IMPROVE- MENTS IN TOOLS AND MACHINERY OR APPARATUS FOR CUTTING SLATE AND OTHER ROCK
Year: 1868

page_text: LETTERS PATENT to John Dickinson Brunton, of 6, Leighton Crescent,
Kentish Town, Middlesex, Engineer, for the Invention of "IMPROVE-
MENTS IN TOOLS AND MACHINERY OR APPARATUS FOR CUTTING SLATE AND
OTHER ROCK,"
Sealed the 5th January 1869, and dated the 11th July 1868.
PROVISIONAL SPECIFICATION left by the said John Dickinson
Brunton at the Office of the Commissioners of Patents, with his
Petition, on the 11th July 1868.
I, JOHN DICKINSON BRUNTON, of 6, Leighton Crescent, Kentish Town,
Middlesex, Engineer, do hereby declare the nature of my said Inven-
tion for "IMPROVEMENTS IN TOOLS AND MACHINERY OR APPARATUS FOR CUTTING
SLATE AND OTHER ROCK," to be as follows:-
This Invention relates to a peculiar tool for cutting state and other
rock, and also to mechanism for holding and actuating the same.
My improved tool consists of a tool chisel the cutting edge of which
is curvilinear or, as I prefer, semicircular, is of the nature of a gauge
bevelled towards the hollow or concave side, and straight down the
back or convex side. The bevel is carried upward at the same angle.

page_text: from all points of the curved or semicircular edge. I round off what
would otherwise be corners at each extremity of the curve or semicircle,
bringing the roundings off to a cutting edge. The stem of the chisel
is made sufficiently narrow to afford clearance, but not more, the object
being to retain all the strength possible. A guide is placed in front
of the chisel against which it slides in working. This guide I prefer
to make very rigid, and to attach it firmly to the carriage, its object
being to hold the tool to its work and prevent its springing away
from the cut. The tool or chisel is intended to chip or split off pieces
from the rock, the form and mode of application being especially designed
to effect this with the least possible attrition and to make the action
one of simple splitting by forcible pressure upon the edge of the tool.
My improved machine is used to cause the chisel to cut grooves or
slots cutting the rock either "in situ" or when detached from its bed,
and consists of a bed with slides resembling a lathe bed so constructed
that the chisel when in operation may be moved the whole length of
the intended groove to be cut and as close as possible to one side of
the bed. The slides and upper face of this bed are planed, and it is
provided with projecting ears by which with moveable clamps it is
held down by bolts to the rock. I prefer to make the necessary holes
for holding down the machine in the line of the intended groove or
slot, removing the bolts as the tool passes, and if required replacing
them after it has passed; these bolts may consist of two side pieces of
a dovetailed form and a centre piece which is wedge formed, and a cotter
by which the centre piece is driven down between the side pieces,
fixing them firmly in the hole which is enlarged at the lower end, and
being cottared together the three form one piece. The upper end of
the wedge is screwed and passes through the clamp and receives a
nut by which the bed is screwed down. Or in cases where the face
of the rock will admit the bed may be held down by atmospheric
pressure exerted on a partial vacuum produced by an air pump in a
chamber or recess formed on the lower edge of the bed, and resting
with a joint of india-rubber on the face of the rock. Upon the bed
as above described I place a rest or carriage which lies upon the top
face of the bed, and is held down upon it by the slides in the same
way as the slide rest of a lathe. This carriage is traversed along the
bed by a screw or rack and pinion actuated by an intermittent ratchet
motion similar to that which gives the feed movement to the tool

page_text: holder of a planing machine. Upon this carriage I place upright
cheeks or guides in which a slide moves, having attached to it the
holder of the cutting chisel already described. This slide and the
chisel attached to it may have imparted to them a rectilinear recipro-
cating motion by a connecting rod from a crank pin fixed in the face
of a circular plate or chuck keyed on a shaft that is mounted on
pedestals resting on the carriage; this shaft may be driven by toothed
gear from another shaft on the same carriage on which is fixed a clip
pulley driven by a wire rope from the prime mover.
I also prefer
to employ a rapidly revolving fly wheel so that the distribution of
the power may be equalised. Direct action either from a steam cylinder
or a hydraulic ram may be employed as a substitute for the above
described crank action. In cutting rock after it is detached from its
place in the quarry I attach the slotting chisel to a slide working in
a suitable frame above a moveable bed, on which I place the rock to
be operated on.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said John Dickinson Brunton in the Great Seal Patent
Office on the 8th January 1869.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
DICKINSON BRUNTON, of 6, Leighton Crescent, Kentish Town, Middlesex,
Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Eleventh day of July, in the year of
our Lord One thousand eight hundred and sixty-eight, in the thirty-
second year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said John Dickinson Brunton, Her special
license that I, the said John Dickinson Brunton, my executors, ad-
ministrators, and assigns, or such others as I, the said John Dickinson
Brunton, my executors, administrators, or assigns, should at any
time agree with, and no others, from time to time and at all times
thereafter during the term therein expressed, should and lawfully
might make, use, exercise, and vend, within the United Kingdom of
Great Britain and Ireland, the Channel Islands, and Isle of Man,
an Invention for "IMPROVEMENTS IN TOOLS AND MACHINERY OR APPARATUS

