Log cutting and rejoining process for lumber manufacture

A process for making composite lumber products from generally cylindrical logs includes the steps of cutting a log radially into a plurality of first sector-shaped pieces having similar included angles and then preferably drying the sector-shaped pieces. After drying, the sector-shaped pieces are preferably machined to provide flat surfaces for subsequent gluing and rejoining steps. The sector-shaped pieces are then divided into at least two members where each plane of cut will be substantially parallel to the chord base plane with at least one of the resulting members having a thickness substantially equal to the thickness of the final composite lumber. At least two of the resulting members, substantially equal in thickness, are then rotated and bonded together along juxtaposed edges into a composite planar piece. Additional members substantially equal in thickness can be alternately rotated and edge bonded to the composite piece thereby forming wider widths. Alternate members in the composite piece can have the taper reversed longitudinally if a higher lumber yield is desired. The wide width composite pieces can then be rip cut longitudinally to yield pieces of the desired width. A finger jointing process and final surfacing can be applied to the composite lumber. The resulting composite lumber is generally flat grained over the two wider faces and each resulting piece will have at least one inclined glue line throughout its length.

BACKGROUND OF THE INVENTION 
This invention relates generally to a process for converting round logs 
into lumber products, primarily dimension lumber. More particularly, it 
relates to a log cutting and subsequent rejoining process for converting 
logs into composite lumber products whereby the yield of lumber from the 
round wood volume is significantly increased. 
In the commonly assigned U.S. Pat. Nos. 3,903,943 and 3,961,654, two 
cutting and rejoining processes are disclosed that can be utilized for 
increasing the lumber yield from logs which include certain of the steps 
employed in the cutting and rejoining process of the present invention. 
The disclosures in the above-cited issued U.S. Patents are incorporated 
herein by reference for purposes of providing a complete description and 
understanding of the present invention. 
The centuries-old conversion process of sawing logs into rectangular lumber 
results in a low yield in that, of the total volume of wood in a log, 
usually less than half is or can be converted into usable lumber. This is 
primarily because of the limitation that square or rectangular pieces are 
cut from a cylindrical log. The actual lumber yields utilizing known 
processes, of course, vary depending upon a number of factors, such as log 
diameter and curvature, but even with the best available 
computer-controlled sawing machines, a normal yield of lumber from an 
average log is 50% of the total wood volume. With smaller logs the yield 
is substantially less. The term "lumber" is intended to mean those wood 
products traditionally having the highest marketable value that are 
derivable from a longitudinal sawing pattern imposed on a log and which 
are generally rectangular in cross-section. 
The most commonly used log-to-lumber converting process is where saws make 
a plurality of longitudinal cuts through the log with each successive cut 
generally being in a plane parallel or perpendicular to an adjacent 
previous cut. With this process, it is obvious that there are yield 
limitations simply from the fact that the beginning raw material is 
cylindrical while the desired final lumber product is rectangular in form. 
The wood volume not converted into lumber is utilized in a variety of 
other ways, none of which offer the value of lumber. The sawdust can be 
used as fuel, particleboard and the like. The solid wood slabs and edgings 
can be chipped into small pieces suitable for wood pulp production or 
likewise they can be used for fuel. 
In the past, there have been many suggestions of ways to increase the 
recovery of solid wood products that could be converted from a log. Veneer 
production and subsequent laminating methods has been one suggestion. In 
veneer production the cylindrical log is converted into pieces of wood 
veneer which can then be laminated together to form various wood products 
such as plywood. Such composite products and their converting processes do 
convert more of the wood volume into wood products, but they do not have 
the characteristics of solid sawn lumber. 
The aforementioned U.S. Pat. No. 3,961,654 incorporated herein by reference 
discloses a process and resulting product that can be employed to greatly 
increase the yield of lumber from cylindrically shaped logs. The process 
as disclosed is best applied to small logs such as from 5 to 15 inches in 
diameter. The process described in issued U.S. Pat. No. 3,903,943 is best 
applied to logs having larger diameters. 
