A machine that applies a spray under pressure on mine timber supports to
preserve and fireproof them. It may also be used for limewashing and water
spraying of dust. The machine is mounted on wheels and operated by
compressed air. Nelson
A screen used for the removal, by spraying, of fine solids present among
or adhering to larger particles. BS, 5
Appliances to damp deposits of dust in tunnels and workings before and
after shotfiring and loading operations. Water sprays are also used along
dusty roadways. Various types of mist projectors and atomizers are used
and effect considerable improvement, but the dust trapped consists chiefly
of the coarser particles. In many dusty mines, a water pipe system extends
throughout the workings and sprays are employed at all loading and other
dusty points. Sprays are also used to suppress dust at coal and ore
processing plants. See also:whale-type jib
See:rinsing water
a. The area covered at a given thickness by a given quantity of such
materials as chippings or road binder. Hammond
b. The surface in proportion to the depth of a stone. Hess
c. The surface or width at the girdle in proportion to the depth of a cut
stone, such as a diamond.
d. The layout of geophone groups from which data from a single shot are
recorded simultaneously. Syn:seismometer spread; seismic spread.
a. A horizontal timber below the cap of a set, to stiffen the legs and to
support the brattice when there are two air courses in the same gangway.
b. A piece of timber stretched across a shaft as a temporary support of
the walls.
c. A tool used in sharpening machine drill bits. Fay
d. A strut in a tunnel or heading timber sets. Nelson
e. A machine which spreads dumped material with its blades. Nelson
Chains joining the end of the tail chain to ends of the spreader.
Zern
See:tripper man
An instrument used in bridge testing to measure any outward spread of an
abutment under load. See also:rotation recorder
a. To enlarge the bottom of a drill hole by small charges of a high
explosive in order to make room for the full charge; to chamber a drill
hole. See also:camouflet
b. To chamber. See also:chamber
c. A general name for any natural discharge of hot or cold pure or
mineralized water.
A heavy tension spring, enclosed in a cylinder, which is connected to the
panline of certain types of shaker conveyors to keep the conveyor in
tension. It is attached to the conveyor by a driving chain and to a prop
by a fixing chain. Keeping the conveyor in tension, it is claimed, will
save the conveyor connections and increase the output. Jones, 1
Force that produces a unit elongation of the spring used in geophysical
instruments. AGI
See:core lifter
a. A tool used to retrieve lost boring gear. Pryor, 3
b. A device to withdraw the steel casing from a borehole when finished.
The casing is cut into convenient lengths and then the spring dart is
lowered to bring up each length separately. The dart springs open
immediately when it meets a cut or recess in the casing, which length it
then grips and lifts to the surface. Nelson
a. A quarry blasting method in which a succession of charges is fired in a
borehole to open up a chamber. BS, 12
b. Enlarging the bottom of a drill hole by exploding a small charge in it.
Nichols, 1
c. In certain types of rock, large quantities of stone can be blasted down
by the method known as springing the shothole. The technique requires that
the rock contains well-defined bedding or jointing planes, such as are
found in most sedimentary and some igneous rocks, particularly granite.
The principle of springing is to drill a borehole with a heavy burden and
then explode a succession of gradually increasing charges of black powder
so that the bedding planes or joints are opened up to permit the placing
of a large final charge. Syn:bullying; overspringing. McAdam, 2
See:springing
See:core lifter
The meeting of the roof arch and the sides of a tunnel. Nichols, 1
Held in contact or engagement by springs. Nichols, 1
A crushing machine similar to the double-roll crusher with the difference
that springs are fixed to the bearings of one roll. Nelson
Crushing rolls used in ore breaking. Two parallel cylinders, mounted
horizontally, are held apart by shims, and pressed together by powerful
springs. Crushable rocks falling between them are drawn down as the
cylinders revolve, but unbreakable material causes the springs to yield
and let it pass without damage. Pryor, 3