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THE COAL TRADE BULLETIN. 47
THE JEFFREY-DRENNEN ADJUSTABLE TURRET COAL CUTTER
By C. E, Waxbom. Engineer. Columbus. Ohio
One of the most economical and novel cutting
machines which has recently been placed on the
market by the Jeffrey Manufacturing Co. of Columbus,
Ohio, is known as "The Jeffrey-Drennen
Adjustable Turret Coal Cutter." This machine
was designed by the Jeffrey Manufacturing Co.'s
engineers at the request and co-oeration of Mr.
Everett Drennen, manager of the Consolidation
Coal Co.'s mines, Elkhorn division, to meet certain
conditions existing at their mines located at
Jenkins, Ky., and to enable the coal company to
economically mine their coal, also to increase the
quality of coal mined.
The coal seam at Jenkins varies from 6 to 8
feet in thickness, and is clean, bright and free
from sulphur or any other impurities, with the
exception of a strata of shale. The shale is located
at a height of from 2 to 5 feet from the
bottom, and varies in thickness from nothing to
19 inches.
With the customary methods of undercutting,
it would be impossible when shooting the coal, to
prevent this shale band from mixing with the
coal, but by the use- of a machine adapted to cutting
out or removing this shale band before the
coal is shot down, this difficulty is overcome.
The machine is mounted on a turn-table truck
which carries four heavy stands on which the machine
proper is moved up and down, or adjusted
to the desired height at which to cut the dirt seam.
The machine is designed for a minimum height
of cut from the bottom to 2 feet and can be adjusted
to cut in any position between 2 to 5 feet
from the bottom. The raising and lowering of
the machine is accomplished by power through a
disc friction clutch, which enables the operator to
absolutely control the raising and lowering of the
machine to a nicety. The machine can be raised
or lowered three feet in about 25 seconds. The
machine is equipped with an automatic cable reel
which automatically winds or unwinds the cable
Jeffrey Turret Coal Cutter Cutting in the Ribs of a Coal Seam
as the machine is going into or coming out of the
room.
The machine is arranged for self-propelling, and
lias a track speed up to 350 feet per minute, the
speed of the truck being controlled by the operator
through a disc friction clutch, thus enabling
the operator to run at any desired speed from
nothing up to maximum. This is a great advantage
to the operator in going over frogs and
switches, minimizes the danger of derailment, and
consequent delays.