Patent Publication Number: US-7222696-B2

Title: Independently adjustable extensions for leveling a ladder

Description:
The present application is a continuation-in-part application of application Ser. No. 10/959,877 filed on Oct. 7, 2004, now U.S. Pat. No. 7,121,382. 

   FIELD OF THE INVENTION 
   The present invention pertains to ladder accessories and attachments for safely deploying a ladder, and more particularly pertains to independently adjustable extensions for leveling a ladder on sloping, uneven or irregular surfaces. 
   BACKGROUND OF THE INVENTION 
   One of the most common pieces of equipment for both household and work use is the ladder in its several embodiments: the extension ladder and the stepladder. Such ladders are used for tasks as diverse as painting, cleaning aluminum siding, cleaning gutters, changing lights and cleaning ceiling fans and stocking shelves. Since the work sites where such ladders are used are often irregular, uneven or sloping, care must be taken in properly setting up and deploying the ladders. Obviously placing a ladder on an uneven or irregular surface decreases the stability of the ladder; and this instability increases with the height or vertical extension of the ladder. Moreover, with the current issues of worker&#39;s compensation and personal injury liability, the improper deployment of a ladder by an employee can result in a physical injury for the employee and the possibility of legal damages and penalties against the employer for improper supervision of the work site. 
   Thus, in order to stabilize a ladder on an uneven or irregular surface the homeowner and employee resort to several common expedients. One expedient is to simply find a handy and available rock to wedge under the lowermost end of one of the side rails of the ladder to balance and level the ladder. Another expedient is to use shims, spacers or boards to level the ladder. However, in both cases the leveling is rough and approximate, and if the ladders needs repositioned, the leveling process must be undertaken anew. In addition, there is also an initial investment of time in searching for such spacers and levelers. And perhaps most importantly, such shims and spacers are not secured to the lower end of the ladder side rails, with the possibility of the ladder slipping off the shim or spacer with the individual falling off the ladder and sustaining serious injury. 
   The prior art discloses a wide variety of attachments and accessories for leveling and stabilizing ladders  9  on uneven and irregular terrain, surfaces and ground. 
   The Gilland patent (U.S. Pat. No. 3,414,082) discloses a ladder leveling apparatus that includes extensible mounting members that are pivotally attached to the side rails of the ladder. 
   The Hurwitz patent (U.S. Pat. No. 3,937,298) discloses a ladder leveling attachment that includes a transverse member attachable to the lower end of the ladder side rails, with the transverse member having opposed sockets for receiving therein adjustable legs for leveling the ladder. 
   The Larson et al. patent (U.S. Pat. No. 3,948,352) discloses a ladder leveler for extension ladders that includes a pair of sleeves each of which encompasses the lower end of the ladder side rails and is vertically adjustable and locks into place by a spring-biased pin. 
   The Fernandez patent (U.S. Pat. No. 4,143,742) discloses a ladder extension that includes a pair of l-shaped members that are bolted to each ladder side rail and are vertically adjustable along the lower portion of each side rail. 
   The Belt patent (U.S. Pat. No. 4,606,432) discloses an adjustable ladder leg that includes adjustable legs that are attached to each side rail by a clamping member and are slidably adjustable within channels that are also mounted to the clamping members. 
   The Huang patent (U.S. Pat. No. 4,671,383) discloses a ladder leveler that includes a pair of interconnected adaptors with each adaptor mounted to the bottom of each side rail, and an adjustable leg affixed to the underside of each adaptor for leveling the ladder. 
   The Katson et al. patent (U.S. Pat. No. 5,305,851) discloses an adjustable ladder leg for both a stepladder and an extension ladder. 
   The Dickerson et al. patent (U.S. Pat. No. 5,476,153) discloses a ladder leveling apparatus that includes a vertical support externally mounted to the lower end of each ladder side rail with each vertical support adjustable on the side rail and locked into place by a manually operable tightening member. 
   The Lovelady patent (U.S. Pat. No. 5,908,085) discloses a ladder leveling system that includes a pair of bands mounted to the lower end of each ladder rail for supporting a leg extension, and the leg extensions are interconnected for adjustment therealong by a spring loaded handle that extends between the ladder rails. 
