摘要 |
In a preferred embodiment the core drilling rig of the present invention includes a base, a vertically extending mast, a movable carriage mounted on the mast, an electric powered motor for rotatably driving a core drill bit, and a control system for controlling the supply of electric power to the drive motor. The control system includes a motion sensitive device for detecting the unwanted movement of the base and suspending the supply of electric power to the motor.
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