Patent Publication Number: US-5896723-A

Title: Laminated wood structural units

Description:
BACKGROUND OF THE INVENTION 
     This application, a continuation-in-part of U.S. patent application Ser. No. 08/493,011, filed Jun. 21, 1995 now U.S. Pat. No. 5,618,371 discloses and claims subject matter not previously considered, taught or claimed in, as well as matter restricted from, the parent application, which uses less-than-perfect half-logs or planks together with spacers to produce its space-containing wood beams. The method of the present invention provides structural products such as paneling, siding, fencing, flooring and the like, in addition to beams; the method also provides an answer to the problem that a significant percentage of small-diameter logs, when handled by conventional methods, are not suitable for use in structural lumber products because of warping and twisting. These distortions, especially severe in new-growth small logs, cause the discarding of up to 20% of an otherwise useful and valuable raw material; by applying the procedures of the method hereinafter disclosed, at least 95% of available logs of this category can be converted successfully into profitable structural products. 
    
    
     FIELD OF THE INVENTION 
     This invention is directed to the production of laminated wood products such as space-containing beams, paneling, siding, fencing, flooring and the like from small-diameter logs and conventional planks. 
     SUMMARY OF THE INVENTION 
     The basic starting materials for producing the products of this invention are half-logs and conventional lumber planks all cut from at least one log and used in varying combinations. To create the half-logs for use, whole logs are bisected longitudinally either at the same time or after a pair of trimming flattening cuts parallel to the lengthwise bisecting cut on each log are made; optionally, a second pair of parallel longitudinal trimming cuts at right angles to the first pair may be advantageously included. 
     A matched pair of lengths of the half-logs thus prepared are positioned so that one is superposed over the other, the flattened surfaces parallel to the diametric bisected surfaces facing one another; adhesive is applied to the flattened surfaces, which are then joined alignedly and held together until the adhesive is caused to set. The resulting symmetrical half-log intermediate assembly is then longitudinally bisected along a plane perpendicular to its upper and lower diametric bisected surfaces, thus forming two asymmetric mirror-image structural units for later assembly into the beams, siding, flooring, fencing, etc. of this invention, as hereinafter described. 
     In similar manner, conventional pre-cut lumber planks may be laminated by adhesively joining them to form aligned vertically stacked piles for bisecting into sections and use in assembly with each other, with other tongue-and-groove planks, or combined with the bisected half-log units into the structural wood products of this invention. 
     The problem of warping and twisting occurring in logs and portions cut therefrom is largely caused by uneven tension of the wood fibers, the effect of which is particularly evident as the log portions are dried. By making patterned cuts or perforations into those longitudinal log or plank surfaces which will not be exposed to view in the ultimate product made therefrom, the fiber tension is greatly relieved, most effectively before the logs or planks are dried, and the warping and twisting tendencies of the logs or lumber products created from them are significantly reduced or eliminated. For logs to be used to make space-containing beams, the tension-relieving patterned cuts are made into the log before bisection; for those used for siding, paneling, etc., the patterned cuts may be made after the bisection, so that the parallel diametric and flattened surfaces of the half-logs may be cut in patterns along with the log&#39;s original outer surface. In both cases, the two half-logs are then arranged so that the flattened surfaces of each face each other, and adhesive is applied to the flattened surfaces; at the same time, the patterned cuts or perforations may be filled with the same adhesive. Pre-cut lumber planks surfaces may be pattern-cut and treated analogously to the half-logs. Both are then bisected; the resulting units of half-log or plank-based units are then piled into a stack and air- or kiln-dried, thereafter being assembled into the beams, paneling, etc. of this invention. 
