Improvements in Coal Mining Machines.
Year: 1887

page_text: COMPLETE SPECIFICATION.
Improvements in Coal Mining Machines.
I, SAMUEL BASTAIN STINE, residing on Curtin Street, Osceola Mills in the County of
Clearfield and State of Pennsylvania one of the United States of America, Machinist,
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:
My invention relates to coal mining machines having special reference to that class
of machines by means of which the body of the coal is underent, so that it may be
dropped by means of a blast in the upper part of the vein; and it has special reference
to that class of mining machines in which a rotating bar carrying cutters is employed
to underent the body of the coal. As these machines have heretofore been constructed
the bar is rotated by means of a chain passing over the bar and engaging with sockets
or squared surfaces thereon, and so turning the bar and causing the knives or cutters
thereon to cut into the coal, the coal so cut out being carried back by means of the driving
or other chains, so that the frame carrying the rotating cutter can be advanced farther
into the coal, the machines generally undercutting about five feet at each operation
thereof.
As it is necessary to provide space for the movement of chain by means of which the
cutter bar was turned certain means have heretofore heen employed for cutting out the
coal in the course of the chain, the first being to place knives at intervals on the chain,
these knives cutting out the coal and so enabling the chain to run free, while in the
second construction the course for the movement of the chain was cut out by means of
a narrow knife in the cutter har passing up within the wide link of the driving
chain, and two like knives on the cutter bar which entered the space on each side of
the narrow link of the chain, these three knives thus cutting out a course within which
the chain travelled without coming in contact with the coal. By means of these
devices the cutter bar was driven so that the knives or cutters thereon cut in a down-
ward direction into the coal, and in this action it was found that a heavy strain or back
pressure was created against the bed of the mining machine and the feeling mechanism
thereof so throwing the heavy strain upon the machine, but as the driving chain was
employed to carry back the larger portion of the cuttings or coal dust it is evident
that it was necessary for the chain to travel backward close to the bottom wall of the

page_text: cut formed so as to carry back the coal dust therewith and for this reason the cutter
bars have always been arranged to move in this direction.
In some cases it was found that the narrow cutter which entered within the links of
the driving chain was liable to wedge therein and cause difficulty in running. The
knives or cutters on the driving chain were also found objectionable as it was difficult
to adjust them in such a manner as to cut the one after the other without throwing
such strain on certain knives as to cause the breaking thereof.
The object of my invention is to provide a means for rotating this cutter bar which
will overcome the difficulties heretofore found where the driving chain passed directly
over the bar, and also to relieve the machine of the strain heretofore brought upon it
on account of the back pressure of the cutter bar when cutting downwardly into the
coal.
This accomplish by employing a separate drive chain shaft mounted immediately
hack of the cutter bar, and cog-gearing connecting the said chain shaft and cutter bar
shaft, the pinion on the cutter har being provided with knives or cutters to cut a course
for the cog-gearing; the cutter bar being thus driven by means of cog-gearing from
the chain shaft and being driven in an opposite direction to the chain and the shaft so
that the knives cut the coal with an upward movement, and, instead of creating a
heavy back pressure upon the machine, it is found that the upward cutting of the
knives creates a slight strain upon the cutter bar, which substantially overcomes the back
pressure and in some cases draws the bar into the coal as it is rotated, while at the
same time the drive chains travel back along the bottom wall of the cut made and carry
back the cuttings or coal dust.
I have also provided a special construction of cog-gearing by means of which the
cutter bar is rotated, so that provision is made for cutting out the coal in the course of the
pinions or cog-gearing, and the knives employed are so disposed as to interfere but
little if any with the strength of the gearing and the form of gear teeth is such that
there is no liability of the coal dust or cuttings entering between the teeth and causing
the clogging or breaking of the same.
To enable others skilled in the art to make and use my invention I will describe the
same more fully, referring to the accompanying drawings in which;
Fig. 1, is a top view of the forward part of a mining machine illustrating my
invention.
Fig. 2, is a side view of the cog-gearing.
Fig. 3, is a perspective view of the same.
Figs. 4, and, 5, are horizontal cross sections of the gearing in different positions,
and,
Fig. 6, is a top view thereof.
