate step is disposable between the supports at a predetermined distance from the side of the tailgate, and a lockout device prevents the tailgate from returning to the tailgate closed position when the tailgate step is deployed.

Description:
RELATED APPLICATIONS 
     This application claims benefit of priority of Provisional Application Ser. Nos. 60/972,559 filed Sep. 14, 2007 and 60/972,916 filed Sep. 17, 2007, hereby incorporated by reference in their entirety. 
    
    
     BACKGROUND OF INVENTION 
     a. Field of Invention 
     The invention relates generally to steps for pick-up trucks, sport utility vehicles (“SUVs”) and other such vehicles, and more particularly, to a retractable tailgate step assembly for facilitating access to the cargo storage area of a vehicle. 
     b. Description of Related Art 
     As is known in the art, vans, SUVs, trucks, and other such vehicles commonly include a cargo bed or similar area for storing and transporting large items that would not otherwise fit in typical sedan sized automobiles. Access to cargo beds onboard vans, SUVs, trucks having bed covers, and other similar vehicles is limited when compared to pickup trucks since users cannot reach over the cargo bed sidewalls to access the cargo bed. With increasing versatility and payloads, even pickup truck cargo beds have become relatively difficult to access because cargo beds and their respective sidewalls are placed higher from ground level. Many users of cargo beds are limited to the tailgate area when manipulating the contents of the cargo bed. Loading and unloading objects into such vehicles can be difficult, especially if the object is heavy or elongated. 
     In an effort to make loading, unloading, and manipulation of objects in vehicle cargo beds easier, the art includes a variety of retractable tailgate steps that are most commonly stowed in or along vehicle tailgates. 
     For example, U.S. Pat. No. 7,264,253 to Cummings discloses a truck tailgate step that folds into a slideable rack system and is mounted both internally and externally to a vehicle tailgate. Once the tailgate is in a horizontal position, the tailgate step slides away from its stowed position within the tailgate by use of a guide rail bracket  16 . The step is then rotated about hinge  30  into a generally vertical position for a user of the cargo bed. Since Cummings discloses a retractable tailgate step that extends from a side of the tailgate, like most steps in the art, it is likely that the horizontal tailgate will obstruct the view of the deployed step when the user, or one of several users, is standing on an opposite side of the tailgate. This scenario creates a hazardous situation in which the user fails to realize that the tailgate step is deployed and attempts to shut the tailgate, thus resulting in potential structural damage to the vehicle. 
     U.S. Pat. No. 7,261,357 to Bechen discloses a similar tailgate ladder apparatus that extends from the interior of a tailgate to a position perpendicular to the tailgate. The Bechen tailgate ladder also rotates to a deployed position once pulled outwards from the side of the tailgate. Bechen, like Cummings, fails to disclose any feature that would prevent inadvertent harm from attempting to close the horizontal tailgate while the tailgate ladder apparatus is deployed. Further, the design of the tailgate ladder apparatus in the stowed position is revealed in  FIG. 3  of Bechen and appears to consume a majority of the length of the internal tailgate cavity. Such an arrangement is not ideal when considering the packaging of tailgate latch components, storage containers, deployable ramps, etc. 
     In another exemplary tailgate step, U.S. Pat. No. 6,905,158 to Bastian teaches a tailgate pocket step that is inserted into an opening in the tailgate. Instead of at least one support arm extending from the tailgate, the pocket step is formed from a substantially planar plate  310  having at least one hinged platform  360  that is integral with the plate. The platform is coplanar with the plate when stowed inside the tailgate, and rotates outward from the plate when deployed to provide a step. The pocket step disposed on the side of the tailgate poses the same threat, as mentioned above, to bystanders and the vehicle body when a user inadvertently attempts to close the tailgate with the pocket step deployed. In an alternative embodiment shown in  FIG. 13 , the pocket step is disposed along the trailing edge of the tailgate when the tailgate is in an open position. Though this arrangement would better prevent inadvertent tailgate closings since the deployed step is more visible, the arrangement is not ideal for ingress/egress to the cargo bed. A user standing on either pocket step in  FIG. 13  obstructs access to and from the cargo bed, especially when loading and unloading wide objects that extend across the width of the cargo bed. 
