Abstract:
A selective plurality of elongate half-logs, lumber planks which may have imperfect or damaged edges, or a combination of both, are superposed on each other and adhesively joined to form an intermediate assembly, which is then divided by one or more beam-long cuts made perpendicularly to the flat surfaces of the half-logs or planks. The resulting outer sections of the intermediate assembly, substantially mirror-images of each other, are reoriented so that the original outer edges face each other and are positioned so that a selected space remains between them. Various spacing and bracing elements are selectively chosen to connect the two outer sections and thus to form a laminated space-containing wood beam structure, on which surface-covering sheathing or coatings may be applied optionally.

Description:
FIELD OF THE INVENTION 
     This invention is directed to the production of laminated space-containing wood beams and related structural elements and to methods therefor, especially from unprocessed legs and lumber of less than top quality. 
     BACKGROUND OF THE INVENTION 
     In current practice, vast quantities of wood materials are under-utilized or discarded as being unfit for use in structural lumber. Logs in the range of an 8 inch diameter or less are considered to be too small for cutting into usable boards, planks or veneers. Planks cut from larger logs are rejected for first-quality applications when they have the defects of having waned, chipped or broken edges, or checked, cracked, split or even dry-rot surfaces. 
     This invention overcomes or neutralizes these deficiencies so that these less-than-perfect materials may be converted into high quality structural products lighter in weight and larger in size than conventional corresponding solid wood by reason of interior spaces therein, without sacrificing strength or appearance. All the defects and damages of the inferior materials are neutralized or concealed within the finished structural products. In addition, the methods of producing structural elements such as beams, joists, etc. disclosed and claimed herein are so highly efficient that they may be used even with first-quality undamaged starting materials to compete successfully in the marketplace against presently available beams or similar wood structural products. 
     It is a primary object of this invention to enhance the utility and value of small logs and imperfect lengths of lumber by creating high quality laminated structural beams, joists, etc., with interior space therein, at low cost and with little or no waste. It is another object of this invention to assemble these novel desirable lumber products efficiently and economically and thereby highly competitively in the structural wood products field, using the methods of this invention. 
     SUMMARY OF THE INVENTION 
     Small-diameter logs, bisected lengthwise into half-logs and flattened by trimming the rounded surface opposite the diametrically cut surface and parallel thereto, and precut planks which may have defective or damaged edges are the basic materials used to form the laminated space-containing wood beams of this invention. The half-logs, planks or combinations thereof are adhesively superposed in aligned stacks of two or more so that the upper and lower portions of the stacked assembly are wider than its central portion. Each stacked assembly is then cut vertically along its length to produce a pair of equally-sized mirror-image sections, which are arranged so that the original outer edges of the stacked intermediate assembly face toward each other in spaced relationship. Interior braces, spacers, outer covering layers or combinations thereof may be adhesively applied to hold the mirror-image sections together, and insulation materials and the like may be inserted into the remaining interior space before applying the covering layers, if any, to complete each laminated beam. 
     Details of all the preferred embodiments of this invention, and the methods used to create them, will be fully described in connection with the accompanying illustrative, but not limiting, drawings, wherein: 
    
    
     SHORT FIGURE DESCRIPTION OF DRAWINGS 
     FIG. 1 is an end perspective partial view of two half-logs of this invention in position to be assembled; 
     FIG. 2 is an end view of the two half-logs of FIG. 1 assembled and in position to be longitudinally bisected; 
     FIG. 3 is an end perspective partial view of the two sections cut as indicated in FIG. 2 spaced, and arranged in position to form a laminated beam structure in accordance with this invention; 
     FIG. 4 is an end perspective partial view of the arrangement of FIG. 3 with vertically disposed bracing spacers connecting the two sections thereof at intervals along their length; 
     FIG. 5 is an end perspective partial view of the two sections of FIG. 3 held together by a vertically disposed spacer plank mounted therebetween and extending their entire length; 
     FIG. 6 is an end perspective partial view of the two sections of FIG. 3 held together by two vertically disposed beam-long spacers extending inwardly from the top and bottom surfaces of the assembly; 
     FIG. 7 is an end perspective partial view of the two sections of FIG. 3 modified by having centrally disposed opposite interior channels cut the length of the two sections; 
     FIG. 8 is an end perspective partial view of the two sections of FIG. 7 assembled into a laminated beam structure with a horizontally disposed spacer plank occupying the interior channels thereof, and with top and bottom surface-facing elements in place; 
     FIG. 9 is an end perspective partial view of the two sections of FIG. 3 similar to FIG. 8, but with a pair of vertically disposed beam-long spacers added; 
