Patent Publication Number: US-2007107987-A1

Title: Improved adjustable ladder support

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
      This application is related to the application by Smith entitled “Adjustable Ladder Support”, now U.S. Pat. No. 6,745,870 B2, which is hereby cross-referenced in its entirety, including any appendices and references thereto. 
    
    
     FIELD OF INVENTION  
      The present invention relates generally to the field of ladder attachments. More specifically, the present invention is related to improved removable and detachable ladder attachments to provide support for a ladder.  
     DISCUSSION OF PRIOR ART  
      Ladders are used extensively in a number of different situations such as construction, painting, building maintenance, etc. At times, the surface a ladder needs to be placed on is uneven or inclined. Yet, placement of a ladder on an uneven surface renders the ladder unstable, which increases the possibility of the ladder toppling over, resulting in injury to workers. Therefore, a number of devices have been developed to adjust the level of the ladder legs so that the ladder is firmly supported, even when placed on uneven surfaces.  
      U.S. Pat. No. 3,447,631 (Smith), U.S. Pat. No. 4,412,599 (McCrudden et al.), U.S. Pat. No. 4,607,726 (Davis et al.), U.S. Pat. No. 4,792,017 (Grove), U.S. Pat. No. 5,551,529 (Molitor), and U.S. Pat. No. 5,678,656 (Lanzafame) describe prior devices and methods supporting ladder legs, but do not provide an adjustable support that is easily and removably secured (attached and detached) without the need for any tools. Further, they do no employ an attachment arrangement that acts to tighten the grip on the ladder during use to insure against slippage.  
      U.S. Pat. No. 6,745,870 B2, also assigned to the applicant, is an example of the prior art that provides for an adjustable ladder support comprising a base unit and clamping member, as illustrated in  FIGS. 1-4 . In the prior art the base unit has a channel  11  formed by web  44  and corresponding sidewalls  42  and  43 . Channel  11  includes a plurality of spaced splices  16  and  17  and extending flanges  33  and  34  at its open end (see  FIG. 1 ). The base unit also has a removable end cap  36  that attaches to the ends of sidewalls  42  and  43 . End cap  36  has first and second flanges  37  and  38  which are designed to grip flanges  33  and  34  of channel  11  (see  FIG. 2 ). To assemble, channel  11  is placed on ladder leg  12 . Sliding clamp member  18  with support rod  26  with swivel foot  27  is placed against ladder leg  12 , and the splices of the channel and clamp grip the ladder leg. End cap  36  is then mounted (see  FIGS. 3 and 4 ).  
      The &#39;870 design provides a removably secure ladder attachment that may be easily assembled. There is still a desire, however, for an improved adjustable ladder support that is easily connected and removably attached without the need for any tools that has a stronger, safer, and more user-friendly design.  
     SUMMARY OF THE INVENTION  
      Generally, an improved ladder attachment that can be removably secured to a ladder leg is provided. The ladder attachment comprises a base unit and a clamping member. The base unit has a channel formed by a two detachable members which form an interior channel or web when connected, and have corresponding sidewalls substantially perpendicular to the formed web. The sidewalls are sufficiently spaced apart to accommodate the ladder leg and the interior surface of each member has a sidewall with sloping splices formed thereon. The clamping member is generally rectangular and has sloping splices formed on its first and second side surfaces. The sloping splices on the clamping member are dimensioned and arranged so as to slidably engage with the sloping splices on the sidewalls of each member. The clamping member also has a bore to adjustably and securely retain a support rod therein. The sloping splices on the clamping member and the sloping splices on the sidewalls are arranged such that, during use, the clamping member is biased towards the ladder leg.  
      The clamp member has a bore that adjustably and securely retains a support rod, which has a swivel foot at one end. The end of the clamp member that is to be placed adjacent the ladder leg and the opposing interior surface of the base unit have a substantially angled configuration to insure slip free purchase against the ladder leg. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIG. 1  illustrates the prior art channel of a ladder attachment&#39;s base unit.  
       FIG. 2  illustrates the prior art end cap of a ladder attachment&#39;s base unit.  
       FIG. 3  illustrates the prior art assembly procedure for a ladder attachment.  
       FIG. 4  illustrates the prior art assembled ladder attachment.  
       FIG. 5  illustrates the preferred embodiment of the ladder support&#39;s base unit.  
       FIGS. 6 and 7  illustrate the assembly procedure for the ladder support.  
       FIG. 8  illustrates an overhead view of the assembled ladder support. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
      While this invention is illustrated and described in a preferred embodiment, the device may be produced in many different configurations, forms and materials. There is depicted in the drawings, and will herein be described in detail, a preferred embodiment of the invention, with the understanding that the present disclosure is to be considered as an exemplification of the principles of the invention and the associated functional specifications for its construction and is not intended to limit the invention to the embodiment illustrated. Those skilled in the art will envision many other possible variations within the scope of the present invention.  
      It is envisioned that the ladder attachment of the present invention is used primarily as a ladder leveler. Other uses, however, are possible. For instance, it may also be used at the top of the ladder in an upside down position for holding ladder stand-offs. Various other variations will also occur to workers in the art without departure from the scope of the invention.  