     Details of all the steps and embodiments of the invention will be fully disclosed and described in connection with the accompanying illustrative, but not limiting, drawings, wherein: 
    
    
     SHORT FIGURE DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a schematic end right perspective partial view of a log in position to be trimmed longitudinally by four simultaneous cuts; 
     FIG. 2 is a schematic right perspective partial view of the trimmed log of FIG. 1 in position to be bisected; 
     FIG. 3 is a schematic end right perspective partial view of the two half-logs formed by the bisection indicated in FIG. 2; 
     FIG. 4 is a schematic end right perspective partial view of a log in position to be trimmed longitudinally by two parallel simultaneous cuts; 
     FIG. 5 is a schematic end right perspective partial view of the log of FIG. 4 in position to be trimmed and bisected longitudinally and simultaneousy by three parallel cuts into two trimmed half-logs; 
     FIG. 6 is a schematic end right perspective partial view of a log in position to be longitudinally trimmed and bisected simultaneously by three parallel cuts into two half-logs; 
     FIG. 7 in a schematic end right perspective partial view of the two half-logs formed from the bisection indicated in FIG. 6; 
     FIG. 8 is a schematic end right perspective partial view of the half-logs of FIG. 3, one alignedly superposed over the other, in position to be assembled; 
     FIG. 9 is a schematic end right perspective partial view of the completed half-log assembly of FIG. 8 in position to be longitudinally bisected; 
     FIG. 10 is a schematic end right perspective partial view of the two asymmetric mirror-image units resulting from the bisection of FIG. 9; 
     FIG. 11 is a schematic end right perspective partial view of the half-logs of FIG. 7 alignedly and adhesively assembled, comparable to the assembly of FIG. 8 and in position for bisection; 
     FIG. 12 is a schematic end right perspective partial view of the two asymmetric mirror-image units resulting from the bisection of FIG. 11; 
     FIG. 13 is a schematic end right perpective partial view of a log, the circumferential surface of which has been subjected to a variety of patterned cuts, in position to be trimmed and bisected longitudinally and simultaneously by three parallel cuts; 
     FIG. 14 is a schematic end right perspective partial view of the two half-logs formed in FIG. 13; 
     FIG. 15 is a schematic end right perspective partial view of the two asymmetric mirror-image units formed from the half-logs of FIG. 14 after they have been adhesively assembled and bisected like those of FIG. 11; 
     FIG. 16 is a schematic end right perspective partial view of a half-log, the longitudinal surfaces of which have been subjected to patterned cuts; 
     FIG. 17 is a schematic end right perspective partial view of a half-log, the longitudinal surfaces of which have been perforated by a spiked roller in an overall pattern; 
     FIG. 18 is a schematic end right perspective partial view of a plurality of asymmetric mirror-image units like those of FIG. 15 stacked in a pile for air- or kiln-drying; 
     FIG. 19 is a schematic end right perspective partial view of a beam assembled from two rearranged units like those of FIG. 15; 
     FIG. 20 is a schematic end right perspective partial view of a beam assembled from two rearranged units like those of FIG. 10 which have been pattern-cut, piled and dried before assembly; 
     FIG. 21 is a front left perspective partial view of paneling or a fence assembled from a plurality of asymmetric mirror-image units like those of FIG. 12; 
     FIG. 22 is a front left perspective partial view of paneling or a fence assembled from a plurality of asymmetric mirror-image units like those of FIG. 10; 
     FIG. 23 is a front right perspective partial view of a floor or deck assembled from a plurality of asymmetric mirror-image structural units like those of FIG. 12; 
     FIG. 24 is a front right perspective partial view of a floor or deck assembled from a plurality of asymmetric mirror-image units like those of FIG. 10; 
     FIG. 25 is a front right perspective partial view of an intermediate assembly of three planks, pattern-cut before assembly on all longitudinal surfaces that will be not visible in the finished product, in position to be bisected; 
     FIG. 26 is a front right perspective partial view of an assembled beam formed from the units created by the bisection indicated in FIG. 25; 
     FIG. 27 is an end elevational view of one of the units of FIG. 10 laminated to a tongue-and-grooved plank; 
     FIG. 28 is an end elevational view of one of the units of FIG. 10 laminated to a tongue-and-grooved plank on each side thereof; 
     FIG. 29 is an end elevational view of a plurality of planks laminated together in a vertical pile with a tongue-and-grooved plank laminated on one side thereof; 
