Classifications

• • 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
  • B27B15/00—Band or strap sawing machines specially designed for length cutting of trunks
  • B27B15/04—Band or strap sawing machines specially designed for length cutting of trunks with vertically-guided saw blade
• • 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
• • 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
  • B27B29/00—Gripping, clamping, or holding devices for the trunk or log in saw mills or sawing machines; Travelling trunk or log carriages
  • B27B29/08—Trunk or log carriages with gripping means designed to pass the saw blade(s), especially for band saws; Arrangement of gripping accessories thereon; Turning devices thereon

Definitions

• the present invention relates to a sawing station according to the preamble of Claim 1, and to a method of using the sawing station.
• the present invention is a development of the method described in SE 9100830.
• the log is first divided into at least two parallel, longitudinally extending and generally diametrical and pith-parallel sections. This results in at least one diametrical and plane-parallel sheet of wood that has part of the log pith in its centre.
• the method also results essentially in a pair of half-logs. Further planks that have standing growth rings are obtained from these half-logs, by dividing the same into generally radial sections obliquely to the pith.
• There remain pieces of wood of triangular cross-section which can be glued together longitudinally with the apices of the triangles disposed in opposite directions with respect to adjacent pairs, to obtain a block of uniform thickness and straight edges.
• Several blocks can be glued together to form thicker blocks, which can be used as starting material in the further manufacture of wood products. This method provides a very high log yield and results in finished products of good quality.
• the generally diametrically pith-parallel section or sections cut from the log provides/provide a plane-parallel plank or planks of wood that contains/contain wood marrow in its/their centre.
• the pith part of a log is of poor quality and is therefore not used in wood products, but is instead cut away.
• EP 97948099.3 with the same Applicant as the present invention describes a method of log disintegration in which during the process of disintegration the log is passed from one specialised station to another, such as to disintegrate the log into desired wood elements in a rational manner.
• the described method and the illustrated plant have been devised and intended for large wood cutting operations in a large sawmill. Small sawmills have also expressed a desire to cut logs into pieces such as to produce the aforesaid types of wood elements. Consequently, there has risen a need for a compact station in which all log cutting can be effected in a positive and rational fashion.
• One object of the invention is to enable logs to be sawn into planks with a good log yield and with sawn wooden products of high quality with the aid of a compact sawing station.
• Another object of the invention is to provide an ordered working procedure for sawing a log into planks and the subsequent working of resultant wood elements that requires as few operators as possible.
• Yet another object of the invention is to provide a log-to-plank sawing system which results in low labour costs and/or low investment costs.
• the present invention relates to a sawing station for sawing a log into planks
• a sawing station for sawing a log into planks
• a log sawing bench which is movable in its longitudinal direction parallel with a stationary sawing device and provided with log fastening devices in connection with the end surfaces of the log, wherein the position of at least one of the fastening devices can be adjusted along the length of the bench and the device therewith adapted to different log lengths, and wherein said fastening devices can be adjusted in a manner to adjust the position of the log transversely to the longitudinal direction of the bench.
• the invention is characterised in that the fastening devices can be displaced transversely to the longitudinal direction of the bench, so that the log fastened in said fastening devices can be moved out over one longitudinal edge of the bench through a distance determined by an operator; and in that said station also includes means for locking the fastening devices as the log is sawn.
• the sawing bench will preferably be pivotal about a longitudinal axis A-A and capable of being locked in angular positions in which planks of desired triangular cross-section can be cut from a sawn-ofF plank that has essentially a semicircular cross-section.
• the sawing bench may be swung to and locked in positions corresponding to +30° and -30°, and also locked in the angular position 0°.
• Each fastening device will preferably include several fastener elements that function to prevent the log from rotating as it is being sawn.
