The invention relates to a method for conveying logs away from a butt end reducer, in which the log is moved away from the butt end reducer by an expulsion device subsequent to the reducing phase. Furthermore, the invention relates to machinery formed in accordance with the method, comprising an expulsion device which is joined to a butt end reducer.

The butt log, which is closest to the tree base, cut from the log of a tree body is processed in a butt end reducer, so that it can be made to be of the same thickness as the other logs cut from the same tree body using a suitable method. Thus, reducing comprises an additional phase, by which the result of wood production is made better.

The thicker end of the butt log is cut in the butt reducing process in accordance with the other part. Generally, the log is moved to the butt end reducer using a conveyor belt, for example, and/or some other type of transfer device. The butt end reducer is most commonly comprised from a milling machine and a V-shaped support structure, to which the log is fastened and/or in which the log is moved during reducing. In the butt end reducer, the log is cut narrower in the bulging base area until it has the same thickness in that area as it has elsewhere. After butt reducing, the log is moved to the next phase using a special expulsion device. The expulsion device, in most cases, is currently a transfer element which moves back and forth, which is at rest beside the log during machining. Thus, it moves the log away from the butt end reducer to the next phase.

Recently, milling production lines have become faster. For this reason, current butt end reducers are not able to move the log butt being machined in the production line away fast enough, instead, it has been necessary to build separate conveyor lines for butt end reducers through which the logs are lead. Thus, a butt end reducer requires that the sawmill make large investments in extra equipment.

The removal of the log from the butt end reducer is a process which takes up relatively much time. This is because with current expulsion devices, it is necessary to wait until the transfer element returns to its original position before the next log can be moved to the butt reducing device. This problem cannot be solved by increasing the speed of the expulsion device, because movements faster than those

presently being used would cause damage to the logs and significantly shorten the service life of the machinery and its structure.

The object of the invention is to provide a method and machinery by which the capacity of the butt end reducer will be increased. The object of the invention is also to provide a method and machinery whereby the log is transferred away from the butt end reducer in an even and calm movement.

The object of the invention is accomplished by a method and machinery, the characteristics of which are presented in the claims.

A characteristic of a method formed in accordance with the invention, is that the next log is conveyed to the reducing station and that log reducing begins while the expulsion device is moving, and that the part of the expulsion device which moves the log goes to the other side of the expulsion device along a path which does not interfere with the conveyance of the next log to the reducing station, or with beginning the reducing of the next butt log. Since the conveyance of the next butt log to the reducing station occurs at the same time that the previous butt log is being moved away, the following log does not have to wait for the expulsion device to return to its original position, rather, the next log can be conveyed to the reducing station immediately, and reducing can begin when the preceding log has been moved away from the butt end reducer. This essentially increases the processing speed of the logs at the reducing station.

In an advantageous application of a method formed in accordance with the invention, the part of the expulsion device which moves the log is rotated during its conveying and resetting movements. By rotating the part which moves the log, a forward and backward motion of the log-moving part is avoided, whereupon the conveyance of the next log to the butt end reducer and the moving of the preceding log away from the butt end reducer can occur simultaneously. The method is simple and functional.

A characteristic of a machinery formed in accordance with the invention is that the part of the expulsion device which moves the log does not have a back motion and it is designed to go to the other side of the expulsion device along a path which does not interfere with the conveyance of the next log into the butt end reducer. The intention behind saying that it"does not have a back motion"is to say that there is no part which moves back and forth. Since the part which moves the log does not have a back motion, the next log can be conveyed to the butt end reducer, according

to a method formed in accordance with the invention, without having to wait for the preceding log to be moved away.

In an advantageous application of machinery formed in accordance with the invention, the expulsion device comprises a rotating device for rotating the part which moves the log during the conveying movement and resetting movement.

With the rotating device, the part which conveys the log must only move in one direction without back motions which cause waiting time. The device is simple, advantageous and reliable.

In a second advantageous application of machinery formed in accordance with the invention, the expulsion device comprises a single or multi-crenellated claw feeder.

The claw feeder is a simple and advantageous expulsion device application which does not have a back motion, which is suitable for a butt end reducer.

In a third advantageous application of machinery formed in accordance with the invention, the expulsion device, which does not have a back motion, comprises a continuous chain or belt which has one or more parts which move logs. With the expulsion device, formed from the continuous chain or belt and parts which move the logs, the desired length of the movement distance can be selected, whereupon a log can be moved from the butt end reducer with one transfer device directly to the next phase.

The invention will now be described in more detail with reference to the accompanying drawings, in which Figure 1 illustrates a front view of a certain butt reducing station formed in accordance with the invention, which comprises an expulsion device, which is based on a claw feeder, for moving the log away from the butt end reducer, Figure 2 illustrates a side view of a butt reducing station formed in accordance with Figure 1, Figure 3 illustrates an overhead view of a butt reducing station formed in accordance with Figures 1 and 2, Figure 4 illustrates a perspective view of a butt end reducer which comprises a butt reducing station formed in accordance with Figures 1-3, and Figure 5 illustrates a sideways view of another certain butt end reducer which comprises a butt reducing station formed in accordance with the invention, which includes a transfer device based on an attachment chain system.

