IMPROVED MACHINERY OR APPARatus FOR CUTTING AND ORNAMENTING STONE AND OTHER MATERIALS FOR THE PURPOSE OF COPYING STATUARY, SCULPTURE, ARTICLES OF VERTU, AND OTHER ARTICLES
Year: 1871

page_text: LETTERS PATENT to George Porter, of Bath, in the County of
Somerset, for the Invention of "IMPROVED MACHINERY OR APPARatus
FOR CUTTING AND ORNAMENTING STONE AND OTHER MATERIALS FOR THE
PURPOSE OF COPYING STATUARY, SCULPTURE, ARTICLES OF VERTU, AND OTHER
ARTICLES,"
Sealed the 19th September 1871, and dated the 24th March 1871.
PROVISIONAL SPECIFICATION left by the said George Porter at the
Office of the Commissioners of Patents, with his Petition, on the
24th March 1871.
I, GEORGE PORTER, of Bath, in the County of Somerset, do hereby
declare the nature of the said Invention for "IMPROVED MACHINERY OR
APPARATUS FOR CUTTING AND ORNAMENTING STONE AND OTHER MATERIALS FOR
THE PURPOSE OF COPYING STATUARY, SCULPTURE, ARTICLES OF VERTU, AND OTHER
ARTICLES," to be as follows:-
This Invention consists of improved machinery or apparatus composed
of the following principal parts, the said machinery or apparatus being
constructed and operated with very much after the manner of the well-
known pentograph used for enlarging or reducing drawings.

page_text: The above-mentioned machinery or apparatus consists of a rectangular
shaped frame, on the top and near each end whereof a square or oblong
plate of metal rests on sliding edges, and in the centre of each of the
said plates a round hole or opening is made of about nine inches
diameter; more or less, or of sufficient size to receive the plinth or
bottom part of the object to be copied. In each of the aforesaid holes I
fit a round plate furnished with suitable mechanism for turning the
said plates partly round-in. their respective holes from time to time, as
may be required. I also connect the two aforesaid square or oblong
plates together by a rack and pinions, or other suitable contrivance, for
causing the said plates to move lengthwise together. And in the centre
of the framing of the machinery I affix an upright piece of metal at the
top whereof a socket is made to receive and hold the universal joint of
another upright piece which carries at its upper end a short revolving
cross shaft, on each end of which a pulley is fixed, one pulley being
employed for driving the machinery, and the other pulley for imparting
rotatory motion to a cutting tool or instrument fixed in one end of a
bar, the other end of the said bar carrying a tracing point. The said
cutting tool and tracer come in a line with or opposite to the centre of
each of the before-mentioned revolving plates, and the bar that carries
the aforesaid tools or instruments is fixed horizontally in the universal
joint piece above referred to, and may be adjusted therein so that each
of the aforesaid tools may be equidistant from the centre of the universal
piece that holds the said bar, in which case suppose a statue or object
to be fixed on one revolving plate aforesaid, and the material or block
of which the copy or fac-simile of the statue or other object to be fixed
on the other revolving plate, the copy would be of the same size as the
statue, and by fixing the aforesaid bar so as not to be equidistant the
copy may be either reduced or enlarged to the required size.
By the above arrangement it will appear evident that as the before-
mentioned tracing point is moved over the surface of the statue the
cutting tool will be similarly moved, and cut the material of the same
shape as the statue, the tracer being guided by the hand of the
operator.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said George Porter in the Great Seal Patent Office on
the 23rd September 1871.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, GEORGE
PORTER, of Bath, in the County of Somerset, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-fourth day of March, in the
year of our Lord One thousand eight hundred and seventy-one, in the
thirty-fourth year of Her reign, did, for Herself, Her heirs and suc-
cessors, give and grant unto me, the said George Porter, Her special
licence that I, the said George Porter, my executors, administrators, and
assigns, or such others as I, the said George Porter, 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 "IMPROVED MACHINERY
OR APPARATUS FOR CUTTING AND ORNAMENTING STONE AND OTHER MATERIALS FOR
THE PURPOSE OF COPYING STATUARY, SCULPTURE, ARTICLES OF VERTU, AND OTHER
ARTICLES," upon the condition (amongst others) that I, the said George
Porter, 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 Porter, 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, to be as follows:-
This Invention consists of improved machinery or apparatus composed
of the following principal parts, the said machinery or apparatus being
constructed and operated with very much after the manner of the well-
known pentograph used for enlarging or reducing drawings.

