Patent Publication Number: US-6904728-B2

Title: Log home construction system

Description:
BACKGROUND 
   1. Field of the Invention 
   The present invention relates generally to structures composed of individual wall members and methods of constructing those structures. More particularly, the present invention relates to log structures and a thru-bolt system for constructing log structures. 
   2. Background of the Invention 
   Log structures are constructed for a variety of purposes. The log structures typically are comprised of walls which include individual wall members that shrink or settle over time. The shrinkage or settling must be accommodated to facilitate a proper fit between the wall members. Without accommodation for the settling, the log structure may develop gaps or cracks in the walls. One previous approach has been to periodically tighten a fastener which compresses the wall members, however, this approach creates an undesirable maintenance burden. 
   Therefore, there is a need for an improved wall and method of constructing a wall which simplifies construction and accommodates shrinkage or settling of the wall members without the need for frequent maintenance. 
   SUMMARY OF THE INVENTION 
   The present invention eliminates the difficulties and disadvantages of the prior art by providing a wall for a structure. In one embodiment the wall comprises a plurality of wall members stacked substantially vertically, including a bottom wall member and a top wall member. Each of the wall members have an upper surface in opposed relation to a lower surface, and a through opening extending from the upper surface to the lower surface. A through opening in each wall member is aligned with a through opening in all other wall members so as to form a through opening in the wall extending from the upper surface of the top wall member to the lower surface of the bottom wall member. A rod is positioned in the through opening of the wall, the rod having an upper end in opposed relation to a lower end and the rod extending along a first axis. A lower fastener is attached to the lower end of the rod and attached to the bottom wall member. The lower fastener comprises a locking nut, and the locking nut includes an internally threaded portion for receiving a threaded portion of the lower end of the rod. The threaded portion of the locking nut extends substantially along the first axis. The locking nut also comprises a flange extending transversely to the first axis for supporting the threaded portion. The flange of the locking nut includes a fastening means attaching the flange to the lower surface of the bottom wall member to secure the lower fastener to the bottom wall member. In addition, the threaded portion of the locking nut comprises a tapered surface opening at an end of the threaded portion for receiving the rod to facilitate attachment of the rod to the lower fastener. The wall also includes an upper fastener attached to the upper end of the rod adjacent the upper surface of the top wall member, and an actuator positioned between the upper fastener and the upper surface of the top wall member for applying a downward force to the top wall member. 
   In a alternate embodiment the wall comprises a plurality of wall members stacked substantially vertically, including a bottom wall member and a top wall member, with each of the wall members including an upper surface in opposed relation to a lower surface and a through opening extending from the upper surface to the lower surface. A through opening in each wall member is aligned with a through opening in all other wall members so as to form a through opening in the wall extending from the upper surface of the top wall member to the lower surface of the bottom wall member. A rod is positioned in the through opening of the wall, the rod having an upper end in opposed relation to a lower end, and the rod extending along a first axis. A lower fastener is attached to the lower end of the rod and attached to the lower surface of the bottom wall member. The lower fastener comprises a locking nut, the locking nut including an internally threaded portion for receiving a threaded portion of the lower end of the rod, and the locking nut further including an unthreaded portion approximately one half inch (1.25 cm) long below the threaded portion. The threaded portion and unthreaded portion of the locking nut extend substantially along the first axis. The locking nut also includes a flange extending transversely to the first axis for supporting the threaded portion, and the flange of the locking nut includes a fastening means attaching the flange to the lower surface of the bottom wall member thereby securing the lower fastener to the bottom wall member. The wall also includes an upper fastener attached to the upper end of the rod adjacent the upper surface of the top wall member. There is an actuator positioned between the upper fastener and the upper surface of the top wall member for applying a downward force to the top wall member. 
