- 行业: Mining
- Number of terms: 33118
- Number of blossaries: 0
- Company Profile:
The U.S. Bureau of Mines (USBM) was the primary United States Government agency conducting scientific research and disseminating information on the extraction, processing, use, and conservation of mineral resources.
Founded on May 16, 1910, through the Organic Act (Public Law 179), USBM's missions ...
A self-acting apparatus for running the hudges (boxes on runners) on inclines in step coalbeds.
Industry:Mining
A self-advancing support for use on long-wall faces. One unit embodies three props. The front prop, which is attached to the face conveyor, carries two roof bars side by side that give cantilever support over the conveyor track. The two rear props are mounted on a common floor bar and carry a single roof bar that passes between the two front bars. The front prop is attached to the rear structure only by the advancing ram within the box structure of the floor bar.
Industry:Mining
A self-advancing support system in which the chocks and/or props are advanced and reset on a longwall face from a point in the gate road leading to the face. Hydraulic pressure and valves are commonly employed and the system is largely in the experimental stage.
Industry:Mining
A self-contained electronic system that makes use of Doppler's principle of frequency shift of waves emanating from a moving source. In this system, a pulsed or continuous wave is sent diagonally downward fore and aft, forward and backward, and the frequencies are compared in order to obtain the true ground speed. The heading is obtained from a special magnetic compass and is maintained by a directional gyro used as an integrating device. The distance thus determined has a precision better than one part in a thousand, which is sufficient for most geophysical surveys.
Industry:Mining
A self-contained instrument with the millivoltmeter mounted in the pyrometer tube; the radiant energy is concentrated by means of an objective lens (quartz or fluorite) rather than by a reflecting mirror.
Industry:Mining
A self-contained mine lamp with a handle for convenience in carrying.
Industry:Mining
A self-contained transportable stone duster. A high-velocity current of air from a fan or blower is mechanically fed from a hopper above, both the fan and the feeding mechanism being driven from the tub axle as it is drawn along by rope haulage, horse, or manually. It delivers about 3/4 lb (0.34 kg) of dust per yard (0.9 m) of travel.
Industry:Mining
A self-contained, light-weight portable conveyor, usually of the belt type, for use in unloading and delivering bulk materials from trucks to domestic storage, and for trimming bulk materials in bins or piles.
Industry:Mining
A self-contained, oil-operated steel support for use on a mechanized long-wall face. It has support frames constructed of rigid roof and floor members supported by yielding hydraulic props. Two- and three-prop units are connected alternately to the armored conveyor by means of jacks mounted in the floor members, to carry long and short cantilever roof beams, respectively.
Industry:Mining
A self-dumping box on wheels, used for raising (or lowering) coal in slopes; a monitor, a skip.
Industry:Mining
