AN IMPROVED APPARATUS OR IMPLEMENT FOR BREAKING DOWN COAL OR OTHER MINERAL WITHOUT THE USE OF EXPLOSIVES."
Year: 1876

page_text: LETTERS PATENT to Martin Macdermott, of the City of London, Architect, and
George William Elliott, of Chowbent, in the County of Lancaster, Mechanical
Engineer, for the Invention of "AN IMPROVED APPARATUS OR IMPLEMENT
FOR BREAKING DOWN COAL OR OTHER MINERAL WITHOUT THE USE OF
EXPLOSIVES."
PROVISIONAL SPECIFICATION left by the said Martin Macdermott and
George William Elliott at the Office of the Commissioners of Patents on the
9th December 1876.
"AN
MARTIN MACDERMOTT, of the City of London, Architect, and GEOrge William
ELLIOTT, of Chowbent, in the County of Lancaster, Mechanical Engineer.
IMPROVED APPARATUS OR IMPLEMENT FOR BREAKING DOWN COAL OR OTHER
MINERAL WITHOUT THE USE OF EXPLOSIVES."
"
This Invention, which relates to improved apparatus for breaking down coal and
other mineral without the use of explosives, consists in a novel and peculiar com-
bination of the wedge, screw, and lever, and has for its object the production of an
implement or apparatus which shall most efficiently exert its power for the purpose
of breaking down or fracturing the coal or mineral at the part most required, that
is, at the inner end or extremity of the drilled hole, and not at the orifice thereof as
heretofore.
In implements or apparatus of a similar nature as hitherto constructed the wedge
has been propelled or driven forward between side pieces into the mass to be
fractured. Among the disadvantages attendant on this mode of action are,-firstly,
that when the maximum amount of expansion has been attained, if the mineral be
not thereby fractured and brought down, the implement cannot be withdrawn, but
must remain in its position until it is either hewn out or the mineral has been
brought down by other means; secondly, that no further expansion can be
given to the pieces which make up the implement, in consequence of their being
so closely jammed together that it is impracticable to obtain an additional wedge
having an edge fine enough and of sufficient strength to be inserted between the
tapered surfaces already in contact; thirdly, the expanding action of the wedge
generally begins and is principally exerted near the orifice of the drilled hole, and

page_text: not near the inner extremity thereof, where its principal force is most required
and should be expended; and, fourthly, the inclined planes of the wedge have
hitherto been formed continuous from end to end, whereby the amount of expansion
is limited to the amount of taper which can be so obtained.
To obviate these disadvantages the implement forming the subject of this Inven-
tion has been designed, on the principle of the reverse action and position of the
wedge to that hitherto in use, the thick end of the wedge being placed foremost,
and the other component parts of the implement being arranged conformably, so
that by the gradual withdrawing of the wedge outwards (in using the implement)
the expansion is obtained first in its greatest degree where it can be most. efficiently
exerted for the purpose of fracture; other points of the Invention overcome the
difficulties which are found to occur where the wedge is driven forward or propelled
into the drilled hole, as will appear from the following description
Our improved implement or apparatus is made with a finely tapered wedge (of
steel or other suitable hard metal) placed between two side pieces or cheeks (of the
like material), the latter having tapered internal surfaces 'corresponding with those
of the wedge, while the external surfaces of all three pieces (namely, of the wedge
and of the side pieces) follow the curvature of the hole for which they are intended,
the three pieces when in juxtaposition forming a cylindrical figure. An outward
continuation of the central wedge is formed as a screw, and is made of a sufficient
length to project considerably beyond the orifice of the drilled hole in which it is
placed when in sit; the side pieces are also made of a sufficient length to pro-
ject just beyond the orifice. The screw passes freely through a distance piece
which abuts on the outer ends of the side pieces and through a nut or female screw
of a length sufficient to give adequate power by turning on the screw to withdraw
the wedge outwards between the side pieces, and in proportion as the wedge is so
withdrawn the side pieces are expanded outwardly or forced apart, and are made
to press with great force against portions of the circumference of the hole drilled in
the mineral. The nut abuts against the distance piece, and may be made polygonal
so that it can be grasped by a spanner..
In the foregoing description the wedge is supposed to have continuous unbroken
inclined planes from end to end, but in order to increase the amount of expansion
each tapered side of the wedge is preferably divided into a succession of two or
more parallel inclined planes arranged end to end, and with which the inclined
surfaces of the side pieces are made to correspond. By this means a greater
expansion is effected (than if the inclined planes were continuous) with a given
travel of the wedge.
The mode of operating the improved implement is as follows:-A hole of the
required diameter and length having been drilled in the mineral the improved
breaking down implement is inserted therein so that the outer extremities of the
side pieces project just beyond the orifice of the hole, the distance piece abutting
against them, and the part of the screw on which the nut is projecting beyond the
distance piece against which the nut abuts. The screw and the wedge (of which,
as above stated, it forms a continuation) are then gradually withdrawn outwards
by exerting a leverage on the nut so as to make it revolve on the screw and
against the distance piece until the maximum expansion, or such an amount of
expansion as may be sufficient to cause a fracture in the mineral mass, is obtained.
If however the fracture of the mineral fail to be obtained with the maximum
expansion attainable with the improved implement a further amount of expansion
may be obtained by reversing the turning of the nut and running it along the
screw a little way backwards, which will allow of the wedge being knocked or tapped
back into the hole, when the implement will only occupy a portion of the expanded
hole, and into the unoccupied space a wedge or piece of metal of suitable section
may be inserted so as to fill up the expanded hole, or nearly so, and the operation
of withdrawing the wedge is again repeated until the desired fracture is pro-
duced.
The above referred to reverse turning of the nut may be caused to propel or drive

