You are an expert at summarizing long articles. Proceed to summarize the following text:

You are an expert at summarizing long articles. Proceed to summarize the following text: 
FIELD OF THE INVENTION 
   The present disclosure relates to ladder support apparatus, and more specifically, to support assemblies for ladders operating on a plurality of support members. 
   BACKGROUND OF THE INVENTION 
   Ladders are ubiquitous devices used in a wide variety of commercial and residential circumstances. In some applications, such as during the intermediate stages of construction of structures (e.g. houses, buildings, aircraft, etc.) it may be desirable for ladders to be used prior to the installation of a uniform floor surface. This may present a challenge because most ladders are not designed to operate in the absence of a uniform floor surface. 
   For example, certain painting and sealing operations on aircraft sections often involve working over open floor beams at heights requiring ladders. Due to the nature of the paint and seal process, the installation of temporary flooring may not be practical. In order to resolve this problem, step ladders have been equipped with elongated rails that have been bolted or nailed to the bottoms of the legs and which extend between and beyond the front and rear legs to serve as supports for the ladders over the open floor beams. 
   Although desirable results have been achieved using such prior art methods, there is room for improvement. For example, it is undesirable to permanently modify the ladder by bolting or nailing the elongated rails onto the legs for various reasons, including, for example, because the ladder is thereafter rendered unable to fold up for storage. The resulting ladder assembly thereafter requires additional storage space than unaltered ladders, and may be unsuitable for other applications in which ladders are required, such as in relatively small spaces. The transport of such ladder assemblies from one work area to another typically requires more effort than the transport of unaltered ladders. Therefore, ladder support apparatus and methods that at least partially mitigate these effects would be useful. 
   SUMMARY OF THE INVENTION 
   The present invention is directed to support assemblies for ladders operating on a plurality of support members. Apparatus and methods in accordance with the present invention may advantageously provide desired support for a ladder during operations over non-uniform surfaces (e.g. a plurality of floor beams) without permanent modification of the ladder, thereby allowing the ladder to be easily converted back to its original configuration for normal use, for transport, and for storage. These and other advantages may be achieved using embodiments of ladder support assemblies in accordance with the present invention. 
   In one embodiment, a support assembly adapted for use with a ladder includes at least one elongated member adapted to extend between first and second legs of the ladder when the ladder is positioned in an operating position, and first and second coupling assemblies coupled to the elongated member at first and second positions on the elongated member, the first and second positions being spaced apart, wherein the first and second coupling assemblies are adapted to be clampably coupled to the first and second legs of the ladder, respectively. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The preferred and alternative embodiments of the present invention are described in detail below with reference to the following drawings. 
       FIG. 1  is an isometric view of a ladder assembly in accordance with an embodiment of the present invention; 
       FIG. 2  is an enlarged isometric view of a left front coupling assembly of the ladder support assembly of  FIG. 1 ; 
       FIG. 3  is an enlarged isometric view of a left rear coupling assembly of the ladder support assembly of  FIG. 1 ; 
       FIG. 4  is a first partially-exploded isometric view of the left front and left rear coupling assemblies of the ladder support assembly of  FIG. 1 ; 
       FIG. 5  is a second partially-exploded isometric view of the left front and left rear coupling assemblies of the ladder support assembly of  FIG. 1 ; 
       FIG. 6  is a third partially-exploded isometric view of the left front and left rear coupling assemblies of the ladder support assembly of  FIG. 1 ; 
       FIG. 7  is a fourth partially-exploded isometric view of the left front and left rear coupling assemblies of the ladder support assembly of  FIG. 1 ; 
       FIG. 8  is an enlarged isometric view of a channel end cap of the ladder support assembly of  FIG. 1 ; 
       FIG. 9  is an isometric view of a ladder assembly in accordance with an alternate embodiment of the present invention; 
       FIG. 10  is an enlarged first isometric view of a clamping assembly of the ladder support assembly of  FIG. 9 ; 
       FIG. 11  is an enlarged second isometric view of the clamping assembly of the ladder support assembly of  FIG. 9 ; 
       FIG. 12  is an exploded view, a partially-exploded view, and an assembled view of one of the front coupling assemblies of  FIG. 9 ; 
       FIG. 13  is an exploded view and an assembled view of a strut assembly of the ladder support assembly of  FIG. 9   
       FIG. 14  is an enlarged elevational view of a side brace assembly of the ladder support assembly  220  of  FIG. 9 ; 
       FIG. 15  is an enlarged isometric view of a lower brace coupling assembly of the side brace assembly of  FIG. 14 ; and 
       FIGS. 16 and 17  are exploded and assembled views of the lower and upper brace coupling assemblies of  FIG. 15 . 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   The present invention relates to support assemblies for ladders operating on a plurality of support members. Many specific details of certain embodiments of the invention are set forth in the following description and in  FIGS. 1–17  to provide a thorough understanding of such embodiments. One skilled in the art, however, will understand that the present invention may have additional embodiments, or that the present invention may be practiced without several of the details described in the following description. 
