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through ventilation

The normal ventilation produced in a mine as the air flows from the intake
to the return, as opposed to ventilation produced locally by auxiliary
fans. Nelson

throw

a. The amplitude of shake of a vibratory screen, concentrating table,
jigger conveyor, etc. Nelson
b. Lateral displacement of a screen, shaking table, or crushing surface in
motion. Pryor, 4
c. The projection of broken rock during blasting. See also:flyrock
Standard, 2; Fay
d. The distance from an air supply opening measured in the direction of
air flow, from the opening to the point where the air velocity is 50
ft/min (15.2 m/min). Strock, 2
e. The amount of vertical displacement up (upthrow) or down (downthrow)
produced by a fault; sometimes, loosely, a dislocation not vertical, the
direction being specified. See also:heave; perpendicular throw;
stratigraphic throw. Fay
f. The vertical component of the net slip on a fault. AGI

thrower belt

See:boxcar loader

throwing clay

Clay plastic enough to be shaped on a potter's wheel.

thrown

a. Faulted or broken up by a fault. Fay
b. Turned, as a piece of ceramic ware on a potter's wheel.
Standard, 2

throw of crusher

See:stroke of crusher

throwoff switch

Aust. A switch by means of which an obstruction is thrown across the rails
of a track, causing the derailment of the trucks. A derailing switch.

throwout bearing

a. A bearing, sliding on a clutch jackshaft, that carries the engage and
disengage mechanism. Nichols, 1
b. A bearing that permits a clutch throwout collar to slide along the
clutch shaft without rotating with it. Nichols, 1

thrust

a. An overriding movement of one crustal unit over another, such as in
thrust faulting. AGI
b. See:thrust fault; fault.
c. A crushing of coal pillars caused by excess weight of the
superincumbent rocks, the floor being harder than the roof. CF:creep
Fay
d. The ruins of a fallen roof, after pillars and stalls have been removed.
Fay
e. The weight or pressure applied to a bit to make it cut. Long

thrust arm

A cable-controlled bar that can slide by power in two directions.
Nichols, 1

thrust bearing

a. A bearing that resists attempts of a shaft to move along its axis.
Pryor, 3
b. A bearing designed to carry axial loads on a shaft. Shell

thrust block

The antifriction part of the thrust yoke attached to the drive rod in the
swivel head of a diamond-drill machine. Also called cage; friction head;
thrust collar. See also:thrust sheet

thrust borer

Mechanism for forcing a hole through an embankment for the insertion of
pipes or cables. Hammond

thrust fault

a. A fault with a dip of 45 degrees or less over much of its extent, on
which the hanging wall appears to have moved upward relative to the
footwall. Horizontal compression rather than vertical displacement is its
characteristic feature. CF:normal fault
Syn:thrust; overthrust. AGI
b. A reverse fault that is characterized by a low angle of inclination
with reference to a horizontal plane. AGI
c. A reverse fault heading at a high angle. BS, 11

thrust nappe

See:thrust sheet

thrust plane

a. The surface of a thrust fault, when the surface is planar. AGI
b. The plane of a thrust or reversed fault. Syn:overthrust plane

thrust plate

The upper and/or lower race parts of the thrust bearing in the thrust
block or cage on the drive rod in a diamond-drill swivel head.
Syn:thrust race

thrust race

See:thrust plate

thrust sheet

The body of rock above a large-scale thrust fault whose surface is
horizontal or very gently dipping. Syn:thrust block; thrust nappe;
thrust plate. AGI

thrust washer

A washer that holds a rotating part from sideward movement in its
bearings. Nichols, 1

thrust yoke

The part connecting the piston rods of the feed mechanism on a
hydraulic-feed diamond-drill swivel head to the thrust block, which forms
the connecting link between the yoke and the drive rod, by means of which
link the longitudinal movements of the feed mechanism are transmitted to
the swivel-head drive rod. Also called back end; cage. Long