An attachment ( 10 ) for operably mounting and supporting a ladder ( 12 ) comprises an angular frame ( 18, 20 ) adapted for receipt by a vehicular hitch ( 14 ). The frame ( 18, 20 ) includes crosspieces ( 26 ) adapted for receiving rungs of the ladder ( 12 ), which are releaseably connected together with fasteners ( 28 ). In the second embodiment, the fasteners ( 28 ′) are captured on the frame ( 18′, 20 ′).

BACKGROUND ART 
     Various types of portable ladders have been used heretofore to facilitate access to elevated locations for construction or maintenance purposes. Such ladders are either self-supporting, such as step ladders, or non-self-supporting, such as straight or extension ladders. Straight ladders are available in various fixed lengths. Extension ladders are also available in various, adjustable lengths. Straight and extension ladders are best suited for use in situations where both ends can be supported on and against suitable surfaces for stability and safety purposes. All such ladders are available with different duty ratings, depending upon their intended use. 
     Of course, regardless of the type of ladder being used, it is important to have it securely supported for stability and safety purposes. Self-supporting step ladders require secure support only at their lower ends. However, straight and extension ladders must be securely supported at both ends. Proper placement and support are critical, especially with long ladders and the higher up workers go on them. Serious injuries can and do result from falling off ladders that move or slip from not being securely supported. 
     Professional contractors and maintenance workers typically carry several types of fixed and extension ladders for use in different situations, although this tends be duplicative and thus expensive. 
     However, there are many applications where ladders simply cannot be used safely, if at all. For example, stringing outdoor lights in tall shrubbery or trees in a yard during the holidays can be difficult and unsafe when there is inadequate support for one or both ends of a ladder, or when it is either too high to reach from the ladder. Scaffolding is heavy and too expensive and time consuming to use in such situations. Aerial ladders and hydraulic lift buckets or ‘cherry pickers’ can sometimes be used in such situations, but they tend to be even more expensive and may not be able to access the desired location without damaging the surrounding yard. 
     A need has thus arisen for an attachment for operably mounting and securely supporting a ladder directly on a vehicle hitch to facilitate access to elevated locations which would otherwise be inaccessible without using expensive scaffolding, aerial ladders and/or cherry pickers. 
     SUMMARY OF INVENTION 
     The present invention comprises a ladder attachment for a vehicular hitch which overcomes the foregoing and other difficulties associated with the prior art. In accordance with the invention there is provided a new and unique ladder attachment that is adapted for use with hitches, such as receiver hitches, on vehicles such as pick-up trucks, SUV's and the like. By means of the ladder attachment herein, a ladder can be removably attached to a vehicular hitch so that the vehicle in effect provides the necessary stability and support while using the ladder. Either a fixed or extension ladder can be used with the attachment herein. 
    
    
     
       BRIEF DESCRIPTION OF DRAWING 
       A better understanding of the invention can be had by reference to the following Detailed Description in conjunction with the accompanying Drawing, wherein: 
         FIG. 1  is a side view way of a ladder attachment incorporating a first embodiment of the invention, secured to the rear hitch of a pick up truck; 
         FIG. 2  is a view similar to  FIG. 1 , showing a ladder mounted on the attachment of the first embodiment; 
         FIG. 3  is a view similar to  FIG. 2 , with the gate of the pick-up truck open; 
         FIG. 4  is an end view of the ladder attachment of the first embodiment, with a ladder mounted thereon; 
         FIG. 5  is a side view of the ladder attachment of the first embodiment, with the ladder and rungs shown in phantom lines; 
         FIG. 6  is a view similar to  FIG. 5 , without the ladder; 
         FIG. 7  is an enlarged perspective view of the ladder attachment of the first embodiment secured to the receiver hitch; 
         FIG. 8  is a perspective view of the ladder attachment of the first embodiment; 
         FIG. 9  is a perspective view way of a ladder attachment incorporating a second embodiment of the invention; 
         FIG. 10  is a side view of the ladder attachment of the second embodiment, with the ladder and rungs shown in phantom lines; 
         FIG. 11  is a side view of the ladder attachment of the second embodiment, without the ladder; 
         FIG. 12  is an exploded perspective view of the ladder attachment of the second embodiment secured to a receiver hitch; and 
         FIG. 13  is an illustration of an optional adjustable leg and an optional offset arm, which can be used with the ladder attachment herein. 
     
