The infeed section of a prior art dry sorter does typically comprise at least one conveyor and e. g. two elevators disposed in pockets, whereby a position orientation in one plane is carried out before the continued feeding into the quality sorting section, the one end edge of the wood being positioned in line. In those prior art dry sorter infeed sections the wood is exposed to substantial damages because the orientation movement of the boards occurs violently, especially when the boards, after a lateral displacement over horizontal conveyors, fall down into the elevator pockets. In order to eliminate the damages to the wood it is known to use so-called"by-pass conveyors", especially in connection with boards of greater dimen- sions, which do in a more delicate way feed this thick- er wood, which does not need sorting in the same way as wood of smaller dimensions, past the elevator pockets.

In contrast thereto, boards of more slender dimensions must pass over the elevators in order to achieve a correct position orientation of the boards, which results in damages.

The object of the present invention is to solve the above-mentioned problem and to provide an elevator, which does not require any elevator pocket involving

risk of damages as explained above. The characteristic features of the invention are set out in the claims.

Thanks to the invention there has been provided an elevator, which can be mounted on-line together with the infeed track and at which the elevator pockets, previously considered necessary, have been eliminated.

An elevator according to the invention can, in response to the dimension of the wood to be processed, be tilted relatively the conveyor by an angle matching that dimension, which makes the handling of the wood much softer. In connection with small dimensions the eleva- tor is raised so that its inclination becomes somewhat steeper, which is necessary for the position orienta- tion of the boards, whereas when thicker dimensions are treated, the inclination angle can be reduced. Accord- ingly, the elevator inclination can be optimized to match each individual wood dimension.

One embodiment of the invention is described below, reference being made to the drawings, in which Fig. 1 is a diagrammatic lateral view showing a con- ventional dry sorter infeed comprising two elevators disposed in elevator pockets, Fig. 2 is a diagrammatic lateral view of a dry sorter infeed comprising one elevator according to the present invention, Fig. 3 does, in a greater scale, illustrate the ele- vator according to the invention shown in Fig.

2 and Fig. 4 illustrates in an end view an S elevator according to the invention.

As appears from Fig. 1, it does show a conventional dry sorter infeed 1 receiving, as seen from the left to the right, incoming wood packages 2 in the shape of boards, which have been dried and are tilted forwards, where- upon they are separated from each other and supplied to a conveyor 3, the stickers between the boards being diverted in the process. The wood is then supplied to a grading section via two elevators 6 and 7 disposed in elevator pockets 4 and 5 and comprising lateral trans- port conveyors 3'and 3".

The basic lay-out of a dry sorter infeed 8 according to the present invention appears from Figs. 2 and 3, the device comprising an S-shaped elevator 9. Boards are diverted from an incoming package 10 and supplied to a conveyor 11 comprising a cross conveyor 12 transporting the boards in the feeding direction straight forwards, and a conveyor 13 supported by a frame work 13'. The device does also include obliquely oriented rollers, not shown in the drawing, which feed the wood forwards and also laterally, so that the one end edge of the wood is brought into line. Further, there is a conveyor 14 movably attached to the frame work 13'for the purpose of feeding wood to the elevator 9. The elevator 9 comprises a conveyor belt 15, which as seen in late- ral view is essentially S-shaped and the straight portion 25 of which can be inclined relatively the horizontal plane by an angle p selected to match the dimension of the wood process. The conveyor 14 which is movably connected to the elevator 9 forms an angle a relatively the horizontal plane to create a smooth transition to the turning end 17 of the elevator 9. The inclination of the elevator 9 is created in the way that it is swingably mounted in a frame 16, the turning end 17 of the elevator 9 being pivotable and vertically swingable. The drive end 18 of the elevator 9 is pivot- ably journaled in the top portion 19 of the frame 16.

Thanks to the movable connection between the conveyor 14 and the frame work 13'and to its swingable connec- tion to the frame 16 at the turning end 17 of the elevator 9, a smooth transition to the elevator 9 can be achieved. In the example shown the inclination angle P has been preset at about 55° and can be varied there- from within an interval of about 10°.

In Fig. 4 there has been shown an end view of the S elevator 9 according to the invention mounted in four units disposed adjacent each other comprising four pairs of transport chains 20, which are pairwise inter- connected by strips or members 21.

The S-shaped conveyor belt 15 forming part of the elevator 9 is constituted by an endless transport chain 20 having members 21 spaced at predetermined distances.

The adjustment of the inclination of the elevator 9 can be performed with the aid of at least one hydraulic cylinder 22 connected to the frame 16 and to the turn- ing end 17 of the elevator. When the hydraulic cylinder 22 is actuated, it lifts the turning end 17, and the opposite drive end 18 of the elevator is simultaneously rotated in its mounting in the frame 16. When the wood has been fed up over the elevator 9, it has been final- ly oriented in position and is then supplied to a subsequent grading section via guide rails 23 and a lateral feeder 24 connected thereto.

The mode of operation of the dry sorter infeed 8 accor- ding to the present invention is as follows. During the feeding of the wood above the infeed 8 the elevator 9 is raised by the hydraulic cylinder 22, if the wood has small dimensions, whereby the inclination angle of the S-shaped conveyor belt 15 is increased. When wood of greater dimensions is processed, the inclination angle of the elevator 9 is reduced. Consequently, when the

present invention is applied, the damages to the wood are reduced thanks to the S elevator 9, the tilting angle of which can be varied within a range of e. g.

10° from a preset value and this in response to the dimensions of the wood processed.