An end clinometer the bottom end of which is shaped to match the
wedge-guide pin on the drive wedge; hence the two can be fastened together
with copper shear rivets. When a drive wedge is driven into a wooden plug
in a borehole the copper rivets break; after the clinometer has been
removed from the borehole, the relation of the bearing and inclination
readings to the flat face of the projection on the bottom of the
clinometer case can be used to orient and place the deflection wedge in a
manner so as to direct the deflected hole to follow the desired course.
CF:plain clinometer; line clinometer. Long
A core-gripping device consisting of a series of three or more
serrated-face, tapered wedges contained in slotted and tapered recesses
cut into the inner surface of a lifter case or sleeve. The case is
threaded to the inner tube of a core barrel. As the core enters the inner
tube, it lifts the wedges up along the case taper. When the barrel is
raised, the wedges are pulled tight, gripping the core. Long
a. A cut in which the central holes are positioned to cause the breakout
of a wedge-shaped section of strata when fired. BS, 12
b. A drill-hole pattern with the cut holes converging to form a V or
wedge. The other holes are drilled to break to the opening made by the cut
holes. See also:V-cut
c. A type of geometry for blasting pattern often used in drifting work. It
can be adopted for all strata conditions. A wedge cut consists of pairs of
holes, usually drilled horizontally, that meet or finish close together at
the back of the cut so that a wedge-shaped section of the rock face will
be removed on blasting. The holes should be drilled at an angle of approx.
60 degrees to the face line. Accordingly, the depth of pull that can be
obtained with this type of cut is governed by the width of the drift, as
this determines the maximum length of drill steel that can be used.
Typically, the pull ranges from 5 ft (1.5 m) in a 12-ft-wide (3.7-m-wide)
drift up to 6-1/2 ft (1.8 m) in a 15-ft-wide (4.6-m-wide) drift.
McAdam, 2
One of several implements used collectively to arrest a cage or skip in
the event of an overwind using a multirope friction winder. Frictional
forces, which gradually increase by virtue of the wedging action of the
guides, are relied upon to bring the cage to rest and hold it in a
stationary position with the aid of jack catches.
See also:detaching hook
To deviate or change the course of a borehole by using a deflecting wedge.
See also:bypass
The edge or line of pinch-out of a lensing or truncated rock formation.
AGI
See:thin out
That part of the bottom end of a Hall-Rowe deflecting wedge that matches
the guide pin on the upper end of the Hall-Rowe drive wedge and by means
of which the deflecting wedge can be oriented to direct the deflected
borehole in the intended direction. Long
A tapered or bullnose rotary bit used to restart drilling after a
deflection wedge has been fitted into a borehole.
See also:wedging reamer; wedge bit. BS, 9
Multiple-hearth vertical furnace. Rabbles rotating on each circular
horizontal hearth work the continuously fed material across alternately to
the periphery and then, on the next hearth below, toward the center, so
that it gravitates through either a central or a peripheral opening and is
at the same time exposed to rising heat or air blown through rabble arms.
Pryor, 3
An expression used on the Comstock lode to designate rock better than
waste but too poor to be classed as "pay ore" or even "second-class ore."
It became a custom to throw a wooden wedge onto a car containing very low
grade ore, hence the term wedge rock. Syn:pin
A serrated-face, hardened-metal, noncoring, cone-shaped bit used primarily
to mill off part of the stabilizing or rose ring on the top end of a
Hall-Rowe deflecting wedge. Long
A diamond bit with wedge-shaped configurations in the crown that are inset
with diamonds.
See:wedge cut
A wire rope attachment in which the rope lies in a too-small groove
between a wedge and housing, so that pull on the rope tightens the wedge.
Nichols, 1
The analysis formulated by Coulomb in 1776 of the force tending to
overturn a retaining wall. Its basis is the weight of the wedge of earth
that will slide forward if the wall fails. Hammond
A screen deck comprising wires of wedge-shaped cross section spaced from
each other at a fixed dimension; the underflow thus passes through an
aperture of increasing cross section. Also called wedge-wire sieve
(undesirable usage). BS, 5
A screen designed to reduce or eliminate clogging of material. It consists
of wedge-shaped parallel wires with their wide edge upward. This type of
screen is used for dewatering coal on vibrating, shaking, or stationary
screens. Nelson
a. A method used in quarrying to obtain large, regular blocks of building
stone, such as syenite, granite, marble, and sandstone. In this method, a
row of holes is drilled, either by hand or by pneumatic drill, close to
each other to create a longitudinal crevice. A gently sloping steel wedge
is driven into this crevice. Usually several wedges are driven, and the
block of stone can be detached without shattering. Stoces
b. The act of changing the course of a borehole by using a deflecting
wedge. Syn:whipstocking
c. The lodging of two or more wedge-shaped pieces of core inside a core
barrel and therefore blocking it. Long
d. The material, moss, or wood used to render a shaft lining tight.
Fay
e. The splitting, breaking, or forcing apart of a rock as if by a wedge,
such as by the growth of salt or mineral crystal in interstices; specif.
frost wedging. AGI
See:wedge bit