Patent Publication Number: US-9422767-B2

Title: Ladders and related methods

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims the benefit of U.S. Provisional Patent Application No. 61/764,439 entitled LADDERS AND RELATED METHODS, filed on Feb. 13, 2013, the disclosure of which is incorporated by reference herein in its entirety. 
    
    
     TECHNICAL FIELD 
     The present invention relates generally to ladders, including stepladders, and methods of making and using such ladders. 
     BACKGROUND 
     Ladders are conventionally utilized to provide a user thereof with improved access to elevated locations that might otherwise be inaccessible. Ladders come in many shapes and sizes, such as straight ladders, straight extension ladders, stepladders, and combination step and extension ladders. So-called combination ladders may incorporate, in a single ladder, many of the benefits of multiple ladder designs. 
     Ladders such as stepladders and step stools are highly utilized by various tradesman as well as homeowners. Such ladders are “self-supporting” in that they do not require the upper end of the ladder to be positioned against a supporting structure, such as against a wall or the edge of a roof. Rather, stepladders (including step stools) include multiple feet (typically either three or four) that are spaced from one another to provide a stable base or foundational structure to support the ladder and a user when placed on, for example, a floor or the ground. This enables a user of the ladder to gain access to elevated areas even though the accessed area may be, for example, in the middle of a room, away from walls or other potential supporting structures that are conventionally required when using a straight ladder or an extension ladder. 
     For these reasons and others, ladders configured as stepladders or step stools are popular configurations that comprise a large segment of the ladder market. However, there are always areas of potential improvement. For example, the rungs on conventional configurations of stepladders typically exhibit relatively short depth, meaning that there is a relatively small amount of surface area for a user to place their foot on while standing on the rungs of a step ladder. Some ladders have attempted to increase the depth of the rungs in an effort to provide a more comfortable or stable support surface for a user of the ladder. However, often the increase in depth of a rung translates to more bulk in the stored ladder. For example, where the rungs are static and rigidly fixed to the side rails, the rail assembly becomes larger in its overall depth. It follows that that the stored ladder (i.e., when folded or collapsed for storage) exhibits a greater depth as well. 
     Some ladders, primarily step stools, have utilized rungs that fold or pivot when the ladder is collapsed for storage. However, these ladders typically include struts or braces coupled to the rungs and to another structure on the ladder such as a platform, a rail, or another rung. The struts or braces typically provide a couple of functions with respect to the rungs. First, the struts or braces are coupled to a cantilevered end of the rung to provide structural support to the rung so that it can bear an anticipated load. Second, the struts or braces act as linkages to help “lift” the rung into a folded position when the ladder is being collapsed for storage. Examples of such configurations are shown in U.S. Pat. No. 3,303,906 to Bouwmeester et al. and U.S. Pat. No. 5,722,507 to Kain. 
     It is a continued desire of the ladder industry to improve the performance of ladders, including stepladders and step stools. For example, it is a continued desire within the ladder industry to provide products that provide a safer working experience for the user, provide added comfort to the user, and enhance the user&#39;s experience in a variety of ways. 
     BRIEF SUMMARY OF THE INVENTION 
     The present invention relates to various configurations of ladders and to methods relating to the use and manufacture of stepladders. 
     In accordance with one embodiment, a ladder is provided that comprises a first assembly having a pair of spaced apart rails and at least one rung extending therebetween and a second assembly having a pair of spaced apart rails, second assembly being hingedly coupled with the first assembly. The at least one rung includes a first component extending between and fixedly coupled to the pair of rails of the first assembly and a second component extending between and rotatably coupled to the pair of rails of the first assembly, wherein when in a first position, a surface of the second component abuts a surface of the first component such that rotation in a first direction is prohibited. 
     In one embodiment the second assembly of the ladder includes at least one bracing member extending between and coupled to the pair of rails of the second assembly, wherein when the second assembly is rotated adjacent the first assembly, the at least one bracing member contacts an undersurface of the second component of the at least one rung. The at least one bracing member may be configured to push against the undersurface of the second component and rotate the second component in a second direction opposite the first direction. In one embodiment, a flexible material component positioned between the first component of the rung and the second component of the rung. 
