| 摘要 |
A trenching tool which includes a lower portion having a blade and a guide tube. The guide or alignment tube is vertically positioned on one edge of the blade. An impact rod slips into the alignment tube and is repeatedly forced, by the operator, to impact the top of the blade, thereby driving the blade into the ground. Through a rocking motion, the channel formed by the blade is widened and the blade is again forced into the ground until the desired depth is obtained. The assembly is then removed and repositioned to extend the channel through the same procedure. The blade has either a rectangular cross section or a triangular cross section permitting the channel to be sloped automatically while the blade is being driven into the soil. A handle, preferably having shock absorption capabilities, allows the operator to slide the impact rod to obtain the driving force. A flexible harness keeps the impact rod from being withdrawn from the alignment tube; and, a pair of handles located on the alignment tube are used to reposition the assembly. In one embodiment of the invention, a plate at the top of the blade prevents the blade from being driven too deeply into the soil; another embodiment allows the plate to be positioned along the face of the blade to provide a depth limiting gauge.
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