   In a different embodiment, the wall comprises a plurality of wall members stacked substantially vertically, including a bottom wall member and a top wall member. Each of the wall members include an upper surface in opposed relation to a lower surface and a through opening extending from the upper surface to the lower surface. A through opening in each wall member is aligned with a through opening in all other wall members so as to form a through opening in the wall extending from the upper surface of the top wall member to the lower surface of the bottom wall member. A rod is positioned in the through opening of the wall, the rod having an upper end in opposed relation to a lower end, and the rod extending along a first axis. A lower fastener is attached to the lower end of the rod and attached to the lower surface of the bottom wall member. The lower fastener comprises a locking nut and the locking nut includes an internally threaded portion for receiving a threaded portion of the lower end of the rod. The threaded portion of the locking nut extends substantially along the first axis and the locking nut has a tapered surface opening at an end of the threaded portion for receiving the rod to facilitate attachment of the rod to the lower fastener. The locking nut also has a flange extending transversely to the first axis for supporting the threaded portion. The flange of the locking nut includes a fastening means attaching the flange to the lower surface of the bottom wall member to secure the lower fastener to the bottom wall member A spring support plate is attached to the upper surface of the top wall member. The spring support plate has an opening for the rod to pass therethrough and the spring support plate also has at least one hole for at least one spring support plate fastener. At least one the spring support plate fastener passes through a hole in the spring support plate thereby attaching the spring support plate to the top wall member. The wall also includes an upper fastener attached to the upper end of the rod adjacent the upper surface of the top wall member and a spring positioned between the upper fastener and the spring support plate for applying a downward force to the top wall member. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Preferred embodiments of the invention will now be described in further detail. Other features, aspects, and advantages of the present invention will become better understood with regard to the following detailed description, appended claims, and accompanying drawings (which are not to scale) where: 
       FIG. 1  is a perspective view of a portion of a wall constructed according to one embodiment of the invention; 
       FIG. 2  is an exploded view of a thru-bolt system for constructing walls in accordance with one embodiment of the invention; 
       FIG. 3  is a sectional view of a lower fastener according to one embodiment of the invention; 
       FIG. 4  is a perspective view of a portion of a wall constructed according to another embodiment of the invention; and 
       FIG. 5  is an exploded view of a thru-bolt system for constructing walls in accordance with another embodiment of the invention. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT(S) 
   With reference now to the drawings in which like reference characters designate like or similar parts throughout the several views,  FIG. 1  provides a perspective view of a portion of a wall  10  constructed according to the invention. Wall members  12  are preferably stacked substantially vertically. In a particularly preferred embodiment, the wall members  12  comprise wooden logs. The wooden logs may be sawed, cut, formed, or otherwise processed prior to being stacked as part of the wall  10 . The wall members  12  can also be formed from other materials such as plastics, resins or other materials suitable for constructing structures. Each wall member  12  includes an upper surface in opposed relation to a lower surface. Preferably, the lower surface of each wall member  12  is substantially parallel to the upper surface of each wall member  12 . 
   The wall members  12  may be of any suitable cross-sectional shape. Such cross-sectional shapes include, but are not limited to, a substantially rectangular shape, a “D” shape (as shown in FIG.  1 ), or a substantially rounded shape. The height, length, and width of the wall members  12  may be selected by those skilled in the art in accordance with the design requirements of the wall  10 . 
   The wall members  12  include a bottom wall member  14  and a top wall member  16 . Although  FIG. 1  only depicts the bottom wall member  14  and the top wall member  16 , it is understood that the wall  10  can, and typically will, include additional wall members  12  positioned between the bottom wall member  14  and the top wall member  16 . The height of wall members  12  and the number of wall members  12  included in the wall  10  control the total height of the wall  10 . Therefore, those skilled in the art can achieve a desired wall height by selecting a given wall member  12  size and stacking enough wall members  12  to reach the desired wall height. 
   The bottom wall member  14  includes a lower surface  18  in opposed relation to an upper surface  20 . Preferably, the bottom wall member lower surface  18  is substantially parallel to the bottom wall member upper surface  20 . In a preferred embodiment, the bottom wall member lower surface  18  is substantially smooth and the bottom wall member upper surface  20  is notched along the length of the bottom wall member  14 . Preferably, the notch along the bottom wall member upper surface  20  is a male notch such that it protrudes above the bottom wall member upper surface  20 . In an alternative embodiment, the notch along the bottom wall member upper surface  20  may be a female notch such that it forms a recess within the bottom wall member  14 . 
