IE56245B1 - Apparatus for feeding a tree trunk - Google Patents

Description

The present invention relates to apparatus for feeding a tree trunk into, for'c;e.xample, a machine for processing round timber, with centering in the lateral and vertical directions.

When feeding a log into round timber processing machines of certain types, e.g. hewing machines, hewing ( saws or butt end trimmers, one has to be able to supply, or feed, the log to the processing cutters, or blades, in a way ensuring that it is centered in lateral and vertical JO direction in accordance with said processing cutters' centre-line (e.g. Finnish patent application No.792067).

In addition, the log must, before it is fed in between the processing cutters or blades, be rotated into proper position in view of its crookedness, for instance with its back downwards. Rotating a crooked log has heretofore been done manually or mechanically with complicated structures in which, for instance, rotation of the log being fed is accomplished with two pairs of chains in which the chains are placed at a V-angle with reference to each ocher. Pairs of wheels have also been used heretofore, the log being turned into correct position A by accordingly rotating these wheels. One way is to feed k the log between opposed wheels rotatable about axles ί which are longitudinal as seen in the direction of the log. turning being accomplished by adjusting the axial lines of the wheels with reference to each other. Furthermore, it has been possible to guide the log between vertical, spring-loaded roller sets, thus forcing the log as It passes between the rollers Into the proper feeding position bearing in mind its crookedness.

The problem in the rotating methods mentioned above is, however, undoubtedly the fact that they fail to centre the log both in the vertical and In the lateral direction and that they have a complex design, being therefore expensive and requiring much maintenance work.

The present invention eliminates the drawbacks mentioned and provides a new type of feeding means which turns a crooked log into correct position and at the same time centres it vertically and laterally.

According to the present Invention there ls provided apparatus for laterally and vertically centering a tree trunk to be fed Into a machine for processing round timber, comprising a feed gutter and a spring wheel both serving as supports for a tree trunk, and at least one feed wheel arranged to engage and apply pressure to the tree trunk between said supports, a carrying wheel being arranged to engage the tree trunk on the opposite side of the tree trunk from said at least one feed wheel.

Preferably the carrying wheel and the said feed wheel on the opposite side of the tree trunk thereto have shaped peripheries to thus laterally grip and centre the tree trunk. This shaping is preferably in the form cf an annular circumferential groove in the respective peripheries .

The present invention will now be further described, by way of example, with reference to the accompanying drawing, in which one embodiment of the present invention is schematically illustrated.

The accompanying drawing schematically illustrates apparatus comprising a feed gutter 2 and a spring wheel » 3, both serving as points of support for a log, together with a feed wheel 4, and a carrying wheel 6 opposed to the latter. The feed wheel 4 has an annular groove extending around its periphery which enables the feed wheel 4 to engage and grip a log. A further feed wheel is provided and rod 8 interconnects pivotal supports for the feed wheel 4 and the carrying wheel 6, to cause the carrying wheel 6 and feed wheel 4 to operate together, i.e. when pivoted they both move either towards or away from a log positioned therebetween. The input end of the feed gutter 2, as viewed in the feeding direction A of a log, is at a higher elevation than the discharge end, and to enable a log to position itself, without hindrance, on the support provided by the feed gutter 2 and the spring wheel 3, the feed wheel 4 is initially located in a high enough position to prevent obstruction. * On positioning a log with its forward end (as viewed in the feeding direction) laying on the spring wheel 3 · and its rear end on the feed gutter 2, a crooked log will tend under gravity to turn about its longitudinal axis to lie with its back pointing downwards. The feed gutter 2 and spring wheel 3 are 'provided with spring suspension so that the longitudinal centre-line B of the log will lie above the feed line C. With the log 1 resting on the feed gutter 2 and the spring wheel 3, the feed wheel 4 is first moved down to bear on the log, whereby the force which it exerts on the log and the peripheral shaping of said wheel, causes the crooked log 1 to positively turn so that its back points downwards. As the feed wheel 4 presses against the log 1, the spring suspension of the feed gutter 2 and spring wheel 3, yield downwards. The supporting wheel 6, synchronized to operate in conformity with the movements of the feed wheel 4, will ascend, to thus clamp the log 1 between the supporting wheel 6 and the feed wheel 4 while on the feed line C. In this position the log 1 will be fed into a processing machine (not shown). Since the feed wheel 4 and the supporting wheel are shaped, i.e. they each have a circumferential groove in their periphery, they develop a lateral centering effect on the log, so that the log will be fed in the correct position as regards the crookedness of the log, with proper centering in the lateral and vertical directions.

Prior to operation, the feed wheel 4 and supporting wheel 6 are moved apart to allow a log to be rested on the feed gutter 2 and spring wheel 3; a guide gutter 7 arranged adjacent to spring wheel 3 aiding the guiding a of the log. In position, feed wheel 4 and supporting wheel 6 move together to engage opposite sides of the log, movement of the feed wheel 4 and supporting wheel 6 being triggered by an actuation pulse, provided, for example, by a photocell (not shown).

Claims (5)

1. Apparatus for laterally and vertically centering a tree trunk to be fed Into a machine for processing round timber, comprising a feed gutter and a $ spring wheel both serving as supports for a tree trunk, and at least one feed wheel arranged to engage and apply pressure to the tree trunk between said supports, a carrying wheel being arranged to engage the tree trunk on the opposite side of the tree trunk from said 10 at least one feed wheel.

2. Apparatus as claimed in claim 1, in which the feed gutter and spring wheel are provided with spring suspension.

3. Apparatus as claimed in claim 1 or claim 2, In 15 which the carrying wheel Is synchronised by means of a transmission member, to operate in conformity with the movements of the opposed feed wheel.

4. Apparatus as claimed in any one of claims 1 to 3, comprising a plurality of feed wheels, the foremost 20 feed wheel as viewed in the tree trunk feeding direction receiving an actuation pulse by means of a photocell. 5. Apparatus as claimed in any one of claims 1 to 4 ? further comprising a guide gutter located after 25 the carrying wheel In the direction of feed. 6. Apparatus as claimed in any one of claims 1 fo 5, in which the peripheries of the carrying wheel and of the feed wheel on the opposite side of the tree trunk thereto, have been shaped to exert a lateral

5. Centering effect on a tree trunk gripped therebetween* 7o Apparatus as claimed in claim 6« in which the feed and carrying wheels are shaped, by an annular circumferential groove being formed in their respective peripheral surfaces . θ 8. Apparatus for laterally and vertically centering a free trunk to be fed into a machine for processing round timber, constructed and arranged substantially as hereinbefore described with reference to and as illustrated in the accompanying drawing.