Note: Descriptions are shown in the official language in which they were submitted.
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A method for dividing a log and for producing a composed
5 wood unit
FIELD OF THE INVEI\ITION AND PRIOR ART
The present invenltion relates to a method for dividing a log ac-
10 cording to the preamble of the appended patent claim 1 as wellas a method for producing a wood unit composed by a plurality
of wood pieces glued to each other, in which it is started from at
least an elongated wood piece having a substantially rectangu-
lar cross-section, on which cuts are applied for obtaining a
15 wood piece for saiid wood unit.
"Rectalngular cross-section" is defined as a cross-section hav-
ing four right-angled corners and does accordingly also com-
prise c3 square cross-section.
A number of diffe!rent techniques for dividing a log are known,
and it is usually proceeded in the way that a number of cuts
paralle~l to each other are applied in the longitudinal direction of
the log for gaining planks and boards from the log with a possi-
25 ble intermediate treatment in an edging machine and/or planingmachirle. Raw unrefined products of a comparatively low quality
is then obtained, which after drying are delivered to the con-
sumers, of which a part is manufacturer of refined wood prod-
ucts, such as for example gluedjoint sheets, pieces of furniture
30 and the like. Thus, the log is in a first line divided without ob-
~ taining any degree of refinement of the products obtained. Fur-
thermore, the main part of the surface near wood will normally
~ get lost with respect to the possibilities to use it for forming
wood products of high quality and this wood is cut into chips.
35 The salme is valid for thinner log parts, which with the conven-
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tional dividing technique only give rise to products of such a low
quality that cutting thereof into chips is often the only realistic
alternative.
5 SUMMARY OF THE INVENTION
The object of the present invention is to provide a method for
dividing a log of the type defined in the introduction, which
makes it possible to find a remedy to the inconveniences men-
10 tioned above of the log dividing methods according to the priorart and especially makes it possible to in a better way utilise
the wood of the log and makes it possible to produce wood
products having improved quality properties, as well as provid-
ing a method for producing wood units composed by a plurality
15 of wood pieces glued to each other according to the preamble
of the appended independent patent claim therefor, through
which glued wood products with improved quality properties
may be produced in both a simple and by that labour saving and
material saving way.
These objects are according to the invention obtained by pro-
viding the methods according to the appended independent
patent claims.
25 By dividing the log in a second step in a plurality of second
wood pieces by applying cuts in the longitudinal direction of the
first wood piece having a substantially rectangular cross-sec-
tion substantially in parallel with a diagonal plane extending
from one corner to another of a rectangle forming the cross-
30 section of the first wood piece, second wood pieces, which mayeasily be glued to each other, by the fact that they have glue
surfaces that matches when they are brought together, in a
number of combinations for obtaining glued wood products
having good quality properties, are obtained in a very simple
35 way. Besides the fact that the second wood pieces resulting in
-
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this way have sur~h cross-section shapes that they may easily
be combined for l~btaining numerous wood products the inven-
tional way of appllying the cuts means that these products may
get very good properties by the fact that they will have a ten-
5 dency to automatically have annual rings standing with respectto several suRace!s thereof, so that these surfaces will be very
wear resistant.
Thank~s to the possibility to in this way remarkably raise the
10 quality of the wood products that may follow upon said dividing
metho~, a greater part of the surface near wood and thin logs
may through the invention be saved from the chips cutter and
instead be used for producing wood products for which a con-
siderably higher prize is set.
By the fact that in l~he method according to the invention for pro-
ducing the wood l~nit composed by a plurality of wood pieces
glued lo each other the cuts are applied in the longitudinal cdi-
rection of the startiing wood piece substantially in parallel with a
20 diagonal plane extending between one corner and another cor-
ner of the rectangle forming the cross-section of the starting
wood piece and a plurality of wood pieces resulting from such
cuts are glued to each other by applying longitudinal surfaces
thereof against each other for obtaining a composed wood unit,
25 glued ~vood products having very good quality properties may
be procluced throuqh very simple means, i.e. in a labour or work
saving way, while ,~t the same time utilising the material of the
starting wood piece. The invention comprises also that wood
pieces resulting from such cuts, which are glued to each other
30 derive frorn different starting wood pieces.