     The ladder may further comprise a platform rotatably coupled with the first assembly and configured to selectively engage the second assembly. In one embodiment a locking mechanism may be configured to selectively lock the platform with a component of the second assembly. 
     The rails of the first assembly may extend beyond a hinge point between the first and second assemblies. A handle may extend between and coupling upper ends of the pair of rails of the first assembly and the handle may further be configured for selective coupling with at least one accessory. 
     In accordance with another embodiment of the present invention, a method of transitioning a ladder from a deployed state to a stowed state is provided. The method includes rotating a first assembly relative to a second assembly in a first direction until an undersurface of a first rung associated with the first assembly is engaged by a component of the second assembly; and continuing to rotate the first assembly relative to the second assembly in the first direction such that the component of the second assembly effects rotation of at least a portion of the first rung relative to a pair of rails of the first assembly. 
     The method may further include rotating the at least a portion of the first rung to lie within an envelope defined by the pair of rails of the first assembly and, further, may include maintaining the first rung in a rotated position with the component of the second assembly while the ladder is in the stowed state. 
     In one embodiment, the method includes engaging an undersurface of a second rung of the first assembly with a second component of the second assembly and continuing to rotate the first assembly relative to the second assembly in the first direction such that the second component of the second assembly effects rotation of at least a portion of the second rung relative to a pair of rails of the first assembly. The at least a portion of the first rung and the at least a portion of the second rung may be rotated in a sequential order upon rotation of the first assembly relative to the second assembly. 
     In accordance with another aspect of the invention, a ladder is provided comprising a first assembly having a pair of spaced apart rails and at least one rung having a first component extending between and pivotally coupled to the pair of rails, the first component including an abutment surface, a platform surface, and a ramped surface. The ladder also includes a second assembly having a pair of spaced apart rails, second assembly being hingedly coupled with the first assembly. The second assembly includes at least one component located and configured to engage the ramped surface of the first component when the second assembly is displaced relative to the first assembly from a deployed state to a collapsed state. 
     In one embodiment, the at least one rung component is configured to rotate the at least one rung relative the rails of the first assembly when the second assembly is displaced relative to the first assembly from a deployed state to a collapsed state. 
     In one embodiment, the first component includes a substantially triangular cross-sectional profile. 
     In accordance with one embodiment, the at least one rung includes a second component extending between and fixedly coupled with the rails of the first assembly. The second component may include a platform surface and an abutment surface. 
     The first component may be configured to rotate from a first position to a second position relative to the second component. In one embodiment, when the first component is in the first position, the platform surface of the first component and the platform surface of the second component lie in a substantially common plane. When the first component is in the second position, the platform surface of the first component is positioned at an angle relative to the platform surface of the second component. Additionally, in one embodiment, when the first component is in the first position, the abutment surface of the first component is in abutting contact with the abutting surface of the second component. 
     In one embodiment, the at least one component includes a brace extending between and fixedly coupled to the rails of the second assembly. 
     Various features and components of any of the embodiments described herein may be combined with features or components of other embodiments without limitation. 
    
    
     
       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 stepladder according to an embodiment of the present invention; 
         FIG. 2  is a perspective view of a portion of the stepladder shown in  FIG. 1  while in a fully closed state; 
         FIG. 3  is another perspective view of a portion of the stepladder shown in  FIG. 1  while in a fully closed state; 
         FIG. 4  is a perspective view of a portion of the stepladder shown in  FIG. 1 ; 
         FIGS. 5A-5C  show partial cross-sectional views of a portion of the stepladder shown in  FIG. 1  in various states of closing or collapsing; 
         FIG. 6  is another perspective view of a portion of the stepladder shown in  FIG. 1  while in a fully closed state; 
         FIG. 7  shows a side perspective view of a portion of the stepladder of  FIG. 1  with an accessory coupled therewith; and 
         FIG. 8  shows a rear perspective view of a portion of the stepladder of  FIG. 1  with an accessory coupled therewith; 
     
    
    
     It is noted that numerous photographs are also included in the detailed description and reference should be made to these photographs in association with  FIG. 1 . 