page_text: POR CUTTING SLATE AND OTHER Rock," upon the condition (amongst others)
that I, the said John Dickinson Brunton, my executors or adminis-
trators, by an instrument in writing under my hand and seal, should
particularly describe and ascertain the nature of the said Invention,
and in what manner the same was to be performed, and cause the
same to be filed in the Great Seal Patent Office within six calendar
months next and immediately after the date of the said Letters
Patent.
NOW KNOW YE, that I, the said John Dickinson Brunton, do
hereby declare the nature of my said Invention, and in what manner
the same is to be performed, to be particularly described and ascertained
in and by the following statement, reference being had to the accom-
panying Drawings, and to the letters and figures marked thereon, that is
to say :-
My said Invention relates to a peculiar tool for cutting slate and other
rock and also to mechanism for holding and actuating such tool.
My improved tool consists of a chisel the cutting edge of which
is curvilinear, or, as I prefer, semicircular, or of the nature of a gouge
bevelled towards the hollow or cancave side aud straight down the
back or convex side. The level is carried upward at the same angle
from all points of the curved or semicircular edge. I round off what
would otherwise be corners at each extremity of the curve or semicircle,
bringing the roundings off to a cutting edge. The stem of the chisel
is made sufficiently narrow to afford clearance, but not more, the object
being to retain all the strength possible. A guide is placed. behind
the chisel, against which it slides in working; this guide I prefer
to make very rigid, and to attach it firmly to the carriage, its object
being to hold the tool to its work and prevent its springing away
from the cut. The tool or chisel is intended to chip or split off
pieces from the rock, the form and mode of application being especially
designed to effect this with the least possible attrition and to make
the action one of simple splitting by forcible pressure upon the edge
of the tool.
My improved machine, the object of which is to cause the chisel
to cut grooves or slots cutting the rock either "in situ " or when
detached from its bed, consists of a bed with slides resembling a lathe
bed so constructed that the chisel when in operation may be moved
the whole length of the intended groove to be cut and as close as

page_text: possible to one side of the bed. The slides and upper face of this
bed are planed, and it is provided with projecting ears by which with
moveable clamps it is held down by bolts to the rock. I prefer to
make the necessary holes for holding down the machine in the line
of the intended groove or slot, removing the bolts as the tool passes,
and if required replacing them after it has passed; these bolts may
consist of two side pieces of a dovetailed form and a centre piece,
which is wedge shaped, and a cottar by which the centre piece which
is driven down between the side pieces is held in its place, thus fixing
them firmly in the hole, which is enlarged at the lower end, and being
cottared together the three form one piece. The upper end of the
wedge is screwed and passes through the clamp and receives a nut
by which the bed is screwed down. Or in cases where the face of the
rock will admit the bed may be held down by atmospheric pressure,
a partial vacuum being produced by an air pump in a chamber or recess
formed on the lower edge of the bed and resting with a joint or packing
of india-rubber on the face of the rock. Upon the bed as above
described I place a rest or carriage which lies upon the top face of the
bed, and is held down upon it by the slides in the same way as the
slide rest of a lathe; this carriage is traversed along the bed by a
screw or rack and pinion actuated by an intermittent ratchet motion
somewhat similar to that which gives the feed movement to the tool
holder of a planing machine. Upon this carriage I place upright cheeks
or guides in which a slide moves having attached to it the holder of
the cutting chisel already described. This slide and the chisel attached
to it may have imparted to them a rectileanear reciprocating motion by
a connecting rod from a crank pin fixed in the face of a circular plate
or chuck keyed on a shaft that is mounted on pedestals resting on the
carriage; this shaft may be driven by toothed gear from another shaft
on the same carriage, on which is fixed a clip or other driving pully
driven by a wire rope or straps from the prime mover. I also prefer
to employ a rapidly revolving fly wheel so that the distribution of
the power may be equalized. Direct action either from a steam cylinder
or a hydraulic ram may be employed as a substitute for the above
described crank action. In cutting rock after it is detached from its
place in the quarry I attach the slotting chisel to a slide working
in a suitable frame above a moveable bed, on which I place the rock
to be operated on.

