Feeding arrangement for boards

Abstract

A feeding arrangement (1) for feeding boards (2) from a board stack (3) in a feeding direction (9). The feeding arrangement (1) comprises at least a first reciprocating feeding unit (7) and a second reciprocating feeding unit (10) configured to alternately feed boards (2) from the board stack (3) in the feeding direction (9).

Description

[0001] FEEDING ARRANGEMENT FOR BOARDS

[0002] FIELD OF THE INVENTION

[0003] The invention relates to a feeding arrangement for feeding boards , such as particle boards , OSB boards and / or MDF boards , from a board stack to a conveyor and along the conveyor forward in a feeding direction . The invention also relates to a method of feeding boards .

[0004] BACKGROUND OF THE INVENTION

[0005] When manufacturing wood-based boards , the boards are often stacked and fed from the board stack one by one to a subsequent processing step or unit . The boards are typically unstacked so that the uppermost board on the board stack is fed to a conveyor and along the conveyor towards the processing unit by a feeding unit . Thereafter, the feeding unit returns to the board stack and feeds the next board from the board stack to the conveyor and along the conveyor towards the processing unit , and so on . The feeding unit thus moves back and forth above the board stack and the conveyor . The feeding unit may comprise a pusher that pushes the board to be fed from the trai ling edge or a wheel that is placed against a top surface of the board to be fed . The rotation of the wheel is prevented in the in the feeding direction of the board and allowed in the opposite direction .

[0006] The drawback of the above-described feeding arrangement is that it is not poss ible to feed boards from the board stack during the return motion of the feeding unit , which limits the cycle time of the feeding arrangement . However, increased board manufacturing line speeds , especially when thin boards are manufactured, and relatively short board lengths would require shorter feeding cycle times .

[0007] SUMMARY

[0008] An obj ect of the present invention is to provide a feeding arrangement and a feeding method by which the above-mentioned drawbacks can be reduced .

[0009] The obj ect according to the invention may be achieved by a feeding arrangement according to claim 1 . The feeding arrangement according to the invention is configured to feed boards from a board stack forward in a feeding direction . The feeding arrangement comprises at least a first reciprocating feeding unit and a second reciprocating feeding unit configured to alternately feed boards from the board stack in the feeding direction .

[0010] The invention offers many advantages . The cycle time of the board feeding arrangement can be significantly reduced since one feeding unit may begin its feeding motion during the return motion of another feeding unit or almost immediately after the preceding board has been fed from the board stack to the conveyor by another feeding unit .

[0011] BRIEF DESCRIPTION OF THE DRAWINGS

[0012] In the following, the invention is described in more detai l by way of examples with reference to the accompanying drawings , in which

[0013] Fig . 1 and 2 show, as a side view, a feeding arrangement according to an embodiment of the invention, Fig. 3 shows, as a top view, the feeding arrangement of fig- 1,

[0014] Fig. 4 shows, as a perspective view, the feeding arrangement of fig. 1.

[0015] DETAILED DESCRIPTION

[0016] The drawings show a feeding arrangement 1 according to an embodiment of the invention. The feeding arrangement 1 may be used in a factory manufacturing wood-based boards 2, such as OSB (Oriented Strand Boards) , MDF (Medium Density Fibreboards) or particle boards, for feeding the boards 2 from a board stack 3 in a feeding direction 9. The feeding arrangement 1 is configured to feed the boards 2 from the board stack 3 one by one. The boards 2 may be fed from the board stack 3 to or towards a processing step or unit 4, such as a sanding unit, stacking unit, painting unit, milling unit, measuring unit, marking unit, machining unit or visual inspection unit. Typically, the width of the boards 2 is 1.8-3.6 m and the length is 5-9 m. Alternatively, the boards 2 may be smaller in size, typically 1.22 m X 2.44 m (4 X 8 feet) or 1.52 m X 2.74 m (5 X 9 feet) .

[0017] The feeding arrangement 1 may comprise a conveyor 5 for receiving boards 2 from the board stack 3. The conveyor 5 may be a roll conveyor comprising rotatable rolls on which the board 2 to be fed is moved in the feeding direction 9. The processing unit 4 or an end of the conveyor 5 may be arranged next to the board stack 3. The second end of the conveyor 5 may be arranged next to the processing unit. In the embodiment shown in the drawings the processing unit 4 has been placed next to the board stack 3.

