CA2027356A1 - Wood unit - Google Patents
Wood unitInfo
- Publication number
- CA2027356A1 CA2027356A1 CA002027356A CA2027356A CA2027356A1 CA 2027356 A1 CA2027356 A1 CA 2027356A1 CA 002027356 A CA002027356 A CA 002027356A CA 2027356 A CA2027356 A CA 2027356A CA 2027356 A1 CA2027356 A1 CA 2027356A1
- Authority
- CA
- Canada
- Prior art keywords
- wood
- cross
- section
- pieces
- piece
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B27—WORKING OR PRESERVING WOOD OR SIMILAR MATERIAL; NAILING OR STAPLING MACHINES IN GENERAL
- B27M—WORKING OF WOOD NOT PROVIDED FOR IN SUBCLASSES B27B - B27L; MANUFACTURE OF SPECIFIC WOODEN ARTICLES
- B27M3/00—Manufacture or reconditioning of specific semi-finished or finished articles
- B27M3/0013—Manufacture or reconditioning of specific semi-finished or finished articles of composite or compound articles
- B27M3/0026—Manufacture or reconditioning of specific semi-finished or finished articles of composite or compound articles characterised by oblong elements connected laterally
- B27M3/0053—Manufacture or reconditioning of specific semi-finished or finished articles of composite or compound articles characterised by oblong elements connected laterally using glue
-
- E—FIXED CONSTRUCTIONS
- E04—BUILDING
- E04C—STRUCTURAL ELEMENTS; BUILDING MATERIALS
- E04C3/00—Structural elongated elements designed for load-supporting
- E04C3/02—Joists; Girders, trusses, or trusslike structures, e.g. prefabricated; Lintels; Transoms; Braces
- E04C3/12—Joists; Girders, trusses, or trusslike structures, e.g. prefabricated; Lintels; Transoms; Braces of wood, e.g. with reinforcements, with tensioning members
- E04C3/127—Joists; Girders, trusses, or trusslike structures, e.g. prefabricated; Lintels; Transoms; Braces of wood, e.g. with reinforcements, with tensioning members with hollow cross section
Landscapes
- Engineering & Computer Science (AREA)
- Life Sciences & Earth Sciences (AREA)
- Architecture (AREA)
- Wood Science & Technology (AREA)
- Manufacturing & Machinery (AREA)
- Forests & Forestry (AREA)
- Civil Engineering (AREA)
- Structural Engineering (AREA)
- Dry Formation Of Fiberboard And The Like (AREA)
- Rod-Shaped Construction Members (AREA)
Abstract
ABSTRACT
In a method for producing wood units it is started from at least one elongated wood piece in the longitudinal direction of which two cuts are made substantially perpendicularly to each other, so that said cuts intersect each other in the centre of the starting wood piece cross section so as to divide the starting wood piece into four elongated wood pieces. The four elongated wood pieces obtained in this way are bonded to each other at the ends of the surfaces formed by said cuts located opposite to the right-angled corner of each piece as seen in cross section and so that the right-angled corners of adjacent elongated pieces are directed perpendicularly to each other, so that the right-angled corners of the elongated wood pieces each form one of the four corners of a wood unit with a rectangular cross section and a longitudinal inner hollow space.
In a method for producing wood units it is started from at least one elongated wood piece in the longitudinal direction of which two cuts are made substantially perpendicularly to each other, so that said cuts intersect each other in the centre of the starting wood piece cross section so as to divide the starting wood piece into four elongated wood pieces. The four elongated wood pieces obtained in this way are bonded to each other at the ends of the surfaces formed by said cuts located opposite to the right-angled corner of each piece as seen in cross section and so that the right-angled corners of adjacent elongated pieces are directed perpendicularly to each other, so that the right-angled corners of the elongated wood pieces each form one of the four corners of a wood unit with a rectangular cross section and a longitudinal inner hollow space.
Description
jo/ih Applicant: HAMMARSTROM, Lars Wood unit TECHNICAL FIELD OF THE INVENTION AND PRIOR ART
The invention relates to a wood unit and a method for producing it.
The invention relates primarily to utilizing thin log members as wood, which members have a low yield on sawing and are therefore mostly used for the production of chips, but the invention is also applyable to coarser logs or thick boards or beams sawn from these. In that case the invention relates to a wood unit with a rectangular cross section. The definition rectangle comprises all forms with four outer right-angled corners and it comprises accordingly also squares and right-angled quadrangles provided with perforations or holes.
Wood units with a rectangular cross section achieved hitherto from thinner log members have a cross section surface often being too small and have been produced while causing a consi-derable waste o~ material with respect to -this cross section surface.
S~MMARY OF THE INVENTION
The object of the present invention is first of all to remedy th.is inconvenience and primarily in thinner log members, but also in another type of wood material, utilize as much as possible of the wood amount available while producing wood units with rectangular cross section and good functional features.
According to the invention this object is obtained by a method for producing wood units according to the appended independent method claim.
The invention may just as well be applied to wood pieces having a circular cross section, such as log ~embers, as wood pieces having a rectangular cross section, such as beams and boards~
Through the understandin~ that a cutting cross applied in the longitudinal direction in a starting wood piece through the centre thereof gives rise to four wood pieces each having a right-angled corner suited for forming a wood unit with a rectangular cross section, wherein said pieces may be used to form the right-angled corners of said wood unit, and that by such an assembly of four elongated wood pieces obtained in this way a wood unit with a longitudinal inner hollow space is obtained, the object of the invention could be obtained in a very satisfying manner.
Through the cross cutting and the reassembling of the wood pieces thus achieved with the material portions located at the centre of the starting wood piece forming the corners of the wood unit obtained, a wood unit having a considerably greater cross section surface is obtained, on condition that the surface of the enclosed hollow space is also considered, than the cross section surface hitherto obtainecl by traditional sawing. There will be little waste produced and thanks to the existenca of the longitudinal inner hollow space a compara tively high wood gain is achieved in the practice if the cross section surface o~ the starting wood piece is compared to the one of the wood unit obtained.