   The top wall member  16  includes a lower surface  22  in opposed relation to an upper surface  24 . The top wall member upper surface  24  is preferably substantially parallel to the top wall member lower surface  22 . In a preferred embodiment, the top wall member upper surface  24  is substantially smooth and the top wall member lower surface  22  is notched along the length of top wall member  16 . Preferably, the notch along the top wall member lower surface  22  is a female notch and forms a recess within the top wall member  16 . Alternatively, the notch along the top wall member lower surface  22  is a male notch and protrudes below the top wall member lower surface  22 . 
   In a preferred embodiment, each wall member  12  is notched along the upper and lower surfaces. In the preferred embodiment, the notches along the upper surfaces of the wall members  12  are male notches and the notches along the lower surfaces of the wall members  12  are female notches. Alternatively, the notches along the upper surfaces of the wall members  12  are female notches and the notches along the lower surfaces of the wall members  12  are male notches. The notches on the upper and lower surfaces of the wall members  12  are of a corresponding cross-sectional shape so that the notches on the upper surfaces of the wall members  12  mate with the notches on the lower surfaces of the wall members  12 . The male notches fit within the female notches to help secure the wall members  12  and to provide a tighter fit between the wall members  12 . 
   The wall members  12  include a through opening extending from the upper surface to the lower surface of each wall member  12 . In a preferred embodiment, the through opening in each wall member  12  has a substantially round cross-sectional shape. However, other cross-sectional shapes of the through opening in each wall member  12  are also acceptable. Preferably, each wall member  12  contains a plurality of through openings. In a particularly preferred embodiment, the through openings are located at twelve inch intervals along the length of each wall member  12 . Preferably, the through openings are drilled or otherwise formed in the wall members  12  prior to the wall members  12  arriving at the site for construction of the wall  10 . Alternatively, the wall members  12  are stacked and then the through openings are drilled through the stacked wall members  12 . 
   The bottom wall member  14  and the top wall member  16  also include through openings extending from the bottom wall member upper surface  20  to the bottom wall member lower surface  18  and the top wall member upper surface  24  to the top wall member lower surface  22  respectively. Preferably, a plurality of through openings are formed in the bottom wall member  14  and the top wall member  16  at twelve inch intervals. 
   As each wall member  12  is stacked, the through openings in the wall members  12  are aligned to create a through opening in the wall  10  extending from the top wall member upper surface  24  to the bottom wall member lower surface  18 . In a preferred embodiment wherein through openings are formed in each wall member  12  at twelve inch intervals, the through openings in each wall member  12  align with the through openings in the other wall members  12  such that through openings in the wall  10  are formed at twelve inches intervals. 
   After the wall members  12  are stacked with the through openings aligned, a rod  26  is inserted into the through opening in the wall  10 . As depicted in  FIG. 2 , the rod  26  extends along a first axis  28 . The rod  26  has an upper end  30  in opposed relation to a lower end  32 . Preferably, the rod  26  is threaded along its entire length. In an alternative embodiment, a portion of the rod upper end  30  and a portion of the rod lower end  32  are threaded. In a particularly preferred embodiment, a plurality of the rods  26  are inserted in multiple through openings along the length of the wall  10 . Preferably, a rod  26  is inserted in a through opening every three feet which allows wiring or other components to be placed in the through openings which do not contain a rod  26 . However, rods  26  may be spaced in any manner along the wall  10  to meet desired design parameters. The length of the rod  26  is preferably sufficient to extend from the bottom wall member lower surface  18  beyond the top wall member upper surface  24  as shown in FIG.  1 . 
   As shown in  FIG. 1 , a lower fastener  34  is attached at the rod lower end  32 . In a preferred embodiment depicted in  FIGS. 1 and 2 , the lower fastener  34  comprises a locking nut. The locking nut includes an internally threaded portion  36  extending substantially along the first axis  28  and a flange  38  extending substantially transversely to the first axis  28 . The flange  38  is fixedly attached to the threaded portion  36 . The flange  38  may be fixedly attached to the threaded portion  36  by welding or other suitable means, or the threaded portion  36  and the flange  38  may be formed as a single piece. The flange  38  supports the threaded portion  36 . Preferably, the flange  38  has a substantially elliptical shape. In an alternative embodiment, the flange  38  is substantially circular in shape. However, the shape of the flange  38 , is not limited to elliptical or circular. 
