Patent Publication Number: US-4583576-A

Title: Means for feeding a tree trunk

Description:
BACKGROUND OF THE INVENTION 
     The present invention concerns a means for feeding a tree trunk into a machine processing round timber, with centering of the trunk 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 direction in accordance with said processing cutters&#39; center-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 the convex side 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 other. Pairs of wheels have also been used heretofore, the log being turned into correct position by accordingly rotating these wheels. One way is to feed the log through between opposed wheels rotatable about axles 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 through between vertical, spring-loaded roller sets, thus forcing the log at it passes through between the rollers into proper feeding position in view of its crookedness. 
     The problem in the rotating methods mentioned above is, however, undoubtedly the fact that they fail to center the log both in the vertical and in the lateral direction and that the feeding machines have a complex design, being therefore expensive and requiring much maintenance work. 
     DESCRIPTION OF INVENTION 
     The present invention eliminates the drawbacks mentioned, and provides a new type of feeding means which turns a crooked log into the correct position and at the same time centers it vertically and laterally i.e. sidewise. 
    
    
     In the following, the invention is described in detail with reference to the attached drawing. 
     The FIGURE presents, schematically, a means according to the invention, comprising an obtuse V-angled feed gutter 2 and a spring wheel 3, both serving as points of support for a log 1, at least one feed wheel 4, and a carrying wheel 6 opposite the feed wheel. The initial end of the feed gutter 2, as viewed in the feeding direction A of the log, is at a higher elevation than the ultimate end. For the log 1 to be able without impediment to position itself on the feed gutter 2 and the spring wheel 3, a guide cutter 7 is provided before the spring wheel 3 and the feed wheel 4 is in a high enough position to not interfere. The spring wheel 3 and feed wheel 4 are concave shaped to provide a laterally centering effect. 
     When the forward end (as viewed in the feed direction) of a crooked log lies on spring wheel 3 and its rear end lies on feed gutter 2, the crooked log tends, under the effect of gravity, to turn about its longitudinal axis so it lies with its convex side downward. The feed gutter and spring wheel have been provided with spring suspension, so that the longitudinal centreline 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 first bears down on the log, whereby the force which it exerts on the log and the shape of said feed wheel 4 cause the crooked log to turn its convex side downwards. As the feed wheel 4 presses against the log 1, the springs of the feed gutter 2 and spring wheel 3 yield downwardly. The carrying or supporting wheel 6 which is synchronized with the aid of a transmission member such as a rod 8 to operate in conformity with the movements of the feed wheel 4, now ascends, whereby the log 1 is clamped between the supporting wheel 6 and the feed wheel 4 while on the feed line, and the log 1 will be fed into the processing machine. Since the feed wheel 4 and the spring wheel 3 are concave shaped so as to develop a lateral centering effect for the log, the feeding of the log will proceed in correct position as regards the crookedness of the log, and with proper centering in both the lateral and vertical directions.