     FIG. 10 is an end elevational view similar to FIG. 2 but using two larger diameter half-logs, in position to be divided by two vertical lengthwise cuts; 
     FIG. 11 is an end elevational view of another embodiment of this invention wherein the two sections have the beam-long laminated plank produced by the cuts of FIG. 10 adhesively connected therebetween; 
     FIG. 12 is an end elevational view of two trimmed half-logs with a plank mounted therebetween in position to be bisected; 
     FIG. 13 is an end perspective partial view of the two sections produced by bisecting the structure of FIG. 12, in position to be secured together by one or more spacers; 
     FIG. 14 is an end elevational view similar to FIG. 10, with a beam-long plank centrally mounted between two larger diameter half-logs, the assembly being in position to be divided by two vertical lengthwise cuts; 
     FIG. 15 is an end perspective partial view of three planks aligned and in position to be assembled in accordance with this invention; 
     FIG. 16 is an end elevational view of the three planks of FIG. 15 now assembled and in position to be longitudinally bisected; 
     FIG. 17 is an end perspective partial view of the two outer sections already cut as indicated in FIG. 16, arranged and spaced in position to be connected to form a laminated beam structure in accordance with this invention; 
     FIG. 18 is an end elevational view of an intermediate assembly similar to that of FIG. 16 but made with wider planks, in position to be divided into three sections by two parallel beam-long cuts; 
     FIG. 19 is an end perspective partial view of the elements produced by the two vertical beam-long cuts of FIG. 18; 
     FIG. 20 is an end elevational view of two wide planks sandwiching two side-by-side narrower planks therebetween, in position to be cut into three sections; 
     FIG. 21 is an end perspective partial view of a laminated beam assembly having cross-shaped bracing spacers placed at intervals along the length of the beam; 
     FIG. 22 is an end perspective partial view of a laminated beam structure with a vertically disposed beam-length spacer inserted therein; 
     FIG. 23 is an end perspective partial view of a laminated beam assembly with a beam-length horizontally disposed spacing element combined with a plurality of vertically disposed spacers above and below the horizontal spacer and positioned at intervals along the beam; 
     FIG. 24 is an end elevational view of two imperfectly edged wider planks at top and bottom, and two narrower planks in similar condition in between, all superposed and adhesively joined to each other, in position to be bisected; 
     FIG. 25 is an end perspective partial view of the two sections formed by the bisecting cut of FIG. 24, in position to be assembled into a laminated beam structure, with four angular cut lines for straightening the walls of the interior space therein before assembly; 
     FIG. 26 is an end perspective partial view of the sections of FIG. 25 after cutting and being assembled into a laminated beam structure by insertion of interior contour-following spacers at intervals along the length of the laminated beams; 
     FIG. 27 is an end elevational view of a horizontal spaced row of a plurality of plank assemblies shown in FIG. 16; 
     FIG. 28 is an end perspective view, partially broken away, of a completed laminated space-containing beam in accordance with this invention; and 
     FIG. 29 is an end perspective partial view of a completed laminated beam surfaced on all faces with a protective coating. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     FIGS. 1-3 illustrate two equal half-log lengths 10 and 12 with their respective diametrically cut flat surfaces 14 and 16 being the basic starting materials for the simplest form of this invention&#39;s laminated beam. Both half-logs 10 and 12 have been trimmed to produce flat surfaces 18 and 20 equal in width to each other, which are opposite and parallel to their respective diametric surfaces 14 and 16. In FIG. 1, half-logs 10 and 12 are in position to be joined together so that flat surfaces 18 and 20 are aligned and facing each other and having adhesive 22 applied to one or both of the facing surfaces. 
     In FIG. 2, half-logs 10 and 12 have been laminated together into intermediate assembly 24, which is to be vertically and longitudinally bisected along plane line 26. The two half-sections 28 and 30 are shown in FIG. 3, spaced from each other to leave interior space 32 therebetween and positioned so that their respective cut surfaces 34 and 36 are now turned away from each other and form the outer facings of assembly halves 28 and 30. The outer contour of halves 28 and 30 combined has assumed the rectangular cross-sectional shape of the to-be-assembled laminated beam of this embodiment of the invention. It should be noted that surfaces 14, 16, 34 and 36 may be smoothed by plane-milling or the like before, during or after the final assembly of the laminated beam structure. 
     FIGS. 4-9 illustrate various support spacers for joining, strengthening and completing the beam structure assembly. In FIG. 4, a plurality of spacers 38, shaped complementarily to the outline of space 32, are positioned and secured adhesively at intervals along the length of the laminated beam. FIG. 5 shows vertically disposed spacer plank 40 installed between assembly halves 28 and 30, plank 40 extending the entire length of the assembled beam structure. In FIG. 6, the vertically oriented bracing spacers 42 and 44 extend inwardly from surfaces 14 and 16, respectively, partway into interior space 32 and longitudinally the length of the laminated beam assembly. 
