IMPROVED MACHINERY OR APPARATUS FOR CUTTING STONE OF EVERY DESCRIPTION
Year: 1861

page_text: PROVISIONAL SPECIFICATION left by William Edward Gedge at the
Office of the Commissioners of Patents, with his Petition, on the 31st
May 1861. A conumunication from abroad by Pierre Martin, of Lyons,
in the Empire of France, Architect.
I, WILLIAM EDWARD GEDGE, of the Firm of John Gedge and Son, No. 11,
Wellington Street, Strand, in the County of Middlesex, Patent Agent, do
hereby declare the nature of the said Invention for "IMPROVED MACHINERY OR
APPARATUS FOR CUTTING STONE OF EVERY DESCRIPTION," (communicated to me
from abroad by Pierre Martin, of Lyons, in the Empire of France, Architect,)
to be as follows:-
The principle of this Invention consists in giving to the cutting tool a
circular movement in parallel plane to the face of the stone to be cut. The
cutting will take place in the moment of contact at the tangental point deter-
mined by the circumference described by the tool, and by the movement of the
stone, which presents successively its several parts to the action of the tool.
The tool will be in form of a vertical cutting blade acting as a knife, or of a
toothed blade, each tooth acting as a chisel when soft stone is to be cut.
For cutting hard stone, the tool will resemble a slightly bent chisel mounted
on a collar, and sliding along a vertical blade, it will act in the same way as
the cutting blade, but successively on small surfaces. The movement of the
tool will be determined by two eccentrics mounted on two parallel shafts, and
the circular march of the eccentrics will be varied by moving their centre
nearer to or further from the axis of their shaft, screws being provided for the

page_text: purpose. To avoid the splitting of the stone, which would result from the
pressure of the tool against a weak part when it had cut to the depth
required, an alternate movement will be given to the above-mentioned shafts,
and consequently to the tool (after it has been placed before the small picco
to be cut). This alternation will be completed by the substitution of a second
tool mounted like the first on the same collar, but in an inverse sense. The
same shaft may carry several tools cutting the same stone, and the shaft nay
be extended, and several stones cut at once.
The stone or stones to be cut will be placed on a carriage sliding in two
grooves, or on bars fixed against the inner sides of the framing, and by means
of a horizontal screw on the cross pieces of the framing, the carriage will be
advanced regularly the distance required (according to the nature of the
stone), and a double ratchet wheel with alternate teeth will be provided to
impart a reverse movement when required. An arrangement of levers com-
manded by the lower shaft will sot the endless screw in motion, and conse-
quently the carriage, when the tool has described its course. A crank may be
placed at the extremity of this horizontal screw to move the carriage rapidly
into position previous to commencing the cutting. The stone will be retained
on the carriage either by wooden wedges or by press screws acting upon
claws, which by means of straps will retain the stone in any required position.
Independently of the steel tools above mentioned, it is proposed to use sand-
stone, the diamond, diamond dust, and other similar substances in cutting
stone or other material susceptible of similar working in plane or curved
surfaces as may be desired. The apparatus may be worked by hand, steam,
or any available power.