Abstract:
A ladder base device having a base platform and a pair of socket-like receptacles for receiving the ends of a pair of ladder rails. The receptacles are pivotally attached to the platform and the platform is reversible with different surfaces for frictional engagement with different types of ground or floor surfaces on each side.

Description:
This application is a continuation-in-part that claims the benefit of non-provisional application Ser. No. 14/171,363. Furthermore, application Ser. No. 14/171,363 is hereby incorporated by reference. 
    
    
     BACKGROUND 
     The present invention generally relates to ladder accessories, and it is specifically directed to devices for easily mounting to the lower ends of the rails of a rigid ladder in order to prevent the ladder from sliding along any of a variety of types of ground surfaces and making the ladder unstable while it is leaning against a vertically extending support structure and its rungs are bearing the weight of a user. 
     There are a variety of devices, in the prior art, designed to better anchor a rigid ladder to the ground and prevent the lower end of a ladder from sliding along the ground while in use. These prior art non-slip devices generally fall within two categories that are distinguishable from one another by how the devices are to be attached to ladder rails. In one such category are non-slip devices that are to be securely attached to ladder rails by use of a mechanical fastener pin, screw, nut &amp; bolt, etc.), and in the other category are non-slip devices to which ladders can be safely mounted by virtue of gravity and/or friction fitting. 
     One example falling within the first category is found in U.S. Patent Application Publication No. 2012/0199416 to Hopkins et al. Hopkins discloses a ladder stabilizing apparatus that principally features a base plate having an attached horizontal shaft that is elevated from the base plate. Ladder leg retainers are pivotally attached to that shaft by rotary bearing, and these leg retainers are each described as being an adjustable channel that forms a three-sided clamp that is locked into place around a ladder rail by a releasable fastener such as a bolt and wingnut assembly. The pivotability of the Hopkins leg retainers accommodates a range of ladder lean angles that a user might prefer, but the configuration of the apparatus ostensibly prevents the base plate from rotating more than 90 degrees when the apparatus is attached to a ladder. Thus, the base plate has definitive top and bottom surfaces, where only the bottom surface engages the ground. Notwithstanding the suggestion that an automobile be placed upon a portion of the base plate in order to anchor it to the ground, it is suggested that the bottom surface could be a friction-enhancing or non-slip surface and is further suggested that the base plate may feature apertures through which stakes or nails could be inserted in order to fasten the apparatus directly to the ground or other support surface. 
     One consequence of the aforementioned inability to completely invert the Hopkins base plate is that only one of its faces can function as a ground-touching surface. So, unless removable surfaces can be attached to that bottom face, it will always have the same topography and friction characteristics—which, invariably, will not be optimum for every conceivable ground or floor surface that a ladder may be used upon. Furthermore, even if extraneous surfaces can be removably attached to the bottom face of the base plate, the act of installing and substituting them can be tedious. It may be similarly tedious to have to insert spikes through holes within the base plate, for example, to provide the type of slide prevention that the base plate, alone, might experience if its bottom face was a spiked surface. Of course, these deficiencies exist for any base surface that is one-sided, in terms of its ground engagement function, because one particular surface topography and material will not be effective in preventing slippage along every ground and floor surface. Therefore, a ladder attachment that features multiple ground-engaging surfaces that have distinct topographies and are easily reversible may be more desirable. 
     To wit, as another example of a slip-inhibiting apparatus that is attached to the base of a ladder using mechanical fastening means, U.S. Pat. No. 2,623,679 to Agombar discloses a non-slip ladder base that features a pair of non-slip members that are each to be bolted to a ladder rail. Each such Agombar non-slip member is pivotable between positions in which either a single spike is downward facing to engage the ground or a frictional shoe is downward facing to do so. This configuration enables a user to select a ground engagement surface that is more effective in prevent sliding along the attendant ground surface. Furthermore, the two non-slip members are rigidly connected together by a transverse tube so that they pivot in unison. This eliminates the type of instability that might otherwise be experienced if the non-slip members were able to move independently while they are each affixed to a ladder rail. 
     A drawback of the Agombar assembly, however, is that its configuration necessarily limits the functional surface sizes of the alternative spiked and frictional surfaces. More specifically, the assembly configuration is such that, if the respective ground engagement surface areas of the non-slip members were expansive in longitudinal dimensions (i.e., in directions transverse to the direction of ladder rungs), the non-slip members might be unable to pivot between the two ground engagement surfaces being in their opposing down positions (due to the ladder interfering with the pivot path of the surfaces). And if those ground engagement surface areas were laterally expansive enough to cover a swath of ground space extending the entire distance between the ladder rails, the upward facing surfaces (those not in the ground-engaging position at a given moment) might obstruct the user&#39;s foot access to the lowest one or two ladder rungs and, thereby, pose a significant use hazard. Similar configuration-imposed size limitations on ground engagement surfaces are characteristic of other prior art non-slip attachments that are to be mechanically fastened to a ladder and are pivotable between alternate ground engagement surfaces. 