   The McCrystal patent (U.S. Pat. No. 6,073,726) discloses an adjustable stepladder having adjustable legs and adjustable steps affixed to at least one pair of the side rails for leveling the ladder. 
   Nonetheless, despite the ingenuity of the above devices, there remains a need for a ladder leveling apparatus that is easily and quickly adjustable for leveling a ladder and is not cumbersome in use or weight when added to the ladder. 
   SUMMARY OF THE INVENTION 
   The present invention comprehends independently adjustable ladder extensions for achieving the stable, safe and level disposition of a ladder on uneven, irregular, sloping or inclined surfaces. The independently adjustable ladder extensions provide for the more flexible accommodation of the ladder on all types of uneven or irregular surfaces. 
   The adjustable ladder extensions include at least one pair of ladder extensions with each ladder extension including a support leg for insertion within the channel of the side rail adjacent the lower end thereof so that the side rail encompasses the support leg. Each support leg includes a plurality of apertures and the apertures align with through holes on the side rail. Each support leg can be slid and adjusted within the channel of the side rail independent of the slidable movement and positioning of the other support leg for stable placement of the ladder on the uneven ground. After the desired position for each support leg is obtained, with the apertures of the support leg aligned with the through holes of the side rail, a locking pin is inserted through the side rail and the support leg for locking the support leg in that position. Pivotally mounted to at the lower end of each support leg is a traction foot for gripping the ground to facilitate the stable and secure disposition of the ladder. In order to further facilitate the level deployment of the ladder on the uneven or irregular surface, a level is integrally affixed to at least one ladder rung. The level further assists the individual in appropriately adjusting each ladder extension to obtain a level disposition of the ladder relative to the uneven or irregular surface. 
   It is an objective of the present invention to provide ladder extensions for a ladder that are independently adjustable for safely setting up the ladder on uneven, irregular surfaces. 
   It is another objective of the present invention to provide ladder extensions that are independently adjustable for leveling a ladder and are easily adjustable by only one individual without requiring the assistance of others. 
   It is yet another objective of the present invention to provide ladder extensions that are independently adjustable and that include an integral level affixed to at least one ladder rung of the ladder for guiding the individual during ladder adjustment so that the level disposition of the ladder can be obtained. 
   It is still yet another objective of the present invention to provide ladder extensions that can be quickly and easily adjusted independent of each other to ensure a stable, secure disposition of the ladder on the particular sloping, uneven or irregular ground surface. 
   Still yet another objective of the present invention is to provide independently adjustable ladder extensions for a ladder that obviates the need to use shims, spacers or wedges beneath the bottom ends of the side rails to level the ladder. 
   A still further objective of the present invention is to provide independently adjustable ladder extensions for a ladder wherein the ladder extensions can be easily and quickly locked into place when the desired position for each ladder extension is obtained, and then can be quickly unlocked for further adjustment should the ladder be repositioned at another location. 