[0018] The feeding arrangement 1 may comprise a lifting platform 11, on which the board stack 3 is placed. The board stack 3 is lifted by the lifting platform during the feeding of the boards 2 so that the uppermost board 2 in the board stack 3 remains at a constant height .

[0019] The feeding arrangement 1 further comprises at least two reciprocating feeding units 7,10, i.e. at least a first feeding unit 7 and a second feeding unit 10. The feeding units 7,10 are configured to alternately feed boards 2 from the board stack 3 in a feeding direction 9, i.e. towards or to the processing unit 4. The first feeding unit 7 and the second feeding units 10 are arranged to move in opposite directions so that when one feeding unit feeds the board 2 in the feeding direction 9, the other feeding unit is simultaneously moved in the opposite direction with respect to the feeding direction 9, i.e. away from the processing unit 4, to be ready to feed the next board 2 from the board stack 3. The feeding units 7,10 are movable independently of each other .

[0020] The feeding units 7,10 are configured to feed the boards 2 one by one from the board stack 3. The first feeding unit 7 and the second feeding unit 10 are configured to reciprocate in the feeding direction 9 of the boards 2. The first feeding unit 7 and the second feeding unit 10 are configured to reciprocate above the board stack 3. The feeding units 7,10 are arranged to feed, e.g. push, the uppermost board 2 in the board stack 3 in the feeding direction 9 towards or to the processing unit 4. The feeding arrangement 1 shown in the drawings comprises two feeding units, but alternatively it may comprise three or more feeding units configured to alternately feed the boards 2 from the board stack 3 in the feeding direction 9 .

[0021] The feeding units 7 , 10 comprise feeding members 8 arranged to be placed against the surface of the board 2 to be fed, e . g . against the top surface and / or the trailing edge of the board 2 . The feeding members 8 are configured to feed, e . g . push, the board 2 from the board stack 3 in the feeding direction 9 . The feeding members 8 may comprise vacuum elements for applying suction to the top surface of the board 2 to be fed .

[0022] The feeding members 8 of the feeding units 7 , 10 are arranged at different points in the transverse direction, which is perpendicular to the feeding direction 9 , to prevent the feeding members 8 from touching each other when the feeding units are moved in the opposite directions . The first feeding unit 7 may comprise a feeding member 8 configured to be placed against the surface of the board 2 at a centre line of the board 2 . The centre line is paral lel to feeding direction 9 of the board 2 . The second feeding unit 10 may comprise two feeding members 8 configured to be placed against the surface of the board 2 on both sides of the centre line , typical ly at equal di stances from the centre l ine . Alternatively, the first feeding unit 7 may comprise two feeding members 8 configured to be placed against the surface of the board 2 on both sides of the centre line , typically at equal distances from the centre line .

[0023] The feeding members 8 of the first feeding unit 7 and the second feeding unit 10 may comprise a wheel that is placed against the top surface of the board 2 . Rotation of the wheel is prevented in the feeding direction 9 of the board 2 and allowed in the opposite direction . Alternatively, the feeding members 8 may comprise a pusher that is placed against the trailing edge and / or top surface of the board 2 to be fed .

[0024] In one embodiment of the invention, the feeding members 8 of the feeding units 7 , 10 are capable of being placed or arranged to be placed against the top surface and / or the trailing edge of a second topmost board of the board stack 3 simultaneously as the topmost board of the board stack 3 is partially on said second topmost board and being fed from the board stack 3 in the feeding direction 9 towards the processing unit 4 .

[0025] The feeding arrangement 1 comprises a frame 12 , on which the first feeding unit 7 and the second feeding unit 10 are mounted . The feeding units 7 , 10 are mounted above the lifting platform 11 . The feeding units 7 , 10 may comprise rails 13 extending in the feeding direction 9 . The feeding members 8 are mounted on and arranged to move along the rails 13 . The feeding units 7 , 10 may comprise a separate rail for each feeding member 8 . The feeding units 7 , 10 further comprise drive motors configured to move the feeding members 8 along the rails 13 . The frame 12 may comprise transverse bars 12 . 1 , to which the rails 13 are attached . The feeding arrangement 1 further comprises a control unit configured to operate the feeding units 7 , 10 .

