Patent Publication Number: US-2005121261-A1

Title: Adjustable stepladders and related methods

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
      This application claims the benefit of U.S. Provisional Patent Application Ser. No. 60/516,330, filed Oct. 31, 2003, for ADJUSTABLE STEPLADDERS AND RELATED METHODS, the disclosure of which is incorporated by reference in its entirety. 
    
    
     BACKGROUND OF THE INVENTION  
      1. Field of the Invention  
      The present invention generally relates to ladders and, more particularly, to stepladders which are adjustable in height and with regard to other parameters.  
      2. State of the Art  
      Ladders are conventionally used to provide a user thereof with improved access to elevated locations. Ladders come in many sizes and configurations including, for example, straight ladders, extension ladders, stepladders, and combination step and extension ladders. Each type of ladder has it advantages and disadvantages relative to other ladder types. In other words, one ladder may be appropriate for use in performing one task while inappropriate or inadequate for accomplishing another task.  
      Stepladders are used in many circumstances as a self-supporting structure to provide temporary access to an elevated location. Step ladders conventionally include a first set of rails or legs having a plurality of rungs disposed therebetween, and a second set of rails or legs angularly coupled with the first set of rails such that the vertex of a defined angle therebetween is the general location of coupling between the first set of rails and the second set of rails. The spaced-apart feet of the rails conventionally form a rectangular or square base which, when placed on a stable surface, supports the stepladder by distributing the weight thereof to the four corners of the rectangular or square base. A user may then climb the rungs of the ladder to access a desired location.  
      While the first and second set of rails of some step ladders may be fixed in position relative to one another such that they maintain their angled configuration, many stepladders include a set of rails which are hinged such that they may collapse against the opposing set of rails to form a more compact structure. While the stepladder is not conventionally utilized to access elevated locations in such a collapsed state, the stepladder may be more easily transported or stored with the sets of rails being collapsed against each other.  
      As noted above, stepladders are a popular tool because of their versatility in being able to support themselves at virtually any location which provides a stable and relatively flat surface (e.g., the ground or a floor). However, conventional stepladders can be somewhat limited in their use because they are configured to maintain a specified height. Thus, if a given step ladder is too short to reach a desired location or, if it is too tall to fit in a particular area, a separate ladder must be obtained and used.  
      Additionally, while relatively versatile, stepladders are not particularly suited for use on uneven surfaces, such as on stairs or on a sloped portion of the ground. For example, if the stepladder is supported by a surface such that the feet of the first set of rails are at a substantially different elevation than the feet of the second set of rails, the first set of rails and associated rungs may be oriented at an angle which makes it either awkward or dangerous for a user to climb. Similarly, an uneven support surface may result in each rail of a set of rails being placed at a different elevations resulting in similar challenges and dangers. While, to a certain extent, almost all ladders face similar issues, stepladders are particularly hampered by such a problem because there is a greater likelihood of experiencing a substantial difference among the feet of the stepladder&#39;s four rails as compared to, for example, the feet of two rails of a straight ladder or an extension ladder.  
      A similar difficulty with regard to stepladders includes the lack of an ability to easily and safely position a stepladder in tight locations, corners, around shrubberies and the like. For example, it can be difficult to position a stepladder in a narrow area or in a corner because the rectangular base which is defined by the feet of the rails does not readily accommodate such positioning.  
      It is also noted that it is an ongoing goal of ladder manufacturers to improve the quality of existing ladders without a substantial increase in the manufacturing cost or, alternatively, to at least maintain the quality of existing ladders while reducing associated manufacturing costs. More specifically, it is an ongoing goal of ladder manufacturers to design and manufacture ladders which provide adequate structural support to a user thereof, and which are also light and simple to transport and store, while maintaining or reducing manufacturing costs of such ladders.  
      In view of the shortcomings in the art, it would be advantageous to provide an improved stepladder which provides appropriate structural support to a user thereof with a reduction in the weight of the ladder. Additionally, it would be desirable to provide a stepladder which is versatile in its configuration and use such as, for example, with respect to its positioning and placement on a support surface and relative to potential obstructions.  
