Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
  • B65G—TRANSPORT OR STORAGE DEVICES, e.g. CONVEYORS FOR LOADING OR TIPPING, SHOP CONVEYOR SYSTEMS OR PNEUMATIC TUBE CONVEYORS
  • B65G47/00—Article or material-handling devices associated with conveyors; Methods employing such devices
  • B65G47/74—Feeding, transfer, or discharging devices of particular kinds or types
  • B65G47/84—Star-shaped wheels or devices having endless travelling belts or chains, the wheels or devices being equipped with article-engaging elements
• • 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
  • B27B31/006—Arrangements for conveying, loading, turning, adjusting, or discharging the log or timber, specially designed for saw mills or sawing machines with chains or belts
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
  • B65G—TRANSPORT OR STORAGE DEVICES, e.g. CONVEYORS FOR LOADING OR TIPPING, SHOP CONVEYOR SYSTEMS OR PNEUMATIC TUBE CONVEYORS
  • B65G17/00—Conveyors having an endless traction element, e.g. a chain, transmitting movement to a continuous or substantially-continuous load-carrying surface or to a series of individual load-carriers; Endless-chain conveyors in which the chains form the load-carrying surface
  • B65G17/30—Details; Auxiliary devices
  • B65G17/32—Individual load-carriers
  • B65G17/326—Clamps, constituted by articulated chain links
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
  • B65G—TRANSPORT OR STORAGE DEVICES, e.g. CONVEYORS FOR LOADING OR TIPPING, SHOP CONVEYOR SYSTEMS OR PNEUMATIC TUBE CONVEYORS
  • B65G17/00—Conveyors having an endless traction element, e.g. a chain, transmitting movement to a continuous or substantially-continuous load-carrying surface or to a series of individual load-carriers; Endless-chain conveyors in which the chains form the load-carrying surface
  • B65G17/30—Details; Auxiliary devices
  • B65G17/46—Means for holding or retaining the loads in fixed position on the load-carriers, e.g. magnetic
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
  • B65G—TRANSPORT OR STORAGE DEVICES, e.g. CONVEYORS FOR LOADING OR TIPPING, SHOP CONVEYOR SYSTEMS OR PNEUMATIC TUBE CONVEYORS
  • B65G2201/00—Indexing codes relating to handling devices, e.g. conveyors, characterised by the type of product or load being conveyed or handled
  • B65G2201/02—Articles
  • B65G2201/0214—Articles of special size, shape or weigh
  • B65G2201/0217—Elongated