   These and other objects, features and advantages will become apparent to one skilled in the art upon a perusal of the following detailed description when read in conjunction with the accompanying drawing figures. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a perspective view of the independently adjustable ladder extensions of the present invention showing their mounting at the lower ends of the ladder side rails; 
       FIG. 2  is a front elevational view of the independently adjustable ladder extensions illustrating the various adjustment positions of each ladder extension for leveling the ladder on uneven ground; 
       FIG. 3  is a sectioned elevational view taken along lines  3 - 3  of  FIG. 2  of the independently adjustable ladder extensions illustrating the disposition of one ladder extension within the lower end of one ladder side rail; 
       FIG. 4  is a sectioned elevational view taken along lines  4 - 4  of  FIG. 1  of the independently adjustable ladder extensions illustrating the insertion of the locking pin through the side rail and the ladder extension for locking the ladder extension in place to the side rail; 
       FIG. 5  is a front elevational view of the independently adjustable ladder extensions illustrating the flap member of the locking pin disposed in the locking position for locking the ladder extension to the lower end of the side rail; 
       FIG. 6  is a front elevational view of the independently adjustable ladder extensions illustrating the disposition of the flap member of the locking pin during the insertion or withdrawal of the locking pin to or from the side rail and the ladder extension; 
       FIG. 7  is a front elevational view of the independently adjustable ladder extensions illustrating a level integrally mounted to one ladder rung of the ladder; 
       FIG. 8  is an elevational view of the independently adjustable ladder extensions illustrating an alternative embodiment for supporting the upper ends of the respective support legs against a pitched roof; 
       FIG. 9  is a side elevational view of the independently adjustable ladder extensions illustrating the disposition of one eave catch with respect to the exterior surface of the pitched roof; 
       FIG. 10  is a perspective view of the independently adjustable ladder extensions illustrating an alternative embodiment for adjusting and rotating the traction foot at the lowermost end of one support leg for accommodating the extension ladder on uneven or irregular terrain; 
       FIG. 11  is a top plan view of the independently adjustable ladder extensions illustrating one rotatable orientation of the traction foot mounted to the lowermost end of one support leg; 
       FIG. 12  is a top plan view of the independently adjustable ladder extensions illustrating a second rotatable orientation of the traction foot mounted to the lowermost end of one support leg; and 
       FIG. 13  is an elevational view of the independently adjustable ladder extensions illustrating the separate dispositions and angled orientations of each traction foot mounted to the lower end of each support leg for stabilizing the ladder on an uneven surface. 
   

   DETAILED DESRCIPTION OF THE PREFERRED EMBODIMENT 
   Illustrated in  FIG. 1-12  are several embodiments for independently adjustable ladder extensions  10  for leveling and stabilizing ladders on uneven, irregular, sloping and inclined surfaces and that eliminates the need for using wedges, shims and spacers to level the ladder. The adjustable extensions  10  can be used with various ladder designs, such as stepladders and extension ladders, so that two adjustable extensions  10  would be used with an extension ladder while four adjustable extensions  10  would be used with a typical foldout stepladder. The extensions  10  are preferably manufactured from aluminum and are independently adjustable up to 12 inches. 
   Thus, with reference to  FIGS. 1 and 2 , the adjustable ladder extensions  10  are used with a representative extension ladder  12  that includes a pair of opposed ladder stiles or side rails  14  interconnected by several ladder rungs  16 . Each side rail  14  defines and interior channel  18  that extends the length of the side rail  14 , and each side rail  14  includes a bottom or lower end  20  that would normally (without the employment of the ladder extensions  10 ) contact and rest against the ground surface  22 , such as the uneven, sloping surface of  FIG. 2 . Adjacent the lower end  20  of each side rail  14  is a plurality of equidistantly spaced through holes  24  that extend through each sidewall  26  of each side rail  14 . Preferably the through holes  24  are spaced either three quarters of an inch or one inch apart. 
   As shown in  FIGS. 1-4 , each ladder extension  10  includes an elongated support or extension leg  28 . The support legs  28  are inserted within the channels  18  of the side rails  14  and are encompassed by the side rails  14  for slidable adjustable movement therein. As shown in  FIG. 3  each support leg  28  includes a plurality of apertures  30  equidistantly spaced from each other either at three quarters of an inch or one inch; this spacing provides for the alignment of the through holes  24  of the side rails  14  with the apertures  30  of the support leg  28  during the adjustment of each support leg  28 . The support legs  28  are adapted for independent slidable telescopic movement up and down within the respective side rails  14  so that the appropriate height for each leg  28  can be obtained for achieving the stable and level disposition of the ladder  12  on the uneven and irregular ground surface  22 . 
