Patent Publication Number: US-6907707-B2

Title: Converted wood article

Description:
RELATED APPLICATION 
   This application is a continuation-in-part of U.S. patent application Ser. No. 09/250,166 filed Feb. 16, 1999, now U.S. Pat. No. 6,286,287 issued Sep. 11, 2001, which is a continuation-in-part of U.S. patent application Ser. No. 08/805,141 filed Feb. 24, 1997, now U.S. Pat. No. 5,870,876 issued Feb. 16, 1999. 

   FIELD 
   The present invention relates to converted wood articles and composite wood products made therefrom for use in general construction primarily but not limited to posts, flooring, walls and support beams, the posts and beams being both structural and non-structural, and a method for fabricating such articles and products. 
   BACKGROUND 
   The depletion of old growth forest has placed increasing demand within the forest industry for alternative wood products which make better use of old growth and stagnant growth timber and which also provide for greater use of second, third and later generation trees. 
   Several alternative wood products have emerged in an effort to address some of the needs in the industry. In this respect U.S. Pat. No. 4,394,409 discloses a composite wood product formed from four elongated triangular-shaped wood pieces. The four pieces are joined to form a composite wood product having a cross-sectional outline of a parallelogram and a hollow interior. An alternative embodiment is disclosed where each wood piece has a pair of machined keys to improve yield. 
   In U.S. Pat. No. 5,299,400 there is disclosed a composite wood product formed from four log parts, each log part having a three sided cross-section forming either right angled sectors and a third curved face or a right triangle. The log parts are assembled into a composite wood product so that their right angles form the corners of a rectangle with a hollow interior which is filled with concrete or other structural enhancing material. Similar examples of this alternative wood structure appear in U.S. Reissue 35,327 and French Patent No. 962589. Other attempts to offer improved composite wood products can be found in French Patent No. 2512729 and German Patent No. 964637. 
   While the composite wood products disclosed in the above mentioned references provide some improvements to the known art, there remains a continuing need for composite wood products providing additional resistance to shearing forces and impact forces, assembled from converted wood parts having a larger bonding surface and having a higher load bearing capacity without the preemptive need for the structural reinforcing material indicated in the prior art. Accordingly, it is an object of the invention to provide alternative converted wood articles for use in making composite wood products to fulfill the above needs in the art. 
   SUMMARY OF THE INVENTION 
   According to the invention there is provided a converted elongated wood article having a first planar face and a longitudinally extending face with rectangular steps whose step surfaces are parallel to a longitudinal extension of the article. A first set of the step surfaces are parallel to and a remaining second set of the step surfaces are perpendicular to the first planar face. The rectangular steps extend from the first planar face to a second planar face coinciding with a parallel one of the first step surfaces. A third face is oriented such that the first planar, the longitudinally extending, the second planar and the third faces form a triangular cross-section. 
   The third face may be a planar face at a right angle to the first planar face. Alternatively, the third face may be a longitudinally extending face having rectangular steps whose step surfaces are parallel to a longitudinal extension of the article and have a first set of step surfaces parallel to, and a second set of step surfaces perpendicular to, the first planar face. Preferably, planes passing through the extremities of the steps each form an equal angle with the longitudinally extending face. 
   The steps of a converted elongated wood article may have substantially similar or different dimensions. In one embodiment, the number of rectangular steps on a stepped face is three. 
   Further included within the scope of this invention is a method of fabricating a composite wood product by gluing together at least two converted elongated wood articles, each having a first planar face and a longitudinally extending face with rectangular steps having step surfaces parallel to a longitudinal extension of the converted elongated wood article. A first set of the step surfaces are parallel to and a second remaining set of the step surfaces are perpendicular to the first planar face. The steps extend to a second planar face coinciding with a parallel one of the first step surfaces. Each converted elongated wood article also has a third face oriented such that the first planar, the longitudinally extending, the second planar and the third faces form a triangular cross-section. The rectangular steps of one of the converted elongated wood articles are joined in mating abutment to the rectangular steps of another of the converted elongated wood articles forming a joint. 