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring generally to  FIG. 1 , a ladder  100  is shown in accordance with an embodiment of the present invention. The ladder  100  shown in  FIG. 1  is configured generally as a platform stepladder and includes a first assembly  102  having a pair of spaced apart rails  104  and a plurality of rungs  106  extending between, and coupled to, the rails  104 . The rungs  106  are substantially evenly spaced, parallel to one another, and are configured to be substantially level when the ladder  100  is in an orientation for intended use, so that they may be used as “steps” to support a user as they ascend the ladder  100  and as will be appreciated by those of ordinary skill in the art. 
     The ladder  100  also includes a second assembly  108  having a pair of spaced apart rails  110 . The second assembly  108  includes bracing members  111  or other structural components that extend between the rails  110  to provide a desired level of structural support and strength to the spaced apart rails  110 . In some embodiments, the bracing members  111  of the second assembly  108  may be configured as rungs to support a user. The second assembly  108 , thus, may be used to help support the ladder  100  when in an intended operational state, such as depicted generally in  FIG. 1 . 
     In the embodiment shown in  FIG. 1 , hinged or pivoting connections  112  couple the first rail assembly  102  and the second rail assembly  108  together such that the two assemblies  102  and  108  may be folded or collapsed into a stored or stowed state. When in a stowed state, the first rail assembly  102  and the second rail assembly  108  are positioned adjacent each other in a relatively thin profile, such as shown in  FIGS. 2 and 3 . 
     It is noted that in the embodiment shown in  FIG. 1 , the rails  104  of the first assembly  102  extend substantially beyond the hinged connections  112  and are coupled with a handle  114 . In such an embodiment, the extended rails  104  and the handle  114  may be used as a handrail to help support or balance a user when they are standing on the ladder  100 . It is noted, however, the present invention is applicable to, and contemplated as being incorporated with, other types of ladders including, for example, stepladders having a conventional top cap that is coupled to both of the first and second assemblies. 
     In the embodiment shown in  FIG. 1 , a platform  116  is positioned above the rungs  106  and extends from the rails  104  of the first assembly  102  to the rails  110  of the second assembly  108 . The platform  116  may be configured to support all, or at least a substantial portion, of a user&#39;s feet, thereby providing a comfortable and safe working surface to the user. In the presently described embodiment, the platform  116  is hingedly coupled to the rails  106  of the first assembly  102  and engages a bracing member  111  associated with the second assembly  108 . In one embodiment, the platform  116  may simply rest on the associated bracing member  111 . In another embodiment, a locking member may be used to selectively couple platform  116  and the associated bracing member  111 . 
     The first and second assemblies  102  and  108  may be formed of a variety of materials and using a variety of manufacturing techniques. For example, in one embodiment, the rails  104  and  110  may be formed of a composite material, such as fiberglass, while the rungs and other structural components may be formed of aluminum or an aluminum alloy. In another embodiment, substantially all of the components of the assemblies may be formed of aluminum or an aluminum alloy. In other embodiments, the assemblies  102  and  108  (and their various components) may be formed of other materials including other composites, plastics, polymers, various metals and metal alloys. 
