Abstract:
Embodiments of the invention related generally to ladders and ramps and, more particularly, to collapsible ladders and ramps for a vehicle tailgate and related systems. In one embodiment, the invention provides a system comprising: a tailgate member for a vehicle, the tailgate member having: an interior wall; an exterior wall; and a cavity between the interior and exterior walls; at least one collapsible ladder device comprising: a pair of substantially parallel elongate members; a plurality of cross members, each of the plurality extending between and lying substantially perpendicular to the pair of substantially elongate members; and an attachment device for non-fixedly securing the at least one collapsible ladder device within the cavity of the tailgate member.

Description:
BACKGROUND 
       [0001]    Embodiments of the invention related generally to ladders and ramps and, more particularly, to collapsible ladders and ramps for a vehicle tailgate and related systems. 
       BRIEF DESCRIPTION OF THE INVENTION 
       [0002]    In one embodiment, the invention provides a system comprising: a tailgate member for a vehicle, the tailgate member having: an interior wall; an exterior wall; and a cavity between the interior and exterior walls; at least one collapsible ladder device comprising: a pair of substantially parallel elongate members; a plurality of cross members, each of the plurality extending between and lying substantially perpendicular to the pair of substantially elongate members; and an attachment device for non-fixedly securing the at least one collapsible ladder device within the cavity of the tailgate member. 
         [0003]    In another embodiment, the invention provides a device comprising: a pair of elongate members; and a plurality of cross members, each of the plurality extending between and lying substantially perpendicular to the pair of elongate members, wherein: each of the pair of elongate members is segmented, with a first segment comprising a first segment of a first elongate member substantially parallel to a first segment of a second elongate member, with at least one of the plurality of cross members disposed therebetween, a second segment of the first elongate member substantially parallel to a second segment of the second elongate member, with at least another of the plurality of cross members disposed therebetween; the second segment, in a collapsed position, lies atop the first segment; and the second segment, in an extended position, lies longitudinally adjacent the first segment. 
         [0004]    In still another embodiment, the invention provides a device comprising: a pair of elongate members, each elongate member including: a first portion having: a first outer dimension; and a first interior cavity with a first cavity dimension; a second portion adjacent to the first portion, the second portion having: a second outer dimension less than the first cavity dimension of the first portion; and a second interior cavity with a second cavity dimension; a plurality of cross members, each of the plurality extending between and lying substantially perpendicular to the pair of elongate members, wherein the second portion is configured, in a collapsed position, to reside at least partially within the first interior cavity of the first portion and, in an extended position, to reside longitudinally adjacent the first portion. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0005]    These and other features of this invention will be more readily understood from the following detailed description of the various aspects of the invention taken in conjunction with the accompanying drawings that depict various embodiments of the invention, in which: 
           [0006]      FIG. 1  shows a collapsible tailgate ladder according to an embodiment of the invention; 
           [0007]      FIG. 2  shows the collapsible tailgate ladder of  FIG. 1  in partially collapsed form; 
           [0008]      FIG. 3  shows a cross-sectional view of the collapsible tailgate ladder of  FIG. 1 ; 
           [0009]      FIG. 4  shows a collapsible tailgate ladder according to another embodiment of the invention; 
           [0010]      FIG. 5  shows the collapsible tailgate ladder of  FIG. 4  in collapsed form; 
           [0011]      FIG. 6  shows a detailed cross-sectional view of the collapsible tailgate ladder of  FIG. 4 ; 
           [0012]      FIG. 7  shows a top-down view of a tailgate including a pair of collapsible tailgate ladders according to an embodiment of the invention; 
           [0013]      FIG. 8  shows a perspective view of the tailgate of  FIG. 7  with the pair of collapsible tailgate ladders in extended form; 
           [0014]      FIG. 9  shows a cross-sectional side view the tailgate and extended tailgate ladder of  FIG. 8 . 
       
    
    