     Such deficiencies in current technology make it desirable to provide a safe and robust tailgate step that would ideally guard against inadvertent closing of the tailgate when the tailgate step is deployed. The step would also grant maximum ingress and egress to the cargo bed for loading and unloading objects. It is further desirable for the tailgate step to compactly stow within or along the tailgate to prevent interference with other tailgate features. 
     SUMMARY OF THE INVENTION 
     The invention provides a side mounted step assist mechanism including a step assist mounted to a side of a tailgate and being extendable to a deployed configuration for respectively facilitating ingress and egress into and from a vehicle bed, and being retractable to a stowed configuration for permitting closing of the tailgate. 
     In an exemplary embodiment, the invention provides a side mounted tailgate step assist mechanism for a vehicle, such as a pickup truck, that may retract from within the tailgate and extend therefrom in order to provide step assist or ingress/egress functions. When the tailgate is moved from a closed or vertical position to a fully open or horizontal position, this may allow the step to be withdrawn from within the step assist module located within an internal cavity of the tailgate and accessible via the side of the tailgate. The step retraction may operate in a cross-car direction by means of a combination of pivoting hinges and slides. In the exemplary embodiment, the step assist module may include a retractable framework, including two horizontal members, housed within static outer horizontal members, that on extending to their fullest extent can be rotated downwards to be positioned in a vertical (or near vertical) orientation to provide a step assist function. At the outer extreme, the retractable members may be joined by a transverse member that creates a step. The step may be released through a latching mechanism, accessible from the side of the tailgate, potentially, but not necessarily within the visible area of the step assist module when stowed. 
     The invention allows a vehicle user to gain access to the truck cargo area via the open tailgate, even when loading goods that might cover the rear (trailing edge) of the tailgate or extend across the width of the cargo bed. In addition to the step, users may support themselves when accessing the truck bed by utilizing a hand hold molded within the D-pillar horizontal trim, or a pivotally mounted step assist arm. While the step assist module is in the extended position, a lockout device may be deployed to prevent the tailgate from being returned from the open or horizontal position to the closed or vertical position. This lockout device, independent of the step module, may operate through a hinged link that is attached to the tailgate at one end and the D-pillar member of the truck bed at the other end. This link may be extended to a locked position when the tailgate is fully extended or open, while optionally requiring a user to release a catch or pin for the link to collapse and allow tailgate closing. This lockout would thus prevent damage to the step or cosmetic damage to the vehicle, should an attempt be made to close the tailgate when the step is deployed. 
     In a particular embodiment, the invention provides a vehicle tailgate side mounted step assist mechanism attachable to a vehicle including a vehicle bed coupled to one or more pillars and a tailgate pivotally attached to the vehicle bed for providing access to the vehicle bed in a tailgate open position and securing contents of the vehicle bed in a tailgate closed position, the tailgate having one or more sides generally orthogonal to the pivotal attachment and capable of engaging a pillar when the tailgate is in the tailgate closed position. The mechanism may include a slide assembly mountable along a side of the tailgate for deployment when the tailgate is in the tailgate open position, the slide assembly including a plurality of guide channels, generally parallel supports that communicate with the guide channels to extend away from and generally orthogonal to the side of the tailgate, a step rotation limit apparatus acting between the guide channels and the supports, and a tailgate step disposable between the supports at a predetermined distance from the side of the tailgate. A lockout device may be disposable between the pillar and the side of the tailgate when the tailgate is in the tailgate open position, the lockout device being capable of preventing the tailgate from returning to the tailgate closed position when the slide assembly is deployed, with the lockout device further capable of stowing between the pillar and the tailgate when the tailgate is in the tailgate closed position. The supports may rotate generally about the side of the tailgate when the supports are extended and the step rotation limit apparatus restricts rotation of the tailgate step when the supports and tailgate step are in a deployed configuration. 