   In general, ladder support assemblies in accordance with the present invention may be removably coupled to the ladder to provide a “floor” wherever it is needed, without altering the ladder itself in any way. Thus, the ladder support assembly may be coupled to the ladder when needed, such as while performing operations over open floor beams, and may be uncoupled from the ladder so that the ladder may be easily folded for transport and storage. 
   For example,  FIG. 1  is an isometric view of a ladder assembly  100  in accordance with an embodiment of the present invention. In this embodiment, the ladder assembly  100  includes a ladder  102  having left and right front legs  104 ,  106 , and left and right rear legs  108 ,  110 . A ladder support assembly  120  includes a left elongated member  122  and a right elongated member  124 . Left and right front coupling assemblies  130   a ,  130   b  couple the left and right front legs  104 ,  106  with the left and right elongated members  122 ,  124 , and left and right rear coupling assemblies  140   a ,  140   b  couple the left and right rear legs  108 ,  110  with the left and right elongated members  122 ,  124 . The left and right elongated members  122 ,  124  are engaged over a plurality of floor beams  126 . The bottoms of the elongated members  122 ,  124  may coated with a layer  125  of a non-skid material, such as, for example, a spray-on polyurethane. 
   In the particular embodiment shown in  FIG. 1 , the ladder  102  is “facing” in a direction that is approximately parallel with an interior wall  103  of an aircraft during an intermediate stage of assembly. It will be appreciated that the elongated members  122 ,  124  are adapted to extend at least between the respective legs of the ladder  102 , and preferably, to extend between and beyond the respective legs of the ladder  102  in order to span a suitable number of floor beams  126  to provide stability to the ladder  102 . Thus, a user may use the ladder assembly  100  to perform certain manufacturing operations (e.g. painting and sealing operations) on the aircraft prior to the installation of temporary flooring on the floor beams  126  within the aircraft. It will be appreciated that the elongated members  122 ,  124  may be any type of suitable elongated members, and that the invention is not limited to the particular embodiment shown in  FIG. 1 . Thus, although the elongated members  122 ,  124  shown in  FIG. 1  are formed using an aluminum channel, in alternate embodiments, the elongated members could be formed from other members and other material types, including, for example, aluminum box section extrusion, steel members, or any other suitable members. 
     FIGS. 2 and 3  are enlarged isometric views of the left front and left rear coupling assemblies  130   a ,  140   a  of the ladder support assembly  120  of  FIG. 1 .  FIGS. 4–7  are partially-exploded isometric views of the left front and left rear coupling assemblies  130   a ,  140   a  of the ladder support assembly  120  of  FIG. 1 . In this embodiment, the left front coupling assembly  130   a  includes a slotted base  132  adapted to slideably engage into a channel  123  of the left elongated member  122  ( FIG. 2 ). An arm member  134  is slideably coupled to the base  132 , and a locking member  136  is coupled to the arm member  134  ( FIG. 7 ). In this embodiment, the locking member  136  projects transversely at an approximately right angle away from the arm member  134 . 