Another advantage of the invention consists in that a stable wood unit with a longitudinal inner hollow space is produced in 3 ~,,f~
a simple way, ancl said hollow space may be used for different purposes, such as hidden laying of different types o wires or conduits and filling the wood unit with heat insulators.
Other preferred features of the invention, such as the gene-rating of a small amount of material waste while creating a wood unit with a rectangular cross section being constant ov~r the entire length thereof from wood pieces tapering conti-nuously from one end to the other, and to assemble two pairs of wood pieces with different cross section surfaces achieved by cross cutting so as to form a wood unit with predetermined desired outer dimensions, will appear from the description following and the appended independent claims.
BRIEF DESCRIPTION OF THE DRAWINGS
With reference to the appended drawings, below follows a specific description of preferred embodiments of the invention cited as examples.
In the drawings:
F'ig 1 is a perspective view of the heart part of a log being cut for producing a wood unit with a square cross section, F'ig 2 is a perspective view of a wood unit obtained by gluing the pieces of the heart part of a log shown in Fig L to each other, Fig 3 is a cross section view illustrating how the cross cutting according to the invention may be carried out starting from a wood piece with a rectangu:Lar cross section, Fig 4 is a cross section view of the wood unit obtained by the cutting illustratecl in Fig 3, Fig 5 is a cross section view Of a wood unit according to a preferred embodiment of the invention, Fig 6 is a cross section view of a wood unit according to another preferred embodiment of the invention, Fig 7 is a perspective view of a conical log member, in which a cut have been made parallelly to the direction of the fibers of the log/ so that a slab with a constant thickness has been obtained, Fig 8 illustrates how two slabs according to Fig 7 may be glued to each other for forming a strong wood unit.
DETAILED DESCRIPTION OF PREFERRED ~MBODIMENTS OF THE INVENTION
As previously mentioned it may when utilizing the method according to the invention so as to produce a wood unit accor-ding to the invention be started from a log, which for the r~st does not have to be made round to a constant diameter, for instance by turning, or a wooden beam with a rectang~lar, prefer,ably s~uare, cross section. In Fig 1 is shown how the cross cutting according to the invention is applied on a log 1 being made round, i.e. which has a constant diameter over its length. The heart member remaining after the round reduction is cut in its longitudinal direction into four substantially identical wood pieces 2. BeEore or after this cutting very thin, preferably with a thickness of about 1. mm at the thickest part, wood parts 3 may be cut away from the periphery of the heart member displaced at 90 around the heart member, the cuts being carried out along the whole length of the heart member and so that the heart member in cross section will have four circular arc members ~ separated by four rectilinear portions 5, which in pairs are parallel to each other and extend sub-stantially perpendicularly to the other two.
When the heart member 1 has been provided with the cuts men-tioned above the wood members 3 are removed so as to be used pre~erably as chips, while the four wood pieces 2 are glued together in the way illustrated in ~ig 2. In doing so the rectilinear portions 5 defining narrow planar surfaces are gluing and the wood pieces 2 are turned in such a way with respect to each other, that the right-angled corner of each of them forms a corner o~ a beem 6 with a substantially square cross sectionO The rectilinear portions 5 coated by glue of each wood piece 2 will each bear against a rectilinear portion of two adjacent pieces, and the beam 6 will as a consequence thereof be very strong. The cirular arc members 4 of the wood piece 2 in ~uestion will be directed inwardly towards the center of the beam, so that a longitudinal hollow space 7 will be produced inside the beam.
It may easily be understood that the wood yield in conventional cutting of a beam with a square cross section out of the round reduced heart member will be very low, but the inventional method comprising the cross cutting will lead to a yield being almost one hundred percent. Yes, it is even so that the method accor~ing to the invention gives rise to a beam 6 which, were it solid, would have considerably more wood than the heart member 1 itself.
It is shown in Fig 3 how the method according to the invention may be carried out starting from a wood piece 8 with a rec-tangular cross section, the dashed lines forming a circle suggest how the wood piece 8 initially may have been obtained from a log member with a c:ircular cross section. Two cuts extending substantially perpendicularly to each other are made in the longitudinal direction of the wood piece 8 (dashed-dotted lines), said cuts intersecting each other in the centre of the cross section of the starting wood piece 8. The cutting cross 10 formed by the cuts 9 is turned around the centre of the wood piece with respect to a cutting cross formed by the diagonal of the cross sectional square. As a consequence o this, the cuts 9 intersect each side of the cross sectional rectangle, which in this case is a square, at a distance from the adjacent rectangle corner as well as the centre of the rectangle side. Thanks to this way of making the cuts it will be possible to glue the four wood pieces 11 obtained after the cutting to each other at the ends of the surfaces formed by the cuts located opposite to the riyht-angled corner 12 of each wood piece 11 as seen in cross section. After cutting the four elongated wood pieces these are brought to pass through a drying apparatus for drying and then the wood pieces 11 are coated by glue on at least portions of the two surfaces 13, 14 which do not extend to the right-angled corner 12 of the wood piece in question. In doing so, the wood pieces 11 are turned so that their right-angled corners 12 are directed outwardly and they are brought together so that the portions of the surfaces 13 and 14 coated by glue will bear against each other.
Finally, a pressure pressing the surfaces coated by glue against each other is applied. However, when a special glue is available it is also possible to coat the wood pieces 11 by glue and glue them to each other immediately after the cutting, without any preceding drying.
Owing to the method now described a wood unit 15 according to Fig 4 is obtained. The surprising and characterizing feature of this method is that, apart from possible saw dust production in cutting the starting wood piece 8, no material waste what ever will occur, but dispite this glue surfaces are obtained on each of the elongated wood pieces 11. The wood unit 15 according to Fig ~ has a considerably laryer cross section surface than the starting wood piece 8 according to Fig 3. More e~actly, the surface of the cross section square accordiny to Fig ~ is the same as the sum of the surface of the cross section square in Fig 3 and the cross section square of the longitudinal hollow space 7 formed inside the wood unit 15. The hollow space 7 has in this case a square cross section, and the "wood gain"
achieved in this way amounts to about 70 % of the starting wood piece 8.