Thus, it will according to the invention be possible to in one
single line achieve division and direct production of refined
glued wood produc:ts having good quality properties, although
35 the invention also comprises the possibility to glue the wood
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pieces resulting from said cuts applied substantially in parallel
with said diagonal plane to each other far later, maybe in an-
other place.
5 According to a preferred embodiment of the method for produc-
ing a composed wood unit the starting wood piece is before the
application of said cuts put with said diagonal plane substan-
tially vertically arranged, and the starting wood piece is kept in
this position during the application of said cuts. The wood
10 pieces to be glued to each other thereafter for obtaining a wood
unit in the form of a glued high quality wood product may in this
way be produced while using simple means through a conven-
tional cutting equipment without any special demands on saw
blades being obliquely positioned or the like.
The invention is applicable to starting wood pieces having sides
extending parallel to the fibres as well as to the centre or core,
said cuts being substantially parallel to said diagonal plane
then being applied substantially in parallel with the fibre direc-
20 tion and the center axis of the starting wood piece, respectively.
All the wood pieces resulting from said cuts are then gettingglue surfaces matching and brought together and which may be
glued to each other for obtaining wood units in the form of high
2~ quality glued wood product, in which the wood pieces resulting
from the cuts applied farthest away from said diagonal plane
and having a cross-section of a right angled triangle as well as
the wood pieces resulting from the cuts applied closer to said
diagonal plane, which have four or six corners (when they are
30 formed by two cuts located on both sides of said diagonal
plane), makes it possible to obtain such high quality glued wood
products without any requirement of any further dividing or ma-
terial removal before gluing.
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Thus, a further preferred embodiment of the invention relates to
a method in which two substantially equal wood pieces obtained
by appllying said cuts and having the cross-section shape of a
right angled trianglle with the hypotenuse formed by a said cut
5 are glued to each other with the surface of the respective wood
pie~e resulting from the respective cut as glue surface while
forming a wood unit having a substantially rectangular ~ross-
section. Surface near wood may in this way be utilised for ob-
taining a glued wood product having a high quality, which in that
10 case will have annular rings standing towards the surfaces
thereof.
Accordiing to a fu~ther preferred embodiment of the invention
two of said cuts are applied on the same side of said diayonal
15 plane so that a wood piece having a substantially trapezoidal
cross-section is o~tained, whereupon four wood pieces so ob-
tained are glued to each other with the opposite suRaces of the
respective wood piece extending obliquely with respect to each
other as gluing suflaces with the parallel sides of the respective
20 wood piece orientated substantially perpendicularly to corre-
sponding sides of an adjacent wood piece while forming a wood
unit ha~ring a subsl:antially rectangular outer cross-section and
an inner longitudinal hollow space having a substantial
rectangular cross-~iection. A high quality wood unit having a
2~ very large outer cross-section with respect to the cross-section
with respect to the wood pieces being parts thereof may be
obtained in this Wcly, and said wood unit will also have wear
resistant surfaces lhanks to the annular rings standing there-
against.
Further advantages as well as advantageous features of the in-
vention appear from the other dependent patent claims as well
as the following description.
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BRIEF DESCRIPTION OF THE DRAWINGS
With reference to the appended drawings, below follows a de-
scription of preferred embodiments of the invention cited as ex-
5 amples.
In the drawings:
Fig. 1 shows schematically how different cuts are applied on
a starting wood piece in a method according to a pre-
ferred embodiment of the invention,
Fig. 2 shows a cross-section of a wood unit produced by a
method according to the invention,
Fig. 3 is a perspective view of a wood unit produced by glu-
ing a plurality of wood units according to Fig. 2 to each
other,
20 Fig. 4 is a wood unit produced according to a method accord-
ing to the invention,
Fig. 5 illustrates schematically how wood pieces resulting
from the division according to the invention may be
glued to each other to form wood units,
Fig. 6 shows a cross-section of a wood unit produced
through a method according to the invention,
~0 Fig. 7 shows a cross-section of a wood unit produced ac-
cording to a further method according to the invention,
Fig. 8 illustrates schematically how a wood piece obtained
by the division shown in Fig. 1 may be divided further
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into two pieces which may be glued to each other for
obtainin~ a wood unit,
Fig. 9 is a vie~ corresponding to Fig. 1 with cuts applied on
a rectangular starting wood piece having adjacent
sides of different len~ths, and
Fig. 10 is a cro~;s-section of a wood unit produced through a
method according to the invention.