   As best shown in  FIGS. 6 and 7 , a side rail  135  projects outwardly from the base  132  along the length of the channel  123 . A top rail  137  is engaged over an upper portion of the base  132  and laterally beyond the channel  123  to approximately the outer edges of the elongated member  122  ( FIG. 2 ). The arm member  134  is positioned on the top rail  137 , and a threaded member  138  is threadedly engaged through the arm member  134  and the top rail  137  to secure the arm member  134  and the top rail  137  in position on the base  132  ( FIGS. 2 and 7 ). 
   In operation, the left front coupling assembly  130   a  is engaged with the left front leg  104  of the ladder  102  by positioning the base  132  into the channel  123  of the left elongated member  122 . The left front leg  104  is also placed in the channel  123  and is engaged against the base  132 . The locking member  136  and the side rail  135  are engaged against the left front leg  104 , and the threaded member  138  is tightened, thereby clamping the left front coupling assembly  130   a  to the channel  123  and securing the left front leg  104  into position in the channel  123 . More specifically, the side rail  135  is engaged against the left front leg  104 , clamping the leg  104  against the side of the channel  123  and preventing lateral movement of the leg  104  within the channel  123 . The locking member  134  is engaged with the leg  104 , preventing the leg from lifting out of the channel  123 . The base  132 , the arm member  134 , and the locking member  136  cooperate to prevent the leg  104  from moving longitudinally along the length of the channel  123 . 
   Similarly, the left rear coupling assembly  140   a  includes a slotted base  142  adapted to slideably engage into the channel  123  ( FIG. 3 ), and an arm member  144  slideably coupled to the base  142 . A locking member  146  is coupled to the arm member  144  and projects outwardly therefrom ( FIG. 6 ). A side rail  145  projects outwardly from the base  142  along the length of the channel  123 . A top rail  147  is engaged over the base  142  and extends laterally beyond the channel  123  to approximately the outer edges of the elongated member  122  ( FIG. 3 ). A threaded member  148  secures the arm member  144  and the top rail  147  in position on the base  142  ( FIGS. 2 and 7 ). 
   The operation of the rear coupling assembly  140   a  is similar to the operation of the front coupling assembly  130   a  described above. In brief, the left rear leg  108  is positioned in the channel  123 , and the base  142  is engaged into the channel  123  and abutted against the left rear leg  108 . The side rail  145  is engaged against the left rear leg  108 , clamping the leg  108  against the side of the channel  123  and preventing lateral movement of the leg  108  within the channel  123 . The locking member  144  is engaged with the left rear leg  108 , preventing the leg from lifting out of the channel  123 . The base  142 , the arm member  144 , and the locking member  146  cooperate to prevent the leg  108  from moving longitudinally along the length of the channel  123  of the elongated members  122 ,  124  ( FIGS. 1 and 2 ). 
     FIG. 8  is an enlarged isometric view of a channel end cap  150  of the ladder support assembly  120  of  FIG. 1 . After the front and rear leg coupling assemblies  130 ,  140  are installed into the channel  123  of the first and second elongated members  122 ,  124 , the channel end cap  150  is secured at each end of the elongated members  122 ,  124  (two visible in  FIG. 1 ). 
   With the ladder support assembly  120  coupled to the ladder  102 , the ladder  102  may be utilized on a variety of non-uniform support surfaces. For example, as shown in  FIG. 1 , because the ladder  102  is supported by the elongated members  122 ,  124 , the ladder  102  may be used over a plurality of floor beams  126 . Of course, it will be appreciated that the ladder support assembly  120  provides a stable support that enables the ladder  102  to be utilized on a variety of non-uniform support surfaces, and is not limited to the specific floor-beam example shown in  FIG. 1 . 