• Supplementary or complementary holder elements may be provided in or adjacent the bench, said elements being adjusted to abut the underpart of the log, and preferably also the underpart of the outwardly projecting log part, or capable of being brought into such abutment.
• each holder element may be individually adjustable, lockable and also capable of being guided, such that each adjustment and locking process can be effected in dependence on the position of the saw blade relative to the sawing bench at any moment in time.
• the invention also relates to a method of sawing a log into planks with the aid of said sawing bench, wherein
• the log is mounted on the sawing bench with the fastening device, so that a longitudinally extending part of the log projects over one longitudinal edge of the bench;
• the log is divided into two longitudinally extending planks of segmental cross-section and an intermediate plank which contains through-penetrating piths, wherein the sawing bench is displaced to its one end position, wherein the log is displaced to a position in which the log is sawn by the stationary sawing device between each division of the log by means of the displaceable fastener device to appropriate positions that are adapted to the position of the sawing device;
• the plank of segmental cross-section that remains on the sawing bench is turned so that its planar part lies against said bench; and D) the plank now resting on the sawing bench is displaced over the bench edge to a position for sawing-off an outwardly projecting part by said sawing device.
• the sawing bench can be swung down about an axis A-A prior to sawing-off the outwardly projecting part in accordance with step D) above, so as to obtain a sawn plank of desired triangular cross-section, this cross-section depending on the angle at which the bench is swung down.
• the bench may be swung down at an angle of 30°. It will be noted, however, that the bench need not be swung down when the plank shall have a right-angled configuration. It will also be noted that the plank may be displaced outwardly in a direction towards the sawing device. A plank that has an approximately rectangular cross- section may also be sawn.
• the plank After drying the plank of segmental cross-section, the plank can be fastened in the fastener devices. A length of segmental cross-section is sawn from the rounded part of the plank, to obtain a plank of triangular cross-section. After sawing off any knots, twigs, etc., that may be present and finger-joining knot-free planks, two planks of triangular cross-section can be glued with those sides from which rounded sides were cut-ofF facing towards one another to obtain a plank of rhombic cross-section. The resultant plank of rhombic cross- section is secured in the fastening devices on the bench and divided into thinner planks, which are edged or trimmed to obtain a rectangular cross-section.
• the described sawing bench which can be moved backwards and forwards past a stationary saw unit, there is obtained an arrangement which requires very little space and which can be readily managed and which is also relatively safe against damage, as the sawing device, such as a saw blade or similar device, has a fixed position.
• the arrangement can be managed by a single person in respect of the actual sawing operations, at least after having placed the large log in position. It can also be readily provided with auxiliary devices for placing sawn items to one side so that these items can also be handled by the same person as that before mentioned.
• the support given to the log from the bench and its devices is significant in preventing the log from moving or changing its shape as a result of the release of so-called inner growth stresses as the log is sawn.
• FIG. 1A illustrates a first embodiment of an inventive sawing bench from above
• Fig. IB is a side view of the sawing bench shown in Fig. 1A
• Fig. 1C is a cross-sectional view taken on the line C-C in Fig. IB;
• Figs. 2A-2F illustrate various method steps according to one embodiment of the invention
• Figs. 2G-2I show how different sawn elements can be mutually combined
• Fig. 3 illustrates a sawn-off cap placed on the sawing bench
• Figs. 4A-4B illustrate an alternative sawing method and show how the pieces obtained can be mutually combined
• Figs. 5A-5D are respectively a perspective view, a plan view, a cross-sectional view and a part view of a second embodiment of an inventive sawing bench;
• Fig. 6 is a perspective view of a second embodiment of a fastener device
• Fig. 7 illustrates a second embodiment of a supporting element for supporting the log from beneath
• Fig. 8 is an end view of a further embodiment of an inventive sawing station.
• Fig. 1A Shown in Fig. 1A is a sawing bench 1 and a bench pivoting device 1' by means of which the bench can be swung about an axis A-A.
• the sawing bench 1 is shown in a horizontal position, i.e. not angled, with a full log 2 placed with its centre line slightly to one side of table 1 in the illustrated case.
