1results about How to "Increased drilling depth" patented technology

This application provides a coal mine gas extraction device, relating to the field of gas extraction technology. It includes a mounting frame, a mounting plate, a drill rod, an extension rod, a lifting assembly, and a rotating assembly. The lifting assembly is mounted on the mounting frame and is used to move the mounting plate up and down. The extension rod is rotatably mounted on the mounting plate via bearings. The rotating assembly is mounted on the mounting plate and is used to rotate the extension rod. The drill rod is slidably sleeved on the extension rod. A first locking assembly is provided between the top of the extension rod and the drill rod, and a second locking assembly is provided between the bottom of the extension rod and the drill rod. The interiors of both the drill rod and the extension rod are hollow, and a through hole is provided at the bottom of the drill rod. By using hollow extension rods and drill rods, and inserting extraction pipes into the extension rods and drill rods, friction between the extraction pipes and the borehole wall is prevented.