   Embodiments of ladder support assemblies in accordance with the present invention may provide significant advantages over the prior art. For example, since the support assembly is clampably coupled to the ladder using the front and rear coupling assemblies  130 ,  140 , there is no need to permanently modify the ladder to utilize the advantages of the ladder support assembly. Also, the support assembly may be easily coupled to, and uncoupled from, the ladder as needed. Because the support assembly may be easily removed from the ladder, the ladder may be easily converted back for normal use, and may be folded up readily in the usual fashion for storage. These and other advantages may be achieved using embodiments of ladder support assemblies in accordance with the present invention. 
     FIG. 9  is an isometric view of a ladder assembly  200  in accordance with an alternate embodiment of the present invention. In this embodiment, the ladder assembly  200  includes a ladder  202  and a ladder support assembly  220 . The ladder support assembly  220  includes front and rear transverse members  222 ,  224  that span transversely between and beyond the left and right front legs  204 ,  206 , and between and beyond the left and right rear legs  208 ,  210 , respectively. The front transverse member  222  is coupled to the front legs  204 ,  206  using front coupling assemblies  230   a ,  230   b . Similarly, the rear transverse member  224  is coupled to the rear legs  208 ,  210  using rear coupling assemblies  240   a ,  240   b . Side brace assemblies  260  brace the outer portions of the front and rear transverse members  222 ,  224 . 
     FIGS. 10 and 11  are enlarged isometric views of front and rear coupling assemblies  230   b ,  240   a  of the ladder support assembly  220  of  FIG. 9 .  FIG. 12  is an exploded view  261 , a partially-exploded view  263 , and an assembled view  264  of the front coupling assembly  230   b  of  FIG. 9 . In this embodiment, the front coupling assembly  230   b  includes a slotted base  232  adapted to slideably engage into a channel  223  of the front transverse member  222 , a support plate  234  coupled to the slotted base  232 , and a locking member  236  coupled to the support plate  234 . 
   As shown in  FIGS. 10 and 12 , in operation, the slotted base  232  is engaged into the channel  223 , and the support plate  234  is coupled to the slotted base  232  and positioned on an upper portion of the front transverse member  222 , spanning across the channel  223 . Finally, the locking member  236  is coupled to the support plate  234  and engaged with the front leg  206  of the ladder  202  ( FIG. 10 ). Thus, the locking member  236  of the front coupling assembly  230   b  securely engages the front leg  206 , thereby coupling the ladder  202  to the front transverse member  222 . Similarly, as best shown in  FIG. 11 , the rear coupling assembly  240   a  includes a slotted base  242  (not visible), a support plate  244 , and a locking member  246 . The components of the rear coupling assembly  240   a  are assembled in the same manner as the components of the front coupling assembly  230   b , and securely engage the rear leg  208  of the ladder  202  with the rear transverse member  224 . 
     FIG. 13  is an exploded view  251  and an assembled view  253  of one end of a strut assembly  250 . The strut assembly is part of the side brace assembly  260  of  FIG. 9 . In this embodiment, the strut assembly  250  includes a strut member  262 , a joint base  252  (two required per strut member) that slidably engages into a strut channel  225 , and a top plate  254  that engages with the joint base  252 . In the assembled position  253 , the upper portion of the strut member  262  is clamped between the top plate  254  and the joint base  252 . A complete assembly  253  is positioned on each end of the strut member  262 . A channel stop block  256  is coupled to each end portion of a strut member  262 . In this embodiment two strut assemblies  250  are employed per transverse members  222 ,  224  ( FIG. 9 ). 