page_text: inward the wedge (in loosening the implement) by causing the nut to work between
two fixed parts, namely, the distance piece and a collar, which may be connected
thereto by a metallic strap or tie piece, or by other eqvivalent means.
From the foregoing it will be seen that in the method of wedging as hitherto
practised the screw was in a state of compression in driving in the wedge, whereas
in the method contemplated by this Invention it is in a state of tension in with-
drawing the wedge, and in this state it is much easier to work and its power can
be more economically utilized,
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Martin Macdermott and George William Elliott in the Great Seal
Patent Office on the 9th June 1877.
MARTIN MACDERMOTT, of the City of London, Architect, and GEORGE WILLIAM
ELLIOTT, of Chowbent, in the County of Lancaster, Mechanical Engineer. "AN
IMPROVED APPARATUS OR IMPLEMENT FOR BREAKING DOWN COAL OR OTHER
MINERAL WITHOUT THE USE OF EXPLOSIVES."
This Invention, which relates to improved apparatus for breaking down coal and
other mineral without the use of explosives, consists in a novel and peculiar com-
bination of the wedge, screw, and lever, and has for its object the production of an
implement or apparatus which shall most efficiently exert its power for the purpose
of fracturing and breaking down the coal or mineral at the part most required, that
is, at the inner end or extremity of the usual hole drilled therein, and not at the
orifice thereof as heretofore.
In implements or apparatus of a similar nature as hitherto constructed or used
the wedge is usually propelled or driven forward between side pieces into the mass
to be fractured and brought down. Among the disadvantages attendant on this
mode of action are, firstly, that when the maximum amount of expansion has
been thus attained, if the mineral be not thereby fractured and brought down, the
implement cannot be withdrawn, but must remain in its position in the hole until
it is either hewn out or the mineral has been brought down by other means;
secondly, that no further expansion can be given to the pieces which make up the
implement, in consequence of their being so closely jammed together that it is
impracticable to obtain an additional wedge having an edge fine enough and of
sufficient strength to be inserted between the tapered surfaces already in contact;
thirdly, the expanding action of the wedge generally begins and is principally
exerted near the orifice of the drilled hole, and not near the inner extremity
thereof, where its principal force is most required and should be expended; and,
fourthly, the inclined planes of the wedge have hitherto been formed continuous
from end to end, whereby the amount of expansion is limited to the amount of
taper which can be so obtained.
To obviate these disadvantages the implement forming the subject of this Inven-
tion has been designed on the principle of the reverse action and position of the
wedge to that above referred to, the thick end of the wedge being placed foremost
and the other component parts of the implement being arranged conformably, so
that (in using the implement) by the gradual outward withdrawing of the wedge
the expansion is obtained first in its greatest degree where it can be most efficiently
exerted for the purpose of fracture; other points of the Invention overcome the
difficulties which are found to occur when the wedge is driven forward or propelled
into the drilled hole, as will appear from the following description :—
Our improved implement or apparatus is illustrated in two modifications of its
construction in Figures 1 to 16 on the accompanying Sheet of Drawings. Of these
Figures, Figures 1 to 8 represent one modification, and Figures 9 to 16 the other.
Figure 1 is a side view of the implement in its unexpanded condition; Figure 2, a
plan view thereof; Figure 3, a side view of the implement in its expanded con-

