Abstract:
A base extending mechanism is provided for a ladder in the form of pivotable lower leg sections which can be independently rotated outwards to provide a wider ladder base. This extension of the ladder base is complementary to and supported by a compatible ladder levelling mechanism.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     (Not Applicable) 
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     (Not Applicable) 
     THE NAMES OF PARTIES TO A JOINT RESEARCH AGREEMENT 
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     INCORPORATION BY REFERENCE OF MATERIAL SUBMITTED ON A COMPACT DISK OR AS A TEXT FILE VIA THE OFFICE ELECTRONIC FILING SYSTEM (EFS-WEB) 
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     STATEMENT REGARDING PRIOR DISCLOSURES BY THE INVENTOR OR A JOINT INVENTOR 
     (Not Applicable) 
     BACKGROUND OF THE INVENTION 
     (1) Field of the Invention 
     In general ladders, and in particular, lean-to ladders are ideal for use on horizontal ground. However, problems arise in using such ladders on uneven ground, and more particularly, on sloping or stepped ground. In such cases it is impossible to stand a lean-to ladder on sloping, stepped or uneven ground with the two ground engaging feet engaging the ground unless the ladder is allowed to tilt to one side or the other. This is particularly undesirable, since it can lead to serious instability of the ladder, with the possibility of the ladder toppling. There is therefore a need for a ladder which addresses the problem of standing a ladder on sloping, stepped or uneven ground. 
     (2) Description of Related Art Including Information Disclosed Under 37 CFR 1.97 and 1.98 
     (Not Applicable) 
     BRIEF SUMMARY OF THE INVENTION 
     The invention provides a ladder preferably for which a securing means is provided for securing the lower leg portion of at least one of the first and second legs which is pivotal intermediate its ends in a selected one of a plurality of selectable angled states, with the lower leg portion diverging at different angles from the other one of the first and second legs. This provides a wider ground base for the ladder, thereby increasing the stability of the ladder. 
     A further advantage of the invention is achieved when the lengths of both legs of the ladder are adjustable. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S) 
       The invention will be more clearly understood from the following description of some preferred embodiments thereof which are given by way of example only with reference to the accompanying drawings in which: 
         FIG. 1  is a front elevation of the ladder in a datum state of no splay and no levelling. 
         FIG. 2  is a front elevational view of the ladder in a splayed state with no levelling. 
         FIG. 3  is a cross-sectional plan of the ladder on the line III-Ill of  FIG. 1   
         FIG. 4  is a cross-sectional plan of the ladder on the line IV-IV of  FIG. 2   
         FIG. 5  is a front elevational view of the ladder in a leveled state for ground rising from left to right with no splay. 
         FIG. 6  is a front elevational view of the ladder in a leveled state for ground rising from right to left with no splay. 
         FIG. 7  is a front elevational view of the ladder in a sample splayed and leveled state for ground rising from left to right. 
         FIG. 8  is a side elevational/sectional view of the lower portion  32  of leg  3  of the sample setting in  FIG. 7 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring to  FIGS. 1 to 8  there is illustrated a ladder according to the invention indicated generally by the reference numeral  1 . The ladder  1  in this embodiment of the invention is a lean-to ladder, and may be an extension lean-to ladder having one or more extension sections (not shown). The ladder  1  comprises a pair of elongated spaced apart first and second legs  2  and  3 , respectively, extending between respective lower ends  4  and upper ends  6 . A plurality of transversely extending rungs  5 , only some of which are illustrated extend between and join the first and second legs  2  and  3  together. The rungs  5  are equi-spaced apart longitudinally along the first and second legs  2  and  3 . The first and second legs and  3  terminate in ground engaging feet  7  for engaging the ground. 
     The first and second legs  2  and  3  of the ladder  1  are pivotal outwardly from an aligned state illustrated in  FIGS. 1, 5 and 6  to selectable ones of a plurality of angled states, some of which are illustrated in  FIGS. 2 and 7  for increasing the base width and in turn the stability of the ladder  1 . Additionally, in this embodiment of the invention, the length of the second leg  3  is adjustable as will be described below. 
