Abstract: A rotary blasthole drilling apparatus comprises a rotary blasthole drill and a drill automation control system. The apparatus includes a pull-down motor and a drill motor. The pull-down motor is driven by a pump to provide a pull-down force to a drill string, and the drill motor is used to provide rotary force to rotate a drill bit of the drill string. The drill automation control system includes a number of functional components including a user interface. Through the user interface, an operator sets a rotary torque set point that determines an amount of torque applied to the drill bit by the drill motor. The control system further includes a detector, for detecting pressure in the pump during a drilling operation, and a processor, which is operative under the control of a program stored therein and responsive to the rotary torque set point and signals from the pull-down pressure sensor for generating an error signal.

Abstract: A reverse percussion device for use with hydraulic percussive drills is provided. The reverse percussion device includes a cycling piston, valve and anvil. The piston and valve move in opposing directions between low and high pressure passages automatically until a lodged drill bit is freed, thereby facilitating removal of the drill bit from the drilled hole and eliminating alternate loosening and tightening of drill string threads. The reverse percussion device preferably includes an automatic disabling feature which causes the reverse percussion operation to cease when the bit is free to retract normally.

Abstract: In an impact drilling apparatus, an impact hammer is provided that includes a body portion and a piston head on the body portion. The piston head has a larger outer periphery than the body portion. The body portion and the piston head have substantially the same cross-sectional area at all points along a longitudinal axis of the hammer. The piston head is disposed at one end of the body portion and is funnel-shaped.

Abstract: A rotary blasthole drilling apparatus comprises a rotary blasthole drill and a drill automation control system. The apparatus includes a pull-down motor and a drill motor. The pull-down motor is driven by a pump to provide a pull-down force to a drill string, and the drill motor is used to provide rotary force to rotate a drill bit of the drill string. The drill automation control system includes a number of functional components including a user interface. Through the user interface, an operator sets a rotary torque set point that determines an amount of torque applied to the drill bit by the drill motor. The control system further includes a detector, for detecting pressure in the pump during a drilling operation, and a processor, which is operative under the control of a program stored therein and responsive to the rotary torque set point and signals from the pull-down pressure sensor for generating an error signal.

Abstract: A digging tooth including a body portion and a plurality of hard water resistant conical inserts. The body portion includes a generally planar distal portion, a medial portion, and a bifurcated proximal portion having at least two prongs separated from each other to form a slot. The conical inserts are secured to and spaced along said distal portion and have a generally cylindrical body portion and a top portion which tapers to a point to form a tip, wherein the ratio of the diameter of the cylindrical body portion to the spacing distance between the tips of the conical inserts is between 0.50 and 0.80 and, preferably, 0.72.

Abstract: A Pneumatic impact drilling tool, particularly useful as a downhole pneumatic drill, includes a housing structure adapted to be connected to a string of drill pipe and supplied with compressed air therethrough. A hammer piston reciprocates in the housing structure along flexible feed and exhaust tubes. Compressed air is directed alternately to the upper and lower ends of the hammer to effect its reciprocation in the housing. The hammer is operable to strike an anvil bit member repeatedly to effect a drilling motion. At the upper end of the housing there is provided a removable annular plug member surrounding the tubular support in which the feeder tube is positioned. The annular plug member defines the volume of the space above the hammer piston and is related to the size of the feeder tube so that the feeder tube and plug member together determine the volume of air utilized at any selected air pressure and the timing of operation of the hammer position.