     Consequently, it may be desirable to employ a ladder slip-inhibiting apparatus that is not to be mechanically fastened to the ladder and, instead, features a base element that can be freely pivoted or flipped between different types of ground engagements. Such an apparatus is found in U.S. Patent Application Publication No. 2009/0200110 to Esselborn. More specifically, Esselborn discloses a generally planar anti-slip platform that has abutments—either in the form of recesses within a face of the platform or in the form of protrusions extending up from the face of the platform—which the ends of ladder rails will press against and will, thereby, prevent the ladder from sliding horizontally along the platform. Furthermore, in at least one embodiment, the Esselborn platform features different types of anti-slip surfaces along its opposing faces so that type of platform surface most suitable for preventing sliding along a particular ground or floor surface can be faced down in ground-contacting position. 
     Nevertheless, while the Esselborn apparatus provides multiple slip-inhibiting surfaces that are reversible without having to manipulate any mechanical fasteners, and while its configuration and engagement with a ladder in no way limits the functional surface area of the ground-engaging platform, it may still be deemed an inadequate solution for some. For example, if a user first positions one side of the platform on bottom, only to determine that its opposite side might be better suited to grip the attendant ground surface, the user will have to lift the ladder from the platform, turn over the platform and remount the ladder atop it. Typically, that sequence will require either (a) two persons (one person to lift and suspend the ladder while the other person flips over the platform) or (b) lifting the ladder, setting it down off of the platform, flipping over the platform and then re-placing the ladder back atop turned platform. 
     Consequently, the present inventors appreciate a need for a slip-inhibiting ladder base device that both (a) features two separate ground engaging surfaces and (b) allows a user to toggle between those two surfaces being in engagement with the ground or floor surface without the steps of mechanically unfastening and refastening the base device to the ladder or the steps of dismounting the ladder from and remounting the ladder to the base device. The present invention for a ladder base device substantially fulfills these needs. 
     SUMMARY 
     Typically, when using a ladder, a user will lean it against a vertical support (e.g., the side of a dwelling) by resting the respective upper ends of the ladder&#39;s legs (or “rails”) against the vertical support while their lower ends rest atop the ground. The horizontally oriented steps (or “rungs”) that connect the rails directly support the weight of a ladder-climbing user. Because of the importance of the ladder remaining stable while it supports a user, the lower ends (or “terminal ends”) of the rails are often capped with rubber “ladder shoes” that are intended to inhibit the rails, which are often fabricated of aluminum, from inadvertently sliding along a floor surface that may not be highly frictional. It is well known that friction is the force resisting the relative motion of solid surfaces, fluid layers, and material elements from sliding against each other. Dry friction, specifically, resists relative lateral motion of two solid surfaces in contact, and the greater the friction between the terminal end of the ladder, the more likely it is that the ladder will remain stable during use. However, since the same ladder may be used indoors or outdoors and on a plethora of different types of ground and floor surfaces that may have vastly different frictional effects on the metal or rubber ends of the ladder, a cap-like ladder shoe certainly may not produce adequate stability in all cases, and prior art base devices may not as well. 
     Therefore, it is an object of the present invention to provide a ladder base device that, by the breadth of its ground platform, may improve the stability, in horizontal dimensions, of a ladder mounted to it. In one aspect of the invention, the present base device features a planar platform element that can be of virtually infinite width in the direction of ladder rung orientation and of considerable width in the perpendicular direction. Although the platform is generally rectangular, it can be pivoted 180 degrees to reverse the orientation of its faces, while a ladder remains mounted onto the base device. This is enabled by the presence of deep inlets formed within the platform and extending from one edge of the platform to just past its lateral centerline. More specifically, these inlets permit the platform rotation to occur without being obstructed by the ladder rails. Consequently, all that limits the longitudinal width of the platform is the height of the lowest ladder rung. The ground-contacting surface area of the platform element of the present device, which far exceeds that of any conventional, cap-like ladder shoe, provides good dimensional stability while the ladder is supporting a user. Providing further such stability is the texture and topography of that functional surface area. 
     In fact, it is another object of the present invention to not only prevent the base of a ladder from sliding along the ground, inadvertently, while the ladder is supporting a user, but to also be adapted to grip and prevent sliding along a variety of different ground and floor surfaces. In another aspect of the invention, the opposing faces of the planar platform have different types of surfaces which are each designed to create friction when mated against different ground surfaces. For example, one face may be fabricated of rubber and have a pattern that inhibits sliding along a hardwood surface, while the opposing surface may be spiked, and even fabricated of a different material, to prevent sliding along a grass or dirt ground surface. 