     FIG. 30 is an end elevational view of a plurality of planks laminated together in a vertical pile with a tongue-and-grooved plank laminated on each side thereof; 
     FIG. 31 is an end elevational view of a laminated composite beam having two FIG. 10 units with a laminated plank therebetween and tongue-and-grooved planks laminated on each side thereof; 
     FIG. 32 is an end elevational view similar to FIG. 31, but with the two FIG. 10 units in reversed position; 
     FIG. 33 is an end elevational view of a laminated composite beam similar to FIG. 31, but with the FIG. 10 units replaced by laminated vertical piles of planks; 
     FIG. 34 is an end elevational view of a laminated beam composed of a FIG. 10 unit, a laminated vertical pile of planks and a laminated plank positioned therebetween; 
     FIG. 35 is an end elevational view of the half-log intermediate assembly of FIG. 9 with a tongue-and-grooved plank laminated on each side thereof, in position to be bisected; 
     FIG. 36 is an end elevational view similar to FIG. 35, but with plain planks laminated on either side; and 
     FIG. 37 is an end elevational view similar to FIG. 27 but with the position of the FIG. 10 unit reversed. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     FIGS. 1-3 illustrate a preferred method of producing half-logs for use in this invention. In FIG. 1, log 10 is in position to be &#34;squared&#34; by simultaneous longitudinal trimming vertical cuts 12 and 14 and horizontal cuts 16 and 18, to produce trimmed log 20, with flattened surfaces 22, 24, 26, and 28 of FIG. 2. Trimmed log 20 is to be longitudinally bisected along plane 30, resulting in the formation of half-logs 32 each with a diametrically cut surface 34. An alternate method of achieving identical half-logs 32 is shown in FIGS. 4 and 5; in FIG. 4, a first cutting step involves two parallel opposite longitudinal trimming cuts 36 and 38 along log 10a, followed in FIG. 5 by three longitudinal parallel cuts at right angles to cuts 36 and 38, including bisecting cut 40 and trimming cuts 42, 44, resulting in two half-logs 32 as shown in FIG. 3. 
     Another embodiment of half-logs to be used for this invention appears in FIGS. 6 and 7, where log 10b is converted by a single cutting step of three longitudinal parallel cuts, trimming cuts 46,48 and bisecting cut 50, into two half-logs 52, each with diametric surface 54 and flattened surface 56 parallel and opposite thereto. 
     FIG. 8 illustrates the joining of the two half-logs 32 shown in FIG. 3, with trimmed flattened surface 22 alignedly and symmetrically superposed and facing corresponding flattened surface 24, both surfaces having been selectively coated with adhesive 58 and being ready to be contacted, adhesive 58 caused to set, thus forming symmetrical intermediate assembly 60 shown in FIG. 9. Assembly 60 is then to be longitudinally bisected along plane 62 of FIG. 9 perpendicular to diametric surfaces 34, resulting in the formation of asymmetric mirror-image units 64 and 66, each with a new flat surface 68 created by the bisection and depicted in FIG. 10. 
     The joining of half-logs 52 from FIG. 7 is a procedure identical to that shown for half-logs 32 in FIGS. 8-10, and the steps of superposing, coating with adhesive, contacting the flattened surfaces and causing the adhesive to set have not been reillustrated; however, symmetrical intermediate assembly 60a is shown in FIG. 11 with flattened surfaces 56a of half-logs 52 adhesively joined by set adhesive 58a and with assembly 60a in position to be bisected longitudinally along plane 62a to produce asymmetric mirror-image structural units 64a, 66a of FIG. 12. It may be noted that sections 64, 66, 64a and 66a are primary structural units for the products of this invention, and they may be used interchangeably in a1 half-log-based products herein-after disclosed. 
     To minimize or eliminate warping and twisting of half-logs and planks used in the products of this invention, the method disclosed in FIGS. 13-18 and 25-26 is highly effective. When handled by conventional methods, up to 20% of logs or their parts, depending in part on the species of wood, have to be rejected or discarded for structural product use because of wood fiber tension distortion; up to 95% of these discards may be avoided by the method hereinafter described. 
     For best results in the practice of this invention, the logs used should be preferably in the diameter size range of four to twelve inches and in undried &#34;green&#34; condition, to provide maximum opportunity for the tension-releasing patterned cuts and perforations of this invention to be most effective. Using this procedure with previously dried logs or planks will help against warping and twisting, but to a somewhat lesser degree. 