     The rungs  106  of the first assembly  102  are formed of multiple components. In the embodiment shown, the rungs  106  each include a first component  106 A that extends between, and is rigidly coupled to, the side rails  104 . The first component  106 A is located near the outward facing portion of the assembly  102  (i.e., the side which faces a user as they ascend and descend the rungs  106 ). In one particular embodiment, the first component  106 A includes a front surface  120  that is substantially flush with the front surface  122  of the rails  104  such that they define a common plane. The rungs  106  further include a second component  106 B that extend between the rails  104  but which are positionable relative to the rails  104 . For example, in one embodiment, the second component  106 B may be hingedly coupled to the rails  104 . In another embodiment, the second component  106 B may be hingedly coupled with the first component. In either case, the second component  106 B may be rotated relative to both the first component  106 A and the rails  104 . For example,  FIG. 4  shows a portion of the ladder  100  where the second component  106 B of one rung (i.e., the uppermost rung shown in  FIG. 4 ) is partially rotated upwards while the second component  106 B of an adjacent rung  106  (i.e., of the lowermost rung shown in  FIG. 4 ) remains in a position such that its upper surface lies substantially in a common plane as the upper surface of its associated first component  106 A. 
     Thus, when the ladder  100  is in folded or collapsed into a stored state, the second components  106 B of the rungs may be folded up within an envelope that may be defined, in one embodiment, by the rails  104  of the first assembly  102 . For example, the envelope may be bound on one side by a plane defined by the front surface  122  of the rails  104 , and bound on another side by a substantially parallel plane defined by the back surface  124  of the rails  104 . The rotated or folded-up position of the second component  106 B may be seen, for example, in  FIGS. 2 and 3  where it is positioned within the defined envelope making the ladder  100  compact and easy to store and transport. In another embodiment, the envelope may be defined, for example, between the front surface  122  of the rails  104  of the first assembly  102 , and an opposing surface  126  of the rails  110  of the second assembly  108 . 
     It is noted that there are no connecting struts, bracing members or other structural components coupled to the second components  106 B of the rungs  106 . For example, no structural components are coupled between the cantilevered ends of the second components (i.e., the ends closest to the second assembly  108  as shown in  FIG. 1 ) and other members of the ladder  100  (e.g., the rails  104  or  110 , other rungs  106 ) to provide additional support to the rungs  106  when placed in a cantilevered state to support the weight of a user. Additionally, there are no components coupled between adjacent rungs  106  to assist in folding and unfolding the second components  106 B of the rungs. Rather, the second components  106 B of the rungs  106 , when in a deployed, useable position (i.e., as shown in  FIG. 1 ) may include a surface that abuts against a back surface of the first component  106 A, preventing it from rotating further and providing support to the second component  106 B when in the cantilevered or deployed position. 
     For example, as may be seen best in the cross-sectional views of  FIG. 5A , the second component  106 B may exhibit substantially triangular cross-sectional geometry with one side (or at least a portion of one side), such as the “short” side of the triangle shown in  FIG. 5A , including an abutting surface configured to abut a side surface (or abutting surface) of the first component  106 A. As also seen in  FIG. 5A , and as noted above, when in the cantilevered position, the upper surface  140  (which may also be referred to as a platform surface or a working surface) of second component  106 B is substantially planar with respect to the upper surface  142  (e.g., a platform surface or working surface) of the first component  106 A so that they cooperatively define a common working surface for the rung  106 . With the second component  106 B extending out beyond the plane defined by the back surfaces of the rails  104 , the rungs  106  provide an extended or enlarged working surface for a user to stand on in comparison to many conventional ladders. 
     The underside  144  of the second component  106 B provides a ramped surface for engagement with a component of the second assembly  108  during the folding or collapsing of the ladder  100 . In one embodiment, the underside of the second component may include a curved surface (e.g., generally convex in cross-sectional profile as seen in  FIG. 5A ). In another embodiment, the underside  144  of the second component may a generally linear or planar surface. 
     Still referring to  FIG. 5A , the first and second assemblies  102  and  108  are configured such that when they are displaced near one another (i.e., during folding or collapsing of the ladder  100 ), a bracing member  111  or other component of the second assembly  108  engages the underside  144  of the second component  106 B of an associated rung  106 . As the first and second assemblies  102  and  108  continue to come closer to each other, the bracing  111  slides beneath the second component  106 B, causing the second component  106 B to rotate upwards about its hinged or pivoting connection  146  such as seen in  FIG. 5B . Continued displacement of the second assembly  108  towards the first assembly  102  causes further rotation of the second component  106 B until the ladder is completely folded or collapsed and the second component  106 B is rotated upwards within a defined envelope, as discussed above, and is maintained in that position by the bracing  111  or other component of the second assembly  108  as shown in  FIG. 5C . 