     BRIEF SUMMARY OF THE INVENTION  
      In accordance with one aspect of the invention a stepladder is provided. The stepladder includes a set of spaced-apart outer rails having a first plurality of rungs coupled therebetween and a set of spaced-apart inner rails having a second plurality of rungs coupled therebetween, wherein the set of inner rails are slidably coupled to the set of outer rails. A single support leg selectively positionable between a first angular position relative to the set of inner rails and at least a second angular position relative to the set of inner rails. A locking mechanism is located and configured to positively lock the single support leg in at least one of the first angular position and the at least a second angular position.  
      In accordance with another aspect of the invention a stepladder is provided. The stepladder includes a set of spaced-apart outer rails having a first plurality of rungs coupled therebetween and a set of spaced-apart inner rails having a second plurality of rungs coupled therebetween, wherein the set of inner rails are slidably coupled to the set of outer rail. A single support leg is hingedly coupled to the set of inner rails. The single support leg includes a first structural member and a second structural member telescopically coupled with the first structural member. Additionally, the first structural support member includes a single unitary member comprising a columnar section and a base section wherein the base section including at least two legs bent relative to the columnar section.  
      In accordance with yet another aspect of the present invention, another stepladder is provided. The stepladder includes a set of spaced-apart outer rails having a first plurality of rungs coupled therebetween and a set of spaced-apart inner rails having a second plurality of rungs coupled therebetween, wherein the set of inner rails are slidably coupled to the set of outer rail. A single support leg is hingedly coupled to the set of inner rails. A base is removably coupled with the single support leg. The base may include, for example, a configuration having multiple feet configured for contacting a supporting surface, a single foot configured for contact with a supporting surface, or a spike member configured to penetrate a supporting surface.  
      In accordance with a further aspect of the present invention a method of forming a ladder is provided. The method includes providing at least one set of spaced apart rails and coupling a plurality of rungs between the at least one set of rails. A single support leg is formed that includes a structural member. The support leg is configured to be selectively positioned between a first angular position relative to the at least one set of spaced apart rails and at least a second angular position relative to the at least one set of spaced apart rails. A locking mechanism is provided to positively and angularly lock the single support leg in at least one of the first angular position and the at least a second angular position.  
      In accordance with yet a further aspect of the present invention, a method of forming a ladder is provided. The method includes providing at least one set of spaced-apart rails and coupling a plurality of rungs therebetween. A single support leg is formed which includes providing a structural member. A first portion of the structural is defined as a columnar member and a second portion of the structural member is defined as a base. The base is formed by substantially symmetrically dividing the second portion of the structural member along a longitudinal axis to define at least two leg members. The leg members are bent so as to extend away from the first portion of the structural member at an angle relative thereto. The single support leg is hingedly coupled to the at least one set of rails.  
      In accordance with a further aspect of the present invention, another step ladder is provided. The stepladder includes a set of spaced-apart outer rails having a first plurality of rungs coupled therebetween and a set of spaced-apart inner rails having a second plurality of rungs coupled therebetween, wherein the set of inner rails are slidably coupled to the set of outer rail. A single support leg is hingedly coupled to the set of inner rails. A locking mechanism is operatively coupled with the set of inner rails and the single support leg, wherein the locking mechanism is configured to lock the single support leg from being angularly displaced relative to the to the set of inner rails. 