   Further included within the scope of this invention is a method of fabricating a converted elongated wood article from a log. The converted elongated wood article is formed with a first planar face and a longitudinally extending face with rectangular steps whose step surfaces are parallel to a longitudinal extension of the converted elongated wood article. A first set of the step surfaces are parallel to, and a second set of the step surfaces are perpendicular to, the first planar face. A second planar face is formed parallel to the first planar face such that the second planar face and the steps are proximate a periphery of the log and the first planar face lies along a diameter of the log. A third face is also formed and oriented such that the first planar, the longitudinally extending, the second planar and the third face form a triangular cross-section. Preferably, the triangular cross-section of the log is such that at least two vertices of the triangular cross-section are outside the periphery of the log and the edges of at least two steps are on the periphery of the log. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The novel features believed characteristic of the invention are set forth in the appended claims. The invention itself, however, as well as other features and advantages thereof, will be best understood by reference to the detailed description which follows, read in conjunction with the accompanying drawings, wherein: 
       FIG. 1  is a perspective view of one converted elongated wood article having two planar faces and one stepped face; 
       FIG. 2  is a cross-sectional view of a portion of the converted elongated wood article in  FIG. 1 ; 
       FIG. 3  is a perspective view of another converted elongated wood article having one planar face and two stepped faces; 
       FIG. 4A  is a cross-sectional view of a portion of the converted elongated wood article in  FIG. 3 ; 
       FIG. 4B  is a cross-sectional view of a log and a converted elongated wood article cut therefrom; 
       FIG. 5  is a perspective view of a composite wood product comprising converted elongated wood articles; 
       FIG. 6  is a cross-sectional view of another composite wood product comprising converted elongated wood articles; 
       FIG. 7A  is a cross-sectional view of another composite wood product; 
       FIG. 7B  is a cross-sectional view of another composite wood product; 
       FIG. 8  is a cross-sectional view of yet another composite wood product comprising an arrangement of converted elongated wood articles; 
       FIG. 9  is a cross-sectional view of yet another composite wood product; 
       FIG. 10  is a perspective view of a composite wood product used in conjunction with other wood boards; 
       FIG. 11  is a cross-sectional view of another composite wood product under this invention; and 
       FIG. 12  is a flow diagram for the method of making converted elongated wood articles and composite wood products. 
   

   DETAIL DESCRIPTION WITH REFERENCE TO THE DRAWINGS 
   Referring to  FIG. 1 , a converted elongated wood article  10  is formed according to the method set out below from a wood piece  11  and having rectangular steps  13  extending longitudinally in the direction of arrow A along stepped face  15 . 
   Referring to  FIG. 2 , converted elongated wood article  10  having a triangular cross-section includes a first planar face  22  and a third planar face  26  and longitudinally extending stepped face  20 . Planar faces  22  and  26  intersect at region  24  forming substantially right angle α. Stepped face  20  intersects with planar face  22  and planar face  26  forming substantially right angles α′ and α″, respectively. Rectangular steps  12   a,    12   b,  and  12   c  form the outline of stepped face  20 . The rectangular steps  12   a,    12   b,  and  12   c  are comprised of a first set of step surfaces  14  and a second set of step surfaces  18  intersecting at substantially right angle corner  16 . In the embodiment illustrated, steps  12   a,    12   b,  and  12   c  are dimensioned and oriented such that each corner  16  substantially lies along a notional straight line  21 . A second planar face is defined as coincident with the first step surface  14  of rectangular step  12   a.    
   Referring to  FIG. 3 , in another converted elongated wood article  30  is formed from elongated wood piece  31  having rectangular steps  37  on longitudinally extending stepped face  33  and stepped face  35 . Stepped face  35  replaces planar face  26  from the converted elongated wood article of FIG.  2 . 
   Referring to  FIG. 4A , converted elongated wood article  30  is shown having stepped faces  33  and  35 , and planar face  42 . Stepped face  33  is formed from rectangular steps  40  with each of rectangular steps  40  having edge  34  and edge  38  which intersect at substantially right angle corner  36 . Stepped face  35  is similarly formed from rectangular steps  44  each having edges  46  and  50  intersecting at substantially right angle corner  48 . Each of rectangular steps  40  and each of steps  44  after first steps  41  and  43  are successively offset from bisecting line  42 . Accordingly, stepped faces  33  and  35  are arranged so that distances δ 1 , δ 3 , and δ 5  from bisecting line  42  and distances δ 2 , δ 4 , and δ 6  from bisecting line  42  are successively larger. 
