Improvements in Coal Cutting Machinery.
Year: 1892

page_text: Date of Application, 14th Apr., 1892
Complete Specification Left. 13th Jan., 1893-Accepted, 25th Feb., 1893
PROVISIONAL SPECIFICATION.
Improvements in Coal Cutting Machinery.
We ARTHUR HIRST and HENRY HIRST both of the Crescent Works, Foundry
Street Dewsbury in the County of York Electrical and Mechanical Engineers do
hereby declare the nature of this invention to be as follows :—
Our invention refers to that class of coal cutting machinery used for under-
cutting the coal preparatory to breaking down the same from the coal face.
The
A coal cutting machine according to our invention is constructed as follows:-
The frame of the machine is mounted upon wheels, and provided towards one
end with a vertical spindle. This spindle is rotated from a driving shaft, (actuated
preferably by an electric motor), by means of a worm wheel fitted at its upper
end, and a worm on the driving shaft. A toothed chain wheel is keyed to the
lower end of the vertical shaft and within the hollow boss of a radial arm.
opposite or free end of this radial arm carries a second wheel. An endless chain
passes round these two wheels and carries the cutters. Extending from wheel to
wheel immediately behind the chain are two slides, against one or other of which
the back of the chain abuts or presses, according as the one or other side of the arm
is towards the coal being cut by the teeth.
The upper part of the boss of the radial arm is provided with a circular
groove arranged to fit in a circular bearing formed in the main frame of the
machine. The outer end of the radial arm is formed separate from the main
portion of the arm, and arranged capable of being slid in or out in a slide formed in
the main portion of the arm; so that the chain can be slackened or tightened up
as desired. This adjustment may be performed by a screw arrangement, and
locking bolts are provided to secure the two portions securely together when
the adjustment is completed.
The circular bearing for the boss of the radial arm is formed partly in the
main frame and partly in a sliding piece fitted to the main frame, and which
sliding piece can be withdrawn for the purpose of removing the radial arm when
required for repairs.
The distance between the wheels of the frame is greater than the length of the
radial arm, so that the latter can be moved out into a position at right angles with
the carriage on either side of the same, and the machine can thus be used with
either side towards the coal face.
The machine is fed forward by means of a rope, attached at one end to a sleeper,
rail or prop, the opposite end being wound round a pulley on the machine; the
pulley being rotated by means of a ratchet wheel, lever, and a tappet or tappets
attached to the vertical spindle or the worm wheel on the same.
A worm wheel or worm sector is attached to the central boss of the radial arm,
so that the latter can be rotated out or in to any desired position through
180 degrees, by means of a worm on the shaft.
In order that the feed of the machine may be automatically adjusted to the
resistance which the coal or other material may offer to the cutting tools, we
provide the following mechanism :-The last mentioned worm shaft is provided
with two collars on opposite sides of a fixed bearing, (or with a single collar or
lock nuts between two fixed bearings). Between each collar or lock nut and the
fixed bearing are provided two strong spiral springs, which normally hold the
shaft in such a position that the worm is in proper position for gearing with
the worm sector, and a double coued tappet on the worm shaft in such a position
as not to interfere with the pawl levers of the feed ratchet wheel. Should how-
ever the resistance to cutting become too great, the radial arm is pushed back

page_text: relatively to the machine; thereby partially rotating the worm sector and pushing
to one side the worm, and consequently the worm shaft (to which it is fixed),
longitudinally in its bearings. This longitudinal motion of the shaft is rendered
possible by the yielding of one or other of the before mentioned spiral springs.
The double cone is also moved along with the shaft, so that the cone part comes
in contact with one of the pawl levers, either lessening or stopping altogether the
stroke of the pawl, and consequently either reducing or stopping altogether the
feed of the machine.
The main frame of the machine is preferably formed in two portions, which
may be hinged together or made detachable in order to facilitate the passage of
the machine round sharp curves or corners.
Dated this 13th day of April 1892.
J. CLARK JEFFERSON, A.R.S.M., Wh. Sc.,
2, East Parade, Leeds, Agent for Applicants.
COMPLETE SPECIFICATION.
Improvements in Coal Cutting Machinery.
We ARTHUR HIRST and HENRY HIRST both of the Crescent Works Foundry
Street Dewsbury in the County of York Electrical and Mechanical Engineers do
hereby declare the nature of this invention and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement :-
Our invention refers to that class of coal cutting machinery used for undercutting
the coal preparatory to breaking down the same from the coal face.
A coal cutting machine according to our invention is constructed as follows:-
The frame of the machine is mounted upon wheels, and provided towards one
end with a vertical spindle. This spindle is rotated from a driving shaft, actuated
preferably by an electric motor, by means of a worm wheel fitted on its upper end
and a worm on the driving shaft. A toothed chain wheel is keyed to the lower
end of the vertical shaft and within the hollow boss of a radial arm. The opposite
or free end of this radial arm carries a second wheel. An endless chain passes
round these two wheels, and carries the cutters. Extending from wheel to wheel
immediately behind the chain are two slides, against one or other of which the
back of the chain abuts or presses, according as the one or other side of the arm is
towards the coal being cut by the teeth.
The upper part of the boss of the radial arm is provided with a circular groove,
arranged to fit in a circular bearing formed in the main frame of the machine.
The outer end of the radial arm is formed separate from the main portion of the
arm, and arranged capable of being slid in or out in a slide formed in the main
portion of the arm, so that the chain can be slackened out or tightened up as
desired. This adjustment may be performed by a screw arrangement, and locking
bolts are provided to secure the two portions securely together when the adjust-
ment is completed.
The circular bearing for the boss of the radial arm is formed partly in the
main frame and partly in a sliding piece fitted to the main frame, and which sliding
piece can be withdrawn for the purpose of removing the radial arm, when required
for repairs.
The distance between the wheels of the frame is greater than the length of the
radial arm, so that the latter can be moved out into a position at right angles with
the carriage on either side of the same, and the machine can thus be used with
either side towards the coal face.
'
The machine is fed forward by means of a rope attached at one end to a sleeper,
rail or prop, the opposite end being wound round a pulley on the machine; the
pulley being rotated by means of a ratchet wheel, lever and tappet, or tappets,
attached to the vertical spindle or the worm wheel on the same.