[0026] The feeding arrangement 1 may further comprise a stopper 14 configured to prevent the double feeding of the boards 2 from the board stack 3 . The stopper 14 is placed at a height where only the topmost board 2 of the board stack 3 is allowed to pass over the stopper 14 at a time . Simultaneously, the stopper 14 prevents the feeding of the second topmost board 2 from the board stack 3 . The stopper 14 may be attached to the frame 12 . The stopper 14 is placed on the side of the leading edge of the boards 2 . The feeding units 7 , 10 may compri se pneumatic actuators for moving the feeding members 8 vertically . This enables the lifting platform 11 to be lifted at the same time as the feeding member 8 is positioned against the top surface of the board 2 .

[0027] The feeding arrangement 1 is operated as follows . The uppermost board 2 in the board stack 3 is fed, i . e . pushed, from the board stack 3 forward in the feeding direction 9 , i . e . towards the processing unit 4 , by the first feeding unit 7 . Simultaneously, the second feeding unit 10 is moved in the opposite direction with respect to the feeding direction 9 to be ready to feed the next board 2 from the board stack 3 . When the feeding movement of the first feeding unit 7 in the feeding direction 9 unit has been completed, the first feeding unit 7 is moved in the opposite direction with respect to the feeding direction 9 to be ready to feed the next board 2 from the board stack 3 . Simultaneously, the uppermost board 2 in the board stack 3 is fed, e . g . pushed, from the board stack 3 in the feeding direction 9 towards the processing unit 4 by the second feeding unit 10 .

[0028] When the feeding movement of the second feeding unit 10 has been completed, the second feeding unit 10 is moved in the opposite direction with respect to the feeding direction 9 to be ready to feed the next board 2 from the board stack 3 . Simultaneously, the uppermost board 2 of the board stack 3 is fed in the feeding direction 9 towards the processing unit 4by the first feeding unit 7 , etc . Thus , the boards 2 are fed from board stack 3 in the feeding direction 9 alternately by the first feeding unit 7 and the second feeding unit 10 . I f the feeding arrangement 1 comprises three or more feeding units , the boards 2 are fed from the board stack 3 in the feeding direction 9 alternately by the feeding units .

[0029] I f the feeding members 8 of the feeding units comprise wheels , the wheels are placed against the top surface of the board 2 to be fed . The board 2 is fed, e . g . pushed, forward in the feeding direction 9 using friction force induced by vertical pressing force of the wheels .

[0030] I f the feeding members 8 comprise pushers , the pushers are placed against the trailing edge and / or top surface of the board 2 to be fed, and the board 2 is fed, e . g . pushed, forward in the feeding direction 9 .

[0031] In one embodiment of the invention, the feeding member ( s ) 8 of the feeding unit 7 , 10 is / are placed against the top surface and / or the trailing edge of a second topmost board of the board stack 3 simultaneously as the topmost board of the board stack 3 is partially on said second topmost board and being fed from the board stack 3 in the feeding direction 9 .

[0032] It i s obvious to a person s ki lled in the art that with the advancement of technology, the basic idea of the invention may be implemented in various ways . The invention and its embodiments are thus not limited to the examples described above , instead they may vary within the scope of the claims .

Claims

CLAIMS1. A feeding arrangement (1) for feeding boards (2) from a board stack (3) in a feeding direction (9) , characterized in that the feeding arrangement (1) comprises at least a first reciprocating feeding unit (7) and a second reciprocating feeding unit (10) configured to alternately feed boards (2) from the board stack (3) in the feeding direction (9) .

2. The feeding arrangement (1) according to claim 1, characterized in that the first feeding unit (7) and the second feeding unit (10) are configured to feed the boards (2) one by one from the board stack (3) in the feeding direction (9) .

3. The feeding arrangement (1) according to claim 1 or 2, characterized in that the first feeding unit (7) and the second feeding unit (10) are arranged to move in opposite directions so that when one feeding unit (7,10) feeds the board (2) in the feeding direction (9) , the other feeding unit (7, 10) is simultaneously moved in an opposite direction to be ready to feed the next board (2) from the board stack (3) .