    
    
     DETAILED DESCRIPTION 
     Referring now to the Drawings, wherein like reference numerals designate like or corresponding elements throughout the views, and particularly referring to  FIGS. 1-8 , there is shown an attachment  10  for mounting a ladder  12  on the hitch  14  of a vehicle  16 . The attachment  10  is not adapted merely for transporting or carrying a ladder to/from a job site on vehicle  16 , as are the carriers of the prior art, although it could be used that way if desired. Rather, when attached to the hitch  14  on vehicle  16 , the attachment  10  provides a secure and stable base for someone using the ladder, without the expense of an aerial ladder or cherry picker. As will be explained more fully hereinafter, attachment  10  has many advantages over the prior art. 
     The attachment  10  comprises an angled upright frame portion  18  secured to the outer end of a generally horizontal frame portion  20 , which portions are preferably co-planar. The upright frame portion  18  may be about four to five feet long, for example. The lower frame portion  20  can be about two feet long, for example, for clearance with the tail gate of vehicle  16  as shown in  FIG. 3 . Upper and lower braces  22  and  24  are preferably secured between the frame portions  18  and  20  as shown, for reinforcement. Furthermore, as can be seen most easily in  FIG. 1  and  FIGS. 5-11 , the lowermost crosspiece  26  secured to upright frame portion  18  is positioned at an elevation lower than that of horizontally extending frame portion  20  extending from hitch  14 . Thus, when the bottommost rung of a ladder  12  is attached to lowermost crosspiece  26 , it becomes placed in a position lower than hitch  14 . Also, as can be seen most easily in  FIGS. 8-11 , crosspieces  26  are secured to the surface of upright frame portion  18  positioned remotely from horizontally extending frame portion  20 , with one crosspiece  26  positioned close to the top end of upright frame portion  18 , one crosspiece  26  positioned close to the bottom end of upright frame portion  18 , two crosspieces  26  supporting adjacent rungs on ladder  12 , and two adjacently-positioned crosspieces  26  supporting of non-adjacent rungs on ladder  12 . 
     In the preferred embodiment, the frame portions  18  and  20  of attachment  10  are constructed from straight sections of tubular steel, such as two inch square tube stock, although any suitable material can be used. The reinforcing braces  22  and  24  can also be constructed from such tubular material, or they can be fashioned in the form of gussets from flat stock, welded together. 
     The included obtuse angle between frame portions  18  and  20  of attachment  10  is somewhat more than 90 degrees or a right angle, but substantially less than 180 degrees, in order to provide a comfortable angle of inclination for the user of ladder  12  mounted thereon. In the preferred embodiment, the angle between frame portions  18  and  20  is about 110 degrees, or about 20 degrees off vertical, plus or minus about five (5) degrees. 
     The attachment  10  further includes a plurality of crosspieces  26  secured in spaced-apart relationship along the upright frame portion  18 , opposite frame portion  20 . The preferred embodiment of attachment  10  has two pairs of such crosspieces, the lower pair of which are adapted to receive a pair of rungs at the lower end of ladder  12 , and the upper pair of which are adapted to receive another pair of rungs further up the ladder. The crosspieces  26  of each pair are preferably centered on the upright portion  18 , mutually spaced apart about 12 inches or one foot, which is the standard spacing between ladder rungs. If desired, as few as one pair of cross pieces  26 , spaced further apart, such as 36 inches or three feet, could be used. Each crosspiece  26  is about eleven inches long, or somewhat less than the typical length of the rungs in ladder  12  so that the ladder  12  will be evenly centered and balanced on the attachment  10 . 
     The crosspieces  26  are preferably formed from steel channel stock. If desired, gussets  27  can be used for reinforcement. 