   In the illustrative embodiment in  FIGS. 1 and 2 , converted elongated wood article  10  is formed from a log with a 100 mm diameter which has been sectioned into 1 meter long segments. Converted elongated wood article  10  has three rectangular steps on stepped face  20 , each step having a height and width of approximately 15 mm. The cross-sectional length of planar faces  22  and  26  are 45 mm each. Converted elongated wood article  30  in  FIGS. 3 and 4A  is cut from log  55  having a diameter of approximately 100 mm which has been sectioned into 1 meter lengths. Each rectangular step of stepped faces  33  and  35  has a height and width of 15 mm, so that planar face  42  has a length of approximately 90 mm. The above dimensions are illustrative of some of the typical converted elongated wood articles contemplated in the present invention. It will be understood, however, that the length, height and width of converted elongated wood articles and the dimensions and number of steps will vary for selected applications. The type of wood source and dimensions of the wood source will also vary. 
   The converted elongated wood articles in  FIGS. 1  to  4 B may be used to form a large variety of composite wood products, as indicated, by way of example, in  FIGS. 5  to  11 . 
   Referring to  FIG. 5 , converted elongated wood articles  52   a  and  52   b  are arranged to form composite wood product  52   c.  Stepped faces  52   d  and  52   e  of converted elongated wood articles  52   a  and  52   b  respectively are oriented inwardly and mate with each other so that composite wood product  52   c  has a rectangular cross-sectional outline. 
   Referring to  FIG. 6 , converted elongated wood articles  54   a  and  54   b  are arranged to form composite wood product  54   c  which in turn is attached to second composite wood product  54   d  to form composite wood product  54   e.  Additional composite wood products (not shown) may be attached to form larger composite wood products. 
   Referring to  FIG. 7A , the cross-section of another composite wood product  60   e  is shown comprising converted elongated wood articles  60   a,    60   b,    60   c,  and  60   d  which are of substantially similar dimension. Stepped faces  60   f  on each of converted elongated wood articles  60   a  to  60   d  are oriented to face inwardly within composite wood product  60   e  so as to abut corresponding stepped faces of neighboring converted elongated wood articles forming hollow rectangular interior  60   h  and substantially rectangular cross-sectional outline  60   g.  Referring to  FIG. 7B , composite wood product  60   e  is shown having reinforcing rod  60   i  fixed within hollow rectangular interior  60   h  to provide enhanced load bearing capacity. 
   Referring to  FIG. 8 , another composite wood product  62   a  is shown having rectangular cross section  62   c  and comprising converted elongated wood articles  62   b  each having stepped faces  62   d  and  62   e.    
   Referring to  FIG. 9 , yet another composite wood product  64   a  is shown comprising two different sets of converted elongated wood articles contemplated herein, namely converted elongated wood articles  64   b  and converted elongated wood articles  64   c.    
   Referring to  FIG. 10 , composite wood product  66   b  is shown located between wood boards  66   a  and wood boards  66   d  which in combination form composite wood product  66   g.  Wood boards  66   a  and  66   d  are shown attached to faces  66   e  and  66   f  of composite wood product  66   b.    
   Referring to  FIG. 11 , composite wood product  68   a  has converted elongated wood articles  68   b  and converted elongated wood articles  68   c  inversely arranged and joined along stepped faces  68   d.  As with the other composite wood products, the number of rectangular steps on any face of converted elongated wood articles  68   b  and  68   c  will vary with the selected application. 
