Year: 1897

page_text: CHARLES M. JOHNSON, 22, Laurence Pountney Lane, Cannon Street, London,
E.C., Mechanical Engineer, do hereby declare the nature of this invention to be as
follows:-
:-
My invention consists of coal mining machinery in which I use for coal mining a
saw of any convenient form, or a cutting tool with saw teeth edge. I find by
experiment that I can cut coal with a saw with about the same rate of speed as
cutting very hard wood. I do not confine myself to any particular form of
operating the saw, or saw shaped cutting tool, for I may use a circular, a band, a
chain saw, or a revolving tool with a saw shaped edge to take out the core, or any
other convenient form without departing from the spirit of the invention.
Dated this Sixth day of September 1897.
CHARLES M. JOHNSON, 22, Laurence Pountney Lane, Cannon Street, London,
E.C., Mechanical Engineer, I do hereby declare the nature of this invention
and in what manner the same is to be performed, to be particularly described and
uscertained in and by the following statement :-
This invention relates to coal-mining machinery in which a saw or saw-shaped
cutting tool is used and has for its object to enable the coal removed in the
operation of undercutting or "holing" to be obtained in large lumps in comparison
with that removed when the same operation is performed by hand labour, and
thereby save the cost of mining.
One way of operating this invention consists essentially in mounting a circular
Baw upon a jointed cantilever arm projected from a horizontal guide in such manner
that the arm may be swung about an axis normal to the plane of the desired cut
for the purpose of entering the saw, and that the saw when so entered may be fed
along the guide bar in order to elongate the entering cut; and in an angular
adjustment of the plane of the saw so that with two cuts a wedge of coal is
severed, the removal of which effects the operation of holing; the corners may be
removed in any suitable manner, or as I prefer, by a revolving core drill.
Reference is to be had to the accompanying drawings forming part of this
specification, wherein :-
Figs. 1 & 2 are elevations, and Fig. 3 an elevation at right angles to Fig. 2.
Fig. 4 is a plan. Figs. 5 & 7 are elevations, and Fig. 6 is a plan. Fig. 8 is a
detail elevation partly in section.

page_text: The same letters of reference denote like parts in all the figures.
Referring to Fig. 5, A is the saw mounted on a spindle driven by worm C,
gearing in wheel B, said worn receiving its motion by means of the shaft D, worm
wheel E, worm F, and mitre wheels G G¹, the latter being fast upon the
prolonged shaft of the electric motor H, as is herein shown.
The part I of the cantilever arm is pivoted on the axis XX, parallel to the axis
of the saw. The axis XX, is also the axis of the nitre wheel G, so that the
arm I may be vibrated while the saw is running. T is a worm wheel segment fast
on the arm I driven by the worm K, whose shaft has square ends, and may be
rotated by means of ratchet hand levers or other suitable means for the
imparting angular movement to the saw and arm I.
purpose of
The portion L, of the cantilever immediately carrying the arm I, is connected to
the socket portion M by means of an external circular flange L', upon L, fitting
in a recess concentric with the motor shaft, and retained therein by a split ring M¹
(as shewn also in Fig. 8), so that the arm I and the saw spindle can be rotated
about the axis of the motor shaft.
The whole of the cantilever is supported by the circular beam N, along which it
is travelled by means of the screw 0 (see Fig. 1) carried by the beam N, and
working in the nut M². The beam N has a key groove along it and in the part M
of the cantilever is a feather N8 engaging therein (see Fig. 5), so that the arm
cannot rotate about the beam N.
In Figs. 1, 2, the beam N is supported in bearings P P¹, and in Fig. 8, P1
having a worm P2 mounted thereon and engaging in a worm wheel segment N¹
fast upon the beam N, so that the angular position of the arm can be determined
in a plane normal to the axis of the beam N.
The bearings P P¹ are mounted upon the columns QQ¹ (Figs. 1, 2), upon
which they are free to slide; their position vertically being determined by the
nuts QQ, screwed on the columns and upon which the bearings P P¹ rest.
The columns QQ are fitted at their upper ends with screw-jack heads, so that
they may be secured in a position by straining them between the floor and roof of
the seam worked.
Fig. 5 shows the saw in position for making the lower cut and Fig. 7 shews its
position in making the top cut.
In Fig. 7 the arm I is shewn inverted from the position shewn in Fig. 5 by its
partial rotation abot the axis SS of the motor shaft upon the ring junction
formed by the parts L' and M¹ of Fig. 5 (which may be locked in any desired
position), and inclined as adjusted by the worm P of Fig. 3, and worm-wheel
segment N¹ before mentioned.
Fig. 4 is a general plan of the apparatus adjusted for making the lower cut,
shewing the cantilever at an extreme position on the supporting bar N; the dotted
circle A being the saw about to enter the face represented by the line U U, and
the dot and dash arc V, the extreme line cut by the saw while swung upon the
axis XX of Fig. 5, the line W W being the contour of the cut made while the
saw travels from the position Y to the position Z.
In operation, any convenient form of motor can be used, and the invention must
not be restricted to coal cutting alone for it can be used for other mining or
tunnelling purposes and the saws may be operated in a different manner without
departing from the spirit of the invention.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is :-
:-
"
1. In a coal mining machine, the means by which a saw or cutting tool may be
operated to cut out the undercutting fall or holing" substantially as is shewn.
2. In a coal mining machine, the combination of the coal cutter and the frame
substantially as is operated and shown.

page_text: 3. In a coal mining machine, the combination of the motor, a coal cutter and the
frame, and means of operating the same substantially as herein shown.
4. The improved coal mining machine substantially as is herein described and
shown.