Definitions

• the invention relates to automatic processing of timber elements, specifically to conveyance of elongated timber elements with a so-called flighted conveyor .
• wood elements are more and more often processed automatically. This provides considerable advantages in terms of saving workforce expenses and improving the machining accuracy.
• One major aspect in the automatic machining of wood elements is its quick and reliable conveyance from the storage site to the machining devices, between the machining devices, and further out of the production line.
• One known solution for conveying timber elements automatically is to use a so-called flighted conveyor in which the timber elements are conveyed so that they are supported by support members, or so- called flights, which are mounted to a belt, chain or the like.
• the flighted conveyor conveys the timber elements in their crosswise direction, which is an ad- vantageous feature for example in arrangements in which the machining means are arranged side by side on the production line for simultaneously machining the heads of an object.
• An example of a flighted conveyor is presented in patent US 4516675.
• flights designated for the front and the back side of the timber elements have been mounted in pairs to a chain which is used as a drawing device for conveying the timber elements so that they are pressed between the flights.
• the solution presented above comprises a number of major problems which make it practically useless in the modern production lines.
• the flight structures as presented are complex.
• the use of a separate front and back flight makes the conveying inefficient, because successive wood objects cannot be positioned close to each other.
• the moving speed of the chain must be raised, which in turn promotes wearing and need for maintenance and makes the conveyor operation vulnerable to malfunctions.
• a high conveying speed past the machining devices complicates the machining operation itself, requiring, for example in the case of a circular saw, a blade rotation speed which may be substantially higher than the optimal rotation speed in terms of the operation of the saw.
• the publication does not disclose how the timber elements could be reliably fed to the conveyor in practice in the solution according to the figures of the publication.
• the fed timber elements are positioned on top of the latter flight at a high level relative to the conveying chain itself, and during feeding they are supported for a long time merely by the back flight, which increases the possibilities for incorrect motion of the objects.
• Another known example is a different type of conveyor developed by Koskovich Company, in which the wood elements are fed to a flighted-conveyor-type conveying device from a horizontal feeding platform. As the back flight lifts the object from below, it is at the same time supported by a separate retainer also from above until it reaches contact with the front flight as well.
• the apparatus enables a bit higher conveying efficiency than the arrangement in accordance with patent US 4516675, but on the other hand, the apparatus is extremely complex.
• the objective of the invention is to provide an efficient and reliable and yet as simple as possible apparatus for automatic conveying of elongated timber elements.
• the apparatus of the invention for conveying elongated timber elements in their crosswise position comprises a flighted conveyor in which flights are supported on an endless drawing member, such as chain, which has been adapted to pass around two idlers posi- tioned at a distance from each other and supported so that they rotate substantially vertically, the flights being supported so that they extend outwards from the link formed by the drawing member, for conveying timber elements along with the motion of the drawing mem- ber so that they are pressed between the flights.
• a timber element refers to any wood element that has been preferably so machined that it has a substantially rectangular cross-section, such as plank, board, lath or the like.
• the timber elements are fed to such flighted conveyor close to one idler when successive flights have become open relative to each other due to the curving path of the drawing member which moves around the idler.
• the tightly pressed timber elements proceed with the drawing member up to the other idler, where they are released as the flights reopen relative to each other. Since the conveyed timber elements may be several metres long, the flighted conveyor normally comprises practically two drawing members as described above, side by side and at a specific distance from each other.
• the flighted conveyor comprises successive flights, each of them comprising a body part and, relative to the moving direction of the drawing member, a push part at the front side and a stop part at the back side, wherein at least one of the push part and the stop part has been arranged to be flexible in the moving direction of the drawing member, for pressing timber elements at the faces between the push part of the latter of two successive flights and the stop part of the preceding one.
• each of the flights operates thus as a back and a front flight for the wood elements. This provides many considerable advantages.
• the flexible movement of the push and/or stop part or in other words adjustment of the flight thickness, enables conveyance of timber elements of varying thickness with a suitable pressing force, yet so that a change in thickness does not require adjustment of the support between the flight and the drawing member.
• all flights of the conveyor, or at least the set of successive flights are preferably mutually similar.
• the stop part is supported on the body part so that it moves by a spring in the longitudinal direction of the drawing member.
• the push part may be fixed relative to the body part of the flight, stabilizing the operation of the conveyor, in particular during feeding the timber elements to the flighted conveyor.
• a flight preferably comprises, for example in the push part, a friction member for increasing the frictional force between the timber element and the flight.
• the friction member may be for example a rubber surface. The greater the frictional force between the flight and the timber element, the more secure is the flawless operation of the conveyor, particularly during the feeding step.
• the flighted conveyor comprises in a pre- ferred embodiment a support member substantially at the level of the drawing member for supporting the side of a timber element against it.
• a support member substantially at the level of the drawing member for supporting the side of a timber element against it.
• the push part of the flight preferably extends to a distance of at least about 100mm from the support member measured perpendicularly relative to the longitudinal direction of the drawing member.
• a height of about 100mm from the support member allows the firm conveyance of timber elements which are up to 250mm wide with one and the same conveyor structure.