     In FIG. 7, intermediate assembly halves 28 and 30 have each been cut into to form beam-long centrally disposed opposite longitudinal channels 46, 46&#39;, provided to accommodate horizontal beam-long plank spacer 48 shown in FIG. 8, which also shows wood sheath 50 covering bottom surface 16 of the laminated beam structure, thus closing off the bottom of interior space 32. Obviously, this covering sheath 50 may be of any desired material in addition to wood, such as plywood, metal, plastic material, etc and may be applied as well to upper surface 14 and even to beam sides 28 and 30 and beam ends, if desired. The beam structure of FIG. 9 is different from that of FIG. 8 by the addition of beam-long vertical spacers 52 and 54 added for greater strength and stress resistance. Spacers 52 and 54 extend respectively from upper surface 14 and from bottom surface 16 inwardly to meet horizontal spacer plank 48. 
     FIG. 10 is a view of an embodiment similar to that of FIG. 2, but with half-logs 10a and 12a cut from a log somewhat larger in circumference than that of FIG. 2. Here, intermediate assembly 24a is to be cut along parallel vertical plane lines 26a and 26&#39; to create two equal outer sections 28a and 30a, as shown in FIG. 11, The center portion of assembly 24a has been transformed into beam-long laminated plank 56, which may be used as a spacer between sections 28a and 30a, as seen in FIG. 11, or for any conventional plank use. 
     The embodiment of FIG. 12 illustrates half-logs 10b and 12b with beam-length board 58 adhesively mounted therebetween in superposed stack assembly 24b. Vertical plane line 26b is shown herein to indicate the longitudinal path along which assembly 24b is to be bisected into resulting halves 28b and 30b, as shown in FIG. 13 with interior space 32b therebetween and in position for the final assembly of the laminated beam structure. 
     FIG. 14 shows intermediate assembly 24c closely resembling those of both FIGS. 10 and 12. Here, larger half-logs 10c and 12c have plank 58a adhesively mounted therebetween to form assembly 24c, which is to be divided by parallel vertical and longitudinal cuts along plane lines 26c and 26&#34;. Obviously, the resulting outer sections formed correspond exactly to sections 28b and 30b of FIG. 13 and may be used as described above, while center section 56a corresponds to laminated plank 56 of FIG. 11 and may be utilized in similar fashion thereto. 
     All the embodiments described above use half-logs as starting material; the embodiments which follow start with planks which may or may not have imperfect or damaged edges. The inferior quality planks will nonetheless produce a laminated beam of first quality. 
     FIG. 15 shows three planks 60, 62 and 64 in superposed position to be assembled into the intermediate assembly 66 of FIG. 16. Planks 60 and 64 are substantially identical in length and width; plank 62, to be sandwiched between planks 60 and 64, is the same length, but narrower and is centrally aligned therebetween and selectively coated on both faces with adhesive 22, leaving a centrally disposed longitudinal stripe 68 of uncoated wood on each face thereof. When planks 60, 62 and 64 have been laminated together to form intermediate assembly 70, as shown in FIG. 16, adhesive 22 is absent from the area of the vertical plane line 72, along stripe 68 where assembly 70 is to be longitudinally bisected. Thus, the cutting action of bisecting the intermediate assembly will encounter no dried adhesive 22 to interfere therewith, and the resulting halves 74 and 76, shown spaced and reoriented in FIG. 17, will have no adhesive on the cut outer surfaces 78 and 80. The latter feature may be advantageous for the appearance and for trouble-free application of a finish on surfaces such as 78 and 80 in the finished laminated beam of this invention. Half-sections 74 and 76 are positioned to leave cross-shaped interior space 82, with parallel channels 84 and 86 extending the length of the to-be-assembled laminated beam. 
     FIG. 18 illustrates another embodiment of the invention, with intermediate assembly 70a comprising planks 60a, 62a and 64a, all relatively wider than the corresponding planks of FIGS. 15-17. Assembly 70a is to be divided by parallel longitudinal cuts along planes 72a and 72&#39;. A wide stripe 68a extending between cutting planes 72a and 72&#39; has been left uncoated with adhesive 22 on the surface of plank 62a. The resulting elements created by these cuts are shown in FIG. 19. Herein, outer sections 74a and 76a are exactly like sections 74 and 76 of FIG. 17 in configuration and orientation and are positioned to be connected into a laminated beam in accordance with this invention. The center section of intermediate assembly 70a, because of the absence of adhesive in areas 68a of FIG. 18, becomes three separate and unlaminated wood strips 88 to be used as spacers or for conventional uses. 