The butt reducing station illustrated in Figures 1-3 comprises a butt end reducer as illustrated in Figure 4, which includes an expulsion device 1 which functions on a claw feeder principle, in accordance with the method in accordance with the invention. It is fastened, in a way known as such, so that it is rotatable, to the frame of the operating butt end reducer 2. The butt end reducer illustrated in Figure 4 comprises a claw feeder 1 functioning as an expulsion device, which comprises log- moving parts, or tines la, the driving axle 18 of the claw feeder and the driving apparatus 19 connected to it, the frame 2 and the outwardly opening V-shaped support structure 2a formed from it, the toothed gears 4 and 4a for rolling the logs, the control device for the gears 5, the cutters 6 elevated to the height of the toothed gears 4 at the butt end, the driving motor for the toothed gears 7, transmission equipment 8, the supporter for an outgoing log 9 and frame bars 10 to connect the butt end reducer to other structures of the production line. Furthermore, in Figures 2 and 3, a dotted line shows the outline of the placement of a log 3 in the butt end reducer, the size of which can vary, as determined by the support structure.

Figure 5 illustrates another certain expulsion device 11 belonging to a butt end reducer formed in accordance with the invention, which is joined in place of the claw feeder 1 of a butt end reducer device formed in accordance with Figure 1. The expulsion device 11 illustrated in Figure 5 comprises two chain pulleys 14 and 15 set at a diagonal angle parallel to the logs'direction of movement, and by which is formed a circulating chain 16. The chain pulleys are fastened longitudinally and positioned to the adjustable frame, whereupon a suitable tightness and the best possible positioning can be adjusted for the chains. Three rakes 11 a serving as log- moving parts are fastened to the chain with aligned implements. The chain and the rakes circulate diagonally upwards on the right side of the V-shaped support structure 17. The other parts of a butt end reducer formed according to Figure 5 are the same as those in the butt end reducer which comprises the butt reducing station which is in accordance with Figure 1.

The operation of the butt reducing station illustrated in Figures 1-4 includes the following phases: 1. The log being cut 3 is conveyed to the butt reducing station by the preceding conveyor onto the V-shaped support structure 2a.

2. The toothed gears 4 and 4a begin to roll the log 3.

3. The cutters 6 are activated and raised against the log 3.

4. The butt end is cut until the log 3 along the length of the cutters 6 is the same thickness as the rest of the log.

5. After the cutting, the claw feeder 1 rotates, whereupon the log 3 is conveyed over the support structure of the claw la which is pushing it to the supporter 9.

6. As soon as the log 3 has been moved the necessary distance forward, the next log is conveyed between the two V-shaped support structures 2a.

7. Cutting is immediately begun on the new butt end which has been placed between the V-shaped support structures 2a.

A butt end reducer formed according to Figure 5 otherwise works in a corresponding way, except that the log is moved away from the reducer with an attachment chain 11, whereupon the parts which move the log are rakes 11 la. Claw feeders 1 or an attachment chain 11 can run continuously or in jerking movements, depending upon the speed and operation of the other functions of the butt end reducer.

In a method formed according to the invention, expulsion devices other than those which do not have a back motion, illustrated in Figures 1-4 and 5 can also be used.

In this context, a more detailed definition of an expulsion device which does not have a back motion is an expulsion device in which the log-moving part rotates underneath the support structures and back to the other side of the log. Thus, it is not necessary to wait for the log-moving parts to return to their starting position before the next log is conveyed to the butt end reducer. In a method formed according to the invention, an expulsion device which does not have a back motion can however also be comprised of a transfer device which moves back and forth. In this case, the back motion must be such that it does not prevent the next log from being conveyed to the butt end reducer as soon as the preceding log is moved away.

The parts which move the log can, for example, be rotated to the side in the direction of the log's movement and, for example, rotated back up by the springback factor. In this case, the back motion can occur even though the next log has already been conveyed to the butt end reducer.

A method according to the invention can be adapted to any presently known butt reducing device or a butt end reducer similar to presently known butt end reducers.

The butt reducing station and the butt end reducer which comprises it can function in all of the conventional ways. A log can be rolled and the cutters hold it in place, or the cutters can move around the log. The log can be moved directly to the next

work phase, or, for example, to some intermediate landing, with the expulsion device.

The structure of the expulsion device and its log-moving part can vary in different applications. The log-moving part can be a support different from the tines or rakes used in the above-mentioned applications.

The invention is not limited to the presented advantageous applications. It can vary within the frames of the inventive idea formed in the claims.