AN IMPROVED METHOD OF QUARRYING CERTAIN SUBSTANCES
Year: 1851

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ROBERT
ROBERTS, of Dolgelly, in the County of Merioneth, Mine Agent, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent under the Great Seal of Great Britain and Ireland, bearing date
at Westminster, the Twenty-fifth day of September, in the fifteenth year
of Her reign, did give and grant unto me, the said Robert Roberts, my exors,
admors, and assigns, Her especial licence, full power, sole privilege and
authority, that I, the said Robert Roberts, my exors, adñors, and assigns,
and such others as I, the said Robert Roberts, my exors, admors, and
assigns, should at any time agree with, and no others, from time to time and at
all times thereafter during the term of years therein mentioned, should and
lawfully might make, use, exercise, and vend my Invention of "AN IMPROVED
METHOD OF QUARRYING CERTAIN SUBSTANCES," within that part of the United
Kingdom of Great Britain and Ireland called England, Her Majesty's
Dominion of Wales, and Town of Berwick-upon-Tweed, and in Her Islands of
Jersey, Guernsey, Alderney, Sark, and Man, and also in all Her Majesty's Co-
lonies and Plantations abroad; in which said Letters Patent there is contained a
proviso requiring that I, the said Robert Roberts, shall particularly describe
and ascertain the nature of my said Invention, and in what manner the

page_text: same is to be performed, by an instrument in writing under my hand and seal,
to be enrolled in Her said Majesty's High Court of Chancery within six calendar
months next and immediately after the date of the said in part recited Letters
Patent, as, reference being thereunto had, will more fully and at large appear.
NOW KNOW YE, that in compliance with the said proviso, I, the said
Robert Roberts, do hereby declare that the nature of my Invention, and
the manner in which the same is to be performed, are particularly described
and ascertained in and by this Specification or Instrument in writing (reference
being had to the Drawings hereunto annexed) in manner following, that is to
say
The mode of quarrying hitherto generally used in working slate and some
other quarries is by raising, removing, or throwing down portions or masses of
the natural slate or other rock, by inserting charges of gunpowder into holes
made in the rock and then by blasting the same. By these means portions or
masses of the rock are thrown down or detached, but the pieces thus obtained
are generally very irregular in shape and much broken, occasioning a large
amount of waste and great uncertainty with respect to the sizes and shapes of
the pieces obtained. My Invention is intended to lessen the above evils in
quarrying and raising and obtaining slate rock and other substances of a like
nature, consists in quarrying slate rock, and other substances to be raised
from quarries, which in the natural rock are laminated in a similar manner to
slate rock, by cutting or forming one or more artificial joints or cuts so as to
form one or more of the edges of each intended table, plate, block, or portion
of the slate, rock, or other substance which is to be quarried or detached from
the quarry, for the purpose of facilitating the severing or detaching such table,
slab, block, or portion of slate rock, or other substance, and diminishing the
waste of material, and which being done, the table, slab, block, or portion
may be detached and raised by means of chisels or wedges driven into what is
usually, in slate quarries, called the cleavage.
The modes I adopt in quarrying slate rock are as follows:-The tops or
hards and valueless parts of the rocks or other substances having been pre-
viously removed or cleared away in the common modes now in use, so as to
leave exposed and ready for operating upon a face or surface of good slate
rock, a table, slab, block, or portion of which is intended to be quarried or
raised, one or more of the edges of the intended table, slab, block, or portion
being also exposed, and capable of being operated upon, I then proceed to
make an artificial foot joint or cut at the lower edge. of the intended table,
slab, block, or portion, in any convenient manner, so as to detach or separate