     The ladder  12  is removably secured to attachment  10  by means of U bolts  28  and associated cross plates and nuts, as best seen in  FIG. 8 . In the preferred embodiment, at least two U bolts  28  and associated cross plates and nuts are provided, one set for each of the uppermost and lowermost crosspieces  26  and associated rungs of ladder  10 . Other suitable connectors could also be used, if desired. 
     As shown, the horizontal portion  18  of attachment  10  is adapted to mate with the hitch  14  on the vehicle  16 . In the preferred embodiment, the hitch  14  is a receiver-type hitch secured underneath to the frame at the rear of vehicle  16 . Such receiver-type hitches are commercially available from various manufacturers, such as Rigid Hitch of Burnsville, Minn., for example. At least one pair of transverse holes  30  are provided in the frame portion  20  for alignment with corresponding holes  32  in hitch  14 , which holes receive a removable clevis or hitch pin  34 , with a retaining clip  35  on its end, in order to releasably secure attachment  10  to hitch  14  on vehicle  16 . Hitch  14  preferably comprises a Class III through Class V receiver-type hitch. 
     Referring now to  FIGS. 9-12 , there is shown a ladder attachment  40  incorporating a second embodiment of the invention. Since attachment  40  incorporates several components or features that are similar to those of attachment  10  of the first embodiment, those have been identified with the same reference numerals, but with prime (′) notations for differentiation. 
     The primary difference between the embodiments is that the attachment  40  incorporates short tubes  42  on the cross pieces  26 ′ so that the U bolts  28 ′ and associated wing nuts are captured and thus, not as apt to be misplaced, as with attachment  10 . 
       FIG. 13  shows two optional accessories that can be used with ladder attachment  10  or  40  of the invention. If additional vertical support is desired, an adjustable leg  50  can be used. Leg  50  has a foot  52  coupled to its lower end at pivot  54 . The upper end of leg  50  includes transverse adjustment holes  56  for alignment with a hole  38  provided near the lower end of frame portion  18  or  18 ′, and then connection with a clevis or pin  60 . 
     Also referring to  FIG. 13 , an offset arm  70  can be used for more flexibility in placement of ladder  12 . The arm  70  includes opposite end portions  72  and  74 , which are preferably coplanar, connected between attachment  10  or  40  and hitch  14 . The outer portion  74  of arm  70  includes transverse holes  76  and is adapted to receive the frame portion  20  or  20 ′ and be connected with a clevis or pin like pin  34 . The inner portion  72  of arm  70  has a transverse hole (not shown) and is similarly adapted for receipt and connection with hitch  14  with a clevis or pin like pin  34 . The obtuse included angle between portions  72  and  74  of arm  70  is preferably about 135 degrees so that ladder  12  can be positioned about 45 degrees left or right off the centerline of vehicle  16 . 
     From the foregoing, it will be appreciated that the present invention comprises a ladder attachment having several advantages over the prior art. The ladder attachment herein is of inexpensive, straightforward construction. It provides extra flexibility with hitches and ladders already used by many homeowners and contractors. Although illustrated herein for use with a rear hitch, it can just as well be used with a front hitch on a vehicle, such as a pick up truck as shown or a sport utility vehicle, for even more versatility. Other advantages will be evident to those skilled in the art. 
     Although particular embodiments of the invention have been illustrated in the accompanying Drawings and described in the foregoing Detailed Description, it will be understood that the invention is not limited only to the embodiments disclosed, but is intended to embrace any alternatives; equivalents, modifications and/or rearrangements of elements falling within the scope of the invention as defined by the following Claims.