     Turning initially to the pivotal aspect of the lower leg portions  32 , in this embodiment of the invention the first and second legs  2  and  3  are pivotal intermediate their lower and upper ends  4  and  6  about respective pivot axes  34  which extend perpendicularly relative to a plane defined by the first and second legs  2  and  3 , so that each first and second leg  2  and  3  comprises an upper leg portion  35  and the lower leg portion  32  which is pivotal relative to the upper leg portion  35  about the corresponding pivot axis  34 . In this embodiment of the invention the first and second legs  2  and  3  are pivotal intermediate the lowermost rung  5   a  and the next adjacent rung  5   b  so that only one rung extends between the lower leg portions  32  of the first and second legs  2  and  3 , namely, the lowermost rung  5   a . The lowermost rung  5   a  is of adjustable length, as will be described below, in order to accommodate pivoting of the lower leg portions  32  of the first and second legs  2  and  3  from the aligned state with the respective lower leg portions  32  aligned with the corresponding upper leg portions  35  and any one of the plurality of angled states with the lower leg portions  32  angled relative to the corresponding upper leg portion  35  and diverging from the lower leg portion  32  of the other one of the first and second legs  2  and  3 . 
     Each lower leg portion  32  is pivotally coupled to the corresponding upper leg portion  35  by a corresponding pivot pin  36  which extends through a bore  39  extending through the lower leg portion  32  and a bore (not shown) extending through the upper leg portion  35 . A plate  42  extends inwardly from the upper leg portion  35  of each first and second leg  2  and is secured to the corresponding upper leg portion  35  and the adjacent rung  5   b  by welding. A plurality of bores  43  extend through each plate  42  and are selectively alignable with a corresponding bore  44  in a securing  15  bracket  45  which extends from the adjacent lower leg portion  32  and is welded thereto. A securing means, namely, a securing screw  47  is engageable with the bore  44  and a selected one of the bores  43  for securing the adjacent lower leg portion  32  in the aligned state or in a selected one of the angled states relative to the corresponding upper leg portion  35 . A nut (not shown) is provided for the securing screw  47  for securing the securing bracket  45  to the corresponding plate  42  with the corresponding lower leg portion  32  in the desired one of the aligned and angled states relative to the corresponding upper leg portion  35 . 
     In this embodiment of the invention the bores  43  through the corresponding plates  42  are disposed so that the lower leg portion  32  of each first and second leg  2  and  3  can be set at an angle θ relative to the corresponding upper leg portion  35  of values of 0° (aligned with the upper leg portion  35 ), 8°, 12° and 16° diverging from the lower leg portion  32  of the other one of the first and second legs  2  and  3 . It is, however, envisaged that in order to provide a greater number of angled states at which the lower leg portions  32  of the first and second legs  2  and  3  can be set relative to the upper leg portions  35 , a plurality of bores  44  would be provided in the securing bracket  45  as well as a plurality of the bores  43  in the plate  42 , and the bores  43  and  44  would be arranged in the plate  42  and the securing bracket  45 , respectively, to provided vernier type adjustment. 
     The lowermost rung  5   a  comprises a pair of rung members  50 , each being pivotally secured to a corresponding one of the lower leg portions  32  by a mounting bracket  51 . Pivot pins  52  through bores  54  and  55  in the rung members  50  and mounting brackets  51 , respectively, pivotally couple the rung members  50  to the mounting brackets  51 . Each rung member  50  terminates in an eye member  57  for slideably engaging the corresponding rung member  50 . Threaded bores  58  in each rung member  50  are alignable with corresponding bores  59  in the eye members  57  for selectively setting the length of the rung members  50  to correspond with the angular setting of the lower leg portions  32 . Screws  60  through the bores  59  in the eye members  57  are engageable with the corresponding aligned threaded bore  58  in the rung members  50  for securing the rung members  50  together so that the lowermost rung  5   a  is of the desired length. 
