IMPROVEMENTS IN APRARATUS POR CUTTING MARBLE, STONE, SLATE, AND COAL
Year: 1864

page_text: LETTERS PATENT to George Hunter, of Maenturog, in the County of'
Merioneth, Engineer, for the Invention of "IMPROVEMENTS IN APRARATUS
POR CUTTING MARBLE, STONE, SLATE, AND COAL."
Sealed the 15th November 1864, and dated the 17th May 1864.
PROVISIONAL SPECIFICATION left by the said George Hunter at the
Office of the Commissioners of Patents, with his Petition, on the
17th May 1864.
I, GEORGE HUNTER, of Maenturog, in the County of Merioneth, Engineer,
do hereby declare the nature of the said Invention for "IMPROVEMENTS IN
APPARATUS FOR CUTTING MARBLE, STONE, SLATE, AND COAL," to be as follows:-
My Invention consists in forming tools for cutting stone, marble, slate, and
coal of a solid bar with an enlarged or trumpet mouth, and that dished or
concave on its face; sometimes I make the mouth horse-shoe shaped. For
cutting or boring tunnels in those substances I mount these tools on the end
of a cylinder, or the segments of a cylinder, which segments are capable of
being drawn towards the centre or forced outwards at will; I place a screw or
angular grooves on the outside for the purpose of leading out the debris. "I'
convenient
mount the cylinder on a carriage and drive it by gearing in any
manner.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said George Hunter in the Great Seal Patent Office on the 17th
November 1864.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, GEORGE
HUNTER, of Maenturog, in the County of Merioneth, Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Seventeenth day of May, in the year of our Lord
One thousand eight hundred and sixty-four, in the twenty-seventh year
of Her reign, did, for Herself, Her heirs and successors, give and grant
unto me, the said George Hunter, Her special licence that I, the said George
Hunter, my executors, administrators, and assigns, or such others as I, the
said George Hunter, my executors, administrators, and 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
APPARATUS FOR CUTTING MARBLE, STONE, SLATE, AND COAL," upon the con-
dition (amongst others) that I, the said George Hunter, my executors or
administrators, by an instrument in writing under my, or their, or one of their
hands and seals, 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 George Hunter, do hereby declare the
nature of my said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement thereof, reference being had to the Drawings hereunto annexed,
that is to say:-
My Invention consists in forming tools for cutting stone, marble, slate, and
coal of a solid bar with an enlarged or trumpet mouth, and that dished or
concave on its face. Figure 4 of the accompanying Drawings represents
several views of one of these tools with a tool holder. Sometimes I make the
mouth horse-shoe shaped. For cutting or boring tunnels in stone, marble,
slate, and coal, I mount my improved tools on the end of a cylinder, or the
segments of a cylinder, which segments are capable of being drawn towards
the centre or forced outwards at will; I place a screw or angular grooves on

page_text: the outside for the purpose of leading out the debris. I mount the cylinder
on a carriage and drive it gearing in any convenient manner.
Figure 1 is a side elevation, partly in section; Figure 2 a back elevation;
and Figure 3 a front elevation of a tunnelling machine fitted with my im-
proved tools and arranged as just described.
8
The machine is driven by a band or rope which passes over a pulley K.
1 is a clutch, and m a handle for putting the machine into and out of gear.
The shaft on which the pulley K is mounted carries at its lower end a bevil
pinion L in gear with a bevil wheel M cast in a piece with which is another
pinion N in gear with a wheel O on another shaft below, which shaft carries
pinion P in gear with a wheel Q keyed on the driving shaft R, the wheel
M runs loose on the shaft R. The shaft R is screw threaded, it may if
required be formed with two screw threads of different pitches for slow and
quick feed. J is a sliding bracket or frame which supports at one end the
toothed gearing and at the other end the boring chuck; it is formed with a
rack underneath, into which the teeth of a pinion take in order that the
bracket or frame J may be readily and rapidly caused to advance or recede
by turning a handle connected to the pinion r. W is a box carrying a half
nut in which the screw threads of the shaft R work, the nut is raised when
required by a screw. H is a carriage which supports the machine, it is fixed
by screws T, T, which may be either let into the rock at the sides and top, or
timber may be placed between them and the rock. G is a cutting or boring
chuck, it is carried on the end of the shaft R, and is fitted with two or more
slides F, F, capable of being moved out or in to the extend of a few inches in
order to regulate the diameter of the hcle bored in the rock. A plate of iron E
shewn detached in Figure 5, is fixed to each of the slides F; this plate carries
a number of cutting or boring tools, and its front edge is curved, as shewn, or
inclined, being narrower at that part next the chuck G. A thin piece of iron
is fastened on the curved edge furnished with a strip of leather, india-rubber,
or other similar material to fill up the cut, as shewn at X, Figure 3;. the
debris or cuttings are thus prevented running past, and being soft the leather
or other material will not become jammed in the cut; but should this not be
sufficient to clear the cut of the debris I employ an additional slide or plate
without cutters, but formed with ribs in the direction indicated by the dotted
lines in Figure 5, each of the ribs acts as a screw to bring out any debris that
may be left. Should water get in through fissures in the rock or otherwise
it will be necessary occasionally to withdraw the machine by means of the
rack and pinion in order to clear out the debris. The line V in Figure 1

page_text: indicates the position the front edge of the plate E occupies when the debris
or cuttings from the tools are free to fall; they may be removed by a scraper
when the machine is in motion. Although I have described and shewn the
machine as driven by a band or rope it may if required be arranged to work
by the direct action of steam, air, or water.
And having now described the nature of my said Invention, and in what
manner the same is to be performed, I declare that I do not limit myself to
the employment of my improved cutting tools in the arrangement of machinery
herein-before described as they may be advantageously employed in other
machines, the machine herein-before described may also when desired be fitted
with cutting tools of any other description, what I claim is,-
First, forming tools for cutting marble, stone, slate, and coal of a solid bar
with an enlarged or trumpet or horse-shoe shaped mouth, and dished or con-
cave on its face, as herein-before described.
Second, the general arrangement of machinery for cutting marble, stone,
slate, and coal, herein-before described and illustrated in the accompanying
Drawings.
In witness whereof, I, the said George Hunter, have hereunto set my
hand and seal, this Fifteenth day of November, One thousand eight
hundred and sixty-four.
GEORGE HUNTER.
(L.S.)