    
    
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS  
      The foregoing and other advantages of the invention will become apparent upon reading the following detailed description and upon reference to the drawings in which:  
       FIG. 1  is a perspective view of a step ladder in accordance with an embodiment of the present invention;  
       FIGS. 2A and 2B  show a perspective view of a hinge assembly and an elevational view of a hinge member respectively;  
       FIG. 3  is a side elevational view of the ladder shown in  FIG. 1 ;  
       FIGS. 4A and 4B  show side elevational views of the ladder shown in  FIG. 1  at various stages of adjustment;  
       FIG. 5  shows a support structure for a step ladder in accordance with an embodiment of the present invention;  
       FIGS. 6A and 6B  show cross-sectional views of a support structure as indicated in  FIG. 4  according to an embodiment of the present invention;  
       FIGS. 7A and 7B  show cross-sectional views of a support structure as indicated in  FIG. 4  in accordance with another embodiment of the present invention;  
       FIGS. 8A-8C  show support structures for a stepladder in accordance with other embodiments of the present invention;  
       FIGS. 9A and 9B  are perspective views of stepladders in accordance with further embodiments of the present invention;  
       FIG. 10  is a side elevational view of a step ladder in accordance with another embodiment of the present invention; and  
       FIG. 11  is a partial sectional view of a portion of the ladder depicted in  FIG. 10 . 
    
    
     DETAILED DESCRIPTION OF THE INVENTION  
      Referring to  FIG. 1 , an exemplary stepladder  100  is shown in accordance with an embodiment of the present invention. The stepladder  100  includes a set of outer rails  102  having a plurality of rungs  104  (referred to herein as outer rungs for purposes of clarity) spanning a distance between the outer rails  102  and also being coupled to each of the outer rails  102 . The stepladder  100  also includes a set of inner rails  106  having a plurality of rungs  108  (referred to herein as inner rungs for purposes of clarity and to distinguish them from the outer rungs  104 ) spanning a distance between the inner rails  106  and also being coupled to each of the inner rails  106 . The outer rungs  104  may be coupled with the outer rails  102 , for example, by means of appropriate fasteners, through the use of an adhesive, welding, brazing or through the use of other appropriate techniques known to those of ordinary skill in the art. Similarly, the inner rungs  108  may coupled with the inner rails  106  by any of a variety of appropriate techniques.  
      The outer and inner rails  102  and  106  and rungs  104  and  108  may be formed of various materials including, but not limited to, metals, metal alloys, plastics, composite materials or combinations thereof. For example, in one embodiment, the inner and outer rails  102  and  106  may be formed of aluminum. Similarly, the rungs  104  and  108  may be formed of aluminum or another appropriate material. In another embodiment, the outer and inner rails  102  and  106 , the rungs  104  and  108 , or both, may be configured of a composite material such as, for example, fiberglass. Of course, a mixture of materials may also be used such that the outer and inner rails  102  and  106  may be formed of one material while the rungs  104  and  108  may be formed of another material. U.S. Patent Publication No. US-2003-0188923-A1, entitled LIGHT WEIGHT LADDER SYSTEMS AND METHODS, the disclosure of which is incorporated in its entirety herein, describes various means of forming inner and outer rails  102  and  106  and interior and exterior rungs  104  and  108 , as well as various means of attaching such rungs  104  and  108  to outer and inner rails  102  and  106 , respectively.  
      Each of the inner rails  106  are disposed adjacent an associated one of the outer rails  102  and are slidable relative thereto. For example, in one embodiment, the outer rails  102  may each be configured as a channel (e.g., exhibiting a substantially C-shaped geometrical cross section as taken transverse to a longitudinal axis  110  thereof). The inner rails  106  may be sized and configured to be received within the interior volume defined by the channel of the outer rails  102  such that the inner rails  106  are slidable relative to the outer rails  102  in a direction along the longitudinal axis  110 . In another embodiment a sleeve member  112 , which may be configured as a channel-type member, may be coupled to each of the external rails  102  and configured to slidingly receive an internal rail  106  therein.  
      Exemplary arrangements of inner and outer rail assemblies, including the use of an exemplary sleeve, are disclosed in U.S. Patent Publication No. US-2004-0140156-A1 entitled COMBINATION LADDERS, LADDER COMPONENTS AND METHODS OF MANUFACTURING SAME, the disclosure of which is incorporated by reference in its entirety herein.  