Yet another new alternative cutting and rejoining process was conceived 
from the concept of cutting logs into sector-shaped pieces. The cutting 
and rejoining process of the present invention results in fewer bonding 
steps, thereby simplifying the process while still yielding a greatly 
increased percentage of composite lumber products. It is anticipated that 
the resulting composite pieces of lumber will have a high value and will 
be accepted in the marketplace as lumber products. 
Accordingly, from the foregoing, one object of the present invention is to 
convert generally cylindrical logs into composite lumber products whereby 
the percentage of log volume that is converted to lumber is substantially 
increased. 
A further object is to simplify the process as disclosed in U.S. Pat. No. 
3,961,654. 
Still a further object is to provide a lumber cutting and rejoining process 
that yields substantially all flat grained composite lumber. 
These and other objects will become more apparent and better understood 
upon reading the following specification in conjunction with the attached 
drawing. 
SUMMARY OF THE INVENTION 
Briefly, this invention is comprised in one form of longitudinally cutting 
a log segment radially into a plurality of first sector-shaped pieces 
having similar included angles. Each of the sector-shaped pieces is then 
divided longitudinally into at least two members where each plane of cut 
will substantially parallel the chord base plane with the thickness of at 
least one of the members being substantially equal to the thickness of the 
resulting composite piece of lumber. At least two resulting members 
substantially equal in thickness are then rotated about a longitudinal 
axis with respect to each other and bonded together along the inclined 
juxtaposed edges into a composite planar piece. Additional bonding and 
machining steps can be performed. The resulting composite lumber products 
are flat grained and each composite piece has at least one inclined, 
longitudinally extending glue line.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
Turning first to FIG. 1, a general description of the complete process will 
be given in order to disclose each of the basic unit processes within the 
overall process so that one skilled in the art of lumber manufacturing 
will have an immediate understanding of the present process and how it 
compares with prior art lumber manufacturing processes. The first unit 
process is depicted by process box 10 entitled "Select Logs." The log 
selection process is concerned primarily with selecting logs meeting 
correct grade and size standards. In carrying out the overall process of 
this invention, logs with substantially sound wood, free of rot and other 
major defects, will be selected for the manufacturing process. In view of 
the fact that the overall process yields a composite lumber product, the 
log grades will necessarily be carefully determined prior to selection for 
use as raw material in the process. Log size is also important in that in 
order to simplify the use of the various machinery within each of the unit 
process steps a given log size class will normally be selected for 
processing over a given time. For example, a minimum number of logs within 
a diameter class ranging from 8.1 inches to 9.2 inches will be 
accumulated, having the proper grade, and they will then be converted into 
the composite lumber product over whatever manufacturing time is required. 
By having the preselected diameter classes and grade, manufacturing time 
can be minimized while maintaining good quality standards in the finished 
composite lumber products. 
The next unit process within the overall manufacturing process is indicated 
by process box 12 entitled "Cross-Cut to Predetermined Length." In this 
step of the process the logs that have been selected according to size and 
grade are simply cross cut or bucked into a standard predetermined length 
which could be on the order of, for example, 8'6". This unit process can 
be carried out on any known equipment for bucking logs, and for high 
processing rates the logs could be processed in what has become known in 
the lumber manufacturing industry as a "merchandizer." A merchandizer is a 
substantially automatic log handling, sizing, cutting and sorting system. 
A merchandizer could, for example, automatically size and grade the 
incoming logs and then cross cut them to the predetermined length and 
automatically sort them according to grade and size into sort pockets. 
Through unit processing steps 10 and 12, the logs are graded and sized 
according to diameter and length. However, they still have their common 
rough tapered envelopes. The unit process box 14 entitled "Roundup to 
Right Frustrum of a Cone" is that step in the overall process whereby the 
logs are machined at their outside surface into a predetermined shape. The 
unit process box 14 is to depict the machining step for smoothing the 
outside envelope of the log with uniform taper or to smooth the outside 
surface of the log and remove the taper. In capturing taper the roundup 
step will remove the minimum amount of surface wood in order to generate a 
right frustum of a cone. If for processing reasons it is determined that 
the taper volume should be removed, then the roundup process will remove 
the minimum amount of wood that smooths the outside surface while removing 
the taper volume, thereby yielding a right cylinder. As will be more fully 
appreciated later, this roundup step to include taper will yield an 
additional increment in product yield from a given volume of incoming raw 
material. 