• a feeding device comprising a sliding sur- face which extends obliquely upwards from the flighted conveyor has preferably been arranged to the apparatus in accordance with the invention near the latter idler relative to the conveying direction of the timber elements, for sliding the timber elements flat along the sliding surface to the flighted conveyor to the front of the flight which moves around the idler.
• the sliding surface enables automatic and fast feeding of the timber elements to the flighted conveyor.
• the sliding surface is preferably at an angle of about 30 degrees relative to the vertical direction. That is a suffi- ciently sharp angle to provide a fast sliding motion, and yet a sufficiently blunt angle to hold the timber elements firmly against the sliding surface by means of gravity.
• a flighted conveyor normally comprises two drawing members side by side at a distance from each other, there is accordingly preferably at least one sliding surface near each drawing member of the conveyor.
• the feeding device preferably also comprises a detector for the po- sition of the flight which moves around the idler, and a holder which is controlled on the base of the position data acquired from the detector for holding in place the timber elements fed to the sliding surface and for releasing them so as to slide to the flighted conveyor at a suitable moment.
• a suitable moment naturally refers to the moment where the timber element slides between the two flights that have opened relative to each other, wherein the latter flight then starts to push it forward.
• Fig. Ia and Ib represent one embodiment of the apparatus in accordance with the invention and the operation of the apparatus, and
• Fig. 2 shows details of the apparatus in ac- cordance with Fig. Ia and Ib.
• Fig. Ia shows a side view of the latter end, relative to the conveying direction, of a flighted conveyor 1 mounted so as to have a horizontal conveying direction.
• the actual moving conveyor is formed by a chain 3 which has been positioned to pass around a chain pulley 2.
• Flights 5 which extend outwards from the link formed by the chain passing around the chain pulley have been mounted to each outer chain link 4 of the chain for conveying planks 6 between the chain pulleys along the upper portion of the link formed by said chain so that the planks are pressed between successive flights at the faces 7.
• the flights are mutu- ally identical, each one operating as an actuating element which pushes the plank in front of it and as a counter-member for the next plank which is being pushed by the flight behind it.
• a feeding apparatus 8 Arranged in conjunction with the latter end of the flighted conveyor shown in Fig. Ia is a feeding apparatus 8 comprising, first of all, a sliding support 9 which extends, relative to the conveying direction of the conveyor, back substantially from the chain pulley and obliquely upwards at an angle of about 30 degrees relative to the vertical direction, and has been positioned aside from the level of the chain pulley 2, so that the planks can be slid along the sliding support to the conveyor to a position where the space between the flight 5a which is still moving around the chain pulley and the flight in front of it has partly opened.
• the feeding device 8 comprises a flight detector 10 which has been arranged near the idler and may be for example an optical or a magnetic indicator. Furthermore, in con- junction with the sliding surface is a holder 12 which is controlled on the base of information acquired from the flight detector and operated for example by a pneumatic or hydraulic cylinder 11 for holding in place the plank 6 or other timber element which has been fed to the sliding surface 9, and for releasing it at the suitable moment so as to slide to the conveyor to the front of the flight which is moving around the idler.
• the holder is returned to the initial position to receive the next plank which is fed to the sliding surface.
• a conveyor provided with the automatic feeding apparatus can be incorporated into an automatic production control system of a timber production line, thus minimizing the need of manual work.
• Each flight of the flighted conveyor 1 comprises in accordance with Fig. 2 a body part 13 which has been mounted directly to the outer chain link 4 of the chain 3 so that it extends perpendicularly out- wards from the chain.
• the flight comprises, relative to the movement direction of the chain, at the front side of the body part a push part 14, and at the back side a stop part 15 which has been supported on the body part by strings 16 so as to move in the longitu- dinal direction of the chain 3.
• the spring-suspended stop part changes the thickness of the flight according to the varying thickness of the timber elements and, on the other hand, ensures that a sufficient pressure force is always applied to the faces 7 of the planks to hold the planks firmly in place during conveyance.
• the required flexibility could also be alternatively realized for example by means of flexible rubber members.
• friction members 17 made from rubber and arranged to the push part enhance the holding in place of the plank, particularly during the feeding step as the plank is initially supported only at the back.
• the friction members could also be realized for example as non-slip metal surfaces.
• each outer chain link 4 of the chain comprises, at the front side of the body part 13 of the flight, a support edge 18 for supporting the side 19 of a timber element against it.
• Lowering the timber element down to the level of the chain minimises the path on which the timber element fed to the conveyor is supported only at the back by the flight 5b which is still mov- ing around the idler before being pressed between two successive flights.
• the distance between the flights 5 and the flexibility of the stop part 15 has been so dimensioned in the apparatus in accordance with the figures that objects with a thickness of 35 - 50mm can be pressed between two successive flights.
• the push and the stop parts of the flight extend to a height of about 100mm from the support edge 18.
• Such dimensioning of the flights enables firm conveyance of timber elements which are up to 250mm wide.
• the apparatus as presented in Fig. Ia, Ib and 2 has been studied in practice and found to provide extremely remarkable advantages in terms of conveying efficiency and reliability compared to the known solu- tions.
• the apparatus has been used for conveying up to 55 planks per minute in long-duration test runs without any malfunctions.

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

Applications Claiming Priority (2)

Publications (1)

Family

ID=37832160

Family Applications (1)

Country Status (2)

Cited By (2)

Citations (3)

• 2007
  • 2007-02-07 FI FI20070114A patent/FI119471B/sv not_active IP Right Cessation
• 2008
  • 2008-02-07 WO PCT/FI2008/050048 patent/WO2008096043A1/en active Application Filing

Patent Citations (3)

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