      A locking mechanism  114  may be used to selectively engage and lock the external rails  102  and internal rails  106  in a desired position relative to one another. The locking mechanism  114  may include, for example, a curved or bent locking pin  116  having one end slidably disposed within an outer rung  104  or otherwise coupled to an outer rail  102 . Another end of the locking pin  116  may be slidably disposed within an opening or aperture  118  formed in an outer rail  102  as well as a corresponding opening or aperture (not shown) formed within the inner rail  106 . The locking pin  116  may be biased, such as by a spring (not shown), such that it normally remains engaged with both the aperture  118  of the outer rails  102  and the aperture of the inner rail  106 . Upon application of an appropriate force, the locking pin  116  may be displaced relative to the outer rung  104 , outer rail  102  and inner rail  106  such that it is no longer engaged with the inner rail  106 . Upon disengagement of the locking pin  116  from the inner rail  106 , the inner rail  106  may be free to slide relative to the outer rail  102 . Multiple apertures may be formed in the inner rail  106  in a longitudinally spaced arrangement such that the locking pin  116  may selectively engage any of such apertures and lock the inner rail  106  at a desired position relative to the outer rail  102 .  
      An end of each of the inner rails  106  may be coupled to a platform  120 . In one embodiment, the platform  120  may be configured as a tray to hold tools, supplies or other materials thereon such that a user of the stepladder  100  may keep various resources within reach while working at an elevated location on the stepladder  100 . A single support leg  122  may also be coupled to the platform  120  and extend therefrom. The single support leg  122 , and the various components it may be comprised of, may be formed of various materials including, for example, metals, metal alloys, plastics, composites or combinations thereof.  
      The single support leg  122  may include a structural member  124  extending from the platform  120  with a base  126  at an end thereof. The base  126  may include a support structure having one or more feet  128  sized, located and configured to support the stepladder  100  when in use. For example, the feet  128  may include two feet spaced apart a desired distance such that, when in use, the stepladder  100  is supported by a traditional rectangular base (i.e., including the feet  128  and the outer rails  102 ).  
      In one exemplary embodiment, the support leg  122  and the inner rails  106  may be rotatable relative to one another about a hinge mechanism  130 . The hinge mechanism  130  may include, for example, a locking hinge configured to lock the support leg  122  and inner rails  106  (and, thus the external rails  102 ) at one or more desired angular positions relative to one another. Referring briefly to  FIGS. 2A and 2B , one exemplary embodiment of a hinge mechanism  130  may include a first hinge member  132  coupled with an inner rail  106  and a second hinge member  134  coupled to the support leg  122 . The two hinge members  132  and  134  may be coupled by way of a pivot pin  136  which extends through corresponding apertures  138 A and  138 B formed in the hinge members  132  and  134  respectively.  
      The hinge mechanism  130  may further include a locking arrangement. The locking arrangement may include one or more locking pins  140  which extend through locking apertures  142 A and  142 B defined in the hinge members  132  and  134 , respectively. For example, the locking pins  140  may be a pair of diametrically opposed pins configured to extend through a first set of diametrically opposed locking apertures in the first hinge member  132  and another set of diametrically opposed locking apertures in the second hinge member  134 . It is noted that the hinge might include fewer or more locking pins  140  than shown and described with respect to  FIGS. 2A and 2B , or it may include a different type of locking mechanism.  
      In operation, the pivot pin  136  and associated locking pins  140  of the hinge mechanism  130  may be axially displaced, as indicated by directional arrow  144 , such that the locking pins  140  disengage at least the locking apertures  142 B of the second hinge member  134  and enable relative rotation of the two hinge members  132  and  134 . Upon alignment of a set of locking apertures  142 A of the first hinge member  132  along with a set of locking apertures  142 B of the second hinge member  134 , the locking pins may be axially displaced so as to reengage such locking apertures  142 A and  142 B to lock the hinge members  132  and  134  at a defined relative angular position and prevent further relative rotation thereof. An exemplary hinge mechanism is shown and described in U.S. Pat. No. 4,697,305, issued to Boothe, the disclosure of which is incorporated by reference in its entirety herein. The use of a locking hinge or similar mechanism enables the support leg  122  to be locked and maintained in a desired angular position relative to the inner rails  106  (and thus the outer rails  102  as well) without use of another structural support member such as, for example, a spreader bar.  