Like letters of reference indicate like parts in each.
In the drawing shown, a, represents the sliding frame at the forward end in which
the cutter bar, h, is mounted in bearings, c, these bearings being so constructed as to
give proper support to the cutter bar, and at the same time to permit the knives or
cutters, d, thereon to cut on each side of the bearing leaving but a small space to be
broken by the forward edge thereof, this construction of bearing and cutter bar being
common in these machines. Mounted back of the cutter bar, 6, is the chain bar, e, this
chain bar being journaled in suitable bearings, 1, and the chains, g, passing over
sprockets on this chain bar, e, so as to rotate the same, these chains being driven by
any suitable power.
The cutter-bar, b, and chain har, e, are parallel with each other, the chain bar being
directly back of the cutter bar, so that the knives thereon cut a course within which
the chain bar enters and the cutter bar, L. is driven by means of the cog-gearing, h,
from the chain bar, e, this cog-gearing consisting of the pinion, i, on the chain shaft, e,
and the pinion, &, on the cutter bar, &, the cuiter bar being rotated by means of this
gearing so that the knives pass in an upward course in front of the cutter bar, that is,
that they cut the kerf or course in the coal upwardly, the knives thus acting to cut the
coal and throw the cuttings over the top of the cutter bar into the course of the drive

page_text: chain, instead of cutting it downwardly and forcing it back into the course of the
drive chain as in all mining machines heretofore constructed.
In cutting the coal in this manner by means of an upward cut it is found that
a large amount of strain upon the mining machine is removed, and that instead of
there being a heavy back pressure upon the stationary bed of the machine and upon
the feeding mechanism by means of which the sliding frame is forced forward, this
pressure is almost entirely removed, it only being necessary to secure the bed firmly
in place, and no special bracing required, and in some cases it is found that the
jacks by means of which the bed is secured against the back pressure are loosened,
showing a drawing strain of the cutter-bar and a tendency for it to be drawn into the
coal as it cuts. It is evident that in rotating the cutter-bar by means of this cog-
gearing two difficulties are found; the first being that unless means are provided for
cutting a course in front of the cog-gearing the teeth thereof will be broken or rather
be worn out by contact with the coal, and the second being that if ordinary cog-
gearing is employed the coal dust or cuttings will enter within the teeth of the cogs
and cause the clogging and breaking of the same.
To overcome the first difficulty I provide the pinion, k, on the cutter shaft, b, with
knives or cutters, l, m, these knives extending out beyond the cog-gear, and so acting
io cut a course for the same. As however, these knives extend beyond the teeth of
the pinion, &, it is evident that they would strike against the teeth of the pinion, i,
as the pinion is rotated. To provide in, said pinion for a reception of these
these knives I have formed the recesses or depressions, n, extending into the peripheral
face thereof and in depth corresponding to the size of the knives, into which recesses
the knives enter, one-half of one tooth in the course of the knife being removed and
the knife entering the recess, n, thus formed, while the remaining half of the tooth acts
to rotate the cutter bar when that portion of the pinions mesh together. The knife, 7,
is formed on one side of the pinion cutting a course for one-half thereof, and the knife
m, is formed on the opposite side thereof cutting a kerf for the other half of the pinion,
the two knives thus serving to cut clearance for the entire face of the pinion, and as
the pinion, i, is directly back of the pinion, k, it also cuts clearance for the course of
this pinion.
In order to prevent the choking of the cog-gearing by means of coal dust or cuttings
I have constructed them as most clearly illustrated in figures, 3, and, 5, the peripheral
faces of the teeth, 2; of the pinions being beveled or inclined from the centre thereof
downwardly towards the edge of the pinion, while the bases, 7, of the depressions, <,
between the teeth of the pinions are correspondingly inclined downwardly from the
centre towards the edges, and as the pinions mesh with each other it is evident that
though the highest portions of the teeth, p, project and fit closely to the highest portions
of the bases, between the teeth, yet that as both these depressions and the peripheral
faces of the teeth are inclined downwardly toward the outer edges as shown, large
spaces between the faces of the teeth are left through which any coal dust or cuttings
would be forced in case there was any tendency for them to clog the cog-gearing.