page_text: And in order that my said Invention may be fully understood I shall
now proceed more particularly to describe the same, and for that purpose
shall refer to the several Figures on the annexed Sheet of Drawings, the
same letters of reference indicating corresponding parts in all the
corresponding Figures.
Figures 1, 2, and 3 of the annexed Drawing represent one form of
my improved tool or chisel for cutting rock either "in situ" or when
in detached slabs.
Figures 4, 5, and 6 represent another form of the improved tool
having two cutting edges. This form would be used in cutting slabs,
and the stroke of the machine would be regulated so that each of the
cutting edges a, b, would in turn operate from opposite surfaces to
the middle or about the middle of the slab. The object of this arrange-
ment is to avoid splitting off fragments from the under face of the
slab, which the tool represented in Figures 1, 2, and 3 is liable to
do by passing through the entire thickness of the slab.
Figures 7 and 8 represent respectively a front and side elevation of
my improved machine by which with either of the tools above described
I cut the required grooves or slots in the rock or slab. This machine
may be used to cut the rock either in the slabs when detached, or it
may be fixed upon the face of the rock itself and be applied to cut
it "in situ."
A is the fixed bed or base plate; B, a slide with upright standards -C
and vertical guides D, in which the tool holder E moves; F, G, are
winch handles by which in the case of cutting slabs, the machine
may be worked by hand, or if preferred a belt may be placed on the
periphery of the fly wheel H conveying motion from a steam engine
or other prime mover, or one of Fowler's clip pulleys may be substituted
for the fly wheel, and the machine may thus be actuated by a wire
rope. I is a spur wheel fast on the shaft I' driven by the pinion K on
the shaft L; M is a crank pin on the face of the wheel I, to which
is attached the connecting rod N which communicates to the tool
holder E its reciprocating motion; O is the cutting tool, and P the
guide secured to the slide B by which this tool is held to its work;
Qis a ratchet wheel worked by the pall R which is moved at each
stroke of the machine by the cam S on the shaft I' against the roller T
on the suspended arm U. A shaft V passes through the ratchet wheel Q

page_text: having a longitudinal slot in which slides a key or feather fixed in
the said wheel, by which arrangement the shaft V is caused to revolve
with the wheel Q at the same time that it is at liberty to slide through
such wheel as the slide B moves along the face of the bed A. On
the other end of the shaft V is the spur wheel W geared into the
wheel X, which actuates the longitudinal screw Y by which the slide B
is caused to travel along the bed A and so feed the tool up to its
work. In Figures 7 and 8 the machine is represented as being bolted
down upon a detached slab Z by means of the bolts c, c, and the
clamps d, d. In the case of cutting "in situ " I prefer that the
machine should be fastened down by the bolts shewn in Figures 9
and 10 passing thro' the clamps or glands e which rest upon flanches
cast on the inner side of the bed A. The holes to receive these bolts
would be made in the rock in the line of the intended slot. In cases
where atmospheric pressure may be advantageously employed as a means
of holding down the bed, I form the lower edge or base of the bed
as shewn in Figure 11 with a recess or recesses f, f, extending along
its whole length, and by means of an air pump produce a partial
vacuum in the recesses, an air-tight junction being established between
the bed and the surface of the slab or rock by means of india-rubber
packing g, g.
Having now described and particularly ascertained the nature of
my said Invention, and the manner in which the same is or may be
used or carried into effect, I would observe in conclusion that what
I consider to be novel and original, and therefore claim as the Invention
secured to me by the herein-before in part recited Letters Patent is,-
First. The peculiar form of the cutting edge of the cutters for cutting
slots or grooves in slate or other rock, as herein-before described and
illustrated by my Drawings.
Second. The use of a guide in combination with the slotting tool
for the purpose of keeping it up to its work, substantially as herein
before described.
Third. The cutting of slate and other rock by means of a slotting
tool or chisel worked by a crank pin or other equivalent mechanical
device carried on a sliding bed which travels along a fixed bed secured
by bolts or otherwise to the face of the rock to be operated upon,
substantially as herein-before described.

page_text: Fourth. The application of atmospheric pressure for holding the fixed
bed down upon or in contact with the rock, as herein-before described.
Fifth. The making the fixed bed hollow and packing the under surface
thereof with india-rubber or other equivalent packing for the purpose
herein-before described.
In witness whereof, I, the said John Dickinson Brunton, have to
this my Specification set my hand and seal, this Sixth day of
January, One thousand eight hundred and sixty-nine.
JOHN DICKINSON BRUNTON. (L.S.)