     For the vehicle tailgate side mounted step assist mechanism described above, the guide channels of the slide assembly may include a primary guide channel that slidably engages a secondary guide channel which engages one of the generally parallel supports. The mechanism may include one or more slots in the primary or secondary guide channels and one or more step positioning tabs mounted to the other of the primary or secondary guide channels for engaging the slot and maintaining the primary and secondary guide channels in a predetermined position relative to each other. The step rotation limit apparatus may include chamfered ends provided on the generally parallel supports for limiting rotation of the supports when the chamfered ends contact the guide channels. The step rotation limit apparatus may include hooks disposed at ends of the generally parallel supports and openings disposed along the guide channels, the hooks capable of engaging the openings in the channels to limit rotation of the supports when the step assist mechanism is deployed. The side of the tailgate may include a cavity for substantially stowing the generally parallel supports and the tailgate step. The mechanism may further include a step lock and release mechanism disposed along the side of the tailgate adjacent the slide assembly for maintaining the slide assembly in a stowed configuration and for selectively releasing the slide assembly to achieve a deployed configuration. 
     The invention also provides a vehicle tailgate side mounted step assist mechanism attachable to a vehicle including a vehicle bed coupled to at least one pillar and a tailgate pivotally attached to the vehicle bed for providing access to the vehicle bed in a tailgate open position and securing contents of the vehicle bed in a tailgate closed position, with the tailgate having sides generally orthogonal to the pivotal attachment and capable of engaging a pillar when the tailgate is in the tailgate closed position. The mechanism may include one or more generally parallel supports rotatably mountable to a side of the tailgate, the supports capable of being deployed when the tailgate is in the tailgate open position and stowed when the tailgate is in the tailgate closed position. The tailgate step may be disposable between the supports at a predetermined distance from the side of the tailgate, and a lockout device may prevent the tailgate from returning to the tailgate closed position when the tailgate step is deployed. The supports may be rotatable generally about the side of the tailgate when the mechanism is mounted to the tailgate and the tailgate is in the tailgate open position to orient the tailgate step for a user of the vehicle bed. 
     For the vehicle tailgate side mounted step assist mechanism described above, the guide channels of the slide assembly may include a primary guide channel that slidably engages a secondary guide channel which engages one of the generally parallel supports. The mechanism may further include one or more slots in the primary or secondary guide channels and one or more step positioning tabs mounted to the other of the primary or secondary guide channels for engaging the slot and maintaining the primary and secondary guide channels in a predetermined position relative to each other. The tailgate step between the generally parallel supports may be pivotally attached to the supports and is capable of rotating and maintaining a generally horizontal step position when the mechanism is deployed for use. The generally parallel supports may include chamfered ends proximal to the guide channels, the ends capable of limiting rotation of the supports when the ends substantially contact the channels. The mechanism may further include hooks disposed at ends of the generally parallel supports and openings disposed along the guide channels, the hooks capable of engaging the openings in the channels to limit rotation of the supports when the step assist mechanism is deployed. Alternatively, the mechanism may include a step lock and release mechanism disposed along the side of the tailgate adjacent the slide assembly for maintaining the slide assembly in a stowed configuration and for selectively releasing the slide assembly to achieve a deployed configuration. 
