| 摘要 |
<p>The auger is designed to cut tree stumps, being rotated about a vertical axis by a machine by which it is suspended. It has a body (2), in the shape of an isosceles triangle, with blades (9,10) on a horizontal base, its head providing the coupling (3) by which it is suspended and driven. A central point (4) projects down from the base and beyond the blades, serving as a simple pivot whilst having a flat form like a lance iron. The point may also incorporate symmetrical half spiral fins (6,7) and two blades with horizontal cutting edges. The blades may straddle the pivot axis, may each cover less than half the radius of the swept area, and may cut external and internal circles respectively.</p> |
