| 摘要 |
<p>The forwardly and outwardly inclined marginal edge of a conventional "cupped" ditcher chain tooth is provided with an elongated longitudinally extending shallow notch including front and rear ends spaced generally one-third the length of the tooth outer marginal edge from the front and rear ends of the tooth. The notch is of a length slightly less than one-third the length of the tooth outer marginal edge and the depth of the notch is between one-quarter and one-third the length of the notch.</p> |