   Referring to  FIG. 12 , one method of manufacturing the converted elongated wood articles and composite wood products made therefrom is shown. Typically elongated wood logs are used as the initial input product to be processed. At step  70  the taper of the wood product is reduced by a cutter that cuts the swollen root end down and the wood is then cut transversely into wood segments which vary in length with the desired finished or semifinished product. In one preferable embodiment, the wood segments are cut substantially into 1 meter lengths to minimize warping when kiln drying at step  78 . Other segment lengths may apply depending on the drying effect of the species and the desired application. The resulting wood segments from step  70  are processed at steps  71  where they are debarked and edge trimmed and at step  72  the segments are put through a doweling machine and then undergo stacking preparation at step  73 . The stacked segments are then each cut longitudinally into elongated wood pieces at step  74 . The wood pieces undergo stickering at step  76 , preplaning at step  75  and are then kiln dried at step  78 . 
   The kiln dried wood pieces from step  78  are given an offset cut at step  77  and then a molding cut at step  84  to form converted elongated wood articles of the type described above having either one or more stepped faces. Alternatively, the kiln dried wood pieces from step  78  may be finger jointed at step  80 , and then given an offset cut at step  77  before undergoing the molding cut at step  84 . One may also use precomposed wood products, typically laminated or solid wood boards, or wood pieces cut from solid wood boards having a wane along one or more edges in step  84  as an alternative to the kiln dried wood pieces from step  78 . 
   The converted elongated wood articles produced at step  84  may be packaged and shipped for subsequent use in assembling the composite wood products described herein. 
   Alternatively, the converted elongated wood articles may then undergo glue lining at step  86 . Glue lining includes the application of bonding material to the surfaces of the stepped face of each converted elongated wood article. The amount and choice of bonding material applied at step  86  to the converted elongated wood articles may vary with the selected application of the final composite wood product. Preferably, the glue lining at step  86  includes application of bonding material to most or substantially all surfaces of each stepped face of the converted elongated wood article. Converted elongated wood articles are also assembled with corresponding converted wood articles in step  86  to form the composite wood products described above. 
   Once the converted elongated wood articles have undergone glue lining and assembly at step  86  the resulting composite wood products are assembled with other corresponding wood articles and pressed at step  90 . Composite wood products from step  90  are double end trimmed at step  92  and planed to final desired dimensions at step  94 , resulting in semifinished or finished composite wood products. Before undergoing pressing at step  90 , composite wood products from step  86  which are arranged having a hollow interior, such as in  FIG. 7B , may first have a reinforcing rod inserted into the hollow interior at step  88  to provide additional load bearing capacity and resistance to shearing and impact forces. Wood boards may also be glued and pressed to the faces of the composite wood product at step  90 . 
   The converted elongated wood articles described herein offer substantially improved surface area on stepped faces for the application of bonding material. The stepped face or faces on each converted elongated wood article further allows for easy assembly with corresponding converted wood articles to form a wide range of composite wood products. The composite wood products formed from the converted elongated wood articles provide significant improvements in resistance to shearing and impact forces and improved load bearing capacity. The composite wood products further avoid many of the complex reinforcing requirements of the prior art. In addition, the significant resistance to shearing and impact forces achieved in the composite wood products above permits the use of wood pieces from old growth and stagnant growth timber as well as younger generation timber for a much broader application of use in the lumber industry. The composite wood products are well suited for use in making flooring, paneling, support beams, and posts, and are also well suited as substitutes to the conventional use of solid wood pieces in the construction of homes and other buildings. The scope of application for smaller wood pieces provided by the converted wood articles further results in less wood waste. 
   It will be obvious to one skilled in the art that while the converted elongated wood articles have one or more stepped faces, the number of steps on any stepped face will vary as required by the desired composite wood product. It will be further obvious that it is not necessary for the steps on any stepped face to lie on a notional straight line. It will be further obvious that the dimensions of each step on a stepped face need not be the same. It will be further obvious that while a reinforcing rod may be inserted during assembly of composite wood products having a hollow interior, any reinforcing material may be inserted. 
   Accordingly, while this invention has been described with reference to illustrative embodiments, this description is not intended to be construed in a limiting sense. Various modifications of the illustrative embodiments, as well as other embodiments of the invention, will be apparent to persons skilled in the art upon reference to this description. It is therefore contemplated that the appended claims will cover any such modifications or embodiments as fall within the true scope of the invention.