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
  • B27B29/00—Gripping, clamping, or holding devices for the trunk or log in saw mills or sawing machines; Travelling trunk or log carriages
• • 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
  • B27B31/00—Arrangements for conveying, loading, turning, adjusting, or discharging the log or timber, specially designed for saw mills or sawing machines
  • B27B31/06—Adjusting equipment, e.g. using optical projection

Definitions

• a method for aligning unedged sawn board with an edging machine, and an arrangement for carrying out the method is provided.
• the present invention relates to a method by which unedged sawn board or like material is brought into alignment with an edging machine, and by which the useful width of the board is determined with the aid of at least one pair of mutually co-acting jaws which are brought into engagement with the board so as to grip the board therebetween.
• the invention also relates to an arrangement of apparatus and of devices for use when aligning a board in accordance with the method.
• Unedged sawn boards such as planks or like timber lengths , here referred to collectively as boards , are edged by passing the boards through an edging machine, which normally comprises two mutually spaced saw blades or cutting blades with which wanes or like edge defects are removed from the boards.
• an edging machine which normally comprises two mutually spaced saw blades or cutting blades with which wanes or like edge defects are removed from the boards.
• the useful width it is essential that as much as possible of the planar part of the unedged board is recovered, this planar board part being referred to hereinafter as the useful width.
• the width or depth extension of the wane or other edge defect of an unedged board varies between the two mutually opposing edges of the board, it is not possible to centre the board in relation to the cutting tools of the edging machine with a starting point from the centre line of the unedged board. Instead, the board must be centred with reference to an offset or displaced centre line which represents the centre line of the useful width of the board.
• the main object of the present invention is to provide a method and an arrangement which will enable an unedged sawn board to be automatically aligned with and guided into an edging machine, in a manner to obtain maximum yield, without requiring the application of complicated expensive and environmentally sensitive technology.
• the centre line representing the useful width of the unedged board is preferably utilized for aligning the board in relation to the cutting devices of the edging machine, so as to obtain downstream of the edging machine an edged board whose centre line coincides with the first mentioned centre line.
• the board gripping jaws are preferably carried by two pivotable legs which can be swung positively in relation to an intermediate centre line, wherewith this centre line can be used as the centre line which is representative of the useful width of a board gripped by the jaws, thereby enabling the board to be aligned with the cutting devices by displacing the frame in a manner to bring the centre line extending between the jaw-carrying legs to a desired position relative to the cutting devices of the edging machine.
• the useful width of the board is determined conveniently by detecting the resultant positions of the jaws when gripping the board, whereafter the positions of the cutting devices of the edging machine can be adjusted accordingly.
• the frame subsequent to engagement of the jaws with the board, is moved to a position in which the centre line between the jaw-carrying legs is located from the fixed saw blade at a distance which corresponds to half the width of the maximum useful board width of the unedged board, and the laterally movable blade is moved to a position located at the same distance from the centre line, but on the opposite side thereof.
• the resilient bodies provided on respective jaws may comprise air-filled casings of rubber, plastic or some equivalent material, and means may be provided for varying the pressure of the air in the casings in accordance with the anticipated width and thickness of the wane of a board or like wooden workpiece.
• the invention also relates to an arrangement of apparatus and devices for use when carrying out the method.
• the features particularly characteristic of the arrangement are set forth in the following apparatus claims.
• FIG. 1 is a perspective illustration of an arrangement constructed in accordance with the invention.
• Figures 2-5 are cross-sectional views of a pair of jaws included in the arrangement of Figure 1 and shown in gripping engagement with boards which exhibit mutually different edge defects.
• the arrangement illustrated in Figure 1 is intended for bringing an unedged board 1 into a desired position of alignment with an edging machine 2, and feeding said unedged board into the machine.
• the arrangement includes two serrated or fluted feed drums 3 and 4 which clamp the board 1 firmly therebetween and advance the board into the vicinity of two cutting devices, which in the illustrated embodiment have the form of saw blades 5 and 6.
• Both of the illustrated blades 5 and 6 are laterally adjustable, so that the blades can be brought to positions corresponding to the desired width dimension of the board, although normally one of the blades, 5, is fixedly located while the other blade, 6, is movable laterally in relation to the first mentioned blade.
• the board 1 need only be aligned so that the centre line representing the useful width of the board coincides with the centre line between the saw blades 5 and 6 , while the mutual distance between the saw blades is adjusted to the maximum width that can be recovered from the unedged board 1.
• FIG. 1 the arrangement illustrated in Figure 1 includes a frame assembly, generally shown at 9, which is movably mounted on guides 7 and 8 and which incorporates an upper frame 10, which is guided on said guides, and a lower frame 11 , which is suspended from the upper frame 10 by means of rigid cross-struts 12.
• the whole of the frame assembly 9 can be moved reciprocatingly on the guides 7 and 8 with the aid of an accurately steered piston-cylinder device 13.
• the lower frame 11 of the frame assembly has depending therefrom three pairs of pivotably mounted legs 14, 15 and 16 , each of which can be pivoted or swung in relation to the other.
• a jaw 17 which is made from a resilient or elastic material and which is intended for gripping engagement with a respective side edge of the illustrated board 1.