      Referring now to  FIG. 3 , an elevational view of the stepladder  100  is shown, illustrating the adjustability of outer rails  102  relative to the inner rails  106  as well as the adjustability of the support leg  122 . As discussed above, the outer rails  102  and inner rails  106  may slide relative to one another along a longitudinal axis  110  as indicated by dashed lines. The support leg  122  may be similarly adjustable. For example, the structural member  124  may include two structural members  124 A and  124 B which are telescopically coupled to one another. A locking mechanism  150  having an engagement member  152  may be coupled to the first structural member  124 A and configured to engage, for example, apertures (not shown in  FIG. 3 ) formed in the second structural member  124 B. The telescoping arrangement of the two structural members  124 A and  124 B, thus, enables the base  126  to be placed in various positions as indicated by dashed lines.  
      Additionally, referring to  FIGS. 4A and 4B , the outer and inner rails  102  and  106  may be placed at various angular positions relative to the support leg  122 . For example, as indicated by dashed lines in  FIG. 4A , two or more usable positions may be defined by engaging the hinge mechanism  130  with the appropriate locking apertures  142 A and  142 B ( FIGS. 2A and 2B ). The angular adjustability of the outer and inner rails  102  and  106  relative to the support leg  122  may enable a user of the stepladder  100  to define, within certain limits, the configuration of the ladder&#39;s support base, as may be desired. Additionally, as shown in  FIG. 4B , the support leg  122  may be collapsed against the outer and inner rails  102  and  106  such that the stepladder  100  may be more easily stored and transported.  
      Referring now to  FIG. 5 , an exemplary support leg  122  is shown in accordance with one embodiment of the present invention. As previously discussed the support leg  122  may include two structural members  124 A and  124 B which are configured in a telescoping arrangement. Also, a locking mechanism  150  may be coupled to one structural member  124 A and include an engagement member  152  configured to selectively engage one of a plurality of apertures  160  formed in the second structural member  124 B. Additionally, in one particular embodiment, the first structural member  124 A and the base  126 ′ may be formed as an integral unitary member. Such a structure provides various advantages over multicomponent structures including, for example, a reduction of weight and ease of manufacturing without compromising the structural integrity of the support leg  122  and the stepladder  100 .  
      For example, the first structural member  124 A may be defined to include a columnar section  161  and a section including the base  126 ′. The base  126 ′ may be formed by substantially symmetrically dividing the first structural member  124 A along a longitudinal axis  163  thereof and then bending each longitudinally divided member to form a leg  164 A and  164 B. The columnar section  161  and the base  126 ′ are thus formed as an integral unit and may be formed, for example, from a single length of tubing or other material.  
      Referring to  FIGS. 6A and 6B  in conjunction with  FIG. 5 , in accordance with one embodiment of the present invention, the columnar section  161  may exhibit a cross-sectional geometry of a substantially square or rectangular tube  162 . As noted above, the base  126 ′ may include two legs  164 A and  164 B which are substantially symmetrically divided and bent relative to the columnar section  161  of the structural member  124 A. Thus, the legs  164 A and  164 B may exhibit a cross-sectional geometry of a structural channel or a C-shape  166  as indicated in  FIG. 6B . Of course the components may exhibit other appropriate geometrical cross sections. For example, as shown in  FIGS. 7A and 7B , the columnar section  161  may exhibit a substantially circular cross section, and the legs  164 A and  164 B may exhibit a cross section which is substantially half of a circle. It is noted that the support leg  122  may be formed of various materials including those set forth above with regard to the support leg. In one exemplary embodiment the first structural member  124 A may be formed of aluminum tubing.  
