Method of cutting a wood block and veneer lathe

摘要

A method of cutting a wood block and a veneer lathe are disclosed. Two groups of first plural contact members and second plural contact members disposed around the wood block for supporting the wood block from the periphery thereof and each having a contact portion contactable with periphery of the wood block. The first and the second contact members are spaced away from each other along the spin axis of the wood block so as to form a space between any two adjacent contact members, respectively, and arranged in such a way that a part of the contact member of one group is insertable into the space between any two adjacent contact members of the other group when the wood block is cut to a predetermined reduced diameter so that the wood block is continued to be supported further.

主权项

1. A veneer lathe comprising:
a pair of rotatable spindles for holding therebetween a generally cylindrical wood block at the opposite ends thereof; a spindle drive mechanism for driving at least one of the spindles thereby to rotate the wood block on spin axis thereof; a movable knife carriage having a veneer knife with a cutting edge engageable with the wood block so as to cut thereinto and a wood block drive mechanism disposed adjacently to the cutting edge for driving the wood block from the periphery thereof; a knife carriage drive mechanism for moving the knife carriage toward the spin axis of the wood block; a first group of a plurality of movable first contact members axially spaced away from each other parallel to the spin axis of the wood block held between the spindles so as to form at least one first space between adjacent first contact members and each first contact member having a contact portion contactable with the periphery of the wood block; a second group of a plurality of movable second contact members axially spaced away from each other parallel to the spin axis of the wood block held between the spindles so as to form at least one second space between adjacent second contact members and each second contact member having a contact portion contactable with the periphery of the wood block, the contact members of the first and the second groups being spaced and arranged in such a way that at least a part of at least one of the first contact members enters into the at least one second space when the first group of contact members and the second group of contact members are moved close together; a first drive mechanism for moving the contact members of the first group; a second drive mechanism for moving the contact members of the second group; a first detecting mechanism for determining current radius of the wood block being cut; a second detecting mechanism for determining time required for the wood block to make a complete revolution; and a control unit operable to control the operation of the knife carriage drive mechanism so that knife carriage is moved for a predetermined distance toward the spin axis of the wood block in the time determined by the second detecting mechanism and also to control the operation of the first drive mechanism and the second drive mechanism so that the contact members of the first and the second groups are moved toward the spin axis of the wood block with the contact portions thereof kept lying on an imaginary spiral curve that extends from the cutting edge of the veneer knife in the direction in which the wood block is rotated for a distance corresponding to a substantially complete revolution of the wood block as seen in transverse section of the wood block, said imaginary spiral curve being a part of an imaginary Archimedean spiral which is determined by said predetermined distance moved by the knife carriage and represents a path of the cutting edge of the veneer knife as seen in transverse section of the wood block during wood block cutting.