Abstract: A mining machine (4) has a vertically movable jib (6) mounted in front of it and carrying a drum shaped drilling head (12) at its forward end. The drilling head is provided with radially projecting picks which rip coal out of a coal seam (1) located between an underburden (3) and an overburden (2). A forwardly-facing directional microphone (16) is mounted on the forward end of the machine (4) between the lines M where it can monitor the resonant frequencies of the picks. Electrical circuitry mounted on the machine controls the position of the jib (6) in accordance with the relative amplitudes of a unique set of natural resonant frequencies produced by the picks during mining.

Abstract: An apparatus for determining thickness of a wall or coal seam includes a ice for measuring the time of sound travel through the thickness; a flexible isolation bellows that mechanically supports the device for measuring the time of sound travel; and a retractable isolation arm attached to the isolation bellows. The device for measuring the time of sound travel may be a single-beam pulse sonar system. The single-beam pulse sonar system includes a pulse generator, a power amplifier, a transmit/receive switch, a reciprocal acoustic transducer, a receiver for determining the thickness, and a display and/or an electronic feedback circuit for steering an autonomous miner.

Abstract: A tungsten carbide tip for a cutting tool has a tapered body with a forward cutting end and a rearward base for mounting in a socket. The body has a plurality of grooves along the length thereof, which in one embodiment extend from the lower surface of the base to a point near the forward cutting end. In a second embodiment, the insert has a cylindrical inner body with a forward cutting end, and around the perimeter of the cylindrical body is a collar. Both the body and the collar are made of tungsten carbide, and the parts are bonded together by flexible material such as brazing material. The rearward surface of the base of such inserts may also be conically shaped complementary to a conically shaped lower surface of the socket into which the insert is fitted.

Abstract: Tungsten carbide inserts which are the cutting tips of a rotating excavating tool have a forwardmost cutting end and an intermediate cutting surface which are formed of tungsten carbide alloys having different degrees of hardness. In a preferred embodiment of the invention, the center of each insert is formed of a harder tungsten carbide material than is the outer cutting portion located rearwardly of the harder center portion. In another embodiment of the invention, the intermediate cutting section comprises a plurality of longitudinally extending buttresses which break up the material being excavated as the insert penetrates the material.

Abstract: A downhole telemetry system is described for optically communicating to the surface operating parameters of a drill bit during ongoing drilling operations. The downhole telemetry system includes sensors mounted with a drill bit for monitoring at least one operating parameter of the drill bit and generating a signal representative thereof. The downhole telemetry system includes means for transforming and optically communicating the signal to the surface as well as means at the surface for producing a visual display of the optically communicated operating parameters of the drill bit.

Abstract: The present invention discloses a system and a method for transmitting data in a shield machine and for calculating the filling amount of a void by detecting the distance to the natural ground. The system and the method are capable of transmitting analogue signals or signals of relatively high frequencies with reliability, enabling an unskilled operator to accurately detect buried articles and accurately carry out the back-filling work. Therefore, an optical rotary joint (100) is disposed between a rotary cutter head (10) and a non-rotary shield body (2) to count time taken to detect the peak value of a reflected signal larger than a standard value or time taken to detect the zero cross position present prior to the peak value. In accordance with the counted time, the distance between the antenna and the natural ground is calculated and displayed. Then, the void volume is calculated in accordance with the distance so that a target value of the back-filling amount is set.

Abstract: A system for supporting the drive of an excavating type underground advancing machine is provided to lighten the operator's burden so that an unskilled operator can perform operation comparable to that of the skilled operator. In this system for supporting the drive, output signals from a group of first sensors (12a) for measuring magnitude of operation of a rocking actuator (10) for orientation control and an output signal from a second sensor (12b) for measuring cutter torque pressure are input into an automatic measurement portion (14). These signals are adjusted in an automatic adjustment portion (15) and input to a fuzzy control portion. The rocking magnitude of an excavating cutter is calculated in a rocking magnitude control aiding system portion (16a) in response to the adjusted signal from the group of the first sensors.

Abstract: An impact ripper (2) mounted on the rear portion of a construction machine, such as a bulldozer (1), for digging a hard soil layer is automatically controlled to reduce the operator's fatigue, to improve operability with regard to the posture of the impact ripper during operation of its vibrating mechanism (3), and to prevent breakdown of the impact ripper caused by wasteful striking. A vehicle tractive force and a vehicle speed required by digging resistance applied to a blade end (2a) of the impact ripper (2) are detected and signals obtained from the detections are inputted to a controller (4). When an automatic strike switch is on, an activating signal is outputted from the controller (4) to the vibrating mechanism (3) of the impact ripper (2) regardless of a vehicle body tractive force when a vehicle speed is less than a predetermined value.

Abstract: A laser positioner is located at a survey base point for projecting a geodetic design pattern depicting design working points onto a working face remote from the base point by use of a laser pattern projector, upon surveying an object route by use of a laser surveying unit. In tunneling operations for example, the design pattern is formed on the working face, so that boring of the holes for charging explosives in the working face can be performed without paint-marking on the working face.

Abstract: The method and apparatus for controlling the displacement of a steerable driven trailing machine with respect to a leading machine by measuring the separation between the machines and inputting such measurement to the trailing machine drive control, and measuring the angular disposition of the trailing machine and inputting the steering control of the trailing machine.

Abstract: A method of steering a double-ended ranging drum mining machine includes the steps of positioning two previous cut roof followers spaced apart longitudinally of the machine, measuring machine tilt using a second means, estimating coal thickness using third means and generating algorithms therefrom whereby height differences between points on the current and previous cut roof can be calculated to control and steer the leading and trailing drums the algorithms being generated in such a manner that cumulative errors along or towards the face are minimized or eliminated.