   As shown in  FIGS. 1 ,  2  and  4 - 7 , a locking means is used to lock the ladder extensions  10  in position after they have been slidably adjusted within the channels  18  of the side rails  14  and set at the desired height for leveling the ladder  12 . The locking means includes one locking or cotter pin  32  for each ladder extension  10  as shown in  FIG. 2 . The locking pin  32  has a ring member  34  for manually gripping by the individual&#39;s finger and a shaft  36  having sufficient length to extend completely through the ladder extension  10  and the side rail  14 . At the end of the shaft  36  is a stop or flap member  38  that can be of flexible spring steel. In order to insert the locking pin  32  through the side rail  14  and the ladder extension  10  disposed therein, the flap member  38  is bent backward so that the shaft  36  of the locking pin  32  can be cleanly inserted through the aligned aperture  30  and through hole  24 ; and after the shaft  36  passes through the respective through hole  24  and aperture  30 , the flap member  38  can be returned to its normal position, as shown in  FIGS. 1 ,  2  and  4 , thereby preventing the accidental withdrawal of the locking pin  32  from the side rail  14 . In order to purposely remove the locking pin  32 , the flap member  38  is deliberately pressed against the shaft  36  so that the locking pin  32  can be withdrawn and removed from the side rail  14 . 
   As shown in  FIGS. 1-4 , to insure the non-slidable disposition of the ladder  12  on the particular surface  22  after the appropriate adjustment of each ladder extension  10 , pivotally mounted to the lowermost end of each support leg  28  is a surface gripping traction foot  40 . Each traction foot  40  includes a pair of spaced-apart brackets  42  that abut the opposite sides of the lowermost end of the support leg  28 , and a dowel or pivot pin  44  is inserted through bracket apertures  46  and the lowest aperture  30  of the support leg  28  thereby pivotally mounting the traction foot  40  to the lowermost end of the support leg  28 . The brackets  42  extend upwardly from a main plate  48 , and attached to the underside of the main plate  48  is a rubberized, irregular, undulating, non-skid traction pad  50 . 
   In order to assist the individual in leveling and stabilizing the ladder  12  during the process of adjusting and positioning of the ladder extensions  10  with respect to each other and the ground surface  22 , at least one level  52  is integrally affixed to one ladder rung  16 . This allows the individual to use the level  52  to determine when the proper level disposition of the ladder  12  has been attained, instead of having to continually step back from the ladder  12  to visually observe the positions of the side rails  14  or the upper step of the ladder (for a foldout stepladder) to decide if the ladder  12  is properly leveled. 
   By way of example, for leveling the ladder  12  on the uneven ground surface  22  illustrated in  FIG. 2 , the individual would first slide one ladder extension  10  within the side rail  14  and then insert the locking pin  32  for locking that support leg  28  to the side rail  14 . Then the other ladder extension  12  would be slidably adjusted in the other side rail  14  to the appropriate height and then locked in position by insertion of the locking pin  32 . The individual would check the level  52  and then adjust one or both of the ladder extensions  10  by sliding the respective support leg  28  up or down in the side rail  14  until the appropriate height for each ladder extension  10  is found for obtaining the level and stable disposition of the ladder  12  upon the ground surface  22 . 
   Illustrated in  FIGS. 8-13  are several embodiments for enhancing the supporting and stabilizing capability of the ladder extensions  10 , and for further stabilizing the ladder  12  on uneven or irregular terrain. Specifically, illustrated in  FIG. 8  is a sidewall or end wall  54  of a structure with the structure including a representative pitched roof  56  at the standard pitch and an eave  58  coextensive with the pitched roof  56 . The ladder  12  includes an independently adjustable supporting means to support the side rails  14  on or against the pitched roof  56 , and to stabilize the ladder  12  when being deployed adjacent the eave  58  of the pitched roof  56 . The independently adjustable support means specifically shown in  FIGS. 8 and 9  includes a pair of elongate extension members  60  with each extension member  60  disposed within the channel  18  of the respective side rail  14  at the upper end  62  of each side rail  14 . Each extension member  60  is disposed within the respective channel  18  for slidable adjustable up or down movement therein. Furthermore, each extension member  60  includes a plurality of extension member apertures  64  spaced along the length of the extension member  60 . The extension member apertures  64  are spaced to align with the equidistantly spaced through holes  24  that are located along the upper end  62  of each side rail  14 . Each extension member  60  also includes an l-shaped eave catch  66  for engaging the eave  58  and thereby additionally supporting the ladder  12  in its angled extension adjacent the sidewall  54  of the structure. As shown in  FIGS. 8 and 9 , the extension members  60  are selectively and independently adjustable relative to each other to accommodate the pitch of the roof  56  and the eave  58 . After each extension member  60  has been appropriately adjusted in a slidable, longitudinal direction relative to the side rail  14  in which it is disposed, a locking pin, such as the locking pin  32 , is inserted through the aligned through holes  24  and extension member apertures  64  thereby locking the extension members  60  in position so that the eave catches  66  can be brought into engagement with the eave  58  of the structure. It should be noted that the slidable movement of the support legs  28  within the channels  18  adjacent the lower ends  20  of the side rails  14  will not interfere with the slidable adjustable movement of the extension members  60  within the channels  18  at the upper ends  62  of the side rails  14 . 
