A continuous feed system for a drill comprising a down-hole drill assembly having a support end and a drilling bit. Rotation is imported to the down-hole drill assembly between the support end and the drilling bit, which results in a torque being applied to the support end. A vertically disposed support chain has two ends, one end of the chain is connected to the support end. The chain resists the torque with limited torsional flexibility. A drive interacts with the chain at a point between the two ends for positively providing axial extension of a length of the chain.

A mounting apparatus for a rotational drive unit. The rotational drive unit includes a socket portion which receives a truck or carrier. Opposing engagement surfaces of the carrier are separated by a distance greater than the length of the socket. The resulting lost motion connection allows for a range of free movement of the rotational head on the carrier.

This invention relates to a mobile drilling rig used for deep wells. The mast structure can be made considerably lighter than previously by translation of the drilling string lifting pressure against the bottom of the mast rather than being supported by the mast itself. A hydraulic cylinder extending upwardly within the raised mast bears against the bottom of the mast, and has a pulley at its top over which a lifting chain passes. One end of the chain is linked to the bottom of the mast, the other to the top drive. As the cylinder extends, the top drive rises, lifting the drilling string, but with virtually the entire lifting force against the bottom of the mast.

Sample gathering apparatus for drivably moving a core sampling assembly into and out of subterranean zones for gathering core samples therewithin, with the apparatus including an elongated frame means which is adapted for adjustable pivotal mounting upon a supporting vehicle. Drive means are provided for delivering power to the core sampling assembly, and coupling means are further provided for releasably securing the drive means to the core sampling assembly. The core sampling assembly is arranged to be driven vertically into the subterranean zones to be sampled, and the coupling means which releasably secures the drive means to the core sampling assembly permits pivotal motion of the core sampling assembly about a generally horizontal axis so as to permit pivotal lifting of the core sampling assembly from the ground surface for easy removal of the sample retained therewithin.

An anvil is formed on one end of an elongated piece and the piece is driven into the ground or the like by impacting the anvil with a reciprocable ram driven by a drive mechanism that is operated by a valve which is reciprocably mounted in a normally balanced two directional fluid pressure circuit to reciprocate in the alternate directions thereof when the circuit is unbalanced in the respective directions thereof. The circuit has a pair of outlets therein which are connected with the opposing ends of the valve and disposed to slidably engage with the ram during the stroke thereof. The ram comprises an anvil impacting body having a striking surface on one end thereof and a pair of grooves in one laterally oriented face thereof which are mutually offset longitudinally the the reciprocable axis of the body on spaced parallel lines to form collateral mutually longitudinally offset lands on the lines. The grooves are adapted in axial extent, respectively, to discharge fluid from one of the outlets while the corresponding land covers the other outlet, and vice versa, to generate opposing fluid pressure differentials in the circuit across the valve and thereby unbalance the circuit in the respective directions thereof, when the body is reciprocably supported and guided in the apparatus and driven by the mechanism so that the lines of the grooves and lands intersect the outlets.