page_text: A worm wheel or worm sector is attached to the central boss of the radial arm,
so that the latter can be rotated out or in to any desired position through
180 degrees by means of a worm and shaft.
In order that the feed of the machine may be automatically adjusted to the
resistance which the coal or other material may offer to the cutters, we provide
the following mechanism :-The last mentioned worm shaft is provided with two
collars on opposite sides of a fixed bearing, (or with a single collar or lock
nuts between two fixed bearings). Between each collar or lock nut and the
fixed bearing are provided two strong spiral springs, which normally hold the
shaft in such a position, that the worm is in proper position for gearing with
the worm sector, and a double coned tappet on the worm shaft in such a position
as not to interfere with the pawl levers of the feed ratchet wheel. Should however
the resistance to cutting become too great, the radial arm is pushed back relatively
to the machine, thereby partially rotating the worm sector and pushing to one side
the worm and consequently the worm shaft, (to which it is fixed), longitudinally
in its bearings. This longitudinal motion of the shaft is rendered possible by the
yielding of one of the before mentioned spiral springs. The double cone is also
moved along with the shaft, so that the cone part comes in contact with one of
the pawl levers, either lessening or stopping altogether the feed of the machine.
The main frame of the machine is preferably formed in two portions, which may
be hinged together or made detachable in order to facilitate the passage of the.
machine round sharp curves or corners.
And in order that our invention and the manner in which the same is to be
performed may be more readily understood, we have annexed hereto the accom-
panying sheet of drawings, in which
Fig. 1 is a plan of a coal cutting machine constructed in accordance with our
invention and Fig. 2 is a vertical elevation, parts of which are shewn in section.
a is the frame of the machine mounted upon the wheels, and provided towards
one end with a vertical spindle c. The spindle c is rotated from the driving shaft d
by means of the worm e and worm wheel t. is a toothed chain wheel keyed to the
lower end of the spindle c and between the forked boss of the radial arm 9 I'.
The free end of the radial arm g' carries a wheel h. An endless chain passes
round the wheels f and hand carries the cutters. The back of the chain abuts
against slides formed separately or as part of the sides of the radial arm g g'.
The upper fork of the boss of the radial arm is formed with a circular groove,
which fits the circular bearing i formed in the main frame a of the machine. The
outer end g¹ of the radial arm is formed separate from the main part ; a slide
being formed in the latter in which the former can be moved. The right and left
handed screw & fits in tapped holes in the two portions of the radial arm g g', so
that the chain can be slackened out or tightened up as desired.
The circular bearing i is formed partly in the main frame a, and partly in the
sliding piece which is fitted to the main frame, and to which it is secured and from
which it can be withdrawn by screwing up or taking out the bolts m m.
The machine is fed forwards by means of a rope attached at one end to a sleeper,
rail or prop; the opposite end being wound round the barrel n attached to the
frame a.
This barrel is rotated by means of the ratchet wheel o, ratchet lever p,
shaft q, lever r and tappets & attached to the worm wheel t.
A worm wheel u (or sector) is attached to the central boss or fork y of the radial
arm, so that the latter can be rotated through 180 degrees by means of the worm v
and shaft w. This arrangement permits the machine to operate towards either end.
The worm shaft w is provided with two collars on opposite sides of the
fixed bearing y; and between this and the collars are provided two strong spiral
springs, which normally hold the shaft (capable of sliding longitudinally in
its bearings 1. 1.) in proper position for gearing with the worm wheel u, and also
the double coned tappet 2 (fixed to the shaft w) in such a position as not to
interfere with the lever 3, which is keyed to the ratchet lever shaft q. Should
however the resistance to cutting become too great, the radial arm is pushed back

page_text: relatively to the machine, thereby partially rotating the worm wheel and pushing
back the worm v and the shaft w, and along with it the tappet cone 2, which thereby
comes in contact with the lever 3 and lessens or stops altogether the stroke of the
pawl lever p (ie the feed of the machine).
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed we declare that what we
claim is :-
1st. In coal cutting machines the combination of a radial arm carrying the cutter
or cutter chain wheels and fitted in a circular bearing with such bearing formed
partly in the main frame and partly in a sliding piece fitting a slot in the main
frane and which sliding piece can be firmly secured to the main frame or with-
drawn therefrom for the purpose herein specified.
2nd. In coal cutting inachines mechanism for automatically controlling the
feeding mechanism consisting of, a worm wheel or sector attached to the radial
arm carrying the cutter or cutter chain wheel, a shaft capable of sliding longitu-
dinally in its bearings and provided with collars and spiral springs on both sides
of a fixed bearing (or the equivalent herein set forth), a double coned tappet, and
a lever or rod engaging with the tappet and connected to the feeding mechanism.
3rd. The general arrangement and construction of the various parts forming our
improved coal cutting machine substantially as herein set forth.
1000
J. CLARK JEFFERSON, A.R.S.M., Wh. Sc.,
2, East Parade, Leeds, Agent for Applicants.