Abstract:
An anchor bolt assembly is provided for connecting a sill to a foundation. The anchor bolt assembly includes an anchor bolt having a threaded end and another end that extends into the foundation. A corrosion resistant bushing extends around a portion of the anchor bolt for isolating the anchor bolt from a treated sill and providing an impervious barrier around a portion of the anchor bolt so as to prevent the anchor bolt from becoming corroded due to the treated nature of the seal.

Description:
FIELD OF THE INVENTION 
   The present invention relates to static structures and more particularly to an anchor bolt assembly for connecting a treated sill to a foundation. 
   BACKGROUND OF THE INVENTION 
   Wood treated for decay and insect resistance is typically used on building construction in applications particularly susceptible to wood destroying organisms. The most common application is for sills, which are generally the elongated wooden plates anchored to the tops of foundations to facilitate connection of floor and wall framing. These plates are generally 2″×6″ or 2″×8″ cross section pieces of treated lumber. In some applications two or more such plates are stacked to create thicker sills. Sills must, by all applicable building codes, be appropriately anchored to the foundations. The most common method of anchorage entails the use of anchor bolts, the unthreaded ends of which are embedded into the tops of foundation walls leaving the threaded ends projecting upwards above the walls. These anchor bolts are embedded at certain intervals along the horizontal length of the foundation wall, and the sills are drilled to provide holes which align with the bolts. The sills are placed over the bolts, and washers and nuts are applied and tightened to secure the sills to the walls. 
   The most commonly used wood treatment material is chromated copper arsenate (CCA). However, due to concerns about leaching of arsenic from the wood and the potential health hazards associated therewith, CCA is being phased out of usage for treating wood. Alternatives are known to be more corrosive to metal components used in conjunction with the treated wood. Corrosion of metal fasteners, such as anchor bolts and washers, presents an important issue of building integrity and safety. There exists then the need for means to protect metal fasteners from the corrosive effects of these chemicals. 
   Several kinds of metal protecting means have been employed or are being considered. Among them are fabrication of anchor bolts from corrosion-resistant alloys, painting impermeable compounds onto anchor bolts, and galvanic coating such as zinc. Corrosion resistant alloys are significantly more expensive than regular steel bolts. Painting materials on the steel bolts is only slightly more expensive, but highly subject to failure due to surface imperfections and scratches occurring in handling and assembly. Galvanic coatings are somewhat more expensive and will provide protection for a time period. However, these coatings work in a sacrificial mode to isolate steel from corrosion and their effectiveness will dissipate over time. 
   Thus there exists a need for a reliable method of protecting anchor bolt assemblies from corrosion arising from wood treatment chemicals. 
   SUMMARY OF THE INVENTION 
   The present invention relates to an anchor bolt assembly that extends through an opening in a treated wood sill for securing the sill to a foundation. Forming a part of the anchor bolt assembly is an anchor bolt having opposed end portions, one end portion adapted to extend into and to be anchored within the foundation and another end portion that is threaded. Additionally, the anchor bolt assembly includes a corrosion resistant bushing that extends around a portion of the anchor bolt for isolating the anchor bolt from the treated sill and providing an impervious barrier around a portion of the anchor bolt so as to prevent the anchor bolt from being corroded due to the treated nature of the sill. 
   Further, the present invention entails a method of protecting an anchor bolt from the corrosive effects of a treated wood sill. This method entails inserting an anchor bolt through an opening in the treated wood sill that forms a part of a building structure and which lies between a support structure such as a foundation and a series of wall studs. Additionally, the method entails inserting a polymeric bushing into the opening and surrounding the anchor bolt with the bushing such that the bushing forms an impervious barrier between the anchor bolt and the treated wood sill. 
   In addition, in one particular embodiment, the present invention entails a method of connecting a sill comprised of one or more treated wood members having a certain thickness to a foundation wherein an anchor bolt is embedded vertically into the top of a foundation with at least an upper threaded portion of the anchor bolt disposed above the foundation. At least one hole or opening is formed in the sill such that the vertically disposed end of the anchor bolt extends through a hole in the sill. Further there is provided a bushing having an elongated tubular section of a selected length and a flange section disposed perpendicular thereto. This tubular section is interposed over the bolt and disposed inside the hole of the sill so that the elongated tubular section is disposed around the bolt and the flange section rests on top of the sill. The length of the tubular section is slightly less than the thickness of the sill and wherein a nut is engaged with the end of the bolt and tightened, thereby causing the sill to be pressed against the foundation and to be compressed between the flange section of the bushing and the top of the foundation such that the bottom end of the elongated tubular section is caused to make contact with the top of the foundation. 