   In a preferred embodiment, the lower fastener  34  is attached to the bottom wall member  14 . Preferably, the flange  38  includes through apertures  40  which allow flange fasteners  42  to pass through the flange  38  and attach the lower fastener  34  to the bottom wall member  14 . Preferably, the flange fasteners  42  comprise nails. In an alternative embodiment, the flange fasteners  42  are screws or bolts. However, the flange fasteners  42  may be any other fastener suitable for attaching the lower fastener  34  to the bottom wall member  14 . In another alternative embodiment, the flange  38  does not include through apertures  40  and the lower fastener  34  is attached to the bottom wall member  14  through other fastening means such as adhesives. Alternatively, the lower fastener  34  is not attached to the bottom wall member  14  and may, for example, be held in place by use of a notched fit. 
   In a particularly preferred embodiment, the flange  38  is countersunk into the bottom wall member  14  such that the flange  38  does not extend substantially beyond the bottom wall member lower surface  18 . This embodiment allows the bottom wall member  14  to lay relatively smoothly on a sub-floor or other foundation on which the wall  10  is to be constructed without modification to the sub-floor or foundation. When the flange  38  is countersunk into the bottom wall member  14 , a shaped recess  39  is formed in the bottom wall member  14  Preferably, the shape of the shaped recess  39  corresponds to the shape of the flange  38 . In a preferred embodiment, the shape of the flange  38  and the corresponding shape of the shaped recess  39  prevent rotation of the lower fastener  34  within the bottom wall member  14 . For example, if the flange  38  is elliptical in shape as illustrated in FIG.  1  and the shaped recess is also elliptical in shape, then the shaped recess will prevent the flange  38  and therefore the lower fastener  34  from rotating. Other shapes, including but not limited to rectangular shapes, of the flange  38  and the shaped recess  39  will prevent rotation of the lower fastener  34 . Alternatively, if the flange  38  is circular in shape (or of another shape which would permit rotation in the bottom wall member  14 ) or if additional fastening means are desired, the flanged  38  may include protrusions, such as dimples or spikes) to engage the bottom wall member  14  and prevent rotation of the lower fastener  34 . 
   Preferably, the diameter of the through opening in the wall  10  is large enough to allow the threaded portion  36  of the lower fastener  34  to be inserted into the through opening. In a preferred embodiment in which a rod  26  is placed into a through opening every three feet, a lower fastener  34  is inserted into the corresponding through openings in the bottom wall member  14  every three feet. In alternative embodiments in which the rods  26  are spaced along the wall  10  at different intervals, the lower fasteners  34  are inserted into the corresponding through openings in the bottom wall member  34 . Preferably, the lower fasteners  34  are inserted into the appropriate through openings in the bottom wall member  14  prior to the wall members  12  being stacked. 
   As the rod  26  is inserted into the through opening of the wall  10 , the rod  26  is received by the internally threaded portion  36  of the lower fastener  34  and is attached to the lower fastener  34  by rotating the rod  26  about the first axis  28  thereby engaging the threads of the threaded portion  36 . With reference to  FIG. 3  in a preferred embodiment, the threaded portion  36  includes a tapered surface opening  44 . As the rod  26  approaches the threaded portion  36 , the rod  26  is guided into the threaded portion  36  by the tapered surface opening  44 . The tapered surface opening  44  facilitates attachment of the rod  26  to the lower fastener  34 . 