      Referring now to  FIGS. 8A through 8C , a support leg  122 ′ in accordance with another embodiment of the present invention is shown. The support leg  122 ′ may include a coupling assembly  170  at an end of the first structural member  124 A. The coupling assembly  170  may be configured to selectively couple the structural member  124 A to a removable base  180 . The removable base  180  may include a pair of feet  182  coupled to a cross member  184 . A coupling stem  186  may be extend from the cross member  184  and be configured for removable coupling with the structural member  124 A.  
      The coupling assembly  170  may include, for example, one or more locking pins  188  configured to engage one or more apertures defined in the structural member  124 A and corresponding apertures in the coupling stem  186  (apertures not shown). Other coupling devices may also be used as will be appreciated by those of ordinary skill in the art.  
      The cross member  184  of the removable base may also be adjustable such that the feet  182  coupled therewith may be laterally adjusted relative to the coupling stem  186  as indicated by dashed lines. Thus, the feet may be placed at a desired width to form a supporting base for the stepladder depending on particular circumstances and conditions of use.  
      The removable base  180  of  FIG. 8A  may be removed and replaced with a differently configured base. For example, referring to  FIG. 8B  a base  180 ′ may include a single foot  190 , thus, effectively turning the stepladder  100  into a tripod or orchard ladder. Referring to  FIG. 8C , another base  180 ″ may include a spiked foot  192  configured to be staked into the ground or other supporting surface. Thus, the modular nature of the removable bases  180 ,  180 ′,  180 ″ provides considerable flexibility in the use of the stepladder  100  in terms of locations and situations in which the ladder may be effectively used.  
      Turning now to  FIGS. 9A and 9B , additional embodiments of the stepladder  100  are shown wherein locking mechanisms are provided to lock the outer and inner sets of rails  102  and  106  relative to the single support leg  122  at a desired angular position. It is noted that the previously described embodiments associated with  FIGS. 1-5  have been discussed in terms of an exemplary hinge and locking mechanism which positively locks the outer and inner rails  102  and  106  relative to the single support leg  122  without the need of an additional locking mechanism or structural support member.  FIGS. 9A and 9B  show other exemplary embodiments of a locking feature which might be used in conjunction with, or in lieu of, other locking mechanism disclosed herein.  
      For example,  FIG. 9A  shows a first locking spreader mechanism  200  which includes a first spreader bar  202  coupled with an outer rail  102  and a second spreader  204  coupled to the opposing outer rail  102 . The spreader bars  202  and  204  may, for example, be hingedly coupled to the outer rails such that they may be displaced from a first position to a second position (the second position be indicated by dashed lines). In the first position, the spreader bars  202  and  204  may form a triangular structural arrangement by being coupled to the single support leg  122 . Upon being coupled to the single support leg  122 , the locking spreader arrangement  200  acts to prevent the angular displacement of the single support leg  122  about the hinge mechanism  130  in either direction relative to the outer and inner rails  102  and  106 . Such a configuration is an advantage over, for example, so-called orchard ladders which do not include spreader bars or other locking arrangements.  
      It is noted that the locking spreader mechanism  200  may include additional features if so desired. For example, the spreader bars  202  and  204  may include individual telescoping sections (e.g.,  202 A and  202 B) such that they may extend and accommodate different spreader distances depending on whether the ladder has been adjusted for height (e.g., see  FIG. 3  and attendant discussion thereof). Additionally, ball joints or universal joints may be used in coupling the spread bars  202  and  204  to the outer rails  102 , to the single support leg  122  or both. Also, in another configuration, the spreader bars  202  and  204  may be coupled with the inner rails  106  rather than the outer rails  102 .  