     The invention yet further provides a vehicle including a tailgate side mounted step assist mechanism, the vehicle including a vehicle bed coupled to one or more pillars, a tailgate pivotally attached to the vehicle bed for providing access to the vehicle bed in a tailgate open position and securing contents of the vehicle bed in a tailgate closed position, the tailgate having sides generally orthogonal to the pivotal attachment and respectively capable of engaging a pillar when the tailgate is in the tailgate closed position. A slide assembly may be disposed along a side of the tailgate for deployment when the tailgate is in the tailgate open position, the slide assembly including a plurality of guide channels, generally parallel supports that communicate with the guide channels to extend away from and generally orthogonal to the side of the tailgate, a step rotation limit apparatus acting between the guide channels and the supports, and a tailgate step disposable between the supports at a predetermined distance from the side of the tailgate. A lockout device may prevent the tailgate from returning to the tailgate closed position when the tailgate step is deployed. The supports may be rotatable when extended to orient the tailgate step for a user of the vehicle bed and the step rotation limit apparatus restricts rotation of the tailgate step when the supports and tailgate step are deployed. 
     For the mechanism described above, a step lock and release mechanism disposed along the side of the tailgate adjacent the slide assembly for maintaining the slide assembly in a stowed configuration and for selectively releasing the slide assembly to achieve a deployed configuration. The guide channels of the slide assembly may include a primary guide channel that slidably engages a secondary guide channel which engages one of the generally parallel supports. The mechanism may further include one or more slots in the primary or secondary guide channels and one or more step positioning tabs mounted to the other of the primary or secondary guide channels for engaging the slot and maintaining the primary and secondary guide channels in a predetermined position relative to each other. 
     Additional features, advantages, and embodiments of the invention may be set forth or apparent from consideration of the following detailed description, drawings, and claims. Moreover, it is to be understood that both the foregoing summary of the invention and the following detailed description are exemplary and intended to provide further explanation without limiting the scope of the invention as claimed. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate preferred embodiments of the invention and together with the detailed description serve to explain the principles of the invention. In the drawings: 
         FIG. 1  is an isometric view of a pick-up truck with a tailgate in an open horizontal position, and a side mounted tailgate step assist according to the present invention in a deployed configuration, with the truck bed including an oversized object that covers the rear (trailing edge) of the tailgate; 
         FIG. 2  is an isometric view of the pick-up truck of  FIG. 1 , with the tailgate in the open horizontal position and the side mounted tailgate step assist of  FIG. 1  retracted, with the step assist shown in hidden, with the truck bed including an oversized object that covers the rear (trailing edge) of the tailgate; 
         FIG. 3  is an isometric view of the pick-up truck of  FIG. 1 , with the tailgate in a closed position and the side mounted tailgate step assist of  FIG. 1  retracted, with the step assist shown in hidden, and with the truck bed including an oversized object disposed therein; 
         FIG. 4  is a side view of a lockout device for preventing inadvertent closing of the tailgate with the side mounted tailgate step assist disposed in the deployed configuration of  FIG. 1 , and the tailgate pivoted upwardly to illustrate operation of the lockout device; 
         FIG. 5  is an enlarged side view of the lockout device of  FIG. 4  with the side mounted tailgate step assist disposed in the deployed configuration of  FIG. 1 ; 
         FIG. 6  is a side view of the lockout device of  FIG. 4  with the side mounted tailgate step assist disposed in the retracted configuration of  FIG. 2 , and the tailgate pivoted upwardly to illustrate operation of the lockout device; 
         FIG. 7  is an isometric view of the lockout device of  FIG. 4  with the side mounted tailgate step assist disposed in the retracted configuration of  FIG. 2 , and the tailgate disposed horizontally to illustrate operation of the lockout device; 
         FIG. 8  is an isometric view of the side mounted tailgate step assist of  FIG. 1  in a retracted configuration; 