   Illustrated in  FIGS. 10-13  is an alternative embodiment for adjustably mounting the foot  40  to the lowermost end  20  of each support leg  28  for further enhancing the stabilizing capacity of the ladder  12  on uneven or irregular terrain or ground surface. Each foot  40  can thus be mounted parallel with respect to the sidewall  54  of the structure or can be turned for sideways mounting to the support leg  28  with the foot  40  thereby oriented perpendicular to the sidewall  54  of the structure.  FIGS. 11 and 12  include longitudinal lines  68  that illustrate the parallel orientation of the foot  40  ( FIG. 11 ) relative to the sidewall  54 , and the sideways or perpendicular orientation ( FIG. 12 ) of the foot  40  relative to the sidewall  54 . Thus, the lowermost ends  20  of the support legs  28  have been modified so that a square-shaped base member  70  can be mounted thereto. The base member  70  includes a pair of base through holes  72  that extend at right angles to each other and extend completely through the interior of the base member  70 . The base through holes  72  intersect each other within the interior middle of the base member  70  and align with the bracket apertures  46  of the brackets  42  so that a pin, such as locking pin  32 , can be inserted through the bracket apertures  46  and base through holes  72  for locking the foot  40  onto the base member  70 . 
   As shown in  FIG. 10  in order to adjust the foot  40  from parallel to sideways securement to the base member  70  at the lower end  20  of the support leg  28 , the foot  40  is rotated 45 degrees in either the clockwise direction or counterclockwise direction as shown by the respective directional arrows  74 . As shown in  FIG. 10  when the foot  40  is mounted in the parallel orientation, the locking pins  32  can be inserted through the brackets  42  and the base member  70  from either side of either bracket  42 ; when the foot  40  is mounted sideways or perpendicular to the sidewall  54 , the locking pin  32  can be inserted through the brackets  42  and the base member  70  from either the front to back or the back to front. It should be noted that each foot  40  is independently adjustable relative to the other foot  40 , so that if circumstances warrant it, one foot  40  can be secured to the base member  70  in the parallel orientation and the other foot  40  can be secured to the base member  70  in the sideways or perpendicular orientation. This is shown in  FIG. 13  where the foot  40  mounted to the base member  70  of the left side rail  14  is disposed in the parallel orientation with respect to the sidewall  54 , and the foot  40  mounted to the base member  70  of the right side rail  14  is disposed in the sideways or perpendicular orientation with respect to the sidewall  54 . (The locking pins  32  have been omitted from  FIG. 13  for clarity.) Also, one preferred dimension for the traction foot  40  is a width of three inches and a length of six inches. The traction feet  40  shown in  FIG. 13  include this dimension. 
   Thus, the embodiments illustrated in  FIGS. 10-13  provide for the rotation and adjustable mounting of the foot  40  to the base member  70  in two orientations—parallel and sideways—as well as the pivotal mounting of the foot  40  to the base member  70  so that the foot  40  is able to pivot front to back (or vice versa), and left to right (or vice versa). This allows for the safe and stationary deployment of the ladder  12  on any irregular or uneven terrain or ground surface, such as the ground surface  76  shown in  FIG. 13 , thereby obtaining maximum stabilization on the ground surface  76  for safely using the ladder  12 . 
   It is to be understood that the present disclosure pertains to a preferred embodiment of the invention and is for illustrative purposes only in so far as numerous modifications, alterations, and variations may be both possible and practicable to those skilled in the art without departing from the spirit of the invention or the scope of the appended claims.