Techniques for analyzing methods used in performing an operation and
measuring the work involved. Work study fosters better use of materials,
plant, and labor, thus ensuring higher productivity.
See also:method study
A spiral tool, shaped like a carpenter's wood-boring auger, with the
bottom end shaped like the cutting end of a diamond point or mud bit. The
tool is rotated inside a casing to loosen and clean out debris or to
loosen and drill through tough clay at the bottom of a borehole. Also
called worm auger; worm-type auger. Long
See:worm
a. A conveyor consisting of a spiral plate encircling and fastened to a
shaft lying longitudinally within a trough; rotation of the spiral pushes
the material forward. Also called screw conveyor. BS, 5
b. See:helical conveyor
A modified spur gear with curved teeth that meshes with a worm.
Nichols, 1
The side of a mineral vein.
A wound rotor induction motor differs from a squirrel cage induction motor
only in the construction of its rotor. The rotor, instead of having
short-circuited copper bars, has a definite winding connected for the same
number of poles as the stator with the leads brought out to slip rings.
The stator and rotor are commonly called the primary and secondary,
respectively, because under locked rotor conditions, the motor becomes a
transformer with a given ratio. This ratio depends upon motor design and
is not standardized. Frequently called a slip ring motor.
Pit and Quarry
Ore screening machine whose screen is woven of steel wire and stretched
tightly on a metal frame. Near the center of the screen is fastened the
vibrating element of a high-speed vibrator, which produces a vibratory
motion at right angles to the plane of the screen. Newton, 1
A tunnel blasting method in which holes are arranged in a geometrical
figure as an incomplete pyramid and not parallel in the planes of the
sides. For tunnel widths less than 25 ft (7.5 m), the WP-cut provides a
greater advance than V-cuts and fan cuts.
A horizontal force tending to distort a rectangular shape into a
parallelogram. Hammond
A conveyor in which the return strand of the belt is driven by a wrap
drive which combines a drive pulley with a snub pulley. NEMA, 2
Same as windup, as applied to the twist in a drill-rod string.
See also:windup
In glassmaking, a wavy appearance in glass, esp. flint glass, due to
defective manufacture. Standard, 2
A steel bar usually from 1 to 2 ft (0.3 to 0.6 m) in length, with one end
drawn to a thin edge, the other curved to a claw. Crispin
A transverse strike-slip fault that is more or less vertical.
In a bucket, the ability to change its digging or dumping angle by power.
Nichols, 1
Type of alloy suitable for forming by mechanical means at temperatures
below the melting point. Light Metal Age
a. A low-carbon iron containing a relatively high proportion of residual
slag that gives it ductility and toughness. Strock, 2
b. A commercial form of iron containing less than 0.3%, and usually less
than 0.1%, carbon; also carrying 1.0% or 2.0% of slag mechanically mixed
with it and originally made directly from ore (as in the Catalan forge)
but subsequently by puddling. See also:iron
Webster 3rd
A metal that has been worked by cold rolling, forging, pressing, drawing,
or extension. Hammond
In metallurgy, a heavy suspension method for the concentration of ores in
which the waste has a specific gravity of 2.7 or more. Minerals having a
specific gravity in excess of 5.25 must be used, since a suspension
containing over 40% solids by volume is too plastic for use. Galena (sp
gr, 7.4 to 7.6) and ferrosilicon (sp gr, 6.7 to 7.0) have been used.
Hess
A tetragonal mineral, PbMoO4 ; prismatic cleavage; soft; resinous;
yellow to brown; sp gr, 6.5 to 7.0; in oxidized zones of lead-molybdenum
veins; a source of molybdenum. Syn:yellow lead ore