Abstract: A self-propelled all terrain drill unit having propulsion means for the chassis, a drilling mast mounted on the latter for movement between horizontal and vertical positions and a drilling head carried by the mast wherein all major functions are performed hydraulically, the hydraulic functions being divided into two groups; those of propelling the vehicle to a drilling site and operating the drill at the site provided by a variable displacement pump and those of adjusting the position of the machine at the site and aligning and positioning the drilling head provided by an independent pump.

Abstract: In a hollow stem auger for earth boring of the kind having spring loaded valve members at the bottom of the stem to permit the passage of test implements such as corers and vane test implements, the auger bit is constructed with a cage formation enclosing the valve member and supporting a bottom ring carrying cutting teeth. Interference of the valve members with a test implement is prevented by using an uncoupleable cylindrical sleeve surrounding the implement which sleeve can be lodged between the valve members to hold them open during use of the implement.