An Improved Wedge for Breaking Down Coal, Stone, and other Strata.
Year: 1889

page_text: Date of Application, 10th Oct., 1889
Complete Specification Left, 8th July, 1890-Accepted, 9th Aug., 1890
PROVISIONAL SPECIFICATION.
An Improved Wedge for Breaking Down Coal, Stone, and other
Strata.
I, ROBERT ELSE MELLOR of 2 Grove Place, Brampton, Chesterfield, in the County
of Derby, Colliery Enginewright, 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, I diminish
the sides as much as possible by forming the wedges of a curved or oval or semi-
oval shape in cross section, so that they resemble spear heads or anchor flukes.
By this construction, I 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. I also produce a wedge which can be much
more quickly and easily driven into the strata than those hitherto in use.
Dated this 10th day of October 1889.
"
CASTLE SMITH,
Per F. W. Golby,
Invention " Office, 54, Fleet Street, London, E.C., Agent for the Applicant.
COMPLETE SPECIFICATION.
An Improved Wedge for Breaking Down Coal, Stone, and other
Strata.
I ROBERT ELSE MELLOR, of 2 Grove Place, Brampton, Chesterfield in the County
of Derby Engine Wright do hereby declare the nature of this invention and in what
manner the same is to be perforined, to 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.
Now according to this invention, I diminish the sides as much as possible by
forming the wedges of a curved or oval or semi-oval shape in cross section, so that
they resemble spear heads or anchor flukes.
By this construction, I 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. I also produce a wedge which can be more
quickly and easily driven into the strata than those hitherto in use.

page_text: To render this invention clearly understood I 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 thin edge of the wedge.
Fig. 3, is a section of Fig. 1, through A B.
Fig. 4, is an end view of Fig. 2.
From these figures it will be seen that the splitting force of the wedge is at right
angles to its broad sides and very little force can be exerted by it on its thin edges,
so that the strata will be split in the plane of its broadest part and in a line with its
thin edges, and no useful force will be exerted at right angles to this plane, and the
force necessary to drive it into the material will be considerably less than that
required for a wedge of a rectangular section.
Having now particularly described and ascertained the nature of my inven-
tion and in what manner the same is to be performed, I declare that what I
claim is:
An improved wedge for breaking down coal, stone, and other strata substantially as
described and illustrated herein.
Dated this 7th day of Luk. 1800