DETAII ED DESCRIPTION OF PREFERRED EMBODIMENTS OF THE
INVENTION
It is illustrated in Fig. 1 how according to a preferred embodi-
15 ment of the invention a log, which has been divided for obtain-
ing a starting wood piece 1 having a substantially square cross-
section and with the center of the log extending substantially
through the center of the square forming the cross-section of
the starting wood piece, may be cut by applying different cuts 2,
20 3, 4, 'i substantiallly in parallel with a diagonal plane extending
from one corner 6 to another corner 7 of said square. A starting
wood piece 1 is then preferably put with said diagonal extend-
ing vertically when the cuts 2-5 are app!ied, so that conven-
tional cutting equipment may easily be utilised, without any re-
25 quiremerlt of obliquely orientated saw blades or the like. It is
emphasised that the invention comprises the application of such
cuts at any distances from said diagonal plane and in any num-
ber for one and the same starting wood piece 1. The wood
pieces 8-12 resulting in this way from the application of the cuts
30 2, 3, 4 and 5 may be glued to other wood pieces obtained in a
similar- way, which may be obtained from one or several other
starting wood pieces or from the same starting wood piece 1.
Some different possibilities to obtain high quality wood units
from wood pieces so obtained will be shown in the following
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figures, but these are not in any way exhausting for the inven-
tion. t e'
It is illustrated in Fig. 2 how two wood pieces 8, 12 obtained
5 through cuts 2, 5 applied on a starting wood piece farthest away
from said diagonal plane may be glued to each other with a
surface resulting from a respective cut against the respective
wood piece as glue surface while forming a wood unit 13 having
a substantially rectangular, in this case a square cross-section,
10 since the starting wood piece has a square cross-section. This
wood unit will command a comparatively high price, in particu-
lar when having in mind that it may be obtained en~irely from
surface near wood, since it will be resistant to wear with the
annual rings standing towards all sur~aces.
It is illustrated in Fig. 3 how a plurality of wood units 13 may be
put side by side and glued together for obtaining a composed
glued wood product 26 in the form of a gluedjoint sheet having
a longitudinal substantially rectangular cross-section.
Another wood unit 14, which may be produced by gluing wood
pieces of the same type as the wood piece 9 and 11 in Fig. 1, is
shown in Fig. 4. Thus, it is obtained by applying two such cuts
on the same side of said diagonal plane, so that a wood piece 9
25 having a substantial trapezoidal cross-section is obtained,
whereupon four wood pieces so obtained are glued to each
other with the opposite surfaces 15 of the respective wood
piece extending obliquely with respect to each other as gluing
surfaces with the parallel sides of the respective wood piece
30 substantially perpendicularly orientated with respect to the cor-
responding sides of the adjacent wood pieces. A wood unit
having a substantially square outer cross-section with an inner
longitudinal hollow space 16 having a substantially square
cross-section is formed in this way. This wood unit has also an-
35 nual rings standing substantially towards the outer surfaces
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thereof and in addition thereto a high quality glued wood prod-
uct having a conlparatively large outer cross-section may be
obtainled from cornparatively little material.
5 A furtlter example of how wood pieces 9 of the type included in
the wood unit according to Fig. 4 may be glued to each other for
obtainling high quality glued wood products is shown in Fig. 5.
Thus, it is possilble to turn the corresponding of the parallel
suRac:es of two e!qual such wood pieces 9 towards each other
10 and to glue such a couple of wood pieces 9 to the couple hav-
ing th,e opposite surfaces turned towards each other in the way
shown in Fig. 5. This may be repeated a desired number of
times by alternating the directions of the surface pieces in this
way for obtaining a glued wood unit having annual rings stand-
15 ing substantially towards large surfaces thereof.
