A NOVEL AND IMPROVED WEDGING APPARATUS FOR BREAKING AWAY COAL OR OTHER MINERAL OR MATERIAL OUT OF THE SOLID, WITHOUT THE USE OF EXPLOSIVES
Year: 1876

page_text: COMPLETE SPECIFICATION filed by the said Martin Macdermott and George
William Elliott at. the Office of the Commissioners of Patents on the 29th
March 1876.
MARTIN MACDERMOTT, of 25 and 26, Pudding Lane, in the City of London,
Architect, and GEORGE WILLIAM ELLIOTT, of Stanley Terrace, Chowbent,
near Manchester, Mechanical Engineer. "A NOVEL AND IMPROVED WEDGING
APPARATUS FOR BREAKING AWAY COAL OR OTHER MINERAL OR MATERIAL OUT
OF THE SOLID, WITHOUT THE USE OF EXPLOSIVES."
This Invention refers to an improved implement for getting coal or other mineral
or material by breaking up with a wedge the mass which it is desired to
displace.
On
An arrangement, consisting of a central wedge driven in for a short distance
from the face of the coal between short metal plates, has long been in use by
miners, and is known to them as the "Plug and Feather," but such an arrange-
ment, exerting its force close to the face of the coal, is necessarily inefficient.
the other hand, very complicated and expensive arrangements of the wedge have
been devised for the purpose of forcing apart segments, rams, and subsidiary wedges
by the application of hydraulic or screw pressure acting within a tube, and so
breaking down the mass of mineral.
The object of the present Invention is to obtain, with a very simple implement
suited to the rough requirements of mines, an apparatus of great power, casily
applied by two arrangements, of which the following are descriptions:-
First arrangement, shewn at Figures 1, 2, 3, and 4. The implement in its
simplest form consists of three parts only, without the use of a tube. Firstly, of a
bar of steel or of iron, or of steel and iron, which for a certain portion of its length
from A to B is round or polygonal in section, with parallel sides, and of which the
remaining portion B to C is tapered off into a fine wedge, the surfaces connecting
the wedge planes being convex. This may be called the wedge bar, a representa-
tion of which is shewn at Figure 2. Secondly and thirdly, it consists of two side
pieces or lugs, two views of each of which are shewn at Figure 3, made either of
steel or iron, or partly of each, these two side pieces being identical in form and
dimensions and interchangeable, and having a certain length F to G and F" to G",
coinciding as to their inner portions when in position with the taper planes of the
wedge, and the outer portions following the same convexity as the surfaces con-
necting the wedge planes, the outer or convex sides being parallel in the direction
of their length to the axis of the wedge. The effect of this arrangement is that
Din

page_text: when the wedge and the two side pieces are laid closely together, so that the inner
surfaces of the side pieces coincide with and lie upon the taper sides of the wedge,
the extreme point of the three pieces also touching an imaginary line at right
angles with the axis of the wedge, as shown at Figure 1, the whole forms in
section a circle, and longitudinally a cylinder, such circle and cylinder being made
almost equal in diameter to that of the hole which is to receive it. The portion of
each side piece or lug which is thus made convex on its outer sides, extends for a
length equal to nearly that of the wedge portion of the bar, and tapers off in the
direction contrary to the taper of the wedge, the remaining portion G to Hand
G' to H' of each side piece or lug being narrowed and thinned to a strip of metal
sufficiently long to extend to the outside of the hole, or a little beyond, when the
three pieces forming the cylinder are placed in the hole in position to commence
their work. The central metal bar, which at its further end forms the wedge, is
made long enough to project a foot or so outside the hole when the extremities of
the three pieces forming the implement are in the position last described, as shewn
in Drawing at Figure 1.
The implement thus described is applied as follows:-The coal or other material
to be broken down having been first undercut or
kirved" in the usual way. Λ
hole is then drilled in the coal or other material to be acted on of a diameter very
slightly greater than that of the cylinder already described formed by the three
segments thereof when in juxtaposition. This hole is drilled so much further into
the coal, as the wedge has to be driven up or in, so as to allow a free space in
advance of the point of the wedge for the latter to enter without obstruction (see
Figures 1 and 4.) The said two side pieces or lugs are then placed in juxtaposition,
the tapered sides of the same facing and opposite to each other, so that the two
pieces conjointly should be of the length of a single piece, and are pushed loosely
into the hole until they have reached the position where the power is to be applied,
which position is to be indicated by the ends only of the thin slips then projecting
out of the hole. The middle wedge is then introduced between the side pieces and
pushed forward until it has become tightly fixed against them. Then the wedge.
bar is driven up with a hammer as far as may be, or as far as may be necessary, to
obtain the required expansion for effecting the fracture of the coal or other mineral
or material acted upon. The amount of expansion thus obtained with a three inch
cylinder formed and put together as already described is about one inch, and this
in most cases is sufficient to cause the fracture and displacement of the mass.
in cases where a further expansion may be required to effect this object the arrange-
ment is to be varied in the following manner:
But
Second arrangement. In this arrangement (see Figures 5, 6, 7, and 8) the middle
wedge A is made with one straight side from end to end, and the other is
tapered at one end to form the wedge, and one of the side pieces is made with a
corresponding taper on the inside, the outside thereof being parallel with the
straight side of the middle wedge, or nearly so, when in position, such outside being
convex, so as to have a good bearing against the concavity of the whole, its thinner
or taper end being continued by a slip projecting to the outside of the hole. The
other side piece is made parallel from end to end, and is only used as a smooth
surface for the straight side of the middle wedge to act upon, or it may be dispensed
with altogether, in which case the straight side of the middle wedge is made convex
so as to have a good bearing against the material to be acted upon. When the
middle wedge is driven up with a hammer, as described for the first arrangement,
a second wedge may be inserted between the first wedge and the tapered side piece
and driven up in like manner, the first middle wedge taking a true bearing against
the material operated on and forming a side piece for the second wedge. This
operation may be repeated if necessary by the insertion of other wedges.
Having thus described the nature of the Invention, and in what manner the
operation of the same is to be performed, it is to be understood that we do not
limit ourselves exactly to the precise details here given, as they may obviously be
varied without departing from the nature of the Invention, but what we claim is--

page_text: First. The improved arrangement and form of each of the three parts constituting
the implement, here described and shewn, which we designate "An Improved Plug
and Feather," and the manner of the combination and operation of these parts, as
substantially herein-before shewn and described as "the first arrangement,"
forming and being a novel and improved wedging apparatus and arrangement for
breaking away coal or other mineral without the use of explosives.
Secondly. Such additional and subsidiary parts and arrangements connected
herewith as are also as "the second arrangement" herein described and shewn.
In witness whereof, I, the said Martin Macdermott for myself and on behalf
of the said George William Elliott, have hereto set my hand and seal, this
Twenty-ninth day of March, in the year of our Lord One thousand eight
hundred and seventy-six.
MARTIN MACDERMOTT. (L.S.)