The next unit processing step is depicted at process box 16 entitled "Cut 
Logs into Sector-Shaped Pieces." At this step in the process, the logs are 
cut into individual elongated sector-shaped pieces, each having a 
predetermined size. Generally the sectors are of a uniform angle size 
between radial faces in order to simplify the manufacturing process. In 
order to yield the maximum amount of composite lumber product from the 
overall process, the angle size selected for the elongated sector-shaped 
pieces will generally have a maximum size of about 60.degree.. This value 
should be taken by way of example only and it is not intended to limit the 
scope of the invention. 
After the elongated sector-shaped pieces have been cut from the selected 
logs in a continuous manufacturing process, they are dried. The unit 
processing box 18 entitled "Dry Resulting Sector-Shaped Pieces" is to 
depict the moisture removal step for the wet green sector-shaped pieces. 
The primary reason for drying the sector-shaped pieces to a moisture 
content of below 20% is for the subsequent bonding steps. While at the 
present time it is within the contemplation of the present invention to 
dry sector-shaped pieces, suitable adhesives can be formulated to bond 
green sector-shaped pieces and thereby eliminate the need for a drying 
step. 
The next unit processing box 20 entitled "Cut Sector-Shaped Pieces Into 
Trapezoidally Shaped Pieces Having Uniform Thickness" is to depict the 
breakdown step for the individual elongated sector-shaped pieces into 
trapezoidally shaped pieces for subsequent rejoinder. Here the 
sector-shaped pieces are longitudinally cut into substantially 
trapezoidally shaped pieces with each having a predetermined thickness 
dimension which is selected according to the finally desired composite 
product thickness. In this step, depending upon whether or not the roundup 
step yields a right frustum of a cone or a perfect right cylinder, as will 
become more apparent later, a smaller elongated triangular-shaped piece 
may result. By definition, the smaller resulting triangular-shaped piece 
will be considered to have a substantially trapezoidally shaped 
cross-section. It is at this step in the manufacturing process where the 
outside curvilinear chord base portion of the log is removed from the 
elongated sector-shaped pieces for conveying out of the present 
manufacturing process. The resulting wood volume can be directed to a chip 
manufacturing facility or it could be, for example, directed to a process 
where it is converted into wood fuel for energy production. As will be 
well apparent to those skilled in the art, one intent within the overall 
manufacturing process would be to cut the smallest volume from the top of 
the sector-shaped pieces, thereby resulting in the highest yield in 
composite lumber product. 
The next step within the overall manufacturing process is depicted in unit 
processing box 22 entitled "Assemble and Edge Bond Trapezoidally Shaped 
Pieces Into Wider Piece." Here, within this unit process step, at least 
two trapezoidally shaped pieces having a substantially similar thickness 
are bonded together edgewise along an inclined bonding line to form a 
wider composite piece. With respect to two trapezoidally shaped pieces 
coming from an elongated sector-shaped piece, one trapezoidally shaped 
piece will be rotated 180.degree. about a longitudinal axis and the two 
will then be bonded together along juxtaposed inclined edges. With the 
just-described orientation of the two trapezoidally shaped pieces, after 
edge bonding the resulting wider composite piece will be a parallelogram 
in cross-section. 
Additionally, if the taper volume is included within the trapezoidally 
shaped pieces, every other piece prior to its being bonded together with 
an adjacent piece, will also be reversed endwise in order to incorporate 
the taper volume within the resulting wider composite piece. In order to 
make infinitely wide composite planar pieces, additional trapezoidally 
shaped pieces of uniform thickness can be edge bonded together, yielding 
the wide piece. These processing steps will be more fully understood when 
referring to other figures of the drawings later during the description. 