       FIG. 5  illustrates the preferred embodiment of the improved ladder attachment&#39;s or ladder support&#39;s base unit. Base unit  500  comprises two detachable outer members  502  and  504 . Outer members  502  and  504  are designed to be assembled or connected to each other such that an interior channel or web is formed therebetween to accommodate a ladder leg, as will be described later. Outer members  502  and  504  may be made of metal, high strength plastic, wood, or other suitable material. Outer member  502  has an elongated sidewall with interior surface  505  with a plurality of spaced splices  506  formed thereon, which slope in a direction downward from the top. Outer member  504  also has an elongated sidewall with an interior surface  507  with a plurality of sloped, spaced splices  508 . Detachable members  502  and  504  are preferably connected via hinge joint. Member  502  also has one extending end  512  with hinge connection  518  and angled edge  524 , and an opposite end with hinge connection  516 . Member  504  has extending end  510  with hinge connection  514 , and an opposite end with hinge connection  520 . Hinge connections  516  and  518  of outer member  502  are provided to connect to corresponding hinge connections  514  and  520  of outer member  504  to form an interior channel. The hinge connections are preferably connected together via pins  522 ; however, any suitable connection device would be within the scope of the invention. Furthermore, although a hinge joint is the preferred connection method, any method of attaching and removably securing the two detachable outer members is within the scope of this invention. Angled edge  524  is designed to be positioned against a ladder leg to thus provide support (as will be further described below). Angled edge  524  may be provided on either outer member  502  or  504 .  
       FIGS. 6 and 7  illustrate the assembly procedure for the ladder support. Clamp member  600  comprises a block of metal, high strength plastic, wood, or other suitable material. Clamp member  600  is preferably of rectangular shape. Also formed on either side surface of clamp member  600  are sloping splices  606 . The width and height of each of the splices  606  is such that they fit into the grooves or spaces between splices  506  and  508  formed on outer members  502  and  504 . Clamp member also has bore  608  extending therethrough to accommodate support rod  604 , which has swivel foot  602  at one end. Support rod is held in place with clamp member  600  and a suitable clamping means (not shown). The clamping means may take many forms, e.g., wedges, bolts, etc. and must be capable of holding rod  604  firmly in place within member  600  without slippage.  
      Outer members  502  and  504  are designed to be secured such that they form a channel for ladder leg  700  to be held within. Hinge connections  514 ,  516 ,  518 , and  520  are easily connected together by sliding pins  522  into the aligned holes (as shown in  FIGS. 5, 6 , and  7 ) on each end of members  502  and  504 . Outer members  502  and  504  are positioned or placed on ladder leg  700 , and sliding clamp member  600  is then positioned at the desired location, preferably just below a ladder rung  702 . Splices  506  and  508  are positioned and slid onto clamp member  600 , with their respective splices and grooves meshing. As shown in  FIGS. 6 and 7 , corresponding hinge connections  516  and  514  and  518  and  520  are interlocked using pins  522 . Splices  506  and  508  on outer members  502  and  504  are then able to grip splices  606  of clamp member  600 , thus allowing for a tight grip on ladder leg  700 .  
      Also, as shown in  FIG. 8 , clamping member  600  has one end that is to be placed adjacent ladder leg  700  which has a substantially V-shaped or double-angled edge configuration  610  to insure a slip free surface against ladder leg  700  by bearing against the leg and at least one edge of a leg rail or flange. Angled edge  524  on interior surface  505  of outer member  502  is also provided against ladder leg  700  to insure a slip-free surface.  
      In use, the forces on the ladder and the adjustable support act to tighten the grip of the channel formed by outer members  502  and  504  and clamp member  600  on ladder leg  700 , thereby insuring against slippage. Clamp member  600  experiences an upward force from rod  604 , while members  502  and  504  experience a downward force from ladder leg  700 . This tends to cause clamp member  600  to move slightly upward relative to outer members  502  and  504 . Because of the sloping splices, clamp member  600  is biased towards ladder leg  700  when it moves upward. Therefore, the slight upward movement caused by the forces act to bias the clamp member towards ladder leg  700 , thereby tightening the grip of the outer members and clamp member on the ladder leg. Ladder leg  700  is held forcibly and tightly against angled edge  524  of outer member  502  to securely support the ladder upon placement on an uneven surface, thus acting as a “ladder leveler.” Support rod  604  may then be adjusted in bore  608  to produce the desired leg extension and locked in place. Thus, as can be seen, no tools of any sort are required to assemble and use the adjustable ladder support according to the invention. The ladder attachment is also capable of being easily connected and removably secured to a ladder leg through the above-described detachable outer members. Furthermore, the design and assembly provide a stronger, safer, and more user-friendly attachment device for extending or adjusting the level of a ladder leg.  
      The foregoing is considered illustrative only of the principles of the invention. Therefore, it will be understood that there is no intent to limit the invention by such disclosure, but rather, it is intended to cover all modifications and alternate constructions falling within the spirit and scope of the invention. For example, while base unit  500  formed of two outer members  502  and  504  has been illustrated, the present invention is not limited thereto to a specific number of pieces. As another alternative, a nut and bolt arrangement, or other screw-type mechanism, can be used in place of pins to provide the connection of the adjustable, substantially inward compressive force as provided by the detachable outer members  502  and  504 .  
     CONCLUSION  
      A system and method has been shown in the above embodiments for the effective implementation of an improved adjustable ladder support. While various preferred embodiments have been shown and described, it will be understood that there is no intent to limit the invention by such disclosure, but rather, it is intended to cover all modifications and alternate constructions falling within the spirit and scope of the invention, as defined in the appended claims. For example, the present invention should not be limited by size, form, materials, or specific manufacturing techniques. Also, the connection of the detachable outer members may include alternate methods that allow for easier assembling and disassembling of the ladder support and should not be limited to hinge mechanisms.