It may also be started from a wood piece with a rectangular cross section not being a square, and in this case an appli-cation of the cuts with an intersection of each rectangle side as above, i.e. between the corners of the rectangle and the centre of the side, will result in two identical wood pieces with the cross section of a right-angled triangle and two identical wood pieces with the cross section oE a pentagon.
These elongated pieces may be turned with their right-angled corners deriving from the center of the cutting cross outwardly and glued to each other, so that the wood pieces located diagonaliy opposite to each other are the ones which are identical. There is not even here any material wasta occurring and ~Ithe wood gain'l is constituted by the cross section surface of the hollow space obtained inside the wood unit with a rectanqular cross section not being a square. From this de-scription it is easily understood how this will be achieved and this is thereEore not further illustrated by drawings. By turning the cutting cross so that the cuts make an angle of 45 with the cross sectional rectangle sides they intersect, it will be possible to starting from a wood piece, the sides of the cross section rectangle of which have a relation of 2:1, obtain a wood unit with a s~uare cross section and a longi-tudinal inner hollow space with a rectangular cross section.
Thus, owing to the cross cutting it is possible to change the configuration oE a wood un.it. For instance a board with the cross section dimensions of 90 x ~5 mm may be converted into a wood unit with the cross section dimensions of 70 x 70 mm.
According to another embodiment of the invention it is started from at least two wood pieces with a circular cross section being constant over the entire length thereof but having different cross section dimensions, i.e. preferably round reduced log members with different diameters. ~fter the cutting to form the elongated wood pieces in the way illustrated in Fig 1 two wood pieces with the same cross section are selected for each pair of wood pieces forming diagonally opposite corners of the wood unit, said wood pieces being selected so that the ones 8 ~ J ~ r ~
belonging to different pairs have different cross section dimensions. The rectilinear portions of one and the same wood piece are made substantially identical, so that a wood unit having a square cross section being constant over ~he entire length thereof is obtained. It is illustrated in Fig 5 how such a wood unit may look like as seen in cross section, the wood pieces 16 emanating from one and the same starting wood piece or different starting wood pieces with the same diameter, and the same is valid for the wood pieces 17. Accordingly, in this case the longitudinal inner hollow space gets an hour-glass-like cross section shape.
The result obtained when essentially the same procedure is carried out starting from at least two wood pieces having a rectangular cross section being constant over the entire length thereof and the same cross section shape but different cross section dimensions is illustrated in Fig 6. The cutting crosses in each star~ing wood piece have been made so that the cuts make the same angle with the cross section rectangle sides in question as the ones in the other starting wood pieces. The cuts are applied in the way described above, i.e. so that they inters~ect each rectagle side at a distance from the adjacent corner and the centre of the side. After the cutting to form the elongated wood pieces two wood pleces with the same cross section, in Fig 6 18 and 19, respectively, are selected for each pair of wood pieces forming diagonally opposite corners of the wood unit. The wood pieces are selected so that the ones belonging to different pairs have different cross section dimensions and the wood pieces cf one and the same pair have the same cross section shape as a wood piece formed on cutting to form the other pair of wood pieces and lying on the same side of a distinct cut as a wood piece belonging to the latter pair. A wood unit with a rectangular cross sec~ion and a longitudinal inner hollow space with an also rectangular cross section is obtained by gluing these two pairs of wood p.ieces to each other. An example of such a wood unit is illustrated in Fig 6 and has been achieved by applying the method just 9 ~ r~ r~ ~
described on two starting wood pieces with different s~uare cross section.
Thus, by means of the method illustrated in Figs 5 and 6 it is possible to start from wood pieces with different cross section dimensions and aEter cross sawing combine these so that an elongated wood unit with a desired rectangular cross s~ction and a longitudinal inner hollow space is obtained. This enables for instance the production of a great quantity of identical wood units with a rectangular cross section and a longitudinal inner hollow space from a great number of starting wood pieces having the same cross section shapes but different cross sectior dimensions. The shape and the sides of the longitudinal inner hollow space may in this way also be varied as desired.
Such a variation of the cross section surface of the longitu-dinal inner hollow space may for the rest also be accomplished by turning the cutting cross of a starting wood piece with rectangular cross section. Turning for instance the cutting cross shown in Fig 3 in the counter-clockwise direction by some degrees will give rise to a wood unit with the forms according to Fig 4, but with a smaller total cross section surface as a conse~uence of a smaller cross section surface of a longitu-dinal inner hollow space~
Another embodiment of the invention concerns a method in which it is started from one single wood piece tapering from a first to the other second end, so that all dimensions of its cross section decrease by a constant factor per length unit towards the centre of the wood piece while the cross section has a constant shape. This is Eor instance the case of a log member with a constant conicity. After the application of the two cuts forming a cross two of the wood pieces are turned by lgO in their longitudinal centre plane with respect to the two other wood pieces. The wood pieces are glued to each other with the two "end turned" wood pieces forming diagonally opposite corners o-f the cross section rectangle of the wood unit, and the ends of the turned pair of wood pi~cé's aériving from the 1 0 ~ ~ ~ J ;~ d ~
first end of the starting wood piece are arranged at the ends of the other pair of wood pieces deriving from the other end of the starting wood piece. A wood unit with a rectangular cross section and a longitudinal inn0r hollow space i5 obtained in this way. In the case of a conical log member as starting wood piece a wood unit with a cross section shape according to Fig 5 may be obtained, and in the case of a starting wood piece having a rectangular cross section a wood unit with the cross section according to Fig 6 may be obtained. In the case that more than one starting wood piece with the same cross section shape and the same tapering per length unit is available, two identical wood pieces obtained after cross cutting may of course be "end turned" and glued to two other mutually iden-tical wood pieces deriving from other starting wood pieces and may be having other cross section dimensions than the first pair.
In the last mentioned case the starting wood piece may itself have been obtained by making longitudinal cuts in a conical log member parallelly to the fiber direction of the log member, so that a starting wood piece with a rectangular, maybe square, cross section decreasing from one end to the other is obtained.
Thus, four cuts are made for achieving such a starting wood piece, and the result of one such cut is shown in Fig 7. It appears that when the cut is made in the fiber direction a slab 20 having a thickness at its thickeet part being constant over its entire length is obtained. Two slabs deriving from the application of such cuts extending parallelly to each other from opposite sides of the centre of a log member may be glued to each other in the way shown in Fig 8. The two slabs 20 have by a longidutinal slight material removal been provided with flat glue surface portions 21. One of the two slabs 20 has been "end turned", so that the two slabs glued to each other have substantially the same width in the middle of the unit obtained by gluiny. In Fig 8 it is also illustrated how two cuts 22 may be made for ~btaining a wood unit with a cross section shape being constant over the entire length thereof. The wood unit 1 1 2 ~ d ~
according to Flg 8 obtained in this way by the slabs produced in the production of a starting wood piece as above have a very high strength thanks to it having been cut and glued in the fiber direction.
In the case that it is started from a conical log member "the wood gain" of the cross section surface of the wood unit obtained with respect to the cross section surface of the log member is broadly speaking the same whether the log member is first of all round reduced and then cross cut or a plane reduction of the log member first takes place and the wood piece with rectangular cross section so obtained than is cross cut in the way illustrated in Fig 3. However, a more useful waste is obtained in -the plane reduction than in the round reduction and the creation of the flat portions of the four wood pieces functioning as glue surfaces, since the slabs achieved in the former case may be used as thinner boards or be glued to each other for forming thicker wood units. Further-more, said plane reduction results in a material piece being easier to handle than the round reduction.
The wood unit according to the different embodiments of the invention may be used in several different fields. Hidden laying of electrical wires inside wooden beams have previously been mentioned and other examples are window and door frames, but the wood units according to the invention may of course also be used where wood units have to have a certain outer dimension, but it is of no importance if they are solid or not.
Thanks to the invention wood units with the required outer dimension may in such cases be obtained while making great real savings of material with respect to the case of solid wood units.
The invention is of course not in any way restricted to the preferred embodiment described above, but a man skilled in the art to which the invention pertains would with knowledge of 1 2 ~ 3 these without any difficulties be able to modify -them without departing from the basic ldea of the invention.
The four elongated pieces forming a wood unit may emanate from four different starting wood pieces, provided that the two diagonally opposite wood pieces of the wood unit have the same cross section.
The invention relates to a wood unit and a method for producing it.
The invention relates primarily to utilizing thin log members as wood, which members have a low yield on sawing and are therefore mostly used for the production of chips, but the invention is also applyable to coarser logs or thick boards or beams sawn from these. In that case the invention relates to a wood unit with a rectangular cross section. The definition rectangle comprises all forms with four outer right-angled corners and it comprises accordingly also squares and right-angled quadrangles provided with perforations or holes.
Wood units with a rectangular cross section achieved hitherto from thinner log members have a cross section surface often being too small and have been produced while causing a consi-derable waste o~ material with respect to -this cross section surface.
S~MMARY OF THE INVENTION
The object of the present invention is first of all to remedy th.is inconvenience and primarily in thinner log members, but also in another type of wood material, utilize as much as possible of the wood amount available while producing wood units with rectangular cross section and good functional features.
According to the invention this object is obtained by a method for producing wood units according to the appended independent method claim.
The invention may just as well be applied to wood pieces having a circular cross section, such as log ~embers, as wood pieces having a rectangular cross section, such as beams and boards~
Through the understandin~ that a cutting cross applied in the longitudinal direction in a starting wood piece through the centre thereof gives rise to four wood pieces each having a right-angled corner suited for forming a wood unit with a rectangular cross section, wherein said pieces may be used to form the right-angled corners of said wood unit, and that by such an assembly of four elongated wood pieces obtained in this way a wood unit with a longitudinal inner hollow space is obtained, the object of the invention could be obtained in a very satisfying manner.
Through the cross cutting and the reassembling of the wood pieces thus achieved with the material portions located at the centre of the starting wood piece forming the corners of the wood unit obtained, a wood unit having a considerably greater cross section surface is obtained, on condition that the surface of the enclosed hollow space is also considered, than the cross section surface hitherto obtainecl by traditional sawing. There will be little waste produced and thanks to the existenca of the longitudinal inner hollow space a compara tively high wood gain is achieved in the practice if the cross section surface o~ the starting wood piece is compared to the one of the wood unit obtained.
Another advantage of the invention consists in that a stable wood unit with a longitudinal inner hollow space is produced in 3 ~,,f~
a simple way, ancl said hollow space may be used for different purposes, such as hidden laying of different types o wires or conduits and filling the wood unit with heat insulators.
Other preferred features of the invention, such as the gene-rating of a small amount of material waste while creating a wood unit with a rectangular cross section being constant ov~r the entire length thereof from wood pieces tapering conti-nuously from one end to the other, and to assemble two pairs of wood pieces with different cross section surfaces achieved by cross cutting so as to form a wood unit with predetermined desired outer dimensions, will appear from the description following and the appended independent claims.
BRIEF DESCRIPTION OF THE DRAWINGS
With reference to the appended drawings, below follows a specific description of preferred embodiments of the invention cited as examples.
In the drawings:
F'ig 1 is a perspective view of the heart part of a log being cut for producing a wood unit with a square cross section, F'ig 2 is a perspective view of a wood unit obtained by gluing the pieces of the heart part of a log shown in Fig L to each other, Fig 3 is a cross section view illustrating how the cross cutting according to the invention may be carried out starting from a wood piece with a rectangu:Lar cross section, Fig 4 is a cross section view of the wood unit obtained by the cutting illustratecl in Fig 3, Fig 5 is a cross section view Of a wood unit according to a preferred embodiment of the invention, Fig 6 is a cross section view of a wood unit according to another preferred embodiment of the invention, Fig 7 is a perspective view of a conical log member, in which a cut have been made parallelly to the direction of the fibers of the log/ so that a slab with a constant thickness has been obtained, Fig 8 illustrates how two slabs according to Fig 7 may be glued to each other for forming a strong wood unit.
DETAILED DESCRIPTION OF PREFERRED ~MBODIMENTS OF THE INVENTION
As previously mentioned it may when utilizing the method according to the invention so as to produce a wood unit accor-ding to the invention be started from a log, which for the r~st does not have to be made round to a constant diameter, for instance by turning, or a wooden beam with a rectang~lar, prefer,ably s~uare, cross section. In Fig 1 is shown how the cross cutting according to the invention is applied on a log 1 being made round, i.e. which has a constant diameter over its length. The heart member remaining after the round reduction is cut in its longitudinal direction into four substantially identical wood pieces 2. BeEore or after this cutting very thin, preferably with a thickness of about 1. mm at the thickest part, wood parts 3 may be cut away from the periphery of the heart member displaced at 90 around the heart member, the cuts being carried out along the whole length of the heart member and so that the heart member in cross section will have four circular arc members ~ separated by four rectilinear portions 5, which in pairs are parallel to each other and extend sub-stantially perpendicularly to the other two.
When the heart member 1 has been provided with the cuts men-tioned above the wood members 3 are removed so as to be used pre~erably as chips, while the four wood pieces 2 are glued together in the way illustrated in ~ig 2. In doing so the rectilinear portions 5 defining narrow planar surfaces are gluing and the wood pieces 2 are turned in such a way with respect to each other, that the right-angled corner of each of them forms a corner o~ a beem 6 with a substantially square cross sectionO The rectilinear portions 5 coated by glue of each wood piece 2 will each bear against a rectilinear portion of two adjacent pieces, and the beam 6 will as a consequence thereof be very strong. The cirular arc members 4 of the wood piece 2 in ~uestion will be directed inwardly towards the center of the beam, so that a longitudinal hollow space 7 will be produced inside the beam.
It may easily be understood that the wood yield in conventional cutting of a beam with a square cross section out of the round reduced heart member will be very low, but the inventional method comprising the cross cutting will lead to a yield being almost one hundred percent. Yes, it is even so that the method accor~ing to the invention gives rise to a beam 6 which, were it solid, would have considerably more wood than the heart member 1 itself.
It is shown in Fig 3 how the method according to the invention may be carried out starting from a wood piece 8 with a rec-tangular cross section, the dashed lines forming a circle suggest how the wood piece 8 initially may have been obtained from a log member with a c:ircular cross section. Two cuts extending substantially perpendicularly to each other are made in the longitudinal direction of the wood piece 8 (dashed-dotted lines), said cuts intersecting each other in the centre of the cross section of the starting wood piece 8. The cutting cross 10 formed by the cuts 9 is turned around the centre of the wood piece with respect to a cutting cross formed by the diagonal of the cross sectional square. As a consequence o this, the cuts 9 intersect each side of the cross sectional rectangle, which in this case is a square, at a distance from the adjacent rectangle corner as well as the centre of the rectangle side. Thanks to this way of making the cuts it will be possible to glue the four wood pieces 11 obtained after the cutting to each other at the ends of the surfaces formed by the cuts located opposite to the riyht-angled corner 12 of each wood piece 11 as seen in cross section. After cutting the four elongated wood pieces these are brought to pass through a drying apparatus for drying and then the wood pieces 11 are coated by glue on at least portions of the two surfaces 13, 14 which do not extend to the right-angled corner 12 of the wood piece in question. In doing so, the wood pieces 11 are turned so that their right-angled corners 12 are directed outwardly and they are brought together so that the portions of the surfaces 13 and 14 coated by glue will bear against each other.
Finally, a pressure pressing the surfaces coated by glue against each other is applied. However, when a special glue is available it is also possible to coat the wood pieces 11 by glue and glue them to each other immediately after the cutting, without any preceding drying.
Owing to the method now described a wood unit 15 according to Fig 4 is obtained. The surprising and characterizing feature of this method is that, apart from possible saw dust production in cutting the starting wood piece 8, no material waste what ever will occur, but dispite this glue surfaces are obtained on each of the elongated wood pieces 11. The wood unit 15 according to Fig ~ has a considerably laryer cross section surface than the starting wood piece 8 according to Fig 3. More e~actly, the surface of the cross section square accordiny to Fig ~ is the same as the sum of the surface of the cross section square in Fig 3 and the cross section square of the longitudinal hollow space 7 formed inside the wood unit 15. The hollow space 7 has in this case a square cross section, and the "wood gain"
achieved in this way amounts to about 70 % of the starting wood piece 8.
It may also be started from a wood piece with a rectangular cross section not being a square, and in this case an appli-cation of the cuts with an intersection of each rectangle side as above, i.e. between the corners of the rectangle and the centre of the side, will result in two identical wood pieces with the cross section of a right-angled triangle and two identical wood pieces with the cross section oE a pentagon.
These elongated pieces may be turned with their right-angled corners deriving from the center of the cutting cross outwardly and glued to each other, so that the wood pieces located diagonaliy opposite to each other are the ones which are identical. There is not even here any material wasta occurring and ~Ithe wood gain'l is constituted by the cross section surface of the hollow space obtained inside the wood unit with a rectanqular cross section not being a square. From this de-scription it is easily understood how this will be achieved and this is thereEore not further illustrated by drawings. By turning the cutting cross so that the cuts make an angle of 45 with the cross sectional rectangle sides they intersect, it will be possible to starting from a wood piece, the sides of the cross section rectangle of which have a relation of 2:1, obtain a wood unit with a s~uare cross section and a longi-tudinal inner hollow space with a rectangular cross section.
Thus, owing to the cross cutting it is possible to change the configuration oE a wood un.it. For instance a board with the cross section dimensions of 90 x ~5 mm may be converted into a wood unit with the cross section dimensions of 70 x 70 mm.
