IMPROVEMENTS IN STONE-CUTTING MACHINERY
Year: 1855

page_text: LETTERS PATENT to James Hunter and George Hunter, both of Leysmill,
in the County of Forfar, Engineers, for the Invention of "IMPROVEMENTS
IN STONE-CUTTING MACHINERY."
Sealed the 23rd October 1855, and dated the 24th April 1855.
PROVISIONAL SPECIFICATION left by the said James Hunter and George
Hunter at the Office of the Commissioners of Patents, with their Petition,
on the 24th April 1855.
We, JAMES HUNTER and GEORGE HUNTER, both of Leysmill, in the County
of Forfar, Engineers, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN STONE-CUTTING MACHINERY" to be as follows:-
Our Invention consists, first, in certain improved tools for cutting stone
and, second, in an improved table for carrying the stone to be cut.
Our improved tools consist of a saw or circular disc of iron, fitted with holders
for the reception of teeth in such manner that the teeth or any of them may be
turned or removed, and fresh teeth substituted for them, during the working of
the machinery. The teeth are circular (or of such other form as will permit
of their being turned round) at their cutting edge, and hollow for some distance
up their stem. They fit into the holders, and are prevented from falling out by
a spring or other suitable contrivance When the under edge of large blocks
is to be preserved, we cause a similarly constructed and smaller tool to cut an
inch or two in advance of the main tool, but below the stone. Rotary motion is
communicated to the tools from any prime mover.

page_text: Our table is furnished with brackets for fixing the stone and with bars for
steadying its motion. We connect to it a hand or foot wheel for drawing it
back, and provide it with rollers to travel upon.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said James Hunter and George Hunter in the Great Seal Patent
Office on the 24th October 1855.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, JAMES
HUNTER and GEORGE HUNTER, both of Leysmill, in the County of Forfar,
Engineers, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-fourth day of April, in the year of our Lord
One thousand eight hundred and fifty-five, in the eighteenth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto us, the
said James Hunter and George Hunter, Her-special licence that we, the said
James Hunter and George Hunter, our executors, administrators, and assigns,
or such others as we, the said James Hunter and George Hunter, our
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 STONE-CUTTING MACHINERY,"
upon the condition (amongst others) that we, the said James Hunter and
George Hunter, or one of us, by an instrument in writing under our hands
and seals, or under the hand and seal of one of us, 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 we, the said James Hunter and George Hunter,
do hereby declare the nature of our said Invention, and in what manner the
same is to be performed, 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:-
Our Invention consists first, in certain improved tools for cutting stone; and,
second, in an improved table for carrying the stone to be cut.
Our improved tools consist of a saw or circular disc of iron, fitted on its

page_text: periphery with holders for the reception of teeth, in such manner thatthe teeth
or any of them may be turned or removed, and fresh teeth substituted for them,
during the working of the machinery. The teeth are circular (or of such other
form as will permit of their being turned round, at their cutting edge, and
hollow for some distance up their stem. They fit into holders, and are pre-
vented from falling out by a spring or other suitable contrivance. When the
under edge of large blocks is to be preserved, we cause a similarly constructed
and smaller tool to be cut an inch or two in advance of the main tool, but below
the stone. Rotary motion is communicated to the tools from any prime mover.
Our table is furnished with brackets for fixing the stone and with bars for
steadying its motion. We connect it to a hand or foot wheel for drawing it
back, and provide it with rollers to travel upon.
In the Drawings hereunto annexed we have shewn the manner in which
we carry our Invention into effect.
Figure 1 represents a side elevation, and Figure 2 a plan, of our improved
machine; Figure 3 represents a section of the holder and tool; and Figure 4
an end view, shewn detached from the disc. Both Figures 3 and 4 are on an
enlarged scale.
A, A, is the basement of the machine; B is a plate or disc of metal, of any
required diameter and thickness, which is amounted upon a shaft C, revolving
in the bearings D, D. This disc has shrunk or otherwise fixed upon its
periphery a malleable iron ring E; or this ring may be fitted on the disc in
two or more pieces. E is one of a series of holders, which is dovetailed into the
ring E, thus rendering it secure in its place, but at the same time capable of
being readily removed. F¹isa tool of steel, which is made hollow in the stem
to facilitate the dressing or sharpening of its edge. This tool is kept in its
place and prevented from falling out of the holder by a spring a, of india-
rubber or other suitable material, sunk into the recess in the holder as shewn
in Figure.3. The disc B is caused to rotate by means of the toothed wheel,G,
keyed upon the shaft C, geared into by the pinion G' on the shaft H. The
speed at which the disc Brotates for ordinary working is about thirty feet per
minute, and the tools are fitted on to the ring at suitable distances apart. I is
a friction roller, revolving in the brackets.c, c. This roller bears against the
side of the disc to prevent the disc yielding when only cutting on one side. In
some cases we find it necessary to use friction rollers on each side of the disc.
J is à table of cast iron, of any desired length and breadth; this table may be
so arranged as to pass under or above the shaft of the disc, and hasuupon its
surface a number of grooves, in which are fixed the heads of the bolts used
for fastening in the brackets K. These brackets K are supplied with screws

page_text: for securing the stone to be cut, and are of various sizes to suit different sized
work. When the stone has been cut or dressed, these brackets fold back to
admit of the slab being readily removed, when they can be again adjusted, and
the block fed for ward to undergo a fresh operation of cutting. The table J is
formed in two parts, connected together at the back if necessary for steadiness,
a sufficient space being left between the parts to allow of the revolution of the
disc and tools. The under side of each half of the table is provided with two
racks, into the teeth of which suitable pinion gear: for feeding forward the
table and stone to be cut. L is a pulley for running back the table. This
pulley is driven by the pulley L' fixed on to the loose pulley M. N is a hand
or foot wheel for moving the table independently of the pullies L and L'.
O, O, are friction rollers on which the table J slides. In small machines,
instead of using friction rollers we prefer to employ slides fixed beneath the
table. P is a clutch box and handle for throwing the pulley L in or out of
mction; Q is a pulley for driving the gearing R, R, in connection with the
feeding table; and S is a pulley driven by a strap from a steam engine or
other motive power for imparting motion to the whole of the machine.
Although we have described the tools and holders as being mounted on a
disc or plate, we do not confine ourselves to that arrangement alone, as the
tools and holders may be fixed to a rod caused to reciprocate by any suitable
combination of machinery, the method of feeding the block being the same
as that before described and represented in the Drawings hereunto annexed-
And having pow described the nature of our said Invention, and in what
manner the same is to be performed, we declare that what we claim as our
improvements in stone-cutting machinery is,-
First, the improved tool and holder, as herein-before described, and repre-
sented in the Drawings hereunto annexed.
And, second, the improved construction of table for carrying the stone
to be cut, furnished with brackets, and worked in the manner herein-béfore
described, and represented in the Drawings hereunto annexed.
. In witness whereof, we, the said James Hunter and George Hunter,
have hereunto set our hands and seals, this Eighth day of October,
One thousand eight hundred and fifty-five.
JAMES HUNTER.
(L.S.)
GEORGE HUNTER. (L.S.)