The unit processing box 24 entitled "Longitudinally Cut Wide Piece Into 
Selected Width Dimension" indicates that if an infinitely wide composite 
piece is produced, it will then be longitudinally cut into predetermined 
widths as determined by the final product dimension. This step is often 
referred to as rip-cutting. The longitudinal cutting step results in 
individual elongated composite lumber products having a predetermined 
thickness, width, and length and the pieces will be suitable for the many 
uses that typical lumber products have. 
The last unit processing box 26 entitled "End Bonding and Crosscut to 
Selected Length, Final Surfacing, Package and Ship" is actually several 
unit processes combined into a single block. The end bonding step is to 
increase the length of the resulting composite pieces from unit processing 
box 24. Here composite pieces of uniform width are end bonded together, 
using any suitable known method and means, typically referred to as end 
gluing in order to produce an infinitely long uniformly wide composite 
lumber product. The resulting infinitely long composite piece is then 
crosscut into selected lengths of predetermined width and thickness. After 
crosscutting to length, the resulting composite piece may be surfaced to 
yield the desired shape and smoothness and then packaged for shipment to 
the customer. 
Turning now to FIGS. 2-5, addition details of unit processing boxes 10-18 
will be given. FIG. 2 shows an isometric end view of a typical log 28 that 
is suitable for processing through the present invention. Log 28 is shown 
with a plurality of radial lines 30 superimposed over the end 
cross-section in order to depict the radial cutting planes for producing 
elongated individual, sector-shaped pieces, each indicated as 32. The 
outside curvilinear envelope of log 28 is indicated at 34 and has 
protruding therefrom a plurality of natural protuberances such as knots 
indicated at 36. 
In FIG. 3, log 28, which has been cut to a predetermined length, is shown 
being rounded up according to unit process 14. The roundup process could 
be carried out on a conventional plywood-type lathe having a pair of 
rotatable spindles 38, 40 together with a pair of end dogging chucks 42, 
44. After log 28 is positioned in the lathe apparatus and chucked solidly 
in place, a transversely extending peeling knife 46 is suitably adjusted 
so as to begin removing a controlled amount of surface wood indicated at 
48 from logs 28. If the logs 28 are being rounded up into a right frustum 
of a cone, the knife 46 will be slightly skewed in order to generate the 
right frustum. The log 28 is turned until the knife blade has moved in a 
predetermined distance to remove the minimum required amount of surface 
wood 48. When log 28 is removed from the lathe apparatus, its outer 
envelope 34 will be substantially smooth and free of the knots 36 and 
other protuberances. Additionally, the log will either be in the form of a 
right frustum of a cone if taper volume is to be utilized or in the form 
of a perfect right cylinder. After logs 28 have been rounded up, they will 
then be conveyed into unit processing area 16 where they will be cut into 
a plurality of elongated sector-shaped pieces. In FIG. 4A, log 28 is 
halved by a typical vertical-plane band saw 50. Log 28 is dogged on a 
typical longitudinally movable carriage assembly depicted generally at 52. 
A pair of dog members 54, 56 serve to bite into log 28 at each end and 
hold log 28 on carriage 52. Typical slide blocks 58, 60 serve to provide 
the lateral position of log 28 and to therefore control the position of 
the halving cut. Band saw 50 will divide log 28 into two half-sections 62, 
64 for further breakdown which is depicted in FIG. 4B. Each half-section 
of log 28, the half-section in FIG. 4B being designated as 62, is then 
again halved into substantially quarter-sector pieces 66, 68. This halving 
process can be carried out on a band-sawing apparatus similar to that 
depicted in FIG. 4A. 
In FIG. 4C, one of the quarter sectors, being depicted as 66, is further 
reduced into a pair of elongated sector-shaped pieces 70, 72 which would 
each have an included angle .theta. of approximately 45.degree.. The 
quarter sector 66 is conveyed longitudinally within a V-shaped conveying 
system having inclined rollers 74 past a vertically disposed band saw 76. 
Additionally, suitable top hold-down rolls 78, 80 are desirable in order 
to hold quarter piece 66 within its intended conveying path as it travels 
past band saw 76. The sawing apparatus as depicted in FIG. 4C may be 
substantially similar to that disclosed in U.S. Pat. No. 3,961,654. As 
disclosed within the aforementioned U.S. patent, rollers 74 can be 
adjustably mounted so as to accept and convey sector-shaped pieces of 
varying included angles. 