page_text: dition Figures 4, 5, 6, and 7, sections respectively through A-B, C-D, E-F,
and G-H; and Figure 8, an end view; and Figures 9 to 15 are similar views to
Figures 1 to 7, the sections being taken through 'I—J, K—L, M-N, and O-P;
and Figure 16, a detail view.
The improved implement is made with a finely tapered wedge 1 (of steel or other
suitable hard metal) placed between two side pieces or cheeks 2 (of the like
material), the latter having inner tapered faces 3 corresponding with those of the
wedge 1 with which they are in contact, while the external surfaces of all three
pieces (namely, of the wedge 1 and of the side pieces 2) follow the curvature of the
hole for which they are intended, the three pieces when in juxtaposition forming a
cylindrical figure, see Figures 4, 5, 6, 12, 13, and 14. An outward continuation of
the wedge 1 is formed as a screw 4, and is made of a sufficient length to project
considerably beyond the orifice of the drilled hole in which it is placed (when in
situl); the side cheeks 2 are also made of a sufficient length to project just beyond
the orifice, and at this part their inner faces 7 are not inclined, but are made
parallel. The screw 4, which may be either round, as shewn in Figures 1, 2, 3,
5, 6, and 8, or flat, as shewn in Figures 9, 10, 11, 13, 14, and 16, passes freely
through a washer, collar, or distance piece 5 (see Figure 16), which abuts against
the outer ends of the side pieces 2, and through a nut or female screw 6 of a length
sufficient to give adequate power by turning on the screw 4 to withdraw the
wedge 1 outwards between the side pieces 2, and in proportion as the wedge 1 is
so withdrawn the side pieces 2 are forced apart or expanded outwardly, and made
to press with great force against portions of the circumference of the hole drilled
in the mineral. The nut 6 abuts against the washer or distance piece 5, and may
be made polygonal, as shewn in Figures 1, 2, 3, and 8 to 11, so that it can be
grasped by a spanner or lever 8, see Figure 8, or it may be made with strong ratchet
teeth and grasped by a ratchet handle.
In the foregoing description the wedge is supposed to have one continuous
unbroken inclined plane at each of two opposite sides (see Figures 1 to 3), but in
order to increase the amount of expansion each tapered side of the wedge 1 may be
divided into a succession of two or more parallel inclined planes arranged end to
end, and with which the inclined faces 3 of the side pieces 2 are made to correspond
(see Figures 9 to 11). This modification allows of a more obtuse wedge being
used, without however diminishing the extent of its bearing surface, so that a
greater expansion is obtainable with a given travel of the wedge than if the
inclined planes of the wedge were continuous, as illustrated in Figures 1 to 3.
+
The mode of using the improved implement is as follows:-A hole of the required
diameter and length having been drilled in the mineral the improved breaking
down implement is inserted therein so that the outer extremities of the side
pieces 2 project just beyond the orifice of the hole, the distance piece 5 abutting
against them, and the end of the screw 4 projecting beyond the nut 6, which abuts
against the distance piece (see Figures 1, 2, 9, and 10). The screw and the wedge
(of which, as above stated, it forms a continuation) are then gradually withdrawn
outwards by exerting a leverage on the nut (by means of the lever, spanner, or
ratchet handle) so as to make it revolve on the screw and against the distance 4
piece until the maximum expansion, or such an amount of expansion as may be
sufficient to cause the fracture and breaking down of the mineral mass, is obtained,
see Figures 3, 7, 11, and 15. If however the breaking down of the mineral fail
to be obtained with the maximum expansion attainable with the improved
implement a further amount of expansion may be obtained by reversing the 5
turning of the nut and running it along the screw a little way backwards, which
will allow of the wedge being knocked or tapped back into the expanded hole,
when the implement will only occupy a portion thereof, and into the unoccupied
space a wedge-shaped piece of metal of suitable section may be inserted so as to
fill up the expanded hole, or nearly so, and the operation of withdrawing the 5
wedge 1 is again repeated until the desired fracture or breaking down of the mineral
is effected.

page_text: The above referred to reverse turning of the nut (in loosening the impleinent)
may be caused to drive the wedge 1 backwards by causing the nut to work
between two immovable connected or fixed parts, namely, the distance piece or
washer 5 and a collar or second distance piece (not shown on the accompanying
Drawings), which may be connected thereto by metallic straps or tie pieces, or by
other equivalent means.
From the foregoing it will be seen that in the breaking down of the mineral by
the method of wedging as hitherto practised the screw was in a state of com-
pression in driving in the wedge, whereas in the method contemplated by this
Invention it is in a state of tension in withdrawing the wedge, and in this state it
is much easier to work, and its power can be more economically utilised.
The inclined planes of the wedge and of the side pieces may be made with either
plane or rounded faces.
The wedge and side pieces may, if required, be magnetized to keep them together
and prevent them falling asunder on the breaking down of the coal.
Having now described the nature and object of our said Invention, together with
the manner in which the same is to be or may be performed or carried into
practical effect, we would remark in conclusion that we claim as our Invention,
the improved and particular construction of wedging implements or apparatus to
be used for fracturing and breaking down coal and other mineral, substantially in
the manner herein-above described and as illustrated on the accompanying
Drawings, and in which the wedge is withdrawn outwardly by the agency of a
screw forming a continuation thereof, and of a screwed nut and spanner or lever,
and effects the breaking down of the mineral by forcing apart free side pieces
or cheeks, the top and bottom or opposite edges of which at all times remain
parallel.
In witness whereof, I, the said Martin Macdermott, on behalf of the said
George William Elliott and myself, have hereunto set my hand and seal,
this Second day of June, in the year of our Lord One thousand eight
hundred and seventy-seven.
MARTIN MACDERMOTT. (L.S.)