   In a preferred embodiment, the threaded portion  36  has sufficient length along the first axis  28  to accommodate debris such as wood particles that may enter into the through opening in the wall  10 . Thus, the length of the threaded portion  36  is preferably longer than necessary to attach the rod  26  to the lower fastener  34 . The additional length allows wood particles or other debris to accumulate within the lower fastener  34  without affecting the ability of the lower fastener  34  to attach to the rod  26 . In a preferred embodiment, the length of the threaded portion  36  of the lower fastener  34  is approximately three inches wherein approximately two inches are used to attach the rod  26  to the lower fastener  34  with the extra one inch used for accumulation of wood particles or other debris. Preferably, the threaded portion  36  is threaded for a length sufficient to attach the rod  26  to the lower fastener  34  and the additional length for accumulation of debris need not be threaded as depicted by unthreaded portion  37  on FIG.  3 . Alternatively, the entire length of the threaded portion  36  is threaded. 
   An actuator  46  is positioned between the top wall member upper surface  24  and an upper fastener  47 . In a preferred embodiment as depicted in  FIGS. 1 and 2 , the actuator  46  includes a spring  48  held in compression between the upper fastener  47  and the top wall member  16 . Preferably, the actuator  46  also includes a spring support plate  50  positioned between the spring  48  and the top wall member  16 . The spring support plate  50  preferably includes a rod hole  51  for allowing the rod  26  to pass through the spring support plate  50 . The spring support plate  50  also preferably includes through holes  52  which allow spring support plate fasteners  54  to pass through and attach the spring support plate  50  to the top wall member  16 . In a preferred embodiment, the spring support plate fasteners  54  are nails. Alternatively, the spring support plate fasteners  54  are screws or bolts although other fasteners capable of attaching the spring support plate  50  to the top wall member  16  are also acceptable. In another alternative embodiment, the spring support plate  50  is not attached to the top wall member  16 .  FIGS. 1 and 2  show one embodiment wherein the spring  48  comprises the actuator  46 , however other embodiments include a hydraulic cylinder or other suitable actuator capable of applying a downward force to the top wall member  16 . 
   With reference to  FIGS. 1 and 2  in a preferred embodiment, the upper fastener  47  includes at least one washer  56  and a nut  58 . The washer or washers  56  are placed about the rod  26  above the actuator  46  and the nut  58  is threaded onto the rod  26 . In a preferred embodiment, the washers  56  and the nut  58  hold the spring  48  in compression. As the wall members  12  settle or shrink, the spring  48  has sufficient travel to allow a downward force to be maintained to the top wall member  16 . Preferably, the length of travel of the spring  48  held in compression is approximately two and one-half inches which accommodates most, if not all, shrinking or settling of the wall members  12 . The downward force exerted by the actuator  46  helps ensure a tight, energy efficient fit between the wall members  12  even as the wall members  12  shrink or settle. 
   With reference to  FIGS. 4 and 5 , in an alternative embodiment the rod  26  may comprise at least two rod members, such as an upper rod member  60  and a lower rod member  62 . This alternative embodiment is particularly useful for higher walls. In this alternative embodiment, the upper rod member  60  and the lower rod member  62  are attached by a coupling  64 . The coupling  64  may comprise a nut or other coupling suitable for attaching the two rod members  60  and  62 . Although  FIGS. 4 and 5  depict only two rod members  60  and  62 , it is contemplated that additional rod members may comprise the rod  26  and be joined together by additional couplings  64 . 
   The upper rod member  60  has an upper end  66  in opposed relation to a lower end  68  and the lower rod member  62  has an upper end  70  in opposed relation to a lower end  72 . The upper rod member upper end  66  is attached to the upper fastener  47  and the upper rod member lower end  68  is attached to the coupling  64 . The lower rod member upper end  70  is also attached to the coupling while the lower rod member lower end  72  is attached to the lower fastener  34 . This alternative embodiment allows multiple rod members to be joined to comprise the rod  26  and accommodate varying heights and configurations of the wall  10 . 
   While the invention has been described in detail, it is to be expressly understood that it will be apparent to persons skilled in the relevant art that the invention may be modified without departing from the spirit of the invention. Various changes of form, design or arrangement may be made to the invention without departing from the spirit and scope of the invention. Therefore, the above mentioned description is to be considered exemplary, rather than limiting, and the true scope of the invention is that defined in the following claims.