     When opening the ladder  100 , or transitioning from the stowed/stored state to a deployed state, the second components  106 B simply “fall” or rotate back into their cantilevered position by reason of gravity. Again, no linkages, struts or other such components are used to effect rotation of the second components  106 B of the rungs  106 , or to provide structural support to them when in a cantilevered position. Thus, deployment of the ladder  100 , including deployment of the second component  106 B, occurs in the reverse order as that shown in  FIGS. 5A-5C . When the bracing  111  is no longer in contact with the second component  106 B, the second component  106 B may be prevented from rotating further by its relationship with the first component  106 A as discussed above. In other embodiments, additional stop or abutment members may, for example, be associated with the rails  104  and configured to maintain the second component  106 B in a desired deployed position. 
     Referring briefly to  FIG. 6 , a portion of a ladder  100  is shown in a transitional state (i.e., between a fully deployed state and a fully folded or stored state). As seen in  FIG. 6 , one of the second components  106 B (i.e., the upper rung  106 ) is engaged by a bracing member  111  and in transition from a deployed state to a stowed state. At the same time, another second component  106 B (i.e., the lower rung  106 ) is not yet engaged by an associated bracing member  111 , but will be upon further collapsing of the two assemblies  102  and  108 . Thus, the folding of the second components may occur somewhat sequentially, with each second component  106 B folding or rotating independent of any other second component  106 B. 
     In certain embodiments, the rungs  106  of the ladder may include additional components. For example, in one embodiment, a flexible material (e.g., rubber or some other polymer material) may extend between the first component  106 A and the second component  106 B along the upper surface. Such a layer may help to conceal a potential pinch point (e.g., when the second component  106 B is rotating relative to the first component  106 A) and may help to keep dirt and debris from entering the space between the two components  106 A and  106 B. The flexible component may also act as a gripping surface to prevent slipping of a user when their foot is placed on the rung  106 . In some embodiments, the flexible material may extend to cover part or substantially all of the upper surface of the first component  106 A, the second component  106 B or both. 
     The ladder  100  may further include other features and components. For example, as shown in  FIGS. 7 and 8 , the handle  116  of the ladder  100  may be configured for selective attachment with one or more accessories  150 . The accessories may be configured, for example, as a paint bucket shown, a tray, a tool holder or other various structures. In one embodiment, a pair of brackets  152  may be formed in, or otherwise coupled with, the handle  116  and configured to receive connection portions  154  of the accessory  150 . The connecting portions  154  may include protrusions or clips sized and configured to extend through and engage the brackets  152  to hold the accessory in place relative to the handle  116 . Thus, in one embodiment, the accessory  150  may be attached by pushing the connection portions  154  through the brackets  152  until they are snugly in place, or until a positive lock holds them in place. The accessory  150  may be removed and replaced by a different accessory when desired by a user of the ladder  100 . It is noted that examples of various accessories and attachment systems are described in U.S. patent application Ser. No. 12/774,637 (Publication No. 2010/0282540) filed on May 5, 2010, entitled LADDERS, LADDER COMPONENTS, LADDER ACCESSORIES, LADDER SYSTEMS AND RELATED METHODS and U.S. patent application Ser. No. 13/402,013, filed on Feb. 22, 2012, entitled LADDER, LADDER COMPONENTS AND RELATED METHODS, the disclosures of which are incorporated by reference herein in their entireties. 
     Other features and components may include, for example, feet  130  on the ends of the rails  104  and  110  which may be configured as clip on components such as described in the above referenced U.S. patent application Ser. No. 13/402,013. 
     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. Of course, one or features of one described embodiment may be utilized in conjunction with one or more features of another described embodiment. 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.