| 摘要 |
<p>An excavating tool arrangement including a bit having a cylindrical shank received in a correspondingly shaped hole in a support block with the forward end of the bit protruding forwardly from the block and being substantially rectangular when viewed from above and greater in width from side to side than in heighth from top to bottom. The bit is keyed to the block in a predetermined oriented position and the leading edge of the working end of the block may be chisel shaped or may be provided with hard wear resistant inserts mounted therein. The described bit may be employed alone for excavating operations or it may be employed in combination with other bits which are symmetrical about a longitudinal axis and terminate in points and which are mounted in blocks that may be identical with the blocks supporting the first mentioned excavating bit.</p> |