         FIG. 9  is an isometric view of the side mounted tailgate step assist of  FIG. 1  in an intermediate extended (deployed) configuration; 
         FIG. 10  is an isometric view of the side mounted tailgate step assist of  FIG. 1  in a fully extended (deployed) configuration; 
         FIG. 11  is an exploded view of the components of the side mounted tailgate step assist of  FIG. 1 ; 
         FIG. 12  is an isometric enlarged view of a primary guide channel for facilitating extension/retraction of the side mounted tailgate step assist of  FIG. 1 ; 
         FIG. 13  is an isometric enlarged view of a secondary guide channel, slidably disposable in the primary guide channel of  FIG. 12 , for facilitating extension/retraction of the side mounted tailgate step assist of  FIG. 1 ; 
         FIG. 14  is an isometric enlarged view of a guide rail, slidably disposable in the primary and secondary guide channels of  FIGS. 12 and 13 , for facilitating extension/retraction of the side mounted tailgate step assist of  FIG. 1 ; 
         FIG. 15  is an isometric cutout view of the side mounted tailgate step assist of  FIG. 1 , illustrating a step positioning tab in a first engaged configuration; 
         FIG. 16  is a top cutout view illustrating the step positioning tab of  FIG. 15  in the first engaged configuration; 
         FIG. 17  is a top cutout view illustrating the step positioning tab of  FIG. 15  in a disengaged configuration; 
         FIG. 18  is an isometric cutout view of the side mounted tailgate step assist of  FIG. 1 , illustrating the step positioning tab of  FIG. 15  in a second engaged configuration; 
         FIG. 19A  is an isometric view of an embodiment of an apparatus for limiting rotation of the tailgate step relative to the tailgate; 
         FIG. 19B  is a side cut-out view of the apparatus of  FIG. 19A ; 
         FIG. 20A  is an isometric view of another embodiment of an apparatus for limiting rotation of the tailgate step relative to the tailgate; 
         FIG. 20B  is a side cut-out view of the apparatus of  FIG. 20A ; 
         FIG. 21  is a side cut-out view of the tailgate step in a deployed position; and 
         FIG. 22  is an isometric view of the tailgate step in a stowed position. 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     Referring now to the drawings wherein like reference numerals designate corresponding parts throughout the several views,  FIGS. 1-20B  illustrate various views of a vehicle tailgate step assist mechanism according to the present invention, the mechanism being hereinafter generally designated “side mounted step assist mechanism  10 .” 
     As shown in  FIGS. 1-3 , side mounted step assist mechanism  10  may generally be mounted onto a vehicle  12 , which in the exemplary embodiment illustrated, may be a pickup truck including a tailgate  14 . As shown in  FIG. 1  and described in greater detail below, in order to facilitate ingress and egress into and from vehicle bed  16  especially in the event of loading or unloading of goods  18  that cover the rear (trailing edge) of the tailgate, mechanism  10  may be deployable from the side of tailgate  14 , and as shown in  FIG. 2  and described in greater detail below, mechanism  10  may be readily retractable within the side of tailgate  14  for allowing opening/closing of the tailgate in a known manner. 
     The various sub-components of side mounted step assist mechanism  10  will now be described in detail with reference to  FIGS. 1-18 . 
     Specifically, as shown in  FIGS. 1-3 , side mounted step assist mechanism  10  may generally include a tailgate step  20  mounted within cavity  22  of tailgate  14  and disposed at side  24  of the tailgate. Those skilled in the art would readily appreciate in view of this disclosure that a mirror-image step may be disposed at the opposite side of the tailgate for facilitating ingress/egress from either side of vehicle  12 . Tailgate step  20  may be slidably extendable to the deployed configuration of  FIG. 1  and slidably retractable to the stowed configuration of  FIG. 2 . In the embodiment illustrated, tailgate step  20  may include parallel supports  26  pivotally mounted at ends  28  thereof to slide assembly  30 , and including a step surface  32  at end  34  thereof. Referring to  FIG. 11 , step surface  32  may be pivotally mounted to supports  26  via pivot pin  36  disposable in complementary apertures  38  provided in supports  26 , with the pivoting feature provided for maintaining the upper surface of step surface  32  in a generally horizontal configuration during use. Further, step surface  32  may be fixedly engaged with L-shaped bracket  40  and reinforcement beam  42 , each of which form the stepping area for step  20  as shown in  FIGS. 1 and 11 . 