   Another embodiment of the present invention entails a wall section for a building. This wall section includes a treated wood sill and a support structure underlying and supporting the treated wood sill. A plurality of studs extend upwardly from the sill and there is provided at least one opening extending through the sill. At least one anchor bolt assembly secures the sill to the support structure. This anchor bolt assembly includes an anchor bolt and a corrosion resistant bushing that extends around a portion of the anchor bolt for isolating the anchor bolt from the treated sill. 
   Other objects and advantages of the present invention will become apparent and obvious from a study of the following description and the accompanying drawings which are merely illustrative of such invention. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is an exploded view of the anchor bolt assembly of the present invention. 
       FIG. 2  is an exploded view of the anchor bolt assembly of the present invention shown in combination with a foundation and a sill. 
       FIG. 3  is a perspective view showing the anchor bolt assembly of the present invention securing the sill to the foundation. 
       FIG. 4  is a sectional view illustrating the anchor bolt assembly anchored within a foundation prior to the securing nut being tightened. 
       FIG. 5  is a view similar to  FIG. 4 , but with the nut being fully tightened. 
       FIG. 6  is a view similar to  FIG. 5  wherein the sill is comprised of two members, one disposed over the other. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   The present invention entails an anchor bolt assembly indicated generally by the numeral  10 . Anchor bolt assembly  10  is utilized to make a connection between a treated wood sill and a foundation by employing an impervious polymeric bushing to effectively prevent contact between the wood and the anchor bolt assembly. As will be appreciated from subsequent portions of the disclosure, in a typical application, a wooden sill is anchored to a masonry foundation by means of a series of anchor bolts embedded in the foundation with threaded ends extending above the foundation. Wooden sills with holes drilled to fit over the extended threaded ends of the anchor bolts is placed on the foundation, and a washer and a nut are used to tighten the connection. The bushing comprises an elongated tubular structure with a perpendicular flange on one end. Upon assembly, the bushing is placed over the threaded end of the anchor bolt and into the hole in the sill thereby effectively preventing contact of the anchor bolt with the wood sill. The flange also provides a positive positioning of the bushing within the hole in the sill and protects the washer and the above disposed nut from the treated wood. It is appreciated that the impervious nature of the bushing is such that any chemicals or compounds emanating from the sill are prevented from having unvented contact with the anchor bolt, securing nut or washer. 
   Turning particularly to the drawings and the description of the anchor bolt assembly, the anchor bolt assembly  10  includes an anchor bolt  12 . Anchor bolt  12  includes an anchor end  12 A, a threaded end  12 B and an intermediate portion  12 C. Intermediate portion  12 C extends between the anchor end  12 A and the threaded end  12 B. While the anchor bolt  12  may assume various shapes, in some embodiments the anchor end  12 A is either turned as shown in  FIG. 1  or can be curved to embed into a foundation. 
   Further, anchor bolt assembly  10  includes a nut  14  and a washer  16 . As will be appreciated from subsequent portions of the disclosure, the nut  14  is utilized to secure the anchor bolt assembly  16  within a sill. In particular, nut  14  is tightened onto the threaded end  12 B of the anchor bolt such that it engages the washer  16  and secures the anchor bolt assembly between the foundation and the sill. 
   A bushing indicated generally by the numeral  20  also forms a part of the anchor bolt assembly  10 . Bushing  20  includes an elongated tubular section  22  and an upper flange  24 . Formed intermediately on the tubular section  22  is a circumferential break line  26 . Essentially, the thickness of the tubular section  22  is reduced around the break line  26  such that the tubular section can be easily broken and separated along the break line  26 . As will be appreciated from subsequent portions of the disclosure, the break line  26  formed in the tubular section  22  of the bushing  20  permits the bushing  20  to be utilized with sills of varying thicknesses. For example, the bushing  20  shown in  FIG. 1  can be utilized in a thicker sill, a sill such as that shown in  FIG. 6  and comprised of two wood members, one laid over the other. By breaking off the lower portion of the tubular section  22 , the bushing  20  is effectively shortened. In that case, the bushing  20  is effective in a single wood member sill such as that shown in  FIGS. 4 and 5 . 