After the individual elongated sector-shaped pieces 70, 72 are cut to their 
final size, they will then be conveyed into any suitable drying apparatus 
82. FIG. 5 depicts a standard dry kiln having a plurality of sidewalls 84 
and end doors 85 enclosing a space within which the individual, 
sector-shaped pieces will be placed for drying. An inlet conduit 86 is 
attached to a source of hot gas which is caused to flow through conduit 86 
and into kiln 82 where it circulates substantially in a predetermined 
manner and exits through outlet conduit 88. The circulating hot gas 
evaporates a portion of the moisture within the elongated sector-shaped 
piece, each of which is singly depicted at 90 and carries it out through 
outlet conduit 88, thereby drying the pieces to a desired moisture 
content. After the pieces are dried, they are removed from kiln 82 and 
will then be ready for the next processing step. 
Additional details of the unit processing step of box 20 will now be 
described. In FIG. 6A an individual, elongated sector-shaped piece 92 is 
depicted that has been cut from log 28 that was a perfect right cylinder. 
This means that the radial dimension at each end of piece 92 is the same 
and that there is no taper volume left within piece 92. The longitudinal 
axis line 94 corresponds to the center line of the right cylinder log. 
Sector-shaped piece 92 has been sized so as to yield two elongated, 
trapezoidally shaped pieces, one being indicated at 96 and the other being 
indicated at 98. In this particular instance, the elongated piece 96 will 
be substantially in the form of a triangle with one apex coinciding with 
the center line of the log. Each piece 96, 98, has a thickness value of T 
as depicted in the figure. It will be pointed out here by way of example 
that if the finally desired thickness of the composite lumber product is 
to be on the order of 11/2 inch in nominal thickness, then each piece 96, 
98 will have a T value of approximately 1.50 inches and therefore the log 
diameter to yield two such pieces from single sector-shaped piece 92 will 
be approximately 6.50 inches, which includes an amount for losses due to 
kerf, drying and surfacing. 
In cutting the pieces 96, 98 from the elongated sector-shaped piece 92, a 
resultant chord segment volume 100 will be generated. It is volume 100 
which, as previously mentioned, is diverted from the process and converted 
to pulp chips or into fuel. As may be seen in FIG. 6A, each plane of cut 
102, 104 made in cutting the elongated pieces 96, 98 is made substantially 
parallel to a chord plane, extending through sector-shaped piece 92. While 
the chord plane may be substantially coplanar with cutting plane 104, it 
is not an absolute requirement. However, they are usually coplanar because 
by making the segment volume 100 the minimum volume possible which would 
make the planes coplanar, addition yield of final composite lumber product 
can be generated. 
In FIG. 6B the condition is depicted where log 28 had been rounded up into 
a right frustum of a cone in order to utilize the taper volume within log 
28. The individual elongated, sector-shaped piece 106 depicted in FIG. 6B 
has a slightly different cutting pattern compared to that of FIG. 6A in 
order to utilize at least a portion of the taper volume. Again, the 
sector-shaped piece 106 has been sized in order to yield a pair of 
substantially trapezoidally shaped pieces 108, 110 with both having 
substantially equal thicknesses over their lengths. When an individual 
elongated sector-shaped piece has taper volume, it means that the radial 
dimension at one end is different than the radial dimension at the other 
end and the parallel cutting planes will be generated at an angle to the 
log center line. In this instance, the log center line which coincides 
with line 112 and one apex is slightly offset from the plane of cut 114 
that generates one face of trapezoidally shaped piece 108. The small, 
elongated, triangular-shaped piece 116 between plane of cut 114 and the 
apex is not usable for making of composite lumber products and may be 
utilized as chips or fuel similar to the chord segment volume 118 produced 
along the top of piece 106. The other parallel planes of cut 120, 122, 
each of which will be substantially parallel to a chord plane with plane 
of cut 120 substantially coinciding therewith, are made so as to generate 
the uniformly thick trapezoidally shaped pieces 108, 110. 