     In one embodiment, as shown in  FIGS. 21 and 22 , tailgate step  20  may include step placement tabs  44  for compactly positioning step surface  32  in the stowed configuration. Step surface  32  may be rotated between the deployed configuration of  FIG. 21  and the stowed configuration of  FIG. 22 . Step placement tabs  44  protrude from the sides of step surface  32  and contact parallel supports  26  when step surface  32  is rotated to the stowed configuration. This configuration allows step surface  32  to align with parallel supports  26  and stow between parallel supports  26  such that tailgate step  20  requires minimal volume within cavity  22  of tailgate  14 . The parallel supports may also have indentations (not shown) so that step placement tabs  44  sit flush along parallel supports  26  when in the stowed configuration. 
     Referring to  FIGS. 1-3  and  8 - 11 , slide assembly  30  may include primary and secondary guide channels  50 ,  52  mounted within tailgate  14  and including guide rails formed as supports  26  slidably disposed therein (note the terms guide rails and supports  26  will hereinafter be used interchangeably). As shown in  FIG. 11 , primary guide channel  50  may include a C-shaped channel  54  for complementary slidable engagement with secondary guide channel  52 . Further, secondary guide channel  52  may include an opening  56  for slidable engagement with guide rail  26 . As shown in  FIG. 11 , additional bracket components  55 ,  57 ,  58  and  59  may be provided for mounting of slide assembly  30 . 
     The sliding movement of slide assembly  30  will now be described in detail with reference to  FIGS. 1-3  and  8 - 18 . 
     Specifically, referring to  FIGS. 1-3 ,  8 - 11  and  15 - 18 , primary guide channel  50  may include slots  60 ,  62  for snap-fit engagement of step positioning tabs  64  mounted to secondary guide channels  52  at location  66 . In the embodiment illustrated, tabs  64  may be made of plastic or another resilient material. Thus when secondary guide channel  52  is disposed in primary guide channel  50 , as step  20  is pulled from the retracted configuration of  FIG. 8  to the extended configurations of  FIGS. 9 and 10 , in the configuration of  FIG. 9 , step positioning tab  64  is disengaged from slot  62  and engaged with slot  60  to thus hold step  20  in the configuration of  FIG. 9 . In this configuration, referring to  FIG. 11 , bottom support  68  of secondary guide channel  52  prevents step  20  from pivoting down to the configuration of  FIG. 10 . As step  20  is pulled further to the configuration of  FIG. 10 , the engagement of tab  64  with slot  60  and as shown in  FIG. 15 , the engagement of detent edges  70 ,  72  respectively of secondary guide channel  52  and mounting bracket  74  prevent further relative sliding movement of secondary guide channel  52  within primary guide channel  50 . 
     At this stage, referring to  FIGS. 9-11 , pivot pins  80  provided within apertures  82  of guide rails (i.e. supports)  26  may slide within elongated slots  84  from first to second ends  86 ,  88  of slots  84 . Once pins  80  engage ends  88  of slots  84 , opening  90  adjacent bottom support  68  may thus allow guide rails  26  to pivot downward to place step  20  in the fully deployed configuration of  FIG. 10 . 
     In order to limit rotation of step  20  relative to the vertical direction to prevent contact of the step with side  24  of the tailgate and to further support a user in a predetermined position when step  20  is deployed, referring to  FIGS. 19A and 19B , a step rotation limit apparatus  140  may be provided. Apparatus  140  may generally include the guide rails  26  including an edge  142  chamfered at approximately 85° relative to upper surface  144 , with edge  142  contiguously engageable with the underside of upper surface  146  of secondary guide channel  52  as shown in  FIG. 19B . Secondary guide channel  52  may also include a chamfered edge  148  at bottom support  68  for engagement with bottom surface  150  of guide rails  26 . In this manner, as illustrated in  FIGS. 19A and 19B , in the fully deployed configuration of  FIG. 10 , step  20  may be disposed at approximately 15° relative to the vertical direction. 