       [0015]    It is noted that the drawings of the invention are not to scale. The drawings are intended to depict only typical aspects of the invention, and therefore should not be considered as limiting the scope of the invention. In the drawings, like numbering represents like elements among the drawings. 
       DETAILED DESCRIPTION OF THE INVENTION 
       [0016]    Referring now to the drawings,  FIG. 1  shows a pair of collapsible tailgate ladder sections  100 ,  200  according to an embodiment of the invention. Tailgate ladder section  100  includes a pair of elongate members  110 ,  112 , between which are disposed a plurality of rungs  150 , as will be recognized by one skilled in the art. Tailgate ladder section  200  includes a corresponding pair of elongate members  210 ,  212  and plurality of rungs  250 . 
         [0017]    The detailed portion of  FIG. 1  shows the juxtaposition of elongate member  112  and elongate member  212 . Elongate member  112  has a first diameter, d 1 , that is less than a second diameter d 2  of elongate member  212 . As such, at least a portion of elongate member  112  is capable of being disposed within elongate member  212 , as will be explained in greater detail below. 
         [0018]      FIG. 2 , for example, shows ladder sections  100 ,  200  in partially collapsed form, such that elongate member  110  of ladder section  100  is disposed within elongate member  210  of ladder section  200  while elongate member  112  of ladder section  100  is similarly disposed within elongate member elongate member  212 . 
         [0019]      FIG. 3  shows a cross-sectional view elongate members  100 ,  200  looking along their longitudinal axes, according to one illustrative embodiment of the invention. Elongate member  110  includes a horizontal portion  120 , from which descend a pair of vertical members  122 ,  123 . A pair of horizontal members  124 ,  125  extend medially from vertical members  122 ,  123  and a pair of rising members  126 ,  127  extend upward from horizontal members  124 ,  125 . Thus, elongate member  110  roughly forms a “G” shape from each half of elongate member  110 . 
         [0020]    Elongate member  210  has a different but corresponding shape as compared to elongate member  110 . That is, elongate member  210  includes a body  220 , from which extend a pair of horizontal members  222 ,  223 . A pair of descending members  224 ,  225  then descend from horizontal members  222 ,  223 . Thus, elongate member  110  roughly forms a “T” shape that is adapted to and capable of being disposed within elongate member  110 , as shown. In this configuration, elongate member  110  of ladder section  100  ( FIG. 2 ) is capable of sliding along and over elongate member  210  of ladder section  200  ( FIG. 2 ), thereby variably adopting extended and collapsed positions. 
         [0021]    The particular shapes of elongate members  110 ,  210  shown in  FIG. 3  are merely illustrative. Other shapes may be employed, as will be recognized by one skilled in the art, and are within the scope of the invention. 
         [0022]    As will be recognized by one skilled in the art, the movement of ladder sections  100 ,  200  with respect to one another may be facilitated or eased in any number of ways and with any number of devices. These might include, for example, ball bearings, liquid lubricants, solid lubricants, etc. Merely for the sake of simplicity in explanation, these are not shown in the drawings, but are within the scope of the various embodiments of the invention. 
         [0023]      FIG. 4  shows three tailgate ladder sections  300 ,  400 ,  500  according to another embodiment of the invention. Here, each ladder section  300 ,  400 ,  500  includes a pair of elongate members  310 ,  312 , and  410 ,  412 , and  510 ,  512 , but a single rung  350 ,  450 ,  550 , respectively. As will be apparent from the following description, however, more than one rung may be included in each section according to other embodiments of the invention. 
         [0024]    In the detailed portion of  FIG. 1 , elongate members  312 ,  412 ,  512  have diameters d 1 , d 2 , d 3 , respectively. As in the embodiment shown in  FIG. 1 , this facilitates the passage of a portion of, for example, elongate member  312  within elongate member  412  and/or elongate member  412  within elongate member  512 .  FIG. 5  shows tailgate ladder sections  300 ,  400 ,  500  in collapsed form. 
         [0025]      FIG. 6  shows a detailed schematic view of portions of elongate members  312 ,  412  according to one embodiment of the invention. Elongate member  312  has a first diameter d 1  and a greater second diameter d 5  across a flange  332  at one end. Elongate member  412  has a corresponding or complimentary shape, including a rim  442  at its end adjacent flange  332 . Opening within rim  442  has a diameter, d 4 , that is greater than first diameter d 1  but less than second diameter d 5 . As such, elongate member  312  may move in direction A within elongate member  412  but is prevented from being removed entirely from within elongate member  412  by the contact of flange  332  and rim  442 . 
         [0026]    As will be recognized by one skilled in the art, any number of ladder sections may be arranged in series in the manner shown in  FIGS. 4-6 . The number of such sections shown herein is merely for the sake of simplicity in explanation and illustration and should not be viewed as limiting the scope of the invention. 
         [0027]      FIG. 7  shows a top-down view of a portion of a vehicle bed  600  and a tailgate member  700  according to an embodiment of the invention. Tailgate member  700  includes a cavity  702  into which is disposed a pair of collapsible ladder devices  100 A,  100 B according to an embodiment of the invention.  FIG. 8  shows a perspective view of the tailgate member  700  of  FIG. 7  with the collapsible ladder devices  100 A,  100 B extended from the cavity  702 . 
         [0028]    As will be understood by one skilled in the art, the components of collapsible ladder devices  100 A,  100 B may be formed of any material suitable for supporting the weight of a motorcycle, an all-terrain vehicle (ATV), a piece of landscaping equipment, or similar vehicle as it is driven or pushed up collapsible ladder devices  100 A,  100 B when extended from cavity  702  to the ground. 
         [0029]    As will similarly be recognized by one skilled in the art, the number of collapsible ladder devices employed may vary depending on the vehicle to be loaded. For example, where a motorcycle is to be loaded onto vehicle bed  600 , a single collapsible ladder device may be employed; where a four-wheeled ATV is to be loaded, a pair of collapsible ladder devices may be employed; and where a three-wheeled ATV is to be loaded, three collapsible ladder devices may be employed. The embodiment shown in  FIGS. 7 and 8 , which show a system including a pair of collapsible ladder devices  100 A,  100 B is shown merely for purposes of explanation and illustration. 
         [0030]      FIG. 9  shows a cross-sectional side view of tailgate member  700  according to one embodiment of the invention. Here, elongate member  110 B includes an attachment device  160 B in contact with a wall  704  of tailgate member  700  within cavity  702 . Attachment device  160 B may be operable to non-fixedly secure elongate member  110 B (and therefore collapsible ladder device  100 B) within cavity  702 . According to some embodiments, attachment device  160 B is a simple plate or ledge, as shown in  FIG. 9 , such that attachment device  160 B lays atop wall  704 . According to other embodiments, attachment device  160 B may include a hook, lip, or similar feature operable to prevent movement of collapsible ladder device  100 B in direction B. 
         [0031]    As used herein, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. 
         [0032]    This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any related or incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal language of the claims.