| 摘要 |
<p>A roller bit cutter comprises:
<UnorderedLists id="ula01" listStyle="none"><ListItem>a) a tough, metallic, generally conical and fracture resistant core having a hollow interior, the core defining an axis,</ListItem><ListItem>b) an annular, metallic, radial bearing layer carried by said core at the interior thereof to support the core for rotation, said bearing layer extending about said axis,</ListItem><ListItem>c) a wear resistant outer metallic layer on the exterior of the core,</ListItem><ListItem>d) metallic teeth integral with the core and protruding outwardly therefrom, at least some of said teeth spaced about said axis,</ListItem><ListItem>e) and an impact and wear resistant layer on each tooth to provide hard cutting edges as the bit cutter is rotated about said axis.</ListItem></UnorderedLists></p> |
