| 摘要 |
PROBLEM TO BE SOLVED: To efficiently crush a waste gypsum plaster board generated when a house or the like is demolished, and to recycle the waste gypsum plaster board as resources. SOLUTION: This cutter drum has cutters 53 fitted to a rotary shaft 51 alternately with spacers 52 so as to interpose each of the spacers 52 between the corresponding adjacent two of the cutters 53, wherein each of the cutters 53 is provided with: a through-hole 55 which is formed at the center of the cutter 53 and used for passing the rotary shaft 51 through; and plural blades 57 which are formed at the outer periphery of the cutter 53 at equal pitches while interposing each of pockets 56 between the corresponding adjacent two of the blades 57 and each of which has a circular-arc- shaped back face 57A, a face 57B intersecting the back face 57A at its end in its rotational direction, a tip 58 that is fixed to the face 57B and made of a cemented carbide or the like, a main cutting edge 59 that is formed at the front end edge of the tip 58 and has a prescribed cutting edge inclination, and an acute-angled minor cutting edge 62 formed at the side edge of the back face 57A along its longitudinal direction. Thus, by using such main cutting edges 59 and minor cutting edges 62, a waste gypsum plaster board can finely be crushed while longitudinally and latitudinally cutting the board. |