page_text: that edge of the table, slab, block, or portion from the rock below it. And
when the size of the intended table, slab, block, or portion renders it necessary
so to do, I also make an artificial joint or cut along the intended line of the
plearage, so as to detach or separate that edge of the table, slab, block, or
portion from the adjoining rock; or I bore one or more holes in the line
of the plearage, as herein-after mentioned.
In Figure 1 have shewn a plan view of a portion of a slate quarry, in which
the planes of the plearage joints are not vertical to the horizon. Figure 2 is
a transverse section of Figure 1, and Figure 3 is a front elevation of the same.
In these Figures A, A, A, indicate the lines of plearage or pillam, and B, B, B,
the cleavage or natural lamina of the slate. In these Figures the planes of
the plearage joints and of the cleavage are both shewn to be oblique to the
horizon, but at right angles to each other. I first mark upon the slanting
face of the slate rock the required line or lines of cut for forming the artificial
foot joint or joints of the intended table, slab, plate, or block, at right angles
to the line or lines of plearage, when so required; I then bore several
holes C, C, C, down to the intended line or surface of cleavage, and after-
wards intermediate holes C¹, C', C, also bored down to the intended line or
surface of cleavage. The intermediate substance left between any two of
these holes will require to be broken or cut away to complete the continuous
line of artificial foot joint or cut at the lower edge of the intended table or
slab by the means herein-after described. Or, instead of boring the holes
apart from each other, and removing the intermediate substance away from
between them, as I have mentioned, a series of holes may, in the first
instance, be, made close together, as seen in the elevation, Figure 5, so as at
once to form the intended artificial foot joint or cut. In forming this kind of
foot joint or cut I prefer temporarily to plug the hole or holes, so as to protect
the lower edge of the block or slab while being separated in the line of
cleavage, and also to facilitate the boring of intermediate or contiguous holes,
the plug being of such a description, and introduced in such a manner, that it
may be withdrawn with facility. I then insert one or more chisels or wedges
at the upper corner of the open side of the intended table, slab, plate, or
block, and continue such operation till I have sufficiently opened the cleavage
down to the artificial foot joint, and to the required breadth, for the size of
the table, slab, plate, or block. I then proceed to divide the plearing in the
usual manner now commonly adopted; but when the intended line of plearage
is long, or the tables or slabs to be raised are of considerable thickness, I also
make a continuous cut along the line of plearage, or otherwise bore one or

page_text: more holes, as seen at D, in Figures 1 and 2, into which hole or holes I drive
a wedge tool known as a plug and feathers, to obtain the severance of that
edge of the intended table or slab from the rock."
In Figures 4, 5, and 6 are shewn a plan view, a section, and an elevation
of a portion of a slate or stone quarry similar to that already described in
Figures 1, 2, and 3, excepting that the planes of the plearage joints are
vertical, or nearly so, to the horizon; the lines of the artificial foot joiut,
being, as before made, at right angles with the plearage joints. The various
parts shewn in Figures 4, 5, and 6 are respectively marked with the same
letters of reference as the similar parts in Figures 1, 2, and 3. When it is
intended to make the artificial foot joint or other cut in a straight line, and in
order that the holes may be bored as nearly as possible in the same plane or
curve! I regulate the working of the borers or tools by means of any con-
venient apparatus. And I have found the double-guide- apparatus, shewn in
Figures 7, 8, and 9, to be convenient for the purpose of making a straight cut.
Figure 7 is a front elevation of this double guide or apparatus. Figure 8 is a
plan view of it; and Figure 9 is an end view of the same. E and F are the
top and bottom plates, which are made of iron, and framed to end pieces, and
supported by pillars secured by nuts screwed on their ends. This guage is
furnished at each end with set screws e, e, and f, f, for fixing the guage at any
required height, and either set screws, as shewn at e, e, or hand screws, with
washers, as shewn at f, f, may be used for this purpose. The top and bottom
plates of the guage have holes which correspond with each other, and of the
proper size to receive the tool or tools to be used, and they are made at such
distances apart as may be required for making the holes in the intended places
or positions. The feet of the standards have also holes for securing the appa-
rátus to the slant or face of the slate rock, or other quarry by means of plug
bolts. Although I have stated that the plates E and F are made of iron, yet
they may be formed of wood, as shewn at Figure 10, or of wood and iron coui-
bined, as shewn at Figure 11. In using this machine it is necessary first to
fasten the standards to the quarry face or slant by plug bolts, which may be
driven into holes made to receive them in the rock, so that the guide will be in
a line with or directly over the line of the intended cut or row of holes. Each
hole is to be bored by working the tool to be used in a pair of holes in the top
and bottom plates, the tool operating in the usual manner, but in its motions
guided by the pair of holes within which it works." In cases where it may be
inconvenient to use the apparatus just described, I use another double-tool
guide, shewn in the top plan view, Figure 12, and side elevation, Figure 13.

