IMPROVEMENTS IN MINING MACHINES.
Year: 1879

page_text: LETTERS PATENT to Henry Howell Doubleday, of the City of Washington, in
""
the District of Columbia, and United States of North America, for the Inven-
tion of "IMPROVEMENTS IN MINING MACHINES. A communication by Francis
Marion Lechner, of Waynesburg, in the County of Starke, and State of Ohio, in
the said United States of North America.
COMPLETE SPECIFICATION filed by the said Henry Howell Doubleday at the
Office of the Commissioners of Patents on the 13th October 1879.
HENRY HOWELL DOUBLEDAY, of the City of Washington, in the District of
Columbia, and United States of North America. "IMPROVEMENTS IN MINING
MACHINES." A communication by Francis Marion Lechner, of Waynesburg, in
the County of Starke, and State of Ohio, in the said United States of North
America.
Figure 1 is a plan view of a portion of a cutter bar having certain of my improve-
ments applied thereto; Figure 2 is a vertical section on line 2, x, of Figure 1;
Figures 3 and 6 are like views on line y, y, of Fig. 1, the former showing the
arrangement of driving chain, and the latter the arrangement of cutter teeth.
Figure 4 is an isometrical view of one of the driving-chain links.
Figure 5 is an elevation of the cutter-bar with the cutting tooth.
Figure 7 represents so much of my machine as is necessary to show the means
employed for moving the sliding-frame backwards, and Figure 8 is a section of
shaft M showing the arrangement of winding spool.
Like letters of reference are employed in the above described Figures of Drawing
to indicate like parts wherever such may occur.
A represents the cutter bar, substantially rhomboidal in cross section (Fig. 2),
except at such points as are traversed by the chains, and other places where it is
mounted upon sliding carriers, at which points it is rounded to fit the bearings in
which it turns. Upon opposite sections of this bar are fitted the cutter plates B, B¹,
the cutting teeth of plate B¹ being arranged to cut out the ridge left by the teeth
of plate B. These cutters are adjustably secured to the bar A by means of screw
bolts b, which pass through slots in the cutter plates, and it will be observed that
the shape of the cutter-bar is such as to provide wide faces upon which to secure
the cutters. The cutter bar is provided with lugs a to engage with the driving
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page_text: chain, and it will be seen that any peculiar construction of bar possesses some
advantages over those heretofore used. For instance, by making the portion
traversed by the chains square in cross section I am enabled to use a chain com-
posed of links of equal length, and provide that each lug shall be acted upon at an
equal distance from the centre of the bar, thus applying the power with uniformity,
while by making the portions of the bar which are occupied by the cutters rhom-
boidal in cross-section I am enabled to furnish wide bearing surfaces for said
cutters, and by constructing parts of the shaft with the long sides or the wide sides
at right angles in cross section to the other sides or faces I am enabled to arrange
the cutters upon all four sides of the bar, thus ensuring a nearly continuous cutting
action and great steadiness in the movements of the cutting devices. The face of
cach lug is formed upon the arc of a circle struck from about the centre of the
opposite side of the same lug, for a purpose presently explained.
The links of the chain are formed of rectangular bars of metal C, C, D, D, con-
nected by means of pivots E, each pivot carrying a friction roller F between two
of such links, the diameter of the rollers in one direction being such as to space the
links properly, and in the opposite direction to cause said roller to project slightly
beyond the end of the links. These rollers perform still another function, presently
explained. Each of the links is beveled upon one side to form a knife or cutting
edge c or d, these edges being formed upon the inner faces of said links, that is to
say, those faces which engage the cutter bar.
I have found in using chains the links of which are of the same thickness upon
both edges that in operating my machine, especially when cutting slate, the fine
dust is sometimes packed upon the cutter-bar by the chain, thus forming a coating
upon the bar, and producing an enlargement at the points traversed by the chain to
such an extent as to increase its tension, and seriously interfere with driving the
cutters, but by using links with knife edges I find that the difficulty is entirely
obviated, as the cutting action of said edges wholly prevents this accumulation and
packing of dust from the slate or other material.
Figure 3 shows clearly the operation of the friction rollers, and it will be seen
that owing to the faces of the lugs a being formed in arcs of circles the friction
rollers traverse the lugs easily, although in close contact therewith, as the cutter-
bar is revolved, hence any unsteadiness or back-lash of the cutter-bar is prevented
by the close contact of the friction rollers with the lugs during their engagement.
