Reaming tools for reaming a borehole and related systems and methods are described herein. In an embodiment, the tool includes a body having a central axis, and a plurality of blades. Each of the plurality of blades includes an uphole section that extends in a first helical direction, a downhole section that extends in a second helical direction that is opposite the first helical direction, and an arcuate central section that continuously extends from the uphole section to the downhole section. The plurality of blades are eccentric about the central axis such that the reaming tool is configured to pass axially through a first diameter and is configured to ream a borehole to a second diameter that is greater than the first diameter when the tool is rotated about the central axis in a cutting direction.

Reaming tools for reaming a borehole and related systems and methods are described herein. In an embodiment, the tool includes a body having a central axis, and a plurality of blades. Each of the plurality of blades includes an uphole section that extends in a first helical direction, a downhole section that extends in a second helical direction that is opposite the first helical direction, and an arcuate central section that continuously extends from the uphole section to the downhole section. The plurality of blades are eccentric about the central axis such that the reaming tool is configured to pass axially through a first diameter and is configured to ream a borehole to a second diameter that is greater than the first diameter when the tool is rotated about the central axis in a cutting direction.

A rotary transfer mechanism is disclosed for a motor, pump, or other downhole tool that accommodates the eccentric motion of a rotor without the need for a flex shaft, articulating joint or CV joint. In one configuration, the rotor is coupled to the drive shaft at a radial offset from the drive shaft axis. The orbiting motion of the rotor, rather than rotation of the rotor about its own axis, generates a torque on the drive shaft, by applying a tangential force to the drive shaft at the location of the radial offset. The radial offset may be set equal to the orbital radius so that no radial movement or flex is required at the drive shaft to accommodate the eccentric rotor movement.

A rotary transfer mechanism is disclosed for a motor, pump, or other downhole tool that accommodates the eccentric motion of a rotor without the need for a flex shaft, articulating joint or CV joint. In one configuration, the rotor is coupled to the drive shaft at a radial offset from the drive shaft axis. The orbiting motion of the rotor, rather than rotation of the rotor about its own axis, generates a torque on the drive shaft, by applying a tangential force to the drive shaft at the location of the radial offset. The radial offset may be set equal to the orbital radius so that no radial movement or flex is required at the drive shaft to accommodate the eccentric rotor movement.

The present disclosure relates to a mining machine adapted for extraction of material from a deposit and a method for controlling operation of such a mining machine. According to an embodiment, the mining machine includes a data handling unit and a control unit. The data handling unit is arranged to receive, from an external storage medium, a data file representative of a user-defined cutting path, and to send, to the control unit, data corresponding to a cutting path selected among the user-defined cutting path and one or more machine-predefined cutting paths. The control unit is configured to control operation of the mining machine using an automatic cutting cycle in accordance with the selected cutting path corresponding to the data received from the data handling unit.

A drill string for rotary drilling of underground mining machines includes a first elongate drill string member and a second elongate drill string member. The first member has a main section and a male end, and the second member has a main section and a female end. The male and female ends each have respective threads to provide a thread coupling between the male and female ends, the thread coupling enabling the male end to be secured inside the female end such that the male and female ends overlap axially. A thread lead of the respective threads of the male and the female ends are greater than a diameter of the male end and the female end.

A drill string for rotary drilling of underground mining machines includes a first elongate drill string member and a second elongate drill string member. The first member has a main section and a male end, and the second member has a main section and a female end. The male and female ends each have respective threads to provide a thread coupling between the male and female ends, the thread coupling enabling the male end to be secured inside the female end such that the male and female ends overlap axially. A thread lead of the respective threads of the male and the female ends are greater than a diameter of the male end and the female end.

A method of mounting a kelly bar on a drilling machine includes a step of installing a mounting tool between the rod of a pull-down cylinder and a rotary carriage of the drilling machine. Once the mounting tool has been installed, the drilling machine can be set up with a kelly bar that is longer than the usual kelly bars.

A method of mounting a kelly bar on a drilling machine includes a step of installing a mounting tool between the rod of a pull-down cylinder and a rotary carriage of the drilling machine. Once the mounting tool has been installed, the drilling machine can be set up with a kelly bar that is longer than the usual kelly bars.

A backhead assembly system for a Down The Hole (DTH) hammer operated by a supply of compressed fluid, that comprises mainly a backhead, said backhead having a central hole capable of transporting the pressurized air to the hammer and an inner cylinder, coaxially disposed and coupled with releasable holding mediums to the backhead, were said backhead has an interior frontal cavity and said releasable holding mediums are in the mentioned frontal cavity. The hammer also comprises a wear sleeve, coaxially disposed to the backhead and inner cylinder, in which the backhead is coupled to the rear side of the wear sleeve. In both embodiments of the present invention, the inner sleeve has a rear section of less diameter and a front side of larger diameter; both sections joined through a portion of generally increasing diameter.