page_text: The above-mentioned machinery or apparatus consists of a rect-
angular-shaped frame, on the top and near each end whereof a square
or oblong plate of metal rests on sliding edges, and in the centre of
each of the said plates a round hole or opening is made of about
nine inches diameter, more or less, or of sufficient size to receive the
plinth or bottom part of the object to be copied. In each of the afore-
said holes I fit a round plate furnished with suitable mechanism for
turning the said plates partly round in their respective holes from time
to time, as may be required. I also connect the two aforesaid square
or oblong plates together by a rack and pinions or other suitable
contrivance for causing the said plates to move lengthwise together;
and in the centre of the framing of the machinery I affix an upright
piece of metal, at the top whereof a socket is made to receive and hold
the universal joint of another upright piece which carries at its upper
end a short revolving cross shaft on each end of which a pulley is fixed,
one pulley being employed for driving the machinery and the other
pulley for imparting rotatory motion to a cutting tool or instrument
fixed in one end of a bar, the other end of the said bar carrying a tracing
point, the said cutting tool and tracer come in a line with or opposite
to the centre of each of the before-mentioned revolving plates, and the
bar that carries the aforesaid tools or instruments is fixed horizontally
in the universal joint piece above referred to, and may be adjusted
therein so that each of the aforesaid tools may be equidistant from the
centre of the universal piece that holds the said bar, in which case
suppose a statue or object to be fixed on one revolving plate aforesaid,
and the material or block of which the copy or fac-simile of the statue
or other object to be fixed on the other revolving plate, the copy
would be of the same size as the statue, and by fixing the aforesaid bar
so as not to be equidistant the copy may be either reduced or enlarged
to the required size.
By the above arrangement it will appear evident that as the before-
mentioned tracing point is moved over the surface of the statue the
cutting tool will be similarly moved and cut the material of the same
shape as the statue, the tracer being guided by the hand of the
operator.
And in order to explain my said Invention more clearly, I now
proceed to describe the means by which it may be effected, reference

page_text: being had to the illustrative Sheet of Drawings accompanying these
Presents, and to the numeral figures and letters of reference marked
thercon, as follows:-
DESCRIPTION OF THE DRAWING.
Figure 1 represents a sectional elevation of my improved machinery;
Figure 2 a top plan view thereof; Fig. 3 is a horizontal section on the
line A, B, at Fig. 1; Figure 4 is an end elevation of the machinery.
At each of the above Figures I employ similar letters of reference to
denote corresponding parts.
A, marks the framing of the machine supporting the following parts:
-B, B¹, are tables sliding in grooves in the framing A. C, C¹, are discs
of metal or revolving tables fitted and working in circular holes in the
tables B, B'. In connection with the tables C, C¹, are worm wheels
D, D, gearing into worms E, E, fixed to or formed upon the spindle G,
mounted in bearings a and fitted with a lever wheel H at each end for
operating the said spindle and the tables C, C¹, for turning round or
partly round the model and block at the same time. I is a rack fixed
to the table B, and K is a toothed wheel gearing into the rack I for
imparting sliding movement to the table B by means of the lever b,
one end whereof is fixed to the table B', and the other end of the lever b
is provided with a pin, which takes into a slot c in the wheel K. By
these means the tables B, B¹, are caused to approach and recede from
each other by turning round the spindle L on which is fixed a toothed
wheel d, which gears into a rack e fixed to the under side of the table B.
M is a horizontal bar mounted on a pivot at z in the piece f; the lower
end of the piece f is made as a ball-and-socket joint, and is supported
by the rod N, which can be slided up or down to regulate the pointer g
and cutter / to the height of the work; the pointer g fits in a slot in
the bar M; is a short spindle having pullies k, l, fixed thereon.
O, P, are endless bands for imparting rotatory motion to the cutter h;
the socket m of this cutter has a small pulley fixed thereon to carry
the band o.
When it is required to make an enlarged copy of a model the same
may be effected by sliding the piece Q towards the model and adjusting
the pointer g in the slot * nearer to the pivot of the bar M. To make
a reduced copy of a model a reverse movement of the piece Q and
pointer g must be effected. n is a revolving wheel for keeping the

page_text: band P always tight. I would here remark that in making enlarged
and reduced copies of models the lever 6 must be so adjusted in the
slot c of the wheel K as to cause one of the tables B, B¹, to move
through more or less space in accordance with the difference of size
between the model and the copy to be made. O is a screw for tightening
the centre rod N at any desired height.
Having now fully described the nature and object of my said Invention
for ::
Improved Machinery or Apparatus for Cutting and. Ornamenting
Stone and other Materials for the Purpose of Copying Statuary, Sculp-
ture, Articles of Vertu, and other Articles," together with the means
by which it may be effected, I would remark in conclusion that I hereby
declare my Invention to consist in, and I claim, the mechanical arrange-
ments and combinations of parts above described and represented with
reference to the accompanying Sheet of Drawings, and the mode of
operating therewith, as constituting improved machinery or apparatus
for cutting and ornamenting stone and other materials for the purpose
of copying statuary, sculpture, articles of vertu, and other articles, as
above stated.
In witness whereof, I, the said George Porter, have hereunto set
my hand and seal, this Twenty-first day of-September, in the year
of our Lord One thousand eight hundred and seventy-one.