     Alternatively, in another embodiment, referring to  FIGS. 20A and 20B , a step rotation limit apparatus  160  may likewise prevent contact of the step with side  24  and support a user in a predetermined position when step  20  is deployed. Apparatus  160  may generally include the guide rails  26  including a hook  162  engageable with opening  164  provided in secondary guide channel  52 . As with apparatus  140 , secondary guide channel  52  may also include a chamfered edge  166  at bottom support  68  for engagement with bottom surface  168  of guide rails  26 . Further, elongated slot  84  of secondary guide channel  52  may include a recessed section  170  for maintaining pivot pins  80  in position when step  20  is deployed, and thus requiring upward lifting of step  20  for moving the step to the retracted configuration of  FIG. 8 . In this manner, as illustrated in  FIGS. 20A and 20B , in the fully deployed configuration of  FIG. 10 , step  20  may be likewise disposed at approximately 15° relative to the vertical direction. Those skilled in the art would readily appreciate in view of this disclosure that the angles of the aforementioned surfaces may be readily modified as needed for changing the overhang angle of step  20 . 
     In order to return step  20  to its retracted configuration of  FIG. 8 , referring to  FIGS. 8-11  and  15 - 18 , with step  20  rotated to the configuration of  FIG. 9  from the  FIG. 10  fully deployed configuration, referring to  FIGS. 16 and 17 , step  20  may be simply pushed inwards towards its fully retracted configuration of  FIG. 8 . In the  FIGS. 16 and 17  configurations, edges  92  of guide rails  26  may push sides  94  of tabs  64  to rotate tabs  64  in the clockwise direction of  FIGS. 16 and 17  and thus disengage tabs  64  from slots  60 . As movement of step  20  is continued to the  FIG. 8  fully retracted position, tabs  64  may eventually engage slots  62  to thus prevent further movement of step  20 . Those skilled in the art would readily appreciate in view of this disclosure that additional stops, such as stops  96  may be provided at end of primary guide channels  50  for providing an additional means of limiting inward movement of step  20 . 
     In the intermediate and fully deployed configurations of  FIGS. 9 and 10 , in order to prevent inadvertent closing of tailgate  14  and thus damage to side mounted step assist mechanism  10  or the vehicle body, as shown in  FIGS. 4-7 , a lockout device  100  may be provided. As shown in  FIG. 4 , which illustrates step  20  in the fully deployed configuration, lockout device  100  may include a primary hinged link  102  pivotally mounted to D-pillar  104  and a secondary hinged link  108  slidably and pivotally disposed via pivot pin  110  in elongated slot  112  provided in link  102 . Secondary hinged link  108  may include a generally L-shaped configuration with a stem  114  disposable under secondary guide channel  52  as shown in  FIGS. 1 ,  4  and  5 . Thus before step  20  is disposed in the deployed configurations of  FIGS. 9 and 10 , secondary hinged link  108 , which is normally rotated upwards parallel to primary hinged link  102  and frictionally engaged therewith, may be pivoted downwards as shown in  FIG. 7 . With secondary hinged link  108  pivoted downwards, step  20  may be deployed as illustrated in  FIGS. 9 and 10 , and in this configuration, if tailgate  14  is rotated towards its closed position of  FIG. 3 , stem  114  slides upwardly via pivot pin  110  in slot  112  to form a rigid link, and in this configuration, stem  114  may further contact the bottom of secondary guide channel  52  to thus prevent tailgate  14  from being pivoted upwards more than approximately 25° as illustrated in  FIGS. 4-6 . Thus in the  FIG. 7  initial deployed configuration, secondary hinged link  108  may be disposed at the bottom of elongated slot  112  and primary hinged link  102  may be disposed at an angle to the D-pillar (as opposed to its stowed position in which link  102  is disposed generally parallel to the D-pillar). As shown in  FIG. 4 , as tailgate  14  is pivoted upwardly with secondary hinged link  108  deployed, primary hinged link may again rotate to its original orientation parallel to the D-pillar to thus allow relative locking of secondary hinged link  108  and prevent further rotation of the tailgate. 