page_text: This apparatus only forms a guide for making one hole each time it is fixed,
and consequently it must be shifted from time to time, as other holes are
required to be made. It is also to be made secure to the quarry face or slant
by the plug bolts, as shewn in the Drawing. In using these machines the
workmen may, when necessary, stand upon platforms suitably adapted for
enabling them to work the tools.
In Figures 14, 15, 16, and 17 I have shewn tools which may be used for
breaking or cutting away the spaces between the holes C, C, C', made for
forming an artificial foot joint. Figure 14 I call a dagger with one flange,
and it is used by being driven into one of the holes, so that the flange will cut
or break away the part of the slate or other rock left between the hole being
operated upon and the hole next to it. Figure 15 is a double-cutting tool
capable of cutting away both sides at the same time, and it is worked in the
ordinary manner. Figure 16 is a tool with three cutters on each side,
capable of cutting in like manner. Figure 17 is in effect a combination
of Figures 14 and 15, and combines a cutter and dagger flange. The whole
of these tools are intended to be used for breaking away or removing the
parts of slate rock left between the holes bored for making an artificial foot
joint, when such holes are not bored into or close to each other. For boring
these holes I prefer to use a jumper, having the ends formed with edges
inclined in opposite directions, as shewn in the Drawing at Figure 18. In
the Drawings I have shewn what I prefer to be the distance between holes
bored for the purpose of making an artificial foot joint or cut, and I have directed
that the line of cut should be at right angles to the plearage joint, yet it is.
evident that the lines may be cut at different angles to the plearage joint, and
that the diameters of the holes and the spaces between them may be varied.
according to the nature of the slate rock or other material to be quarried, or
that the lines may be in a curved or other form if required.
In Figures 19, 20, 21, 22, and 23, I have shewn an apparatus or machine
O made of wrought or cast iron. The parts may be made of wood, which may
be used in making or completing artificial foot joints. Figure 19 is a side
elevation of the apparatus with the tool raised ready for working. Figure 20
is a top plan view; Figure 21. is an end view of the standard and slide
which carries the tool; 'Figure 22 is a transverse section, shewing a face
view of the standard and slotting tool and guide; and Figure 23 is a detached
view of the upright tool carrier, and which has a groove for a stop. pin to.
prevent its being raised too high. G is the frame or bed of the machine,
having V. guides for carrying the sliding standard, and in which works! the

page_text: slide carrying the slotting tool H. This tool is held firm by a screw T which
passes through the staple, as seen in the Drawing. I is a pillar, the top of
which forms the fulcrum of the hand lever.J, and which, by means of the
lifting bar K, raises and lowers the cutting tool H. In order that the tool
shall progressively advance so as to make a fresh cut, the sliding standard L is
drawn forwards by means of the carrying screw M, one end of which works
in the upright, collar N. This screw is also provided with a ratchet wheel O
and a short lever P and pall Q, which lever is worked by a connecting rod R
also attached to the hand lever J. It will be evident as the handle is raised
or depressed the cutting tool H will be caused to rise or fall by means
of the lifting bar K, and also made to advance by means of the connecting
rod R, which works the ratchet wheel O, and causes the screw M to revolve.
This machine must also be secured to the slate slant by plug bolts or screws
s, s, over the line of holes already described. When holes. are bored along
the line of an intended cnt to be made or completed by means of this
_machine, such holes may be bored at much greater distances apart.
I have described the aforesaid several modes of operating in making cuts or
joints, and the aforesaid several instruments or apparatus which may be used
in making such cuts, for the purpose of shewing or illustrating the manner in
which my Invention is to be carried into effect; but the cuts or joints which
must be made in quarrying, according to my Invention, may be made in any
other manner which may be found to be most economical, according to the
nature of the material to be operated upon. Instead of raising or detaching
only one layer of the slate rock, or other laminated material or other substance
to be quarried, two or more of such layers may in some cases be detached
and raised in one piece, table, or slab at the same time, and the layers or
some of them may afterwards (if required) be separated or detached from each
other. Plates, tables, blocks, or slabs of slate rock, or other laminated sub-
stances, after being quarried according to this inethod, are, when removed
from the beds or plates from which they have been severed, to be dressed or
otherwise treated in any manner ordinarily used in treating such substances.
After such portions of slate rock or other laminated substances have been
detached according to this inėthod of quarrying, the top edge of the next
portion of slate rock or other substance immediately below will generally be
found free from broken material and ready to be quarried in a similar
manner.
Having now described the nature of my said Invention, and the manner in
which the same is to be performed, I hereby declare that I claim as of my

page_text: said Invention the quarrying of slate rock and other laminated substances in
manner herein-before described.
In witness whereof, I, the said Robert Roberts, have hereunto set my
hand and seal, this Twenty-second day of March, One thousand eight
hundred and fifty-two.