• the sawing bench 1 includes at one end thereof and along its length two slide paths 3 and 4, and an elongated slide path 5 which extends transversely across the slide paths 3 and 4 and which can be moved in the direction of arrow PI and which is mounted so that it can be moved along the slide paths 3 and 4.
• An immovable slide path 6 is positioned transversely across the sawing bench 1 close to its other end.
• a slide 7 that can move along the slide path 5
• a slide 8 that can move along the slide path 6.
• the slides 7 and 8 can be raised and lowered through the medium of respective holders 9 and 10, for fastening to a respective end of the log 2 in a position displaced from the centre of the log and at an adapted height, so that the holders 9 and 10 will hold the log 2 firmly in a position outwardly projected from the bench 1 over the axis A-A, so as to enable the log 2 to be divided into one or more parallel planks 12 (see Fig. 2A) transversely through the log on each side of its centre line.
• Each slide 7, 8 includes a respective locking device 7' and 8' for locking the slides immediately a setting has been effected.
• the entire bench 1 can be moved in the direction of the arrow P2 adjacent a stationary saw arrangement or the like which functions to saw the log.
• the first piece to be sawn from the log is a "cap" 21, i.e. a plank that has an approximately semicircular cross-section, and thereafter a centre part that shall include the log pith 11 and the major part of the juvenile wood.
• a "cap” 21 is sawn off slightly outside the actual juvenile wood 11, as indicated in Fig. 1A, in which it is shown that a saw blade 22 or some other kind of log parting means, for instance a powerful water jet, has cut slightly into the log 2 from one end thereof.
• the bench 1 has therewith been moved from a distal end position in the direction of arrow P2. It will be understood that although not shown a stop is provided at both ends for preventing the bench from moving excessively in either direction.
• Fig. 1 A also shows that after the saw has passed the position in which it runs parallel with the position of the slide 8 on the bench, a holder 23 is applied to the end of the cap 21 so as to hold this part of the log in a horizontal position, such as to prevent the "cap” from falling obliquely and twisting as the saw reaches the other end position of the log.
• the holder 23 may, for instance, be seated withdrawn in a raisable unit 23 A that is lowered so as to come into alignment with the side 8 and move the holder 23 outwards when the saw blade or circular saw 22 has passed.
• the sawn-off "cap” 21 is placed on one side after its removal from the log.
• One or more planks 12 are sawn parallel with the first sawing, it being ensured that the unusable juvenile wood in the centre of the log is sawn away.
• Each sawn plank is then turned through an angle of 90° and a part of the plank surrounding its pith is sawn away so that the plank or planks will be free from the juvenile wood, in other words each plank becomes two planks of similar lengths as the earlier plank but with less than half the original width of the earlier plank. This can be done at some place other than at the sawing bench. As shown in Figs.
• the sawing bench can be further improved by providing it with a number of log-supporting devices 24 that can be raised and adjusted along the length of the log 2.
• Each supporting device 24 has a log carrier 25 at its upper end. These carriers can be adjusted to follow the log surface along the outer line of the log transversely, optionally both in side and height respects. Naturally, the arrangement may be such as to follow said line automatically.
• the carrier is then locked in its adjusted position so as to fixate the carrier during sawing of the log.
• a braking and locking device 26 is activated when sawing commences, therewith locking the support devices 24 or a pivotal part 27 thereof in their respective settings.
• a supportive device that can be adjusted and locked manually may be provided centrally of the log as a support against sagging of the log during a sawing operation.
• the bench 1 need not solely include supports 24, 25 on that side of the log which is fastened to the table, but may also include supports on the other side of the blade chain for preventing the sawn-off cap from breaking free when sawing through a log section is almost completed. Consequently, the holder 23 (see Fig. 1 A) is caused to be "moved” firmly against the log subsequent to the saw blade 22 having cut through a part of said log section - provided that the support 24 and the saw blade do not touch each other (see Fig. 1A).
• a similar holder may be provided at the other end of the sawing bench, so as to hold securely the whole of the cap 21 during the entire sawing procedure.
• a log is placed on a movable sawing bench of the kind illustrated in Figs. 1A-1C, for example.