In FIG. 6C there is depicted a larger elongated sector-shaped piece 124, 
having taper volume and which has a plurality of cutting planes 126 
parallel to one another (and to a chord plane) to result in three 
substantially trapezoidally shaped pieces 128, 130 and 132, together with 
a resulting smaller elongated triangular-shaped piece 134 along the 
bottom. Again, a resulting segment volume 136 is generated that can be 
utilized for chips or fuel along with piece 134. The three resulting 
trapezoidally shaped pieces are all of substantially uniform thickness and 
suitable for use in making the wider composite piece within unit 
processing step 22. 
FIG. 7 depicts a sawing machine that can be utilized for generating three 
longitudinally extending parallel planes of cut in an individual elongated 
sector-shaped piece depicted at 138. Again, a plurality of vertically 
biased rollers 140 form a V-shaped conveying channel through the plurality 
of vertically spaced, horizontally disposed band saws 142. A plurality of 
top hold-down rolls 144 positioned on a horizontal plane serve to 
constrain the traveling sector-shaped piece 138 in its proper orientation 
during this cutting step. The sawing machine of FIG. 7 could take other 
forms and the apparatus depicted is only one example of a suitable sawing 
machine. For example, in order to make the top and bottom parallel planes 
of cut on an individual sector-shaped piece that has taper volume, 
suitable chipping heads could be employed and would be positioned 
accordingly. The rollers 140 are preferably angularly adjustable so as to 
accept sector-shaped pieces with different included angles .theta.. 
Similarly, the vertical spacing of individual band saws 142 could be 
adjustable in order to generate varying thicknesses in the resulting 
trapezoidally shaped pieces. 
Turning now to a more complete description of the unit processing step of 
box 22, reference will be made to FIG. 8 wherein the assembly and edge 
bonding process is depicted. Here individual trapezoidally shaped pieces 
146 of uniform thickness will have their inclined side edges spread with 
suitable adhesive as they pass through adhesive applicators indicated at 
148 and 150. Pieces 146 will be fed through their respective adhesive 
applicator alternately, from either side of the accumulating section of an 
edge press, indicated generally at 152. Each of the individual pieces 146 
will have been cut from a similarly sized elongated sector-shaped piece in 
order to have the opposed inclined side edges of the adjacent pieces 
compatible with one another. When the inclined edges are compatible, the 
resulting wider piece will be substantially planar, having parallel top 
and bottom surfaces. The opposed side feeding is to allow the pieces with 
taper to be inserted alternately in order to maintain uniformity along the 
increasing end edges of the resulting wider piece. 
The edge press 152 may be comprised of, for example, a pair of spaced 
supporting rails 154, 156 on top of which are carried the individual 
trapezoidally shaped pieces 146. The slidable edge platen 158 serves to 
exert a pressure on first edge of the first piece 146 of the wider 
composite member. It is adapted to slide as additional individual pieces 
146 are pushed toward it by the pusher platen 160. A pair of top hold-down 
rails 162, 164 are provided in order to constrain the wider composite 
piece 166 as it increases in size. As the individual pieces 146 are 
alternately fed into press 152 to a position atop rails 154, 156, platen 
160 will then push the two new pieces in a direction toward platen 158 so 
the loading section will be ready to receive the next two incoming 
trapezoidally shaped pieces. The press 152 is extended in a downstream 
direction an amount necessary to provide suitable cure time for the 
inclined edge bonding lines. As earlier mentioned, the edge-bonded wider 
composite piece 166 could be made infinitely wide, provided there was an 
infinitely long edge press. The edge press is, as previously mentioned, 
only long enough to allow for sufficient cure time and the composite 
pieces 166 will be longitudinally cut in sheet form to a finite width at 
the outfeed end of press 152. 
In FIG. 9, one of the resulting wider composite members 166 in sheet form 
is depicted and is shown being longitudinally cut into individual 
elongated composite members, each indicated at 168. A plurality of 
vertically disposed round saws 170 make the cuts and each composite piece 
is shown with a uniform width dimension "W" and thickness dimension "T." 
