IMPROVEMENTS IN MACHINERY FOR BREAKING STONES, ORBS, AND OTHER HARD SUBSTANCES
Year: 1866

page_text: PROVISIONAL SPECIFICATION left by Sylvester Franklin Schoonmaker
at the Office of the Commissioners of Patents, with his Petition, on the
14th April 1866.
I, SYLVESTER FRANKLIN SCHOONMAKER, of Great Russell Street, Bloomsbury,
in the County of Middlesex, Engineer, do hereby declare the nature of the
said Invention for "IMPROVEMENTS IN MACHINERY FOR BREAKING STONES, ORBS,
AND OTHER HARD SUBSTANCES," to be as follows:-
The said improvements consist in the construction of machinery in which
by the percussive and centrifugal force of rapidly revolving metal arms stones.
or other hard substances are subjected to a succession of violent blows from
several series of metal bars; the stones being alternately struck by and thrown
against the said bars till reduced to the required size, when they are allowed
to escape from the machine into any suitable receptacle. A strong disc of
cast iron is fixed upon a central shaft which turns in suitable bearings secured
to the framing of the machine. This disc is caused to revolve rapidly in the
required direction either by a driving belt passing over a pulley fixed on the
said shaft or by other suitable means. A projection or shoulder is formed on
each face of the revolving disc extending from the periphery thereof inwards
to act as a back or support to a series of bars or rods of steel or chilled iron
bolted or otherwise firmly secured in front of the said projections. The said
disc is enclosed within a cylinder or case of cast iron or other suitable material,
through the sides of which the central shaft extends into its bearings. In the
lower part of this case a series of steel bars are secured in a direction parallel

page_text: with the direction of motion of the revolving disc. These bars are provided
to support the stones to be broken in a favourable position to be struck by the
bars fixed on the said disc; the revolving bars are so arranged that every other
one in the series passes between two of the fixed bars in the bottom of the
case which are set sufficiently far apart for the purpose. The remainder of
the series of revolving bars are just long enough to pass freely over the top of
the fixed bars. A receiver or hopper is attached in communication with the
lower part of the cylinder or case through which the stones or other substance
to be broken-are fed into the said case upon the top of the steel bars. To
ensure the stones entering exactly at the right moment to be struck by the
revolving bars the hopper is provided with a piston operated by an excentrio
or other suitable device from the central shaft. The strokes of this piston
coincide with the revolutions of the revolving disc, and the hopper and piston
are so formed that the stones placed in the said hopper cannot enter the
cylinder or case till forced in by the piston in its forward stroke. An aperture
is formed in the upper part of the cylinder or case communicating with a
spout or passage, whose other end is closed by another series of bars. This
aperture and spout are so arranged that the pieces of stone carried round with
the revolving disc will escape tangentially through the aperture and will be
thrown with a momemtum derived from the rapid rotary motion of the said
disc against the bars at the end of the spout. The end of the spout behind
the bars is closed by a strong plate of iron, which serves as a support to 'the
said bars, an opening is formed on the under side of the spout at the end
thereof closed by the bars. This opening communicates with a hopper fur-
nished with a piston similar to the one already described, and the said hopper
opens into a second cylinder or case enclosing a revolving disc also furnished
with a series of bars, and revolving with still greater rapidity than the first
disc and in the opposite direction. The second disc is driven by toothed
wheels geared in connection with the shaft carrying the first disc or by
any convenient method. The second cylinder also has an aperture in its
upper part communicating with a spout or passage leading to a fourth series
of fixed bars arranged on the side of the first cylinder opposite to the side on
which the stones are first introduced. These bars are opened and are set the
required distance apart to regulate the size of the stones, which when
sufficiently reduced will pass between the said bars, while all those that are
not properly broken fall into a hopper furnished with a piston working in
connection with the hopper and piston into which the stones are first placed.
This hopper carries the stones into contact with a series of revolving bars
similar to the first series, but smaller, and arranged on the opposite side of the

page_text: revolving disc. From these bars the stones are returned through the first
spout or passage to the second cylinder and subjected to a repetition of blows
from the several series of bars as already described till they again arrive at
the open grating, whence they either escape or are again returned into the
machine according as they are more or less perfectly broken. In the arrange-
ment of parts herein described the revolving dises must be arranged to work
in a vertical direction, but by a slight modification in the construction and
arrangement of the said parts a machine may be advantageously constructed
with the revolving dises to turn horizontally; or instead of a disc the steel
bars may be supported upon revolving arms secured upon the central shaft,
and arranged either vertically or horizontally as preferred.