     The ground engaging element  61  of lower leg portion  32  of leg  2  is of fixed height. As mentioned above, the length of the second leg  3  of the ladder  1  is adjustable. In this embodiment of the invention a second ground engaging element  62  which comprises an elongated member  63  which is telescopingly slideable within the lower leg portion  32  of the second leg  3 . For urging the second ground engaging element  61  inwardly and outwardly of the lower leg portion  32  of the second leg  3 , a plurality of retaining bores  64  extend transversely through the second ground engaging element  62 , and are selectively alignable with an alignable bore  65  which extends transversely through the lower leg portion  32  of the second leg  3 . A retaining means, namely, a retaining screw  66  is engageable with the alignable bore  65  in the second leg  3  and a selected one of the retaining bores  64  in the second ground engaging element  62  for securing the second ground engaging element  62  in a desired state relative to the second leg  3 . Screw threads are provided in the alignable bore  65  for engaging the retaining screw  66 , for securing the second ground engaging element  62  in a desired state relative to the lower leg portion  32  of the second leg  3  so that the portion  67  of the second leg  3  below the lowermost rung  5   a  is of the desired length. 
     In use, one or both of the lower leg portions  32  are initially pivoted about the corresponding pivot pin  36  in order to set the lower leg portion  32  in the desired angled states relative to the corresponding upper leg portions  35  in order to provide the ladder  1  with the desired degree of stability. The lower leg portions  32  may be set at similar or different angled states. Once the lower leg portions  32  have been set at the desired angled states, or indeed in the aligned state, the securing brackets  45  are secured to the corresponding plates  42  by the securing screws  47  and nuts  48 . The rung members  50  of the lowermost rung  5   a  are then secured to each other by the screws  60  through the bores  58  in the rung members  50  and the threaded bores  59  in the eye members  57 . 
     Thereafter the second ground engaging element  62  is adjusted relative to the corresponding lower portion  32  of the second leg  3  until the length of the second leg  3  is adjusted to the desired length. The second ground engaging element  62  is then secured in position by the screw  66  through the alignable bore  65  and the selected one of the retaining bores  64 . Thereafter, the ladder is ready for use. 
     While the ladders have been described as being lean-to ladders, it is envisaged that the ladders may be provided in the form of an A-frame ladder, in which case both elements of the A-frame ladder would be provided with at least one adjustable leg. Additionally, it is envisaged that both elements of the A-frame ladder would be provided with at least one leg pivotally connected intermediate its legs to define an upper leg portion and a lower leg portion similar to the upper and lower leg portions  35  and  32  of the ladder  1 . 
     While the ladder  1  described with reference to  FIGS. 1 to 8  has been described as comprising one leg of adjustable length, it is envisaged that the ladder  1  may be provided with both legs being of adjustable length. 
     While the ground engaging element has been described as telescoping into the adjustable leg, while this is desirable, it is not essential. In certain cases, the adjustable leg may telescope into the ground engaging element. Indeed, it is also envisaged that while it is desirable to have the ground engaging element telescoping relative to the adjustable leg, any other mounting arrangement which permits movement of the ground engaging element relative to the adjustable leg may be used. 
     It is also envisaged that the pivot axes about which the legs are pivotal intermediate their ends may be located between any pair of rungs or adjacent any rungs, for example, between the second and third rungs from the lower end of the ladder. In which case both the lowermost rung and the second rung would be of adjustable length, to accommodate outward pivoting of the lower leg portions  32 . It is also envisaged that the first and second legs of the ladders may be pivotal towards the upper end thereof for facilitating splaying of the upper ends of the ladders. Such pivoting of the upper end portions of the ladder would be similar to the pivoting of the lower leg portions thereof. 
     While the ladders have been described as comprising one or both legs being of adjustable length, it is envisaged that the ladder  1  described with reference to  FIGS. 1 to 8  may be provided without the legs being of adjustable length, in which case, the ladder  1  of  FIGS. 1 to 8  may be provided with only one leg being pivotal intermediate its ends to be pivoted from an aligned state to one or more angled states, or the ladder  1  of  FIGS. 1 to 8  may be provided with both legs pivotal intermediate their ends to be pivoted between respective aligned states and one or more angled states.