As may be clearly seen in FIG. 9, each resulting elongated composite 
member 168 has a plurality of inclined edge bonding lines joining the 
individual, trapezoidally shaped pieces together. The resulting composite 
members 168 will have what is commonly referred to as a flat grain pattern 
over their wider faces. This resulting grain pattern may be contrasted 
with the resulting grain pattern from the process as disclosed in the 
aforementioned U.S. Pat. No. 3,961,654, which yields a composite lumber 
product having a vertical grain pattern over its wider faces. 
FIG. 10 depicts the processing step of box 26 in more detail, but is still 
depicted in schematic form since all of the individual steps are well 
known in the lumber manufacturing art. Beginning with one of the composite 
members 168 generated by the longitudinal cutting step depicted in FIG. 9, 
the end bonding step is performed. Any suitable end bonding process is 
within the contemplation of the present invention; however, in most 
typical instances, the process is a finger-joining process where the first 
step is the machining of suitable fingers on either end of a composite 
member 168 and then a suitable adhesive is applied to the resulting 
fingers with the next step being the joining together of two similar 
composite members 168 to form the longer composite member. The next step 
in the end bonding process is to cure the joint such that the adhesive is 
allowed to fully cure and form a strong and satisfactory joint. In most 
end-gluing processes, the process is continuous and member of selected 
length will result. The result is the composite elongated member depicted 
at 172 in FIG. 10. The composite member 172 has a plurality of finger 
joints 174 along its length. Since the composite member 172 now has the 
desired thickness, width and length, it is then ready for final surfacing 
and shaping. The piece 172 can be passed through a planing machine or an 
abrasive planer or any other suitable surfacing and/or shaping apparatus. 
A suitable number of similar elongated composite pieces are then 
accumulated and packaged for shipment. 
The graph in FIG. 11 shows curves depicting the yield of a composite lumber 
product in terms of board footage per cubic volume of raw material for a 
range of log diameters. The graph coordinates show log diameters from 4 
inches up to 12.5 inches and yields from 800 up to 1,300 BF/CCF (board 
feet per 100 cu. ft. of log volume). The "Basic or Parallelogram" curve 
depicts the yield, over the log diameter range, of composite lumber 
product of the process disclosed in the aforementioned U.S. Pat. No. 
3,961,654. The lower three downwardly sloping curves are for three 
variations of the present process. The lowermost curve, labeled "1 Piece," 
shows yields when a single trapezoidally shaped piece is cut from a 
sector-shaped piece previously cut from a log. The curve labeled "2 
Pieces" is indicative of where two trapezoidally shaped pieces are cut 
from the sector-shaped piece and rejoined according to the present 
process. As may be seen from FIG. 11, the yields in this case resulting 
from log diameters between 7 to 10.3 range from 1,100 BF/CCF up to 
approximately 1,200 BF/CCF, well above the yields of a typical rectangular 
sawing process. The curve "3 Pieces" is indicative of the yield when a 
sector-shaped piece is cut into three trapezoidally shaped pieces and 
edgebonded together, resulting in yields higher than for the two-piece 
case, ranging from 1,220 BF/CCF up to 1,240 BF/CCF for logs of from 10.3 
inches to 12.5 inches in diameter. 
The three curves each show yields well above any of the traditional 
rectangular sawing processes, but all are slightly below the yields 
obtainable over the same diameter range from the basic sector-sawing 
process, as disclosed in the aforementioned U.S. patent. The single curve 
labeled "AVERAGE" is to depict what the average yield might be over the 
range of diameters when using the present invention. It should be apparent 
to one skilled in the lumber manufacturing art that the process of the 
present invention and the resulting elongated composite lumber products 
offer a significant increase in yield over other prior art processes. When 
compared to the process of the aforementioned U.S. patent, the process of 
the present invention has the advantage of requiring one less bonding step 
in order to yield the final composite product. 
While a detailed description of the basic process and resulting composite 
lumber product has been made, it is to be understood that many additional 
changes and modifications may be made to the invention without departing 
from its true scope. All such modifications and changes are intended to be 
included within the scope of the appended claims.