Each luga is provided with a cutting spur a¹, Fig. 1, to remove the coal as it
advances, leaving but a thin wall of coal uncut in front of each chain link. Two
or three such teeth may be employed if desired, one between the links, as shown,
and the other two on opposite sides thereof. In order to firmly secure the single
cutting tooth a¹ in the cutter bar A. I form in the latter a mortice or socket aⓇ to
receive the shank A2, which is by preference square or rectangular in cross section.
The upper end of the tooth is tapering, and by preference tetragonal, with three or
more sides of unequal length in cross section. a³ is a keeper, having near one end
a recess of such form and size as will fit closely the tapering portion of the tooth at
that point where it projects beyond the face of the cutter-bar when said tooth is in
working position, the keeper being secured to the bar by a bolt or set screw a*, and
thus securing the tooth firmly in place.
In my former Patent I showed a cutter-bar having recesses formed in its sides,
and a chain, the links of which are provided centrally with projecting lugs, which
take into the recesses; but my present construction possesses many advantages
over the former one, in that I am enabled to mount friction rollers on the chain-
link pivots, said rollers engaging lugs on the cutter bar; and again, the use of lugs
on the bar enables me to use knife-edged chain links, which I could not construct
with lugs projecting from the knife edges, as there is not thickness enough of metal
upon the under edges to support lugs at that point.
My Invention further relates to devices for withdrawing the cutter-bar from the
coal, and as these devices are to be applied to the machine heretofore patented by
me it will only be necessary to refer to those parts thereof as are more intimately

page_text: connected with these devices. Referring to Figures 7 and 8, G is one of the sills
which rests on the floor of the mine and support the other parts of the machine.
H is the cutter-bar driving chain driven from shaft H, which in turn is driven
from shaft K by chain k¹, the latter shaft being driven from the engine shaft
through the gearing K, k. A post or standard L rises from the rear girt of the
main frame, and is connected by a rope or chain with a drum on shaft M, which
shaft is supported upon the sliding frame, and is rotated by a chain m from shaft K'.
A spool 0, 01, 02, Fig. 8, loosely mounted on shaft M between a cone M¹ rigidly
connected with or formed upon said shaft, and a cone N' connected with a shaft by
a feather or spline m', so that this cone may rotate with the shaft, and permit it to
slide thereon longitudinally. The cone N₁ is provided with a sprocket wheel N,
the spurs n of which engage the links of chain m, which connects the sprocket
wheel with a like wheel (not shown) upon shaft K.
The cone is further provided with a grooved hub N³, with which a forked lever
or other equivalent devices engages to slide said cone endwise on the shaft M. The
ends 0, 0, of the spool are inade flaring to fit close upon the cones M', N¹,
respectively, and 0, 0, are flanges on the spool to insure a proper winding of the
rope. It will be readily understood that when the cone N₁ is forced inward
toward the cone M¹ the spool will be firmly held between them, and rotate
with the shaft M to wind the rope on said spool to draw the sliding frame and
cutter rearward toward the post L, the cone M¹ serving as a stop to support the
spool against the end thrust of the cone N¹, and a collar or flange might be sub-
stituted for said cone M¹.
Having now described my Invention what I claim is,—
1st. The chain herein-before described, consisting of links C, C, D, D, pivots E,
and friction rollers F, as set forth.
2d. The cutter shaft, having lugs a whose engaging faces are formed in arcs of
circles, in combination with the chain provided with friction rollers, as set forth.
3d. A chain link for mining machines, having a bevelled cutting edge, as and for
the purpose specified.
4tb. A cutter bar for mining machines, having sections which are square in cross
section to receive the driving-chain, and having other sections which are rhom-
boidal in cross section to receive the cutters, as set forth.
5th. The cutter bar A, having sections which are rhomboidal in cross section,
and having other sections, also rhomboidal in cross-section, but having their under
faces arranged in planes at right angles to the planes of the wider faces of the
adjoining sections, substantially as and for the purposes set forth.
6th. The combination with the cutter-bar provided with a socket of the cutting-
tooth a', and the keeper a³, as and for the purpose specified.
7th. In a mining machine the combination with the main supporting frame G
and its standard L, and the sliding frame G₁, of the rope or chain, and the spool
and mechanism whereby the spool is connected with the driving shaft by a friction
clutch, as set forth.
8th. The combination with the spool of the shaft M, having a stop M and the
cone N', substantially as and for the purpose specified.
In witness whereof, I, the said Henry Howell Doubleday, have hereunto set
my hand and seal, this Thirteenth day of October, in the year of our Lord
One thousand eight hundred and seventy nine.
HENRY HOWELL DOUBLEDAY. (L.S.)