4. The feeding arrangement (1) according to any of the preceding claims, characterized in that the first feeding unit (7) and the second feeding unit (10) comprise at least one feeding member (8) configured to feed, e.g. push, the board (2) from the board stack (3) in the feeding direction (9) .

5. The feeding arrangement (1) according to claim 4, characterized in that the feeding members (8) of the first feeding unit (7) and the second feeding unit (10) are configured to be placed against a top surface and / or a trailing edge of the board (2) to be fed .

6. The feeding arrangement (1) according to claim 5, characterized in that the feeding member (s) (8) of the feeding unit (7, 10) is / are configured to be placed against the top surface and / or the trailing edge of a second topmost board of the board stack (3) simultaneously as the topmost board of the board stack (3) is partially on said second topmost board and being fed from the board stack (3) in the feeding direction (9) .

7. The feeding arrangement (1) according to claim 4, characterized in that the feeding members (8) of the first feeding unit (7) and the second feeding unit (10) are configured to be pressed against a top surface of the board (2) and to move, e.g. push, the board (2) in the feed direction (9) using friction force induced by vertical pressing force of the feeding members ( 8 ) .

8. The feeding arrangement (1) according to any of claims 4 to 7, characterized in that the feeding members (8) of the first feeding unit (7) and the second feeding unit (10) comprise a vacuum element for applying suction to a top surface of the board (2) .

9. The feeding arrangement (1) according to any of the preceding claims, characterized in that the first feeding unit (7) comprises a feeding member (8) arranged to be placed against the surface of the board (2) at a centre line of the board (2) , the centre line being parallel to the feeding direction (9) of the board (2) , and the second feeding unit (10) comprises two feeding members (8) arranged to be placed against the surface of the board (2) on both sides of the centre line.

10. The feeding arrangement (1) according to any of preceding claims 1-8, characterized in that thefirst feeding unit (7) comprises two feeding members (8) arranged to be placed against the surface of the board (2) on both sides of the centre line of the board (2) , the centre line being parallel to the feeding direction (9) of the board (2) , and the second feeding unit (10) comprises two feeding members (8) arranged to be placed against the surface of the board (2) on both sides of the centre line.

11. The feeding arrangement (1) according to any of preceding claims 4 to 10, characterized in that the feeding members (8) of the first feeding unit (7) and the second feeding unit (10) comprise a wheel configured to be placed against a top surface of the board (2) , rotation of the wheel being prevented in the feeding direction (9) and allowed in the opposite direction.

12. The feeding arrangement (1) according to any of preceding claims 4 to 10, characterized in that the feeding members (8) of the first feeding unit (7) and the second feeding unit (10) comprise a pusher configured to be placed against a trailing edge and / or top surface of the board (2) to be fed.

13. The feeding arrangement (1) according to any of the preceding claims, characterized in that the feeding arrangement (1) comprises a stopper (14) configured to prevent the double feeding of the boards (2) from the board stack (3) .

14. A method of feeding boards (2) from a board stack (3) using a feeding arrangement (1) according to any of the preceding claims, characterized in that the boards (2) are fed from the board stack (3) in a feeding direction (9) alternately by at least a first feeding unit (7) and a second feeding unit (10) .

15. The method according to claim 14, characterized in that the boards (2) are pushed from the board stack in the feeding direction (9) by at least the first feeding unit (7) and the second feeding unit (10) .

16. The method according to claim 14 or 15, characterized in that the boards (2) are fed one by one from the board stack (3) in the feeding direction (9) .

17. The method according to any of claims 14 to 16, characterized in that the first feeding unit (7) and the second feeding unit (10) comprise feeding members (8) that are placed against a top surface and / or a trailing edge of the board (2) to be fed.

18. The feeding arrangement (1) according to claim 17, characterized in that the feeding member (s) (8) of the feeding unit (7, 10) is / are placed against the top surface and / or the trailing edge of a second topmost board of the board stack (3) simultaneously as the topmost board of the board stack (3) is partially on said second topmost board and being fed from the board stack (3) in the feeding direction (9) .

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