     The intermediate assembly 90 of FIG. 20 will produce two laminated beams. Wide planks 92 and 94 are adhesively attached respectively above and below two narrower planks 96 spaced in side-by-side relationship. When assembly 90 is cut longitudinally along vertical plane lines 98 and 100, the resultant center section 102 formed therefrom is a completed beam structure without further processing. Outer sections 104 and 106 are identical to sections 74 and 76 of FIG. 17, and, when reoriented, may be assembled into a finished beam structure just as the corresponding sections 74, 76 and 74a, 76a in FIGS. 17-19 as described above. 
     FIGS. 21-23 illustrate various spacers inserted into and adhesively joined in interior space 82 to outer sections 74, 76 of FIG. 17 to hold together and strengthen the laminated beam structures formed therefrom. FIG. 21 shows a plurality of spacers 108 positioned at intervals along the length of completed beam structure 110. Each spacer 108 is shaped in the form of a cross, complementary to and fittingly inserted into interior space 82. A centrally disposed opening 112 in spacers 108 may be provided selectively for access into space 82 for insertion therein of pipes, conduits, etc. to carry utilities through beam 110. Also shown in FIG. 21 is insulation or similar material 114 inserted into interior space 82 between spacers 108; the placement of any of these materials shown illustratively in this embodiment may optionally and selectively be practiced with all the other beam embodiments in this specification. In FIG. 22, vertically disposed spacer 116 connects sections 74 and 76 and extends centrally through interior space 82 the entire length of the laminated beam structure. 
     The embodiment of FIG. 23 shows sections 74 and 76 joined, spaced and strengthened by horizontally disposed plank spacer 118 extending into and fittingly engaging channels 84 and 86. In space 82 above and below spacer 118, a plurality of supporting spacers 120 are positioned in vertical orientation at intervals along the laminated beam&#39;s length. In addition, plywood sheath layer 122 is shown illustratively as being mounted on the bottom surface of the laminated beam, closing off space 82 therein. As noted above in connection with FIG. 8, sheath surfacing elements of various materials may be applied to any or all the surfaces of the laminated beam. 
     In FIG. 24, intermediate assembly 124 has four planks with irregular edges adhesively superposed in aligned fashion on one another. Top and bottom planks 126 and 128 are wider than centrally positioned planks 130 and 132, and all four planks have imperfect edges 134 which may be waned, chipped or damaged in other ways. Plane line 136 designates the cutting path along which assembly 124 is to be bisected. The resultant sections 138 and 140 are rearranged in FIG. 25, as with the previously described embodiments so that imperfect edges face inwardly and may be provided with channels as in the embodiment of FIG. 7, or, as shown in FIG. 25, may have irregular edges 134 trimmed along cut lines 142 to define a generally diamond-shaped rectangular space 144 (FIG. 26) therebetween. A plurality of bracing spacers 146, diamond-shaped to engage the trimmed walls of interior space 144 fittingly, are positioned at intervals along the assembled laminated beam. Each spacer 146 may have a centrally disposed opening 148, to be used in the manner described in connection with opening 112 in FIG. 21. 
     FIG. 27 illustrates a highly efficient cost-saving procedure for rapid production of laminated beams. A series of intermediate assemblies 70 (see FIG. 16) are spaced in a horizontal row and each is joined to its adjacent neighbor by horizontal spacer planks 118 (FIG. 23). When longitudinal cuts are made along vertical plane lines 72, each of the sections 150 produced thereby between adjacent cut lines are already assembled beam structures; only the extreme end half-sections remain to be connected in the manner shown in FIGS. 16 and 17. 
     The finished laminated beam 152 illustratively shown in FIG. 28 has covering sheaths 154 overlying top, bottom and end surfaces thereof. Front and rear surfaces may also have sheathing applied to conceal lamination lines 156, if desired. A variety of materials may be used selectively for sheathing 154, including, for example, wood, plywood, artificial wood formed from aligned wood fibers dispersed in highly resistant synthetic resin, metal sheeting, plastic sheeting, fabric or the like. FIG. 29 displays a laminated, beam 158 completely covered with a unitary sheath 160 made of plastic, as shown, or other highly resistant coating materials. 
     The adhesive 22 used in all the various embodiments is preferably of the cold-setting synthetic resin type, although other available types may be used successfully. It should also be noted that creating designs in the laminated beams of this invention is possible. Thus, by using half-logs or planks of different wood species having varying colors and combining them, attractive beams having multiple colors may be produced. Also, by using half-sections of intermediate assemblies of different wood species the outer facing of a laminated beam might be of a weather-resistant species, while the opposite face of the same beam might be selected to be an attractively grained wood interior surface. 
     The various preferred embodiments and the best methods of producing them as now contemplated have been fully described herein. It will be evident to one skilled in the art that modifications, substitutions and combinations other than those described may be made without departing from the concepts of the invention disclosed herein, which are limited only by the scope of the ensuing claims, wherein: