Abstract:
Laminated siding pieces and a method of producing them. A laminated siding work piece is provided including a substantially flat piece of display material having a first major surface that is laminated to a beveled piece of support material. The substantially flat piece of display material is cut through to form a laminated siding piece having a flat piece of display material, possessing a freshly cut major surface, laminated to a beveled piece of support material.

Description:
RELATED APPLICATIONS 
     This application is a CIP of PCT application PCT/US99/07556, filed Apr. 6, 1999, which claims priority from U.S. application Ser. No. 09/058,076 filed Apr. 8, 1998, now U.S. Pat. No. 6,042,680, issued on Mar. 28, 2000. 
    
    
     BACKGROUND OF THE INVENTION 
     In a world with a great abundance of easily harvested cedar trees, every house could have an exterior surface of natural cedar siding. Unfortunately, this is not the case. Cedar trees are increasingly rare, and the wood from these trees is increasingly expensive. In particular it is difficult to obtain, even at prices of $1,600 per 1,000 board feet or more, clear (i.e. without visible knots) cedar siding as unitary pieces (i.e. that have not been assembled from shorter pieces finger jointed together) in uniform 16 foot lengths. Obtaining siding pieces in shorter lengths greatly increases the work of the carpenters constructing a house, because more pieces must be nailed onto the frame to complete the construction. If the pieces are nonuniform in length, a certain amount of planning is added to the carpenters&#39; work. The present invention has to do with a laminated wood product and method for producing the same, that permits a more efficient use of available cedar wood for providing siding material for houses. 
     Referring to FIGS. 1 a - 1   d , long siding pieces that are formed by joining a first piece of cedar  10  and a second piece of cedar  12  together with finger-joints are too unsightly to be used to form the siding of a house unless they are covered with paint. Finger-joints are made by forming fingers  14  in both first piece  10  and second piece  12 . Fingers  14  are separated in the thickness dimension, and extend from top to bottom in piece  10  and piece  12 , which are fit together, by interleaving and adhering fingers  14 , to form a finger-jointed board  16 . 
     To produce siding pieces in the familiar beveled shape, piece  16  is cut diagonally from top to bottom, as shown in FIG. l c  to form two identically shaped siding pieces  20 . Unfortunately, this diagonal cut causes the crooked finger joint pattern to be displayed as a crooked seam  22  on a beveled or sloping display surface  24  of each siding piece, as shown in FIG. 1 d . This ruins the potential of the siding pieces as a display of natural cedar. Therefore, when finger-jointed cedar siding pieces are used, they are typically covered with a coat of paint. As used in this application the term beveled may refer to a surface such as surface  24  which is sloped relative to the other. surfaces of piece  20  or may be used to describe a piece having such a sloped or beveled surface. 
     U.S. Pat. No. 3,041,231, issued to Fountain, describes a method for making laminated boards from rotten wood in which the rotten wood is laminated between two higher grade wood pieces and cut in two to create two laminated pieces having rotten wood adhered to high grade wood. The rotten wood is then treated, for example by sand blasting, so that it may be used as a sort of a rustic display. The Fountain patent thus is not directed toward beveled siding pieces, nor is it aimed at producing more pieces of high grade clear cedar siding from a fixed amount of clear cedar wood than is possible with conventional techniques. 
     One persistent problem faced by wood pieces that are designed for exterior use, where they are exposed to the elements, is the threat of delamination. There has been a very famous case in which a wood product siding material has decomposed in actual use and resulted in hundreds of millions of dollars in liability claims against the manufacturer. As a result wood industry participants are now very wary of the problem of delamination in any laminated product produced for exterior use. Of particular concern with respect to siding pieces is the bottom edge of the siding piece. Water can remain suspended from the bottom edge for a considerable period of time, working its way between the lamina and eventually potentially causing delamination. 
     What is still desired, then, is a way to provide a greater amount of siding having a pleasing appearance and the weather-resisting qualities of clear cedar, from a limited amount of cedar wood, than has previously been possible. 
     SUMMARY 
     The present invention is a laminated siding piece comprising a beveled piece of support material and a substantially flat piece of display material laminated to said beveled piece of support material. 
     The foregoing and other objectives, features, and advantages of the invention will be more readily understood upon consideration of the following detailed description of the invention, taken in conjunction with the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 a  is a top view of a prior art board that is made of two pieces that are finger jointed together. 
     FIG. 1 b  is a side view of the board of FIG. 1 a.    
     FIG. 1 c  is a side view of two pieces of siding that have been produced by cutting the board of FIG. 1 a.    
     FIG. 1 d  is a perspective view of one of the siding pieces of FIG. 1 c.    
     FIG. 2 a  is a top view of a laminated siding workpiece according to a step in a preferred method of the present invention. 
     FIG. 2 b  is a side view of the laminated siding workpiece of FIG. 2 a.    
     FIG. 2 c  is a side view of two pieces of siding that have been produced by cutting the siding workpiece of FIG. 2 a.    
     FIG. 3 a  is a top view of a laminated siding workpiece according to a step in an alternative preferred method of the present invention. 
     FIG. 3 b  is a side view of the laminated siding workpiece of FIG. 3 a.    
     FIG. 3 c  is a side view of two pieces of siding that have been produced by cutting the siding workpiece of FIG. 3 a.    
     FIG. 4 a  is a top view of a laminated siding workpiece according to a step in a second alternative preferred method of the present invention. 
     FIG. 4 b  is a side view of the laminated siding workpiece of FIG. 4 a.    
     FIG. 4 c  is a side view of two pieces of siding that have been produced by cutting the siding workpiece of FIG. 4 a.    
     FIG. 5 is an isometric view of one of the identically shaped siding pieces shown in FIG. 2 c.    
     FIG. 6 is an isometric view of an alternative embodiment of a laminated siding piece, including a protective strip on the bottom edge. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring to FIGS. 2 a  and  2   b , a preferred method for producing siding pieces according to the present invention begins with the production of a laminated siding workpiece  110  in which a first display material piece  112  and a second display material piece  113 , which are joined together by finger joint  116 , are laminated between two beveled support pieces  114 , preferably made of a material such as pine or fir wood. Display material pieces  112  and  113  are most typically clear cedar. Beveled support pieces  114  are offset in position and orientation from each other, as shown, so that laminated siding workpiece  110  is rectangular in cross-section. Alternatively, display support pieces  112  and  113  could be held together by being adhered to support piece  114  rather than with finger joint  116 . In another alternative, a unitary piece of cedar could be used in place of joined display material pieces  112  and  113 . Pieces  112  and  113  are flat, in the sense that word is used in this application, meaning that they are not beveled as are pieces  114 , but are generally of uniform thickness. 
     Referring to FIG. 2 c , laminated siding workpiece  110  is cut in two through display material pieces  112  and  113  to form two identically shaped siding pieces  120  having cut display material pieces  112 ′ and  113 ′. Referring to FIG. 5, the seam  122 , formed on the display face  124  of each siding piece  120  at the location of finger joint  116 , is straight rather than crooked, as in prior art siding pieces  20 . The fact that seam  122  is straight is an advantage to the present invention. Because seam  22  from the prior art was unsightly enough to preclude the use of prior art siding pieces  20  as display pieces, there was little effort among those producing siding pieces  20  to match up cedar pieces  10  and  12  so that there would be a reasonable continuity of coloration and grain across seam  22 . In the present invention, however, if pieces  112  and  113  are well matched, seam  122  is unobtrusive enough to permit pieces  120  to be used as a natural display of cedar. As a result, it is possible, using the process of the present invention, to economically produce uniform sixteen-foot siding pieces that are suitable for display (to remain unpainted) on a house. 
     A first advantage of the preferred method described above is that display material pieces  112  and  113  are protected by support pieces  114  as laminated siding workpiece  110  is handled during the production process. Moreover, the sawing of pieces  112  and  113  imparts a desirable smoothness to resultant display face  124 . A second advantage is that laminated siding workpiece  110  is rectangular in cross-section, which makes it more easily handled by the standard equipment found in many sawmills, which is typically adapted for handling boards that are rectangular in cross-section. 
     In FIGS. 3 a - 3   c  features which are alike to the features of FIGS. 2 a - 2   c  are referenced with numerals which are alike but which have been incremented by 100. Similar to FIGS. 2 a - 2   c , FIGS. 3 a - 3   c  show a preferred method for producing siding pieces according to the present invention. This process begins with the production of a laminated siding workpiece  210 , in which a first display material piece  212  and a second display material piece  213 , which are interconnected with each other by a finger joint  216 , are adhesively laminated between two beveled support pieces  214 , preferably made of a material such as pine or fir wood. Laminated siding workpiece  210  is cut in two through display material pieces  212  and  213  to form two identically shaped siding pieces  220  having cut display material pieces  212 ′ and  213 ′. 
     Display material pieces  212  and  213  are most typically clear cedar. Beveled support pieces  214  are offset from each other in position and orientation so that laminated siding workpiece  210  is trapezoidal. Referring specifically to FIG. 3 a , display material piece  212  may be made of two or more constituent pieces that are joined by finger joints  216 . 
     Laminated siding workpiece  110  or  210  may be made by laminating already beveled support pieces  114  or  214  to display material piece  112  and  113  or  212  and  213  or by laminating flat support material pieces to display material pieces  112  and  113  or  212  and  213  and then cutting the flat support material pieces diagonally to create beveled support pieces  114  or  214 . 
     Referring to FIGS. 4 a - 4   c , it is possible to form an intermediate laminate  310  by adhering a single flat support material piece  314  between two flat display material pieces  312  and then cutting support material piece  314  diagonally to create two beveled siding pieces  320 . This method has the drawback that display material pieces  312  may be damaged both in the laminating process and in being handled before and during the cutting process. Therefore, the surface of the display material should be cut or shaved away after siding pieces  320  are otherwise formed to reveal a new, freshly cut surface. As shown in FIG. 4 a , display material piece  312  may each comprise two constituent pieces held together by a finger joint  316 . 
     An alternative embodiment, which is addressed to the problem of avoiding delamination, is shown in FIG. 6. A siding piece  410 , having a piece of display material  412  and a piece of support material  414 , also includes a polyurethane strip  416  that prevents water, which may remain suspended on the bottom edge of piece  410  for a considerable period of time, from penetrating into piece  410  and thereby causing delamination. In a preferred embodiment, the polyurethane strip  416  is of a material available under product name U-100-B Synthetic Patch/Pails and product code 100921110 from Willamette Valley Company of Eugene, Oreg. The seam between display wood  412  and polyurethane strip  416  extends downwardly at a 45° angle from the corner of the support material  414 . This is a good angle for avoiding the collection of water at the seam and a resultant attack on the seam integrity. 
     Additionally, a paper or other printable material  418  is laminated to the side of piece  410  that is not displayed in use. Paper  418  affords the producer and or distributor with a surface to print the product name, user information and advertising information and images. 
     Beveled support pieces  114 ,  214 ,  314  and  414  are typically made of pine, fir, Douglas fir, larch or hemlock, but may also be of any inexpensive, structurally sound wood. Also, wood products and cellulose fiber products such as plywood, parallel strand lumber, particle board or wood chip board may be used for pieces  114 ,  214 ,  314  and  414 , although care must be taken to avoid water exposure damage for this type of material. In addition, composite material could be used for pieces  114 ,  214 ,  314  and  414 . One popular type of composite material is made of cellulose fiber and Portland cement and is sold under the name of Hardie Plank®. If both display pieces and support material pieces are made of wood, the process of lamination may be performed according to the well-known art of laminating wood pieces together with any commonly available wood glue. If the support material pieces are not made of wood the lamination process is also well known, through the use of an all-purpose glue, such as epoxy glue. Support pieces  114 ,  214 ,  314  and  414  are typically about ⅜ inch thick at their thickest and about {fraction (1/16)} inch thick at their thinnest. Display material pieces  112 ,  113 ,  212  and  213  are typically about ¼ inch thick, so that cut display pieces  112 ′,  113 ′,  212 ′,  213 ′ and pieces  312  are typically slightly less than ⅛ inch thick because some material is lost to the saw blade. The sawing process is done according to standard well-known techniques with an effort made to minimize the loss of valuable cedar to the saw blade. This thinness permits considerably more siding pieces to produced from the same quantity of display material. Although cedar, due to its pleasant appearance and excellent ability to withstand weathering, is generally the most sought after siding material, display material pieces  112 ,  113 ,  212 ,  213  and  312  could be made of any material with similar properties, such as redwood. 
     The method of the present invention makes practical the production of siding pieces in a broad range of dimensions, ranging in width from 4 inches to 16 inches and in length from 2 feet to 16 feet or more. This also makes practical the use of producing the siding pieces in custom dimensions for a builder&#39;s particular job. For example, in the case of a 40 foot exterior wall a builder could order two 16 foot pieces and one 8 foot piece for each complete siding strip. 
     There may be a problem with delamination when using a display material with a different temperature coefficient of expansion or moisture content coefficient of expansion from the support piece material coefficient of expansion. For this reason it is generally advisable to pick materials with similar coefficients of expansion. For example, depending on the environment, it may be advisable to pick materials with coefficients of expansion that are within ±5%, ±10%, ±15% or ±20% of each other. Along these lines the use of high-grade wood of a particular species as the display material and low-grade wood of the same species as the support piece material offers one method of matching coefficients of expansion. 
     The terms and expressions which have been employed in the foregoing specification are used therein as terms of description and not of limitation, and there is no intention, in the use of such terms and expressions, of excluding equivalents of the features shown and described or portions thereof, it being recognized that the scope of the invention is defined and limited only by the claims which follow.