      Referring to  FIG. 9B , another exemplary configuration of a locking spreader mechanism  200 ′ is shown. The locking spreader mechanism  200 ′ may include a structural cross member  210  coupled to, for example, the outer rails  102 . A spreader bar  212  may be coupled between the single support leg  122  and the structural cross member  210  in a “T” configuration. In one particular embodiment, one or more structural members  214  may be selectively engageable with the spreader bar  212  at multiple positions so as to define a span or distance between the outer and inners rails  102  and  106  and the single support leg  122 . For example, one or more apertures (not shown) may be formed in the spreader bar  212  for alignment with one or more apertures  216  formed in the structural members  214 . A pin  218  may be inserted through aligned apertures to lock the spreader bar  212  in a desired position relative to the structural members  214 .  
      In another embodiment, the structural members  216  may be hingedly coupled with the structural cross members  210 , the spreader bar  212  may be hingedly coupled to the support leg  122  with the pin  218  acting as a pivot point such that the locking spreader mechanism  200 ′ is collapsible, as shown generally in dashed lines, upon rotation of the single support leg  122  about the hinge mechanism  130  relative to the outer and inner rails  102  and  106 . Other features, such as described with respect to  FIG. 9A , may also be incorporated with the locking spreader mechanism  200 ′.  
      Referring now to  FIGS. 10 and 11 , a ladder  300  is shown in accordance with another embodiment of the present invention. The ladder  300  includes outer and inner rails  102  and  106  such as described hereinabove with respect to other embodiments. The ladder also includes a single support leg  122  such as described hereinabove. In one embodiment, a coupling structure  302  may be integrally formed with, or otherwise coupled with the platform  120 . The coupling structure  302  is sized and configured to matingly receive an end of the support leg  122  and, more particularly, an end of the second structural member  124 B. The coupling structure  302  may include a locking pin  304  or other structure or mechanism configured to maintain the support leg  122  in a coupled relationship therewith. As such, the coupling structure  302  acts like a locking mechanism to positively lock the support leg  122  one or more angular positions relative to the outer and inner rails  102  and  106 .  
      In one exemplary embodiment, the coupling structure  302  may be configured to enable selective positioning of the support leg  122  relative to the outer and inner rails  102  and  106 . For example, as shown in  FIG. 11 , the coupling structure may be configured to include a first coupling sleeve  306 A and a second coupling sleeve  306 B. Thus, as indicated in  FIG. 10  by directional arrow  308 , the support leg  122  may be removed from the first coupling sleeve  306 A of the coupling structure  302  and then inserted in the second sleeve  306 B of the coupling structure  302  (as shown in dashed lines). The sleeves  306 A and  306 A may be configured to exhibit a similar cross-sectional geometry as that of the support leg  122 . Thus, for example, the sleeves  306 A and  306 B may exhibit a generally circular cross-sectional geometry so as to cooperatively and matingly receive a support leg  122  also exhibiting a substantially circular cross-sectional geometry (or at least the end of the support leg which is inserted into or otherwise engages the sleeves  306 A and  306 B). Of course, the sleeves  306 A and  306 B and support leg  122  may exhibit other cross-sectional geometries including, for example, oval, rectangular, square, or other polygonal geometries.  
      The locking pin  304  or other mechanism may be operated to maintain the support leg  122  in either coupling sleeve  306 A or  306 B. Such a structure again enables the support leg to be selectively maintained between multiple positions with or without other structural support mechanisms such as, for example, spreader bars. It will be appreciated by those of skill in the art that the coupling structure  302  may be configured to maintain the support leg  122  in multiple positions other than those depicted in  FIGS. 10 and 11 . Thus, for example, the coupling structure may be configured to selectively maintain the support leg  122  in three or in four positions instead of two. Additionally, instead of having a coupling structure  302  with multiple sleeves  306 A and  306 A, the coupling structure  302  may include a structural plate positioned on each lateral side of the support leg  122  with multiple locking pins  304  extending through the plates and the support leg  122 .  
      While the invention may be susceptible to various modifications and alternative forms, specific embodiments have been shown by way of example in the drawings and have been described in detail herein. However, it should be understood that the invention is not intended to be limited to the particular forms disclosed. Rather, the invention includes all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the following appended claims.