By so constructing the faces of the teeth and the depressions between them, as is
clearly shown in the drawings, I provide clearance for all such coal dust and cuttings
and assure the operation of the cog-gearing even though the coal dust is thrown by the
cutter bars right over the top of the cog-gearing and between the working faces of the
same where they mesh.
At
When my improved mining machine is in operation, as the sliding frame, 4, is
advanced by the feeding mechanism the drive chains, g, travel forward over the chain
shaft, e, and backwards along the floor of the mine or cut made under the coal.
the same time the pinion, i, on the chain shaft meshes with the pinion, k, on the cutter
bar and rotates said bar in such direction that the knives or cutters, d, rise in cutting
the coal and carry the cutting over the bar throwing them back toward the drive chains,g,
by means of which they are carried back out of the kerf or cut made, the chains
carrying back the cuttings for the reason that they travel backward close to the floor
or lower surface of the cut made.
It has been practically proven that when the cutter bar rotates in the direction

page_text: described, so that the knives cut with an upward movement the machine is relieved
from the heavy back pressure found when the cutter bar rotates in the other direction,
and that loss force is required to rotate the cutter bar, the bar running more freely as
its knives are not pressing against a mass of cuttings and no force is required to push
the cuttings back to the chains, the cuttings being thrown back over where they do
not impede the movement of the bar.
During the cutting of the kerf the knives, l, m, on the pinion, k, cut a course or
path for the cog-gearing, the knife, 1, cutting one-half the path and the knife, m,
cutting the other half thereof, and the knives, as the gearing rotates entering the
recesses, n, in the pinion, /, while the half teeth, 7, in the pinions, i, and, k, sustain the
pressure or strain of the gearing at these points. As the cog-gears engage with each
other the central portions of the teeth p, extend close to the central portions of the
bases,
of the depressions, , between the teeth, and the gearing having sufficient
strength for all strain brought upon it, while, as the faces of these teeth, and the bases
of the depressions are downwardly inclined full space is formed within the meshing
faces of the gearing into which any cuttings, obstructing the proper meshing of the
teeth may be forced, the crowding or breaking of the cog-gearing being thus prevented.
In case any portion of either pinion should be broken it can be quickly replaced, extra
sets of pinions being supplied for this purpose.
Having now particularly described and ascertained the nature of the said invention
and in what manner the same is to be performed I declare that what I claim is :—
1. In a mining machine, the combination of a cutter bar carrying a series of knives
and rotating in such direction as to cut with an upward movement, and one or more
drive chains travelling backwardly along the floor of the cut made, substantially as and
for the purposes set forth.
2. In a mining machine, the combination of a chain shaft, driving chains rotating
said shaft, a cutter bar mounted in front of said chain shaft, and power driving
connections directly between said shaft and cutter bar, substantially as and for the
purposes set forth.
3. In a mining machine, the combination of a cutter, the shaft mounted back of and
parallel therewith, and cog-gearing connecting said shafts, substantially as and for the
purposes set forth.
4. In a mining machine, the combination of a cutter bar carrying a pinion provided
with one or more cutters and a shaft mounted back of and parallel with the cutter bar,
and carrying a pinion having one or more recesses to receive said cutiers, substantially
as and for the purposes set forth.
5. The combination of the pinion, k, carrying the knife 7, on one side of and adapted
to cut a kerf for one half the pinion and the knife, m, on the other side of and adapted
to cut a kerf for the other side of the pinion, and the pinion, /, having depressions, i,
in the course of said knives, substantially as and for the purposes set forth.
6. The combination of the pinion, & carrying the knives 1, m, the pinion, i, having
the depressions, n, in the course of the knives and the half teeth, t, substantially as and
for the purposes set forth.
7. In a mining machine, cog-gearing having the peripheral faces of its teeth or cogs
downwardly inclined from the centre towards the edges to provide clearance for the
cuttings substantially as set forth.
8. In a mining machine cog-gearing having the faces of the teeth and the bases of
the depressions between the teeth, downwardly inclined or beveled from the centre
ioward the outer edges, substantially as and for the purposes set forth.