     FIG. 13 shows log 10c, the circumferential surface of which has had cuts 70 with an illustrative pattern of assorted shapes at varying angles, including lines parallel, transverse and angular to the longitudinal axis of log 10c and thus to wood fiber strands therein, V&#39;s and X&#39;s in all attitudes. It may be noted that in practicing this invention, any single one, or any combination, of the patterned cuts 70 indicated in the drawings may be used to good effect; it may be noted also that the ability of cuts 70 to reduce uneven fiber tension and thereby to reduce distortion of log 10c is not significantly affected by whether or not log 10c has been debarked. The depth of cuts 70 should range from at least 5% to no more than 20% of the thickness of the log or half-log at the point where each cut 70 (or perforation 76, FIG. 17) is made, when cuts 70 are not treated further, but where cuts 70 are to be filled with adhesive when the half-logs are coated, their depth may be increased to as much as 35% of the log&#39;s, half-log&#39;s or plank&#39;s thickness without reducing the strength of the final product. 
     The bisecting and trimming of log 10c by parallel longitudinal cuts along planes 46a 48a and 50a in FIG. 13 results in two half-logs 52a shown in FIG. 14, each having a planar diametric surface 54a and parallel trimmed surfaces 56a free of cuts 70. For the manufacture of space-containing beams (see FIG. 19), surfaces 54a of half-logs 52a form part of the outer exposed portion of the finished beam and hence cannot be pattern-cut; and surfaces 56a are to be joined adhesively together (as in FIGS. 8,9). so that their being pattern-cut as a separate step is optional and does not significantly contribute to overcoming warping or twisting significantly; units 64b and 66b formed by the joining of half-logs 52a by bisection of the intermediate assembly thereof (not shown) appear in FIG. 15. In contrast, for the production of siding, paneling, flooring, etc., none of the outer longitudinal surfaces of half-log 52b in FIG. 16 will be visible when the final product is assembled; therefore, the log from which half-log 52b was cut (not shown) was bisected and trimmed before pattern-cuts 70 over all the longitudinal surfaces of half-log 52b were made. 
     An alternative pre-treatment of logs (not shown) or half-logs is illustrated in FIG. 17, where the surfaces of half-log 52c have been penetrated by spikes 72 of roller 74, forming an overall pattern of perforations 76 therein to relieve the half-log&#39;s fiber tension. 
     FIG. 18 illustrates the next step in the procedure to which each of the asymmetric mirror-image units 64, 66, 64a, 66a, 64b and 66b are identically treated; for simplicity, only the units 64a and 66a are shown herein, it being understood that the other units are to be handled exactly the same way. Structural units 64a, 66a are shown piled into stack 78 in FIG. 18, in position to be allowed to air-dry or to be placed in a kiln for force-drying. The weight of units 64a, 66a on each other and the restraint of their side-by-side positioning as the drying process occurs help to overcome any residual tendency for warping or twisting therein. After drying, the mirror-image asymmetric units are ready to be assembled into the structural products described in the following drawings. 
     Space-containing wood beam 80 shown in FIG. 19 has been assembled by arranging two dried units 64a, 66a, made from half-logs 56, in position so that cut faces 54 and 68a form the rectangular outer profile of the finished beam and no pattern cuts 70 are visible thereon. In FIG. 20, the space-containing beam 80a is identical to beam 80 except that it has been assembled with sections 64, 66 from half-logs 32 of log 10, flattened on four sides; as a result, beam 80a is square rather than rectangular in cross-section. 
     FIG. 21 shows vertical assembly 82 of dried units 64a, 66a made from half-logs 52, 52a, 52b or 52c which might serve as paneling, fencing, or, when turned 90 degrees, as siding (not shown). Here, only the surfaces 68a, which have a uniform planar uncut aspect, are visible in finished products. Units 64, 64a may be held in position and supported in any convenient way, one of which, transverse plank 84 is shown. Exactly analogously, vertical assembly 82a of dried units 64, 66 in FIG. 22 may be used for the same purposes as assembly 82, and because of the extra flat trimmed surfaces 26 and 28 provided thereon, is more compact and stronger, with units 64, 66 held together by adhesive or conventional methods and presenting smooth planar surfaces 68 to view. 
     The same structural units as those used for paneling, etc. in FIGS. 21 and 22 are shown in FIGS. 23 and 24, respectively, attached in horizontal array to provide flooring or decking; thus, in FIG. 23, a plurality of units 64a, 66a joined and fixed together in a horizontal row, with only planar uncut surfaces 68a exposed, form floor or deck 86 mounted on support 88; in FIG. 24, units 64, 66 are similarly joined horizontally and mounted on support 88a to form floor or deck 86a, with surfaces 68 acting as the floor or deck surface. 