• Fig. 2A logs are divided into two "caps" 21, 28 with a through-extending intermediate plank 12 enclosing pith (juvenile wood). The log is fixed in fixture according to Fig. 1A.
• the "cap" 28 remaining on the table is turned on the sawing bench so as to lie with its planar part against the bench.
• the cap is preferably fixed with the fixture again in this position, so that the cap can be moved out over the edge of the bench, particularly towards that side on which the axis A-A is located. This can be achieved with the aid of the slides 7 and 8, which are then locked.
• the table is pivoted to an angle of -30° (in this embodiment) with the log outwardly projected through an adapted distance beyond the edge containing the axis A-A.
• a 60° "prism" 28A having an approximate triangular cross-section is then sawn-out centred. (It will be understood that other angular positions can be used, particularly in respect of different types of areas of use for planks of triangular cross-section.)
• Fig. 2D the remainder of the cap 28 is again moved outwards and a plank 28B of roughly rectangular cross-section is sawn out.
• the table is first moved to its outer end position, the cap is shifted and the sawing bench moved in the direction of arrow P2, so that the part of the cap projecting out over the edge of the saw table will be moved towards the saw blade.
• Fig. 2E the table is swung up to an angle of +30° (in this embodiment), whereafter a plank 28C that in section appears as a 60° "prism" of triangular cross- section is sawn out.
• the cap can be further displaced outwards and
• plank 28C another plank of roughly rectangular cross-section can be sawn out.
• Sawing of the plank 28C will preferably be effected so that the size is adapted to a desired area of use of the plank, either alone or glued to another plank.
• part of a remaining plank of symmetrical shape can be divided centrally into two parts or, as indicated in 2F, part of the remaining plank can be divided into two symmetrical planks 28D, 28E of triangular shape and an intermediate plank 28F of approximately rectangular cross-section.
• planks of roughly segmental cross-sections are dried and, in accordance with Fig. 2G, are cut free from the circular outer part so as to obtain a truly triangular cross- section, whereafter the planks are smoothed.
• This latter operation may be achieved solely by planing or by sanding the planks.
• the plank may be fastened to the bench so as to be firmly held. Parts that contain knots or the like may be cut away and knot-free parts joined together by finger joints.
• Fig. 2H two "triangles" (e.g. 28D and 28E) are glued together with the now planar outer surface 28E' and 28D 1 lying against each other, so as to obtain an rhombic cross-section.
• the log 28 is positioned and moved out over the table edge, so that its centre line lies outside the table, as shown in Fig. 4A.
• a cut is then made analogous with that shown in Fig. 2C, but through the media line of the "cap" 28 in 0° position, i.e. with the table kept horizontal, in other words not angled.
• the third, rounded side on the two outer planks is cut and planed or sanded so as to be straight and flat.
• the treated planks 29A and 29B of triangular cross-section are then glued together with the now planar outer sides 29A and 29B' lying against each other, so as to obtain a thick plank of roughly square cross-section.
• This plank can then be cut into narrower planks or used as it is in the construction of building frameworks.
• the other "cap" is treated in the same way, so that two thick planks of square cross-section and at least two planks from which the juvenile wood has been sawn away are obtained.
• Planks that are obtained by sawing and joining processes in accordance with Figs. 4A and 4B also provide a plank that can be turned effectively in a lathe, e.g., to produce posts for handrails, banisters and like structures.
• the embodiment illustrated in Figs. 5A-5D includes only one slide path 32 along the bench 31.
• a slide 33 can be moved reciprocatingly along the slide path.
• the slide carries an outwardly projecting plate 34 that has a holder 35 which can be moved along the plate and locked in a set position by means of a locking device 35'.
• the slide 33 is movable along the bench 31 and can be locked by means of a locking device 33' in an appropriate or suitable position, where the holder attachment 36 shall be inserted into the end of the log 37 so as to firmly hold the log.
• the holder 35 can be raised and lowered to adapted heights that are set prior to inserting the holder attachment into the end of the log.
• the other end of the sawing bench also includes a raised, outwardly projecting plate 38 having a holder 39 that can be moved along the plate 38 and that is of the same kind as the holder 35 with a raisable and lowerable attachment 40 for holding the log 37.
• a latch 44 which releases a spring force 45 that, in turn, advances an additional support 42 (only functionally shown in Fig. 5A), to a position in which said support will fasten to the outer log cap 43 that is to be sawn-off first.