     Finally, it is another object of the present invention to provide a ladder base device that attaches to a ladder without the use of any mechanical fasteners and features a base platform that is rotatable, from one side to another, while the device remains attached to a ladder. As previously mentioned, the base platform has a pair of inlets formed within in it that permit such rotation without obstruction by ladder rails. Furthermore, in another aspect of the invention, two cap-like receptacles that ladder rails insert into are pivotably mounted to the platform within these inlets. In most cases, the receptacles will form a frictional plug fit around the bare, lower ends of the ladder rails. In such cases, the ladder can be lifted from the ground and the base device will remain attached. In other cases where these rail-receiving receptacles do not frictionally fit onto particular ladder rails, the platform can be simply flipped over without lifting the ladder or the receptacles, and gravity will allow the ladder rails to remain nestled within the receptacles. In any event, there need not be any intervening steps of unfastening and refastening the present device to a ladder when reversing the orientation of its base platform. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a top perspective view of a ladder base device in accordance with the present disclosure, the device being shown with a rigid ladder mounted to it; 
         FIG. 2A  is a top plan view of the ladder base device of  FIG. 1 ; 
         FIG. 2B  is as top perspective view of the same; 
         FIG. 2B  is as top perspective view of the same; 
         FIG. 2C  is as front elevational view of the same; 
         FIG. 2D  is as side elevational view of the same; 
         FIG. 3  is a top perspective view of a ladder base device in accordance with the present disclosure, the device being shown in a disassembled state; and 
         FIG. 4  is a bottom perspective view of the ladder base device of  FIG. 1 , the device being shown with a ladder mounted to it and while the platform element of the device is being rotated relative to the ladder. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring now to  FIGS. 1 and 4 , there is illustrated a preferred embodiment of the ladder base device  1  of the present invention with a ladder  102  mounted thereto. The present device  1  provides a base for a ladder  102  to be mounted upon for the purpose of inhibiting sliding movement of the ladder&#39;s rails  104  along the ground or a floor surface. 
     Generally speaking, when a ladder  102  is leaned against a vertical support (e.g., a vertical wall) and load is placed along its rungs  106  (e.g., the weight of a user), the rails  104  of the ladder  102  may be urged, by that load, to slide along the ground. If a base device is not being used, the frictional forces between the rails  104  and the ground surface that they are in direct contact with are overcome, the ladder  102  will slide along the ground—potentially causing catastrophe for the user. However, by mounting the ladder  102  atop the present base device  1 , that potential is severely reduced. 
     The present base device  1  shown in the accompanying drawings comprises two main components, a platform  10  and a pair of ladder rail receptacles  20  that are pivotably connected by a rod  30 . In a preferred embodiment, the platform  10  is a planar object that is generally rectangular and is longer in its lateral dimension (i.e., the direction of ladder rungs  106 ) than it is in its longitudinal dimension. In fact, the longitudinal width of the rectangular platform  10  ideally measures just short of twice the height of the lowest rung  106  along a ladder  102  to be mounted to the base device  1 . Therefore, when the platform  10  is rotated and is momentarily co-planar with the ladder rails  104 , as depicted in  FIG. 4 , the platform  10  freely circulates beneath that rung  106 . Furthermore, two laterally spaced, longitudinally extending inlets are formed within one lateral edge  12  of the platform  10 . The lateral width of each inlet is greater than the lateral width of a typical ladder rail  104 —allowing the rails  104  passage through the platform  10  as the platform  10  is pivoted 180 degrees from one side  18  facing groundward to the other side  16  contacting the ground. 
     The platform  10  can be principally made of any of a variety of rigid materials, including various metals, woods, plastics and rubbers. In any case, the opposing platform faces  16 ,  18  have dramatically different surface topographies that are configured to reversibly engage different types of ground surfaces. The platform faces  16 ,  18  may even be fabricated of different materials. For example, in one embodiment, the platform  10  is fabricated of a high density polyethylene composition and is molded to have a first surface  16  with a series of ground spike protrusions along it that are efficacious for engaging and penetrating a grass, dirt, or mulch ground surface. Then, adhesively bonded to the platform&#39;s other surface  18  is a soft rubber corrugated mat  22  that is efficacious for frictionally engaging a wood or tile floor, for example. 
     In a preferred embodiment, each rail receptacle  20  has a rectangular tubular upper portion that forms a frictional, cap-like fit over the ends of a typical ladder rail  104 , and it has a solid lower portion with a bore  26  through which the pivot rod  30  passes. The bottoms of the rail receptacles  20  are rounded to make them rockable along, the ground and accommodating of a range of ladder lean angles. The upper portion of the receptacles  20  are deep enough that ladder rails  104  remain securely housed within them throughout a wide range of ladder lean angles, even if the receptacles  20  do not frictionally fit onto the rails  104 . 
     Finally, as can be gleaned from  FIG. 4 , the pivot rod  30  extends laterally through a bore  24  within the platform  10  and axially aligned holes  26  within both rail receptacles  20 . In manufacturing a preferred embodiment of the platform  10 , it is molded around the rod  30  so that the ends of the lateral bore  24  within the platform  10  keep the rod  30  contained within the platform  10 . 
     Aspects of various embodiments of the present invention that are not recited above or claimed below may be noted from observing the illustrations included herein.