   It is contemplated that the bushing  20  will be made of a material that will resist corrosion and particularly the harmful effects of any chemicals or compositions that are used to treat the wood sill. In one embodiment it is contemplated that the bushing  20  will be made of a plastic or polymeric material. 
   In  FIGS. 2-6 , there is shown the anchor bolt assembly  10  being utilized to connect one or more sills to a foundation wall. For purposes of reference, the foundation comprises a series of concrete blocks  30 . Blocks  30  include hollow cavities that receive concrete fill  32 . Other forms of support structures or foundation walls can be utilized. Disposed over the foundation is one or more sills with each sill being indicated by the numeral  40 . As noted above, it is typically to use sills that are generally 2″ by 6″ or 2″ by 8″ and which have been appropriately treated. 
   Turning to  FIG. 2 , the anchor bolt assembly  10  is illustrated therein and shown in an exploded configuration in relationship to the foundation and a single sill  40 . Note that the anchor bolt  12  is embedded in the concrete fill  32  and projects upwardly therefrom through an opening in the sill  40 . Typically a wall structure would include a series of anchor bolt assemblies  10  uniformly spaced along the foundation wall. In any event, threaded portion  12 B of the anchor bolt is projected through the opening in the sill. Because only one sill  40  is utilized, the lower portion of the bushing  20  has been separated along the break line  26 , leaving a relatively short bushing  20 . 
   Turning to  FIG. 4 , the anchor bolt assembly  10  is shown extending upwardly through the concrete fill  32  and through an opening formed in a single sill  40 . In FIG.  4 , the nut  14  has not been tightened down on the threaded portion  12 B of the anchor bolt  12 . Note in  FIG. 4  where the lower terminal end of the tubular section  22  of the bushing  20  is spaced slightly above the foundation. In other words, the lower terminal end of the bushing  20  terminates short of the bottom of the sill  40 . 
     FIG. 5  shows the anchor bolt assembly  10  fully secured between the foundation and the sill  40 . The length of the bushing  20  should be established based on the height of the sill  40 . It is contemplated that the length of the tubular section  22  should be slightly less than the height of the sill  40 . Thus, when the nut  14  is tightened down on the washer  16  it is appreciated that the washer  16  will engage the upper face of the flange  24 . Once the nut  14  has caused the washer  16  to engage the flange and push the flange against the top of the sill  40 , the length of the bushing  20  may still be such that the lower terminal end does not quite reach the bottom of the sill  40 . However, by continuing to tighten the nut  14  the washer  16  will be driven downwardly against the flange  24  and the flange  24  can slightly compress the wood of the sill  40  causing the top portion of the sill underneath the flange  24  to be slightly compressed. This amount of compression should allow the lower terminal end of the tubular section  22  of the bushing to extend downwardly and seat against the foundation. 
   As noted above, in certain situations the sill can comprise two members disposed one over the other. This is illustrated in  FIG. 6 . In this case, the tubular section  22  assumes the length shown in  FIG. 1 . That is, the lower portion has not been broken off along the break line  26 . Indeed the break line  26  can be seen in  FIG. 6 . However, the length of the tubular section  22  that forms a part of the bushing  20  in one embodiment would be of a length such that when the flange fits flush against the top surface of the top sill, that the lower terminal end of the tubular section  22  would terminate just short of the foundation or short of the bottom surface of the lower most sill  40 . Again, the nut  14  can be tightened down on the washer  16  so as to drive the same into contact with the flange  24  and to press the flange into the top surface of the top sill  40 . This compression will result in the lower terminal end of the tubular section  22  seating against the foundation. 
   From the foregoing specification and discussion, it is appreciated that by interposing the bushing  20  between the sill  40  and the anchor bolt assembly, than an impervious barrier is formed that prevents corrosion causing chemicals and compositions from reaching the metal components of the anchor bolt assembly  10 . This, of course, prevents the components of the anchor bolt assembly  10  from becoming corroded, which in turn compromises the strength and integrity of these connectors. 
   The present invention may, of course, be carried out in other specific ways than those herein set forth without departing from the scope and the essential characteristics of the invention. The present embodiments are therefore to be construed in all aspects as illustrative and not restrictive and all changes coming within the meaning and equivalency range of the appended claims are intended to be embraced therein.