     FIGS. 25 and 26 illustrate the use of the fiber-tension-relief method described above on pre-cut planks. Intermediate assembly 90 shown in FIG. 25 comprises identical upper and lower planks 92 sandwiching therebetween narrower plank 94 in a symmetrical pile alignedly and adhesively held together, to be bisected longitudinally along plane 96 to form asymmetric mirror-image units 98 seen in FIG. 26 adhesively combined with spacing element 100 to form beam 102. Planks 92 and 94 have pattern-cuts 70 made on all surfaces that will be concealed in finished beam 102, either before or after intermediate assembly 90 is formed, to minimize or eliminate fiber tension and consequent warping. 
     An assortment of laminated wood structural products assembled in accordance with this invention of superior characteristics are illustrated in FIGS. 27-36, featuring tongue-and grooved planks adhesively secured to asymmetric log units and/or piles of laminated planks. The resulting siding or beams, when erected, form structures of greatly enhanced strength, stability and weather resistance, eliminating air and water penetration. FIG. 27 shows siding 104 comprising asymmetric mirror-image unit 66 (or 64), its flattened surfaces 28 (or 26) being laminated to plank 106, which has longitudinally extending tongue 108 along its top edge and groove 110 along its bottom; FIG. 36 has siding 104a with tongue-and-grooved plank 106 laminated to the opposite surface 68 of unit 66; and beam or siding 112 in FIG. 28 is exactly like siding 104, except that a second tongue-and-grooved plank 106 has been laminated to unit 66 on its side opposite first plank 106. FIG. 29 shows siding 114 with laminated vertical plank pile 116 replacing unit 66 of siding 104, and FIG. 30 has beam 118 with plank pile 116 replacing section 66 of beam 112. 
     The double-tongue-and grooved beam 120 of FIG. 31 is composed of two siding assemblies 104, surfaces 68 of which are adhesively joined on either side of laminated wood panel 122; beam 120a of FIG. 32 has siding assemblies 104a replacing two assemblies 104 of FIG. 31, sandwiching therebetween laminated wood panel 122. In FIG. 33, beam 124 replaces the two siding assemblies 104 with laminated plank pile sidings 114 of FIG. 29. 
     Two alternate methods of producing siding 104 (FIG. 27) are illustrated in FIGS. 34 and 35. In FIG. 34, intermediate assembly 60 is prepared as described above, then a tongue-and-grooved plank 106 is laminated on either side to surfaces 26, 28 thereof, creating a beam 126 which may be used as such or thereafter bisected longitudinally along plane 128 to produce two mirror-image pieces of siding 104. The alternate method of FIG. 35, producing beam 126a is identical to that just described, except that planks 106a without tongues and grooves are laminated to surfaces 26, 28 of half-log intermadiate assembly 60. Beam 126a may be used as such, may have tongue-and-groove cuts made in one or both planks 106a after assembly, or may be longitudinally bisected along plane 128a to form identical structural units, which may then be provided with tongue and groove if desired. 
     A final illustrative embodiment of this invention is shown in FIG. 37, wherein composite rectangular beam 130 is shown comprising asymmetric half-log-derived unit 66 and laminated vertically stacked plank pile 116 secured adhesively to laminated wood panel therebetween. It may be noted that beam 130 may be used as is or may have a tongue-and-grooved plank 106 or a plain plank 106a adhesively mounted on either side thereof. 
     The methods of this invention are applicable to the wide variety of wood species available; for example, the choice of hardwood for floors or decking and such species as cedar and Douglas fir for panelling or siding will be obvious. It also will be apparent that this invention makes it possible to utilize small-diameter newer-growth logs more fully instead of relying on relatively scarce and expensive old-growth timber, and using wood of lesser quality where not visible. 
     Best modes now contemplated for practicing this invention and its concepts have been fully described. It will be evident to those skilled in the art that modifications, alterations and substitutions may be made in the details of the procedures and products disclosed without departing from the spirit and concepts of this invention, which are limited only by the scope of the ensuing claims, wherein: