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
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B27—WORKING OR PRESERVING WOOD OR SIMILAR MATERIAL; NAILING OR STAPLING MACHINES IN GENERAL
  • B27B—SAWS FOR WOOD OR SIMILAR MATERIAL; COMPONENTS OR ACCESSORIES THEREFOR
  • B27B1/00—Methods for subdividing trunks or logs essentially involving sawing
  • B27B1/005—Methods for subdividing trunks or logs essentially involving sawing including the step of dividing the log into sector-shaped segments
• • 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
  • E04C3/14—Joists; Girders, trusses, or trusslike structures, e.g. prefabricated; Lintels; Transoms; Braces of wood, e.g. with reinforcements, with tensioning members with substantially solid, i.e. unapertured, web

Definitions

• the present invention relates to a method for dividing a log.
• Such methods aim at obtaining a wood piece from a log which as such has good wood properties or may be assembled to wood units having such properties, and which by that stipulates a higher price.
• "Log” also comprises the case of a log already round-reduced before carrying out the method.
• the object of the present invention is to provide a method of the type defined in the introduction, in which the disadvantages just mentioned of such methods already known are reduced to a large extent.
• This object is according to the invention obtained in such a method by applying two first cuts on each side of the centre axis of the log in the longitudinal direction of the log for removing surface-near material along two planes extending substantially in parallel with each other in the transversal direction of the log for forming first cut surfaces, and a) at least one second cut is applied on the log in the longitudinal direction thereof between said planes and extending substantially in parallel with said planes in the transversal direction of the log and b) at least a third cut is applied substantially perpendicularly to said planes while intersecting the first cut surfaces so that sub-surfaces thereof result on each side of the third cut so that at least four first wood pieces having one said sub-surface each are formed, in which a) is carried out before b) or b) is carried out before a).
• This method may be carried out by means of a conventional simple saw mill equipment, and this means that a main part of the volume of the log may result in so called “cross-sawn industrial wood” by the fact that said third cut is applied substantially perpendicularly to the first and second cuts.
• Another important advantage of this method is that "cross-sawn industrial wood” is a defined article, which facilitates quality certification of the products produced by this wood article.
• two cuts are applied on each side of the centre axis of the log for forming a centre wood piece resulting from second cuts and restricted by these cuts.
• a wood piece will have substantially standing annual rings of at least the two surfaces resulting from said second cuts, i.e. is to be considered as industrial wood.
• the first wood pieces receive substantially standing annual rings for the surfaces resulting from the third cut, which is to be compared with a conventional dividing of a log, in which only the very centre deal receives surfaces having substantially standing annual rings.
• a third second cut is applied along a plane including the centre axis of the log. This is advantageous in the case of larger log dimensions, since an adaptation of the wood output to the log dimension takes place in this way, and it is at large log dimensions well be possible to apply even more than three second cuts for obtaining a higher number of centre wood pieces.
• the centre wood piece or pieces resulting from the application of the second cuts are cut by applying cuts being substantially perpendicular to the second cuts on each side of the centre axis for removing surface-near material and obtaining at least one centre wood piece having a substantially rectangular cross- section.
• the centre wood piece or the centre wood pieces gets in this way a pleasant appearance.
• two cuts are applied on the centre wood piece substantially perpendicularly to said second cuts on each side of the centre axis and comparatively close thereto for removing the marrow streak of the log while obtaining part centre wood pieces located on each side thereof.
• Such part centre wood pieces form high quality cross-sawn industrial wood having substantially standing annual rings for at least three surfaces.
• step b) two third cuts are applied on each side of the centre axis of the log for forming a second wood piece having a substan- tially rectangular cross-section with the sides of the cross- section rectangle formed by the two third cuts, a part of one first cut surface and a part of one second cut.
• a second wood piece is also to be considered as a high quality cross-sawn industrial wood having substantially standing annual rings for at least two sides thereof.
• Such second wood pieces will of course be obtained on each side of said second cuts, i.e. two for each log.
• said sub-surface and a surface of each said first wood piece emanating from a second cut are used as guide surfaces for material removing machining of the respective first wood piece. It will by this be very easy to machine the first wood piece further for refining it, so that for example this machining is carried out by removing material in the longitudinal direction of the log along a surface extending in the transversal direction substantially perpendicularly to said guide surfaces on the opposite side of the first wood piece with respect to the surface generated by the respective third cut, which constitutes a further preferred embodiment of the invention. Wood pieces having two surfaces suited for glueing to other corresponding such wood pieces for forming a wood unit according to the appended independent claim having a very high shape stability and substantially standing annual rings of all sides may by this be obtained.
• said first cuts are applied substantially in parallel with the extension of the fibres of the log in the longitudinal direction of the log, and according to another preferred embodiment of the invention said first cuts are applied substantially in parallel with the centre axis of the log.
• the corresponding possibilities are also offered for the other cuts.
• sawing or cutting in parallel with the fibres as well as in parallel with the heart may be utilised for the method according to the invention.
• Fig. 1 is a cross-section view of a part of a log , in which cuts intended to be applied on the log according to a division method according to a preferred embodiment of the invention are shown,
• Fig. 2 is a cross-section view of a wood unit produced from wood pieces obtained by the division method illustrated in Fig. 1 and machined further, and
• Fig 3 is a view corresponding to Fig. 1 illustrating a division method according to another preferred embodiment of the invention.
• a method for dividing a log according to a preferred embodiment of the invention is composed will now be described with reference to Fig. 1 .
• surface-near material is removed according to two first cuts 2, 3 applied in the longitudinal direction of the log on each side of the centre axis of the log along two planes extending in the transversal direction of the log substantially in parallel with each other for forming first cut surfaces 4.
• two second cuts 5, 6 are applied on the log in the longitudinal direction thereof between the planes defined by said cut surfaces 4 and extending in the transversal direction of the log substantially in parallel with these planes, so that a centre wood piece 7 is obtained.
• a further cut 8 is then applied on this centre wood piece7 at the ends thereof for removing surface-near material and obtaining at least one centre wood piece having a substantially rectangular cross-section.
• Two third cuts 17, 18 are then applied on each of the two outer pieces 15, 16 obtained by applying the second cuts 5, 6 on each side of the centre axis of the log, i.e. when looking at the log not divided yet, substantially perpendicularly to the first cut surface 4 while intersecting them so that sub-surfaces 19, 20 result on each side of the respective third cut, so that four first wood pieces 21 having one said sub-surface 19 are formed in this way.
• Two second wood pieces 22 in the form of cross-sawn industrial wood having very good properties are in this way ob- tained, which have a substantially rectangular cross-section with the side of the cross-section rectangle formed by the two third cuts 17, 18, a part 20 of the first cut surface as well as a part of a second cut 5 and 6, respectively.
• the first wood pieces 21 may then be placed in for example a planning machine while utilising the sub-surface 19 and the part of the second cut 5 or 6 extending substantially in parallel therewith as guide surfaces when planning, in which material is removed in the longitudinal direction of the log along a surface extending in the transversal direction substantially perpendicu- larly to said guide surfaces on opposite side of the first wood piece with respect to the surface generated by the respective third cut 17, 18. It is then possible to carry out the machining so that groove or tongue is formed in the surface resulting from the machining.
• a wood unit 23 having a longitudinal inner hollow space 24 according to Fig. 2.
• This wood unit has substantially standing annual rings at all surfaces, and the area inscribed by the outer outline thereof is considerably larger than the total cross-section area of the four wood pieces thereof, so that a considerable "wood gain” is made. It is also well possible to machine the circle arc surface of the respective wood piece 21 shown in Fig. 1 and 2 in an optional desired way before the gluing of the pieces together or for using the wood pieces so obtained in another way than by gluing them together with three other such ones, for example by flat planning this surface.
• a method according to a second preferred embodiment of the invention may look like, in which this method only differs from that shown in Fig. 1 by the application of three second cuts, i.e. a second cut 25 extending sub- stantially through the centre axis of the log is also applied, and the marrow streak is in this case not removed, which however is well possible.
• This method is suited for larger log dimensions. It would also be possible to apply further second cuts when the dimensions are very large, and it would also be possible to ap- ply more than two third cuts in such cases.
• the invention is of course not in any way restricted to the preferred embodiments described above, but many possibilities to modifications thereof would be apparent to a man with ordinary skill in the art without departing from the basic idea of the in- vention as defined in the claims.
• Said second cuts may for example be applied in a sawmill and then the first and third cuts be applied on said outer pieces after transport thereof to another sawmill.

Landscapes

• Engineering & Computer Science (AREA)
• Life Sciences & Earth Sciences (AREA)
• Wood Science & Technology (AREA)
• Architecture (AREA)
• Forests & Forestry (AREA)
• Mechanical Engineering (AREA)
• Manufacturing & Machinery (AREA)
• Civil Engineering (AREA)
• Structural Engineering (AREA)
• Debarking, Splitting, And Disintegration Of Timber (AREA)
• Joining Of Building Structures In Genera (AREA)

Priority Applications (2)

Applications Claiming Priority (2)

Publications (1)

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Cited By (2)

Citations (5)

• 1998
  • 1998-05-29 SE SE9801911A patent/SE510493C2/sv unknown
• 1999
  • 1999-05-28 EP EP99930038A patent/EP1115540B1/en not_active Expired - Lifetime
  • 1999-05-28 AT AT99930038T patent/ATE317750T1/de active
  • 1999-05-28 DE DE69929884T patent/DE69929884T2/de not_active Expired - Lifetime
  • 1999-05-28 WO PCT/SE1999/000914 patent/WO1999062679A1/en active IP Right Grant

Patent Citations (5)

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