     FIG. 14  is an enlarged elevational view of a side brace assembly  260  of the ladder support assembly  220  of  FIG. 9 .  FIG. 15  is an enlarged isometric view of a lower brace coupling assembly  270  of the side brace assembly  260  of  FIG. 14 .  FIGS. 16 and 17  are exploded and assembled views of the lower and upper brace coupling assemblies  270 ,  280  of  FIG. 15 . As best shown in  FIG. 14 , in this embodiment, the side brace assembly  260  includes a strut member  262  that is coupled to the rear transverse member  224  by the lower brace coupling assembly  270 , and to the left rear leg  208  of the ladder  202  by the upper brace coupling assembly  280 . As shown in  FIG. 9 , the ladder support assembly  220  may include four side brace assemblies  260 . One skilled in the art will appreciate that the side braces shown in  FIG. 9  protect the cantilevered portions of the transverse members  222 ,  224  from bending under load. Transverse members of heavier cross section might not require side braces, but at the cost of increased weight. 
   Referring to  FIGS. 15 and 16 , the lower brace coupling assembly  270  includes a slotted base  272  that engages into the channel of the transverse member  224 . A coupling tab  274  is hingeably coupled to a clamp plate  276  which, in turn, is coupled to the slotted base  272 . In operation, the clamp plate  276  and the slotted base  272  cooperate to clampably secure the lower brace coupling assembly  270  to the transverse member  224 . The coupling tab  274  is coupled to a strut top plate of the strut member  262 . In one particular embodiment, the strut member  262  is coupled to the coupling tab  274  such that it may rotate with respect to the coupling tab  274  and provide an additional degree of freedom to account for the compound angle at which the strut typically meets the transverse member. 
   The construction of the upper brace assembly  280  is similar to the lower brace assembly  270 . As shown in  FIG. 17 , the upper brace assembly  280  includes a slotted base  282  that is engaged with the rear leg  208  of the ladder  202  ( FIG. 14 ). A coupling tab  284  is hingeably coupled to a clamp plate  286 . In operation, the clamp plate  286  and the slotted base  282  cooperate to clampably secure the upper brace coupling assembly  280  to the rear leg  208 , and the coupling tab  284  is coupled to a strut top plate of the strut member  262 . Again, in one embodiment, the brace member  262  is rotatably coupled to the coupling tab  284  to provide an additional degree of freedom to account for the compound angle at which the strut typically meets the ladder. 
   It will be appreciated that the ladder support assembly  220  described above with reference to  FIGS. 9–17  advantageously expands the manner in which the ladder  202  may be used over non-uniform surfaces. For example, because the front and rear transverse members  222 ,  224  extend between and beyond the front and rear legs, respectively, the ladder  202  may be used in a different direction over the plurality of floor beams  126  shown in  FIG. 1 . More specifically, the ladder support assembly  220  enables the ladder  202  to be used with the ladder “facing” the interior wall  103  of the aircraft. This allows a user to perform necessary operations on the interior wall  103  without twisting the user&#39;s body or requiring the user to stand “sideways” on the ladder  202 . Thus, the above-noted advantages of ladder support assemblies in accordance with the present invention may be achieved in an alternate embodiment that permits the ladder  202  to be utilized in a direction that faces along or approximately parallel with the plurality of floor beams  126 , thereby improving the versatility of the ladder  202 . 
   While preferred and alternate embodiments of the invention have been illustrated and described, as noted above, many changes can be made without departing from the spirit and scope of the invention. Accordingly, the scope of the invention is not limited by the disclosure of the preferred and alternate embodiments. Instead, the invention should be determined entirely by reference to the claims that follow.

Summary:
Ladder support apparatus and methods are disclosed. In one embodiment, a support assembly adapted for use with a ladder includes at least one elongated member adapted to extend between first and second legs of the ladder when the ladder is positioned in an operating position. First and second coupling assemblies are coupled to the elongated member at spaced-apart positions on the elongated member. The first and second coupling assemblies are adapted to be clampably coupled to the first and second legs of the ladder, respectively. The support assembly advantageously permits the ladder to be operated over non-uniform surfaces without permanent modification of the ladder.