A drilling method utilizeing a great number of short blows in quick
succession rather than a few heavy blows from a relatively considerable
altitude. In this method, the bit is fixed either to a rod or to a rope,
so that it pounds the bottom in quick succession with short blows and at
the same time rotates. Stoces
An improved cycle and system of operation to achieve rapid advance and
continuous operation in low-drillability rock. SME, 1
A fast moving plow with picks attached. The rapid plow is a continuous
longwall cutter loader capable of working unattended on the face. For this
reason, it is one of the safest machines in operation.
See also:hard-coal plow
Som. To wedge down blocks of stone in underground quarries.
Excess in size of a casting because the mold is larger than the pattern
when the latter is unduly rapped, as with the hand, for drawing.
Standard, 2
In foundry work, loosening of pattern before its withdrawal from molding
sand in flask. Pryor, 3
An eccentric roller or a roller fitted with devices such as bars welded
longitudinally along its outer casing, so arranged as to rap the belt and
knock off fine coal or dust adhering to the return belt, or to centralize
the coal on the carrying belt. Nelson
Oxides of a series of 15 metallic elements, from lanthanum (atomic number
57) to lutetium (71), and of two other elements; yttrium (39), and
scandium (21). These elements are not esp. rare in the Earth's crust, but
concentrations are. The rare earth metals resemble one another very
closely in chemical and physical properties, thus making it most difficult
to separate them. The rare earths are constituents of certain minerals,
esp. monazite, bastnaesite, and xenotime. Abbrev: REE. AGI
a. The process or act of making rare or less dense; increase of volume,
the mass remaining the same: now usually of gases; also, the state of
being rarified; as, the rarefaction of the atmosphere on a high mountain.
Standard, 2
b. Diminution of air pressure below normal, as in alternate half-cycles in
the transmission of a sound wave past a point. CTD
A very friable carbonaceous clay, with numerous slickensides and sometimes
streaks of coal. Rashings may underlie, overlie, or be interstratified
with the coal; a very weak material and breaks up around the face
supports. See also:brashings
See:kernite
An instrument used in a borehole for fishing operations, for reducing the
length of the box, or for coupling lost tools. Also called mill; rose bit.
Long
a. See:rhodochrosite
b. Pink tourmaline.
A monoclinic mineral, PbWO4 ; dimorphous with stolzite; forms small
tabular brownish-yellow crystals having intense adamantine luster; at
Broken Hill, N.S.W., Australia.
A set of teeth that are vertical on one side and sloped on the other;
holds a pawl moving in one direction, but allows it to move in another.
Nichols, 1
A cogwheel (ratchet) with which a single pivoted catch (pawl) engages,
thereby preventing any backward turning. Hammond
A hand drill in which the drill holder is revolved intermittently by a
lever through a ratchet wheel and pawl. A drill used for boring slate.
Webster 3rd; Fay
The worker who operates the duckbill loader when mining with duckbill
conveyors. Lewis
See:rait
As used in flotation, the component of proportional plus rate action or of
proportional plus reset plus rate action for which there is a continuous
linear relation between the rate of change of the controlled variable and
the position of a final control element. Fuerstenau
The load that a new wire rope or wire rope sling may handle under given
operating conditions and at an assumed design factor.