Method to split logs into quarters and machine for its implementation

#The present invention relates to a method of splitting a log with its medullar rays so as to produce quarters that can be converted into thin-cut sections or planks through being split along the wood grain and with its medullar rays. It especially relates to such a splitting method in which the log is held by jaws that can pivot at both its ends, thus getting the axis of its core, i.e. its longitudinal gravity axis, into a horizontal position, and is then split into four, eight or twelve quarters under the action of two opposite pairs of splitting tools that can rotate when undergoing the thrust of control cylinders, whereby one pair of tools lies in a nearly vertical plane and acts upon one end of the log for its initial splitting into four, the other pair lying in a nearly horizontal plane and acting upon the other end of the log, the splitting of the latter into eight or twelve quarters being achieved through giving the plane of this pair of tools a chosen inclination, the pairs of tools being always adjusted perpendicularly to one another.

#Besides, the present invention concerns a machine of splitting logs, with the medullar rays of each log in order to produce quarters that can be converted into thin-cut sections while following the wood grain of the log and without breaking or cutting its fibers.

#It should be especially noted that this splitting method and this splitting machine are designed, according to the invention, to produce quarters that can be converted into thin-cut sections along the wood grain by using the splitting method and the machine its implementation for which the U.S. Pat. No. 5,090,463 has been accorded.

#Further characteristics of the present invention will be provided through the following description of one possible realization of a machine splitting logs into wood quarters, the machine being represented, as an example and in a very schematic way, in the attached drawings where:

#FIG. 1 is a schematic front view of the splitting machine according to the invention;

#FIG. 2 is a cutaway view along line 2--2 of FIG. 1 in the direction of the arrow heads;

#As shown in FIG. 1, the splitting machine comprises a rigid support chassis (1) bearing sliding frames (2, 3) at its extremities, the alternate moving being controlled respectively by control cylinders (4, 5) represented with dotted lines. Each sliding frame bears a set of two jaws, one set (6) in a horizontal position on the frame (2) and one set (7) in a vertical position on the frame (3). A central support identified by the numeral (8) is mounted on frame (2) and (9) a central support frame (3). The set of jaws (6), borne by the frame (2), is mounted in to be able to reciprocate in a horizontal plane whereas the opposite set (7), borne by the frame (3), is mounted to be able to reciprocate in a vertical plane. The frame (2) also bears a set (10) of two splitting tools adapted to be able to rotate individually during their splitting travel and the cutting edges (10a, 10b) which are maintained, when at rest, in the same vertical plane by means of a guiding cam (11), along with the two respective driving control cylinders (12) of the set (10) of tools that are set in the same vertical plane for the splitting of a log (B) into four quarters (see FIG. 2). The frame (3) also bears a set (13) of two splitting tools adapted to be able to rotate individually during their splitting travel and the cutting edges (13a, 13b) which are maintained, when at rest, in the same horizontal plane by means of a guiding cam (14), along with the two respective driving control cylinders (15) of the set (13) of tools that are set in the same horizontal plane for the splitting of the log (B) into four quarters.

#It should be noted that the two splitting tools of each set (10,13) are separated from one another on either side of the respective central support (8, 9), as is better shown in FIGS. 2 and 3, in order to be able to cross the two opposite splitting tools in the course of a splitting operation, during the splitting travel on the one hand, and during the return course to their rest position on the other hand, even if each of these four tools can rotate independently from the others, thus deviating from its initial cutting plan so as to split the wood with its medullar rays.

#Moreover, it is to be noted that each set of two jaws is mounted on the corresponding central support (8,9) through a parallelogram-like mounting that is identical for each frame but set in a horizontal position on the frame (2) and in a vertical position on the frame (3). Each mounting is made up of two bars (16, 17) pivoted on the associated central support at the middle and upon the extremities of which long bars (18, 19) are respectively hinged, long bars (18, 19) respectively bearing one of the two jaws of the corresponding set (6, 7), the jaw being hinged upon that free extremity of the bar near the log (B), each jaw being however held, when at rest, perpendicularly to its bar by means of springs (20). In order to prevent the bars (16, 17) that make up two sides of the parallelogram-like mounting from being too much inclined when leaning against the corresponding cut end face of the log (B), a triangular stop motion device (21) has been mounted on the corresponding central support, a device on which the extremities of the back bar (16) can rest.