An Improved Wedge for Breaking Down Coal, Stone, and any other Strata.
Year: 1893

page_text: Date of Application, 12th July, 1893
Complete Specification Left, 9th May, 1894-Accepted, 9th June, 1894
PROVISIONAL SPECIFICATION.
An Improved Wedge for Breaking Down Coal, Stone, and any
other Strata.
We, ROBERT ELSE MELLOR, of 2, Grove Place, Brampton, Chesterfield, in
the County of Derby, Engineer, and JOHN WILLIAM OGDEN, of 33, Fir Street
Walkley, in the City of Sheffield, Steel and Tool Manufacturer, do hereby
declare the nature of this invention to be as follows:-
'
The object of this invention is to produce a wedge by the use of which coal,
stone, and other strata, can be broken down, without the expenditure of unnecessary
force, which tends to disintegrate the strata in a line at right angles to the line of
fracture required.
Wedges as at present in use are constructed in the form of a rectangular
pyramid, but the flat sides of these wedges have to compress the strata so much,
that it requires considerable unnecessary force to drive the wedges in, and moreover
pressure is exerted at right angles to the line of the fracture required, and tends to
unnecessarily disintegrate the strata. Now according to this invention, we do away
with all side friction, by making the wedges broader across the point, than at any
other part, & the sides slightly tapering from the point to the head of the wedges.
The wedges being of a rectangular shape in cross section.
By this construction, we ensure that the strata will be broken-in the plane of the
broadest part of the wedge, and no useful force will be expended in breaking the
strata at right angles to this plane. We also produce a wedge which can be much
more quickly and easily driven into the strata than those hitherto in use, & the
wedge presents a greater area to the strata (for lifting) nearest the point.
Dated this 8th day of July 1893.
ROBERT ELSE MELLOR.
JOHN WILLIAM OGDEN.
COMPLETE SPECIFICATION.
An Improved Wedge for Breaking Down Coal, Stone, and any
other Strata.
We, ROBERT ELSE MELLOR, of 2 Grove Place, Brampton, Chesterfield," in
the County of Derby, Engineer, and JOHN WILLIAM OGDEN of 33, Fir Street,
Walkley, in the City of Sheffield, Steel and Tool Manufacturer, 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 :-
.
The object of this invention is to produce a wedge by the use of which coal,
stone, and other strata can be broken down without the expenditure of unnecessary
force, which tends to disintegrate the strata in a line at right angles to the line of
fracture required.
Wedges as at present in use are constructed in the form of a rectangular
pyramid, but the flat sides of these wedges have to compress the strata so much
that it requires considerable unnecessary force to drive the wedges in, and moreover
pressure is exerted at right angles to the line of fracture required, and tends to
unnecessarily disintegrate the strata.

page_text: Now, according to this invention, we do away with all side friction, by making
the wedges broader across the point, than at any other part, and the sides slightly
tapering from the point to the head of the wedges. The wedges being of a
rectangular shape in cross section up to the broadest part of the wedge, but we do
not limit ourselves to any particular length of point.
By this construction, we ensure that the strata will be broken in the plane of the
broadest part of the wedge, and no useful force will be expended in breaking the
strata at right angles to this plane. We also produce a wedge which can be much
more quickly and easily driven into the strata than those hitherto in use, and the
wedge presents a greater area to the strata (for lifting) nearest the point.
To render this invention clearly understood we annex one sheet of drawings in
which
Fig. 1 represents a view looking at the broad side of the wedge.
Fig. 2, is a view looking at the narrow side of the wedge.
Fig. 3, is a view looking at the top of the head of the wedge.
Fig. 4, is a section of Fig. 1 through A. B.
Fig. 5 is a section of Fig. 1 at the point, through C. D.
From these figures it will be seen that the splitting force of the wedge is in the
plane of the broadest part of the wedge, and no force be exerted by it at right
angles to this plane, so that the strata will be split in the plane of the broadest
part of the wedge, and the force necessary to drive it into the material will be
considerably less than that required to drive a wedge of triangular longitudinal
section as in the old form of wedge..
Having now particularly described and ascertained the nature of our invention,
and in what manner the same is to be performed we declare that what we
claim is;-
An improved wedge for breaking down coal, stone, and other strata substantially
as described and illustrated herein.