According to another embodiment of the invention it is started from at least two wood pieces with a circular cross section being constant over the entire length thereof but having different cross section dimensions, i.e. preferably round reduced log members with different diameters. ~fter the cutting to form the elongated wood pieces in the way illustrated in Fig 1 two wood pieces with the same cross section are selected for each pair of wood pieces forming diagonally opposite corners of the wood unit, said wood pieces being selected so that the ones 8 ~ J ~ r ~
belonging to different pairs have different cross section dimensions. The rectilinear portions of one and the same wood piece are made substantially identical, so that a wood unit having a square cross section being constant over ~he entire length thereof is obtained. It is illustrated in Fig 5 how such a wood unit may look like as seen in cross section, the wood pieces 16 emanating from one and the same starting wood piece or different starting wood pieces with the same diameter, and the same is valid for the wood pieces 17. Accordingly, in this case the longitudinal inner hollow space gets an hour-glass-like cross section shape.
The result obtained when essentially the same procedure is carried out starting from at least two wood pieces having a rectangular cross section being constant over the entire length thereof and the same cross section shape but different cross section dimensions is illustrated in Fig 6. The cutting crosses in each star~ing wood piece have been made so that the cuts make the same angle with the cross section rectangle sides in question as the ones in the other starting wood pieces. The cuts are applied in the way described above, i.e. so that they inters~ect each rectagle side at a distance from the adjacent corner and the centre of the side. After the cutting to form the elongated wood pieces two wood pleces with the same cross section, in Fig 6 18 and 19, respectively, are selected for each pair of wood pieces forming diagonally opposite corners of the wood unit. The wood pieces are selected so that the ones belonging to different pairs have different cross section dimensions and the wood pieces cf one and the same pair have the same cross section shape as a wood piece formed on cutting to form the other pair of wood pieces and lying on the same side of a distinct cut as a wood piece belonging to the latter pair. A wood unit with a rectangular cross sec~ion and a longitudinal inner hollow space with an also rectangular cross section is obtained by gluing these two pairs of wood p.ieces to each other. An example of such a wood unit is illustrated in Fig 6 and has been achieved by applying the method just 9 ~ r~ r~ ~
described on two starting wood pieces with different s~uare cross section.
Thus, by means of the method illustrated in Figs 5 and 6 it is possible to start from wood pieces with different cross section dimensions and aEter cross sawing combine these so that an elongated wood unit with a desired rectangular cross s~ction and a longitudinal inner hollow space is obtained. This enables for instance the production of a great quantity of identical wood units with a rectangular cross section and a longitudinal inner hollow space from a great number of starting wood pieces having the same cross section shapes but different cross sectior dimensions. The shape and the sides of the longitudinal inner hollow space may in this way also be varied as desired.
Such a variation of the cross section surface of the longitu-dinal inner hollow space may for the rest also be accomplished by turning the cutting cross of a starting wood piece with rectangular cross section. Turning for instance the cutting cross shown in Fig 3 in the counter-clockwise direction by some degrees will give rise to a wood unit with the forms according to Fig 4, but with a smaller total cross section surface as a conse~uence of a smaller cross section surface of a longitu-dinal inner hollow space~
Another embodiment of the invention concerns a method in which it is started from one single wood piece tapering from a first to the other second end, so that all dimensions of its cross section decrease by a constant factor per length unit towards the centre of the wood piece while the cross section has a constant shape. This is Eor instance the case of a log member with a constant conicity. After the application of the two cuts forming a cross two of the wood pieces are turned by lgO in their longitudinal centre plane with respect to the two other wood pieces. The wood pieces are glued to each other with the two "end turned" wood pieces forming diagonally opposite corners o-f the cross section rectangle of the wood unit, and the ends of the turned pair of wood pi~cé's aériving from the 1 0 ~ ~ ~ J ;~ d ~
first end of the starting wood piece are arranged at the ends of the other pair of wood pieces deriving from the other end of the starting wood piece. A wood unit with a rectangular cross section and a longitudinal inn0r hollow space i5 obtained in this way. In the case of a conical log member as starting wood piece a wood unit with a cross section shape according to Fig 5 may be obtained, and in the case of a starting wood piece having a rectangular cross section a wood unit with the cross section according to Fig 6 may be obtained. In the case that more than one starting wood piece with the same cross section shape and the same tapering per length unit is available, two identical wood pieces obtained after cross cutting may of course be "end turned" and glued to two other mutually iden-tical wood pieces deriving from other starting wood pieces and may be having other cross section dimensions than the first pair.
In the last mentioned case the starting wood piece may itself have been obtained by making longitudinal cuts in a conical log member parallelly to the fiber direction of the log member, so that a starting wood piece with a rectangular, maybe square, cross section decreasing from one end to the other is obtained.
Thus, four cuts are made for achieving such a starting wood piece, and the result of one such cut is shown in Fig 7. It appears that when the cut is made in the fiber direction a slab 20 having a thickness at its thickeet part being constant over its entire length is obtained. Two slabs deriving from the application of such cuts extending parallelly to each other from opposite sides of the centre of a log member may be glued to each other in the way shown in Fig 8. The two slabs 20 have by a longidutinal slight material removal been provided with flat glue surface portions 21. One of the two slabs 20 has been "end turned", so that the two slabs glued to each other have substantially the same width in the middle of the unit obtained by gluiny. In Fig 8 it is also illustrated how two cuts 22 may be made for ~btaining a wood unit with a cross section shape being constant over the entire length thereof. The wood unit 1 1 2 ~ d ~
according to Flg 8 obtained in this way by the slabs produced in the production of a starting wood piece as above have a very high strength thanks to it having been cut and glued in the fiber direction.