     Step lock and release mechanism  130  will now be described in detail with reference to  FIGS. 1-3  and  8 - 11 . 
     Specifically, referring to  FIGS. 8-10 , step lock and release mechanism  130  may be provided for maintaining step  20  in the retracted (i.e. stowed) configuration of  FIG. 2  and permitting deployment of step  20  upon disengagement of mechanism  130 . As shown  FIGS. 8 and 11 , mechanism  130  may generally include a lock tab  132  rotatably mounted to reinforcement beam  42  of step  20 . Lock tab  132  may be rotatable upwardly or downwardly in the configuration of  FIG. 8  to engage a separately mounted lock extension  134  (or alternatively mounting bracket  74  if lock extension  134  is omitted) to thus maintain step  20  in the retracted (i.e. stowed) configuration of  FIG. 2 . 
     The general operation of side mounted step assist mechanism  10  will now be described in detail with reference to  FIGS. 1-11 . 
     Specifically, referring to  FIGS. 1-3 , in order to operate mechanism  10  for loading or unloading of goods  18  that cover the rear (trailing edge) of tailgate  14 , a user may first rotate tailgate  14  to its horizontal position of  FIG. 2 . At this stage, the user may disengage step lock and release mechanism  130  by rotating lock tab  132  to the disengaged position of  FIG. 9 , and simultaneously rotate secondary hinged link  108  downwards as shown in  FIG. 7  to thus prevent inadvertent closing of tailgate  14  with step  20  deployed. The user may then pull step  20  out from cavity  22  of tailgate  14  to the positions of  FIG. 9  and thereafter  FIG. 10 , and allow step  20  to pivot downwards from its weight as shown in  FIG. 10 . With step  20  fully deployed, the user may thus use step  20  to climb onto the side of tailgate  14  and into vehicle bed  16  to maneuver goods  18  as needed. Once finished maneuvering of goods  18 , the user may simply follow the reverse sequence discussed above for exiting vehicle bed  16  and thereafter retracting step  20  to the position of  FIG. 8 . 
     To summarize, the invention thus allows a vehicle user to gain access to the truck cargo area via the open tailgate, even when loading of goods that might cover the rear (trailing edge) of the tailgate. In this regard, even if an object protrudes through the back of a truck bed, a user may climb into the truck bed from the sides of the tailgate, or alternatively, if two steps are provided, two users may climb onto the sides of the tailgate to assist with removal or placement of an oversized object from or into a truck bed. Referring to  FIG. 1 , in addition to step  20 , users may support themselves when accessing the truck bed by utilizing a hand hold (not shown) molded within the D-pillar horizontal trim, or a pivotally mounted step assist arm. 
     Those skilled in the art would readily appreciate in view of this disclosure that various modifications could be made to the aforementioned components, without departing from the scope of the present invention. For example, instead of guide channels or rails  50 ,  52 ,  26 , other slide assemblies may be used, as long as mechanism  10  is mounted on the side of a tailgate as discussed above. Further, instead of lockout device  100  or step lock and release mechanism  130 , other mechanisms may be used for preventing inadvertent closing of the tailgate with step  20  deployed, or for releasing/locking step  20  in place as needed. Alternatively, more than one step, similar to tailgate step  20 , may be disposed at predetermined locations between parallel supports  26 . 
     Although particular embodiments have been described in detail herein with reference to the accompanying drawings, it is to be understood that the invention is not limited to those particular embodiments, and that various changes and modifications may be affected therein by one skilled in the art without departing from the scope or spirit of the invention as defined in the appended claims.