CRACKING STOPPING AND CORE DRAWING APPARATUS FOR LONG- SIZED TIMBER

摘要

PROBLEM TO BE SOLVED: To longitudinally place an apparatus and to alternately rotate a timber and a drill in a reverse direction so that a strong centripetal force is operated to draw a core, since the mark of a twig exists as a node at the core of the timber and there is the deviation of an annual ring.;SOLUTION: In this apparatus, the timber 3 and the drill 6 are assembled to be longitudinally placed so as not to bring about a distortion, and both are reversely rotated as shown by arrows in Fig. to perforate.;COPYRIGHT: (C)2003,JPO