See:roller bit
A type of roller bit with cutter cones arranged to cut an annular ring
leaving an uncut section in the center as core. Long
A series of rolls supported in a frame over which objects are advanced
manually, by gravity or by power.
See also:controlled velocity roller conveyor; el conveyor;
gravity conveyor; herringbone roller conveyor;
hydrostatic roller conveyor; portable conveyor.
Syn:gravity roller conveyor
See:roller bit
Hollow cylindrical crest gate controlling a dam spillway.
See also:sector gate; sliding gate. Hammond
A device for clutching a traction cable between grooved sheaves or
rollers.
In mining, a laborer who inspects idler rollers or pulleys over which a
cable passes along inclined haulageways, oiling or greasing rollers,
resetting displaced ones, and repairing or replacing damaged ones. Also
called pulley man; pulley repairer; pulley repairman; roller repairman;
sheaveman; wheelman. DOT
See:rollerman
A rotary bit fitted with two or more hardened steel or
tungsten-carbide-tipped rollers of cylindrical or conical form. Variously
known as two-cone bit, three-cone bit, four-cutter bit, etc.
See also:roller bit
See:revolving screen
a. A smooth, fluted, or cleated roll or drum that rotates to deliver
packages, objects, or bulk materials.
b. A circular drum, plain or ribbed, rotating on a horizontal shaft and
situated at the mouth of a bunker or hopper to control the rate of
discharge of material therefrom. BS, 5
A roll orebody of the Wyoming type, which is bounded on the concave side
by oxidized altered rock typically containing hematite or limonite, and on
the convex side by relatively reduced altered rock typically containing
pyrite and organic matter. See also:roll orebody
A sampling method in which the sample is formed into the requisite flat
heap by placing it upon a rubber or other smooth sheet and, by lifting the
corners of this sheet in proper rotation, rolling the material to and fro.
The resultant heap is then quartered and alternate quarters are taken.
This method is used with smaller bulk and smaller sizes of material.
Truscott
A rod slide equipped with rollers that contact the rods and over which the
rods roll on being pulled or lowered into an angle borehole. Long
See:roller bit
A rolling mill or establishment for rolling metal into forms.
Standard, 2
a. The sum of the external forces opposing motion over level terrain.
Carson, 1
b. The tractive resistance caused by friction between the rails and
wheels, which forms the major resistance on level tracks.
See also:tractive force
A type of frame weir, the frame of which remains upright, being rolled up
from the bottom. Hammond
A crusher of the same general type as the Blake or Dodge, but the moving
jaw has a rolling instead of an oscillating motion. Liddell
In beneficiation, one who tends rolls that are used to crush ore, which
has already been broken into small pieces in a crusher, to a fine size
preparatory to the extraction of the valuable minerals. DOT