• the frame assembly 9 can be moved laterally to the left in said Figure, so as to collect a board 1 advanced on a board conveyor 18, whereupon the board is gripped by the jaws 17 and, as the frame assembly is moved to the right in the Figure 1 , lifted onto rollers 19, which feed the board into the edging machine 2.
• the board 1 is held in a correct position of alignment in relation to the edging machine with the aid of two toothed wheels 20, which press the board against the rollers, such as to maintain the position of alignment of the board when the jaws 17 release their hold thereon.
• the upper ends of the legs 14 are pivotably mounted in the lower frame 11 at the centre of a respective toothed segment 21 and 22, which mesh with each other.
• the leg connected to the toothed segment 21 is also by an arm 23 connected to the piston rod 24 of an auxiliary piston-cylinder device 25 mounted on the upper frame 10 of the frame assembly 9. Consequently, as the piston rod 24 moves in its axial direction the legs 14 will be symmetrically moved in a corresponding direction towards or away from each other while centred around the centre line between the leg suspension points, due to the positive steering of the legs in relation to one another achieved through the mutual meshing engagement of the toothed segments 21 and 22.
• the pairs of legs 15, 16 are suspended from the lower frame 11 and positively steered and manipulated in a manner corresponding to that described with regard to the leg pair 14.
• the arrangement In order to align a board exactly, the arrangement must incorporate at least two pairs of legs, suitably one pair of legs at each end of the board. Consequently, the intermediate leg pair 15 of the Figure 1 embodiment need only be used when edging a board which is too short to extend from the legs 16 to the legs 14.
• the reference 26 identifies a pivot device which enables adjustments to be made to the angle at which respective jaws of an associated leg pair engage the board.
• the jaws 17 are made of, or comprise, a resilient material, such that a wane or like edge defect present on the board to be edged will be pressed into the jaw in engagement therewith. Consequently, when a board is gripped between the jaws, the useful width of the board can be determined by detecting the movement carried out by the piston rod 24, or the terminal position of the piston rod. Furthermore, it is known that the line passing along the centre of the useful width of the board 1 coincides essentially with the centre line between the pivot axes of the toothed segments 21 and 22. This is illustrated more closely in Figures 2-5.
• the jaws 17 are shown gripping a board 1 having planar side edges.
• the gripping force acting on the legs 14 is adapted so that the edges of the board 1 will not be pressed into the resilient jaws 17 to any appreciable extent. Consequently, the centre line A-A representing the useful width of the board 1, which in this case coincides with the centre line representing the total width of the illustrated board, will coincide with the centre line between the legs 14.
• Figure 3 illustrates a board with which the opposing side edges thereof have mutually different wane configurations.
• the gripping force is adapted so that the wanes, or defective edges, are pressed essentially completely into respective jaws 17.
• the centre line A-A representing the useful width of the board will, also in this case, coincide with the centre line between the jaws 14 and is therefore common thereto. In the case of the Figure 3 illustration, however, this common centre line is offset in relation to the centre line representive of the total width of the board 1 , including the wane edges.
• Figure 4 illustrates a corresponding case, although in this illustration one edge of the board is planar and the other defective. As shown, essentially only the defective edge of the board is pressed into its associated jaw 17.
• the centre line A-A is also in this case the correct centre line of the useful width of the board.
• Figure 5 illustrates the same principle, but with the board 1 turned so that its broadest face is upwards .
• the frame assembly 9 when using an edging machine in which both saw blades 5 and 6 are movable laterally in relation to an intermediate, longitudinal centre line, the frame assembly 9 , subsequent to collecting a board and gripping the board between the jaws as aforedescribed, need only be moved laterally to a position in which the frame assembly centre line extending between the suspension points of the toothed segments 21 and 22 coincides with the centre line between the saw blades 5 and 6.
• the distance between the blades is therewith adjusted in accordance with the detected width of the board which is obtained from the auxiliary piston-cylinder device 25. Movement of the piston rod 24 and its terminal position can be determined, to this end, in some suitable known manner and the resultant value used to control the adjustment of the saw blades.
• the legs 14 may be suspended and positively steered in relation to one another in a manner different to that illustrated, and the position of the auxiliary piston-cylinder devices may be varied so that said devices, e.g., engage directly between the legs.
• the piston-cylinder devices used may be either pneumatically operated or hydraulically operated devices.
• the resilient jaws 17 may comprise homogenous bodies of resilient material, instead of the air-filled bladder-like casings of rubber, plastic or like material from which the illustrated jaws are comprised.
• the jaws may have any desired form and can be made from expanded rubber having closed cells.

Landscapes

• Life Sciences & Earth Sciences (AREA)
• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Wood Science & Technology (AREA)
• Forests & Forestry (AREA)
• Details Of Cutting Devices (AREA)
• Manipulator (AREA)
• Machines For Manufacturing Corrugated Board In Mechanical Paper-Making Processes (AREA)
• Sawing (AREA)
• Veneer Processing And Manufacture Of Plywood (AREA)
• Investigating Strength Of Materials By Application Of Mechanical Stress (AREA)

Priority Applications (2)

Applications Claiming Priority (2)

Publications (1)

Family

ID=20364152

Family Applications (1)

Country Status (3)

Cited By (1)

Families Citing this family (1)

Citations (7)

• 1986
  • 1986-04-11 SE SE8601648A patent/SE451188B/sv not_active IP Right Cessation
• 1987
  • 1987-04-10 WO PCT/SE1987/000184 patent/WO1987006174A1/en active IP Right Grant
• 1988
  • 1988-10-07 FI FI884628A patent/FI84565C/sv not_active IP Right Cessation

Patent Citations (7)

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