In the case that it is started from a conical log member "the wood gain" of the cross section surface of the wood unit obtained with respect to the cross section surface of the log member is broadly speaking the same whether the log member is first of all round reduced and then cross cut or a plane reduction of the log member first takes place and the wood piece with rectangular cross section so obtained than is cross cut in the way illustrated in Fig 3. However, a more useful waste is obtained in -the plane reduction than in the round reduction and the creation of the flat portions of the four wood pieces functioning as glue surfaces, since the slabs achieved in the former case may be used as thinner boards or be glued to each other for forming thicker wood units. Further-more, said plane reduction results in a material piece being easier to handle than the round reduction.
The wood unit according to the different embodiments of the invention may be used in several different fields. Hidden laying of electrical wires inside wooden beams have previously been mentioned and other examples are window and door frames, but the wood units according to the invention may of course also be used where wood units have to have a certain outer dimension, but it is of no importance if they are solid or not.
Thanks to the invention wood units with the required outer dimension may in such cases be obtained while making great real savings of material with respect to the case of solid wood units.
The invention is of course not in any way restricted to the preferred embodiment described above, but a man skilled in the art to which the invention pertains would with knowledge of 1 2 ~ 3 these without any difficulties be able to modify -them without departing from the basic ldea of the invention.
The four elongated pieces forming a wood unit may emanate from four different starting wood pieces, provided that the two diagonally opposite wood pieces of the wood unit have the same cross section.
Claims (16)
1. A wood unit comprising four elongated wood pieces obtained by making two cuts in at least one starting wood piece substan-tially perpendicularly to each other and in the longitudinal direction of the latter, said cuts intersecting each other in the centre of the starting wood piece cross section, said elongated wood pieces being bonded to each other at the ends of the surfaces formed by said cuts located opposite to a right-angled corner of each piece as seen in cross section and so that the right-angled corners of adjacent elongated pieces are directed perpendicularly to each other, said right-angled corners of the elongated wood pieces each forming one of the four corners of a wood unit with a rectangular cross section and a longitudinal inner hollow space.
2. A wood unit as defined in claim 1, in which the four elon-gated wood pieces have a cross section with substantially the shape of a right-angled sector of a circle, the two ends of the circular arc of each piece being chamfered by a narrow planar surface extending substantially perpendicularly to the adjacent side of the sector, said four pieces being glued to each other with said narrow planar surfaces of the pieces bearing against each other.
3. A wood unit as defined in claim 1, in which the four elon-gated wood pieces being obtained from at least one starting wood piece with rectangular cross section, the cross formed by the cuts in this piece being applied so that the cuts intersect each rectangle side at a distance from the adjacent rectangle corner as well as the centre of said rectangle side, at least the two wood pieces forming the diagonally opposite corners of the cross section rectangle of the wood unit having substan-tially the same cross section, at least two of the wood pieces having more than three cross sectional corners, said longitu-dinal inner hollow space having a rectanqular cross section.
4. A wood unit as defined in claim 3, in which the four elon-gated wood pieces are obtained from at least one wood piece with square cross section, so that they have four cross sec-tional corners, at least portions of the two surfaces not extending to the right angled corner of each elongated wood piece each forming a glue surface bearing against the adjacent wood piece, so that the wood unit has four glue surface pairs.
5. A wood unit as defined in claim 2, in which the four elon-gated wood pieces are obtained from one single starting wood piece tapering from the first end to the other second end, so that all dimensions of its cross section decrease by a constant factor per length unit towards the center of the wood piece, while the cross section thereof has a constant shape, a first pair of wood pieces forming diagonally opposite corners of the cross section rectangle of the wood unit being turned 180° in their longitudinal center plane with respect to the other two wood pieces, so that the ends of the first pair of wood pieces deriving from the first end of the starting wood piece are disposed at the ends of the second pair of wood pieces deriving from the second end of the starting wood piece, the wood unit having a cross section being constant in the longitudinal direction.
6. A wood unit as defined in claim 3, in which the four elon-gated wood pieces are obtained from one single starting wood piece tapering from the first end to the other second end, so that all dimensions of its cross section decrease by a constant factor per length unit towards the center of the wood piece, while the cross section thereof has a constant shape, a first pair of wood pieces forming diagonally opposite corners of the cross section rectangle of the wood unit being turned 180° in their longitudinal center plane with respect to the other two wood pieces, so that the ends of the first pair of wood pieces deriving from the first end of the starting wood piece are disposed at the ends of the second pair of wood pieces deriving from the second end of the starting wood piece, the wood unit having a cross section being constant in the longitudinal direction.
7. A wood unit as defined in claim 2, in which each starting wood piece has a circular cross section being constant over the entire length thereof, two wood pieces forming not diagonally opposite corners of the wood unit being obtained from starting wood pieces with different diameters, said wood pieces forming diagonally opposite corners having the same cross section, said wood unit having a square cross section being constant over the entire length thereof.
8. Wood unit as defined in claim 3, in which each starting wood piece has a rectangular cross section being constant over the entire length thereof, the wood pieces forming not diagonally opposite corners of the cross section rectangle of the wood unit being obtained from starting wood pieces having the same cross sectional shapes but different dimensions, said wood pieces being wood pieces obtained by applying the cutting crosses while making the same angles with the cross section rectangle sides in question of the different starting wood pieces, two wood pieces in one and the same of said pairs having the same cross section, the wood pieces of one pair having the same cross section as a wood piece achieved on making the cuts for the second pair of wood pieces and lying on the same side of a distinct cut as a wood piece being a part of the last mentioned pair.
9. A method for producing wood units, in which it is started from at least one elongated wood piece in the longitudinal direction of which two cuts are made substantially perpendi-cularly to each other, so that said cuts intersect each other in the centre of the starting wood piece cross section so as to divide the starting wood piece into four elongated wood pieces, four elongated wood pieces obtained in this way being bonded to each other at the ends of the surfaces formed by said cuts located opposite to a right-angled corner of each piece as seen in cross section and so that the right-angled corners of adjacent elongated pieces are directed perpendicularly to each other, so that the right-angled corners of the elongated wood pieces each forming one of the four corners of a wood unit with a rectangular cross section and a longitudinal inner hollow space.