• the support 42 supports the progressively sawn-off cap 43, so that it will not break loose at the final sawing stage.
• a holder 46 for the support 42 is seated on a slide plate 47.
• Fig. 5D illustrates another embodiment in which the outer part of a slide plate 47' with holder 46' can be folded in beneath the bench 31 and folded up against some type of spring force (not shown) so as to firmly clamp the cap 43 with its support 42'.
• Fig. 6 illustrates an embodiment which includes a support 50 that corresponds to the support 42 and that functions to lock the cap 43 against the log 37 as the cap is sawn-off.
• the support 50 includes at least two, preferably more, pointed elements 51 that have a common base which presses the pointed elements firmly into the cap on each side of the saw cut, therewith fixing the cap to the log.
• the pointed elements may be made slightly resilient 52 in an axial direction, so as to be able to function effectively against an uneven or rugged surface.
• the unit shown in Fig. 6 may also be used solely as the support 42.
• this type of support that includes several pointed elements 51 may also be used as the supports 9 and 10, and also as the support 23, in Fig. 1A.
• the use of a support that has this property effectively prevents the log from twisting subsequent to being mounted. This provides additional security when sawing-off caps and planks that contain juvenile wood.
• Fig. 7 illustrates an alternative method in which the cap 43 is supported on its underside by means of one or more pivotal supports 53 which is/are moved in beneath both log 37 and cap 43 subsequent to the saw blade 41 having passed the location of the pivotal support 53.
• Fig. 7 shows the support mounted at one end of the table 31 with its pivot axle 54 fastened to said end of the table.
• the support 53 is normally in the downwardly swung angled position shown in Fig. 7, when no log is on the table and prior to commencing a sawing operation.
• the end of the support 53 is moved out past the pivotal axis A-A of the table and up to the full-line position, either manually by the operator carrying out the sawing operation or is moved into abutment with the underside of the log by means of a snap-device or spring device (not shown) triggered by the operator and supported in this position by some form of support 55, which can also be triggered by the operator, for instance in conjunction with the snap-device or spring-device.
• FIG. 8 Another alternative, as shown in Fig. 8, is to provide the sawing bench 60 (corresponding to 1 or 31) with a parallel bench 61 on the other side of the saw blade 62.
• the bench 61 is firmly connected at its rear end, distal in respect of sawing, to the bench 60 (not shown). The connection lies beyond a full cut made when sawing a log.
• the bench 61 will preferably have a movement centre at its pivot point, which essentially lies in the same axis centre A-A as the bench 60.
• the bench 61 can be swung about the axis A-A directly, e.g. with the aid of setting devices that are preferably at least two in number.
• the bench 61 may be fixed horizontally and provided at a number of positions along its length with, e.g., a four-joint mechanism 63A-63D.
• this mechanism includes a vertical rod 64 that has pivotally mounted at each end rods 65, 66 that can be locked in their respective pivoted positions.
• the pivotal rods 65 and 66 can be dropped to a vertical position during sawing of the log and when sawing planks of roughly triangular cross-section with right angles, as shown in Fig. 4A.
• the rods are swung to the angles shown in Fig. 8, e.g.
• the pivotal axis of the sawing table or tables lies in the cut made by the saw blade, i.e. along the axis B-B in Fig. 1, instead of at the axis A-A in Fig. 1. This may require simple setting adjustments when adjusting the position of the log/the log segment prior to sawing. On the other hand, it is necessary to angle the sawing table 1 with the aid of separate setting devices, which is easy to achieve.

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• Life Sciences & Earth Sciences (AREA)
• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Wood Science & Technology (AREA)
• Forests & Forestry (AREA)
• Sawing (AREA)

Priority Applications (3)

Applications Claiming Priority (2)

Publications (1)

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ID=20418036

Family Applications (1)

Country Status (5)

Cited By (3)

Citations (5)

• 1999
  • 1999-12-08 SE SE9904479A patent/SE517828C2/sv not_active IP Right Cessation
• 2000
  • 2000-12-07 EE EEP200200299A patent/EE200200299A/et unknown
  • 2000-12-07 WO PCT/SE2000/002454 patent/WO2001041986A1/en not_active Application Discontinuation
  • 2000-12-07 EP EP00983644A patent/EP1235669A1/en not_active Withdrawn
• 2002
  • 2002-06-05 NO NO20022646A patent/NO20022646D0/no not_active Application Discontinuation

Patent Citations (5)

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