| 摘要 |
A tool for excavating material from the bottom of a hole formed in the earth has a rotatable crankshaft adjacent one end of which is a hollow housing open at one end and coupled to the crankshaft for rotation therewith about a vertical axis and for rocking movements relative to the crank about a horizontal axis. The housing has a bottom wall and upstanding side walls for supporting loose material excavated from the hole in response to rotation of the crankshaft and the housing within the hole. The pivotal coupling of the housing to the crankshaft is such that gravity biases the housing to a position in which the contents of the housing are restrained from passing through the open end as the crankshaft and the housing are withdrawn from the hole.
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