10. A method as defined in claim 9, in which the at least one starting wood piece has a circular cross section, either a) four thin members are removed from the periphery of the star-ting wood piece in the longitudinal direction thereof before the cuts forming said cross are made and so that the starting wood piece gets a cross section with four circular arcs being divided by rectilinear portions being in pairs parallel to each other, located at opposite sides of the piece and extending substantially perpendicularly to the other two, the cuts dividing the starting piece into four pieces being made so that they divide each rectilinear portion substantially in two equal portions, or b) the four pieces are provided with said recti-linear cross section portions at both ends of their cross sectional circular arc after the cutting producing the four elongated pieces, the bonding of the four pieces to each other being achieved by gluing their planar portions and bringing these to bear against each other.
11. A method as defined in claim 9, in which the at least one starting wood piece has a rectangular cross section for obtai-ning a wood unit having a longitudinal inner hollow space with a rectangular cross section, said cuts being made so that they intersect each rectangle side at a distance from the adjacent rectangle corner as well as the centre of said rectangle side, two wood pieces having substantially the same cross section being selected to form the diagonally opposite corners of the cross section rectangle of the wood unit, at least two wood pieces having more than three cross sectional corners being selected as members of the wood unit.
12. A method as defined in claim 11, in which the at least one starting wood piece has a square section, so that the four elongated wood pieces have a cross section with four corners, said wood pieces being glued to each other with at least portions of the two surfaces not extending to the right-angled corner thereof each forming a glue surface against the adjacent wood piece, so that the wood unit has four glue surface pairs.
13. A method as defined in claim 9, in which it is started from one single wood piece tapering from a first end to the other second end, so that all dimensions of its cross section de-crease by a constant factor per length unit towards the centre of the wood piece while the cross section has a constant shape, after making the two cuts forming a cross two of the wood pieces being turned 180° in their longitudinal centre plane with respect to the two other wood pieces, said wood pieces being glued to each other so that the two turned wood pieces form diagonally opposite corners of the cross section rectangle of the wood unit, the ends of the turned pair of wood pieces deriving from the first end of the starting wood piece being disposed at the ends of the other pair of wood pieces deriving from the second end of the starting wood piece.
14. A metod as defined in claim 10, in which it is started from at least two wood pieces having a circular cross section being constant over their entire length but having mutually different cross section dimensions, after making the cuts for the elon-gated wood pieces by applying said cuts on the starting wood pieces two wood pieces having the same cross section being selected for each pair of wood pieces forming diagonally opposite corners of the wood unit, said wood pieces being selected so that the ones belonging to different pairs have different cross section dimensions, said rectilinear portions of one and the same wood piece being made substantially iden-tical, so that a wood unit having a square section being constant over the entire length thereof is obtained.
15. A method as defined in claim 11, in which it is started from at least two wood pieces having a rectangular cross section being constant over the entire length thereof and the same cross section shape but different cross section dimen-sions, the cutting cross of each starting wood piece being applied so that the cuts make the same angles with the cross sectional rectangle sides in question as the ones in the other starting wood pieces, after the cutting for obtaining the elongated wood pieces for each pair of wood pieces forming diagonally opposite corners of the wood unit two wood pieces with the same cross section being selected, the wood pieces being selected so that the ones belonging to different pairs have different cross section dimensions and the wood pieces in one and the same pair have the same cross section shape as a wood piece achieved on making the cuts for the second pair of wood pieces and lying on the same side of a distinct cut as a wood piece being a part of the last mentioned pair.
16. A method as defined in claim 9, in which after the cutting for obtaining the four elongated wood pieces, these are brought to pass through a drying apparatus for drying the pieces, the pieces thereupon being glued to each other by gluing onto the surfaces intended to bear against each other, followed by applying of pressure pressing these surfaces against each other.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| SE8903365A SE469880B (en) | 1989-10-13 | 1989-10-13 | Wooden unit and a process for its production |
| SE8903365-8 | 1989-10-13 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2027356A1 true CA2027356A1 (en) | 1991-04-14 |
Family
ID=20377125
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002027356A Abandoned CA2027356A1 (en) | 1989-10-13 | 1990-10-11 | Wood unit |
Country Status (2)
| Country | Link |
|---|---|
| CA (1) | CA2027356A1 (en) |
| SE (1) | SE469880B (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0549744A1 (en) * | 1991-07-03 | 1993-07-07 | Peter Sing | Method of converting logs and resultant product. |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| SE510494C2 (en) * | 1995-02-02 | 1999-05-31 | Lars Hammarstroem | Process for decomposing a log and for making a composite wood unit |
| FI105790B (en) | 1999-01-28 | 2000-10-13 | Johan Tore Karlstroem | A method of making stiffeners and a system of fins |
| LT5083B (en) | 2002-04-17 | 2003-12-29 | Erowa Ag | Apparatus for clamping a work piece |
| LT5383B (en) | 2006-01-27 | 2006-11-27 | Sergej Saveljev | Wood unit and method for manufacturing it |
| SE538283C2 (en) * | 2014-08-08 | 2016-04-26 | Stora Enso Oyj | A gluelam structural member and a method of producing such agluelam structural member |
-
1989
- 1989-10-13 SE SE8903365A patent/SE469880B/en not_active IP Right Cessation
-
1990
- 1990-10-11 CA CA002027356A patent/CA2027356A1/en not_active Abandoned
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0549744A1 (en) * | 1991-07-03 | 1993-07-07 | Peter Sing | Method of converting logs and resultant product. |
| EP0549744A4 (en) * | 1991-07-03 | 1993-12-29 | Peter Sing | Method of converting logs and resultant product |
| USRE35327E (en) * | 1991-07-03 | 1996-09-10 | Sing; Peter | Method of converting logs and resultant product |
Also Published As
| Publication number | Publication date |
|---|---|
| SE8903365D0 (en) | 1989-10-13 |
| SE8903365L (en) | 1991-04-14 |
| SE469880B (en) | 1993-10-04 |
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