It is illustrated in Fig. 6 how it is possible to obtain a composedwood u~it 18 by gluing wood pieces of the same type as the
wood pieces 1 and 12 in Fig. 1 to each other, so that a wood
20 unit having a longitudinal rectangular cross-section is obtained,
which has annual rings standing towards the large sides 19
thereof. Thus, two such wood pieces 11 having a substantial
trapez:oidal cross--section are glued to each other with the short
and p~arallel side~i against each other, wherein a wood piece 12
25 havin~g a cross-s~sction of a right angled triangle is glued into
the respective V-shaped slot so formed, so that the hypotenuse
of the respective cross-section triangle will form one side of
said elongated rectangular cross-section.
30 It is pointed out that it when it is stated that such a wood piece
having a substantially trapezoidal cross-section is obtained by
applying two cuts on the same side of said diagonal plane, this
also comprises that one of the cuts is applied according to said
diagonal plane.
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It is illustrated in Fig. 7 how a wood unit 20 having an octagonal
cross-section may be obtained by gluing wood pieces of the
same type as the wood piece 10 in Fig. 1 to each other, i.e. by
gluing wood pieces obtained by applying cuts on both sides of
5 said diagonal plane, which have an hexagonal cross section, to
each other with a surface 22 adjacent to the respective right
angled corner 21 as gluing suRace of each wood piece against
adjacent wood pieces and with the parallel sides of the respec-
tive wood piece substantially perpendicularly directed towards
10 the corresponding sides of the adjacent wood pieces while
forming a wood unit having an octagonal outer cross-section
with an inner elongated hollow space 23 having a substantially
square cross-section. This wood unit will have the same advan-
tages with respect to "cross-section gain" and wear resistance
15 in the form of annual rings standing towards the outer surfaces
thereof as the wood unit illustrated in Fig. 4.
It is illustrated in Fig. 8 how a wood piece obtained in the way
according to the invention having a substantially trapezoidal
20 cross-section may be divided further by applying cuts 24 sub-
stantially perpendicularly to the two parallel sides, whereupon
for one of the wood pieces so obtained end is shifted for end
and these are then glued together to each other for obtaining a
wood unit 25 having a substantially rectangular cross-section
25 and annual rings standing towards the surfaces thereof.
It is illustrated in Figs. 9 and 10 how the method according to
the invention may be applied to a starting wood piece having a
rectangular cross-section with adjacent sides of different
30 lengths by applying the three cuts 26-28 substantial in parallel
with a diagonal (corresponding to the cut 26) of a cross-section
rectangle and gluing the wood pieces 29-32 so resulted to the
wood unit 34 according to Fig. 10. This will, besides the fact
that it has annual rings standing towards the large sides
35 thereo~, have an inner elongated hollow space 33 having a
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11
parallelogram-shaped cross-section, which means an increase
of the area inscribed by l:he outer contour of the cross-section.
Thus, through the dividing or disintegrating method according to
5 the invention divicling according to cuts in parallel with said di-
agonal plane and gluing wood pieces SG obtained to each other
is realised in one single production line for obtaining a glued
wood product having a remarkable degree of refinement already
in connection with the division of a log. This may primarily be
10 obtainled by the falct that the wood pieces resulting from the di-
vision according to the invention have such shapes that they are
easy to glue to each other while being pressed against each
other. The strong raise of quality of the glued wood products is
fu~hermore ensured by the special orientation that these sur-
15 faces will get with respect to the respective annual rings.
It is emphasised that the methods according to the inventioncomprises fibre parallel as well as center parallel cutting, so
that the definition "cuts are applied in the longitudinal direction
20 of the starting wood piece substantially in parallel with a diago-
nal plane" in the patent claims also comprises such fibre paral-
lel cutting, in whic:h said cuts extend along lines being in paral-
lel with a diagonal line running from one corner to another in
each cross-section plane, although the surfaces formed in real-
25 ity by the cutting will not be completely parallel to said diagonalplane.
The invention is of course not in any way restricted to the pre-
ferred embodiments described above, but several possibilities
30 to modifications thereof would be apparent to a man skilled in
the art without departing from the basic idea of the invention.
.,
