IMPROVEMENTS IN MACHINES FOR BREAKING OR REDUCING STONES AND OTHER MATERIALS
Year: 1880

page_text: LETTERS PATENT to David Stratton, of Edinburgh, in the County of
Midlothian, North Britain, for an Invention of "IMPROVEMENTS IN MACHINES
FOR BREAKING OR REDUCING STONES AND OTHER MATERIALS." A communi-
cation from abroad by Arthur Hope, of Melbourne, Australia.
PROVISIONAL SPECIFICATION left by the said David Stratton at the Office
of the Commissioners of Patents on the 4th November 1880.
DAVID STRATTON, of Edinburgh, in the County of Midlothian, North Britain.
"IMPROVEMENTS IN MACHINES FOR BREAKING OR REDUCING STONES AND OTHER
MATERIALS." A communication from abroad by Arthur Hope, of Melbourne,
Australia.
This Invention relates to machines for breaking or reducing stones and other
materials, and of the class having a fixed jaw, near which an inclined jaw works
with a small vibratory motion, whilst the stones or materials pass down between
the jaws, and become gradually broken or reduced. The vibrating jaw is worked
by a rotating crank, which gives a vertical reciprocating movement to a connecting
bar forming the middle piece of a toggle combination acting horizontally or nearly
so between the back of the vibrating jaw and a stationary bolster, which last is
adjustable by a wedge for setting the vibrating jaw at a suitable distance from the
fixed jaw. Toggle pieces or struts are placed between the vibrating jaw and the
middle piece, and between the middle piece and the bolster; and the present
Invention consists principally in shaping the toggle pieces and the parts between
and on which they act, so as to obtain two or three strokes for one as compared
with existing machines of the same class. The ordinary toggle piece is made with
a single bearing or acting point or surface at each end, but each toggle piece of the
improved arrangement is made with a single bearing part at one end, and with two
or three bearing parts at the other end. The bearing parts of the toggle pieces may
be convex, and fit in concavities formed on the jaw, middle piece, and bolster; or
the toggle pieces may be made with concave bearing parts, and the jaw, middle
piece, and bolster with convexities. The effect of the improved arrangement is as
though during one revolution of the crank shaft the middle piece were acting on
two or three pairs of toggle pieces in succession, instead of on a single pair, and in
consequence the number of bites of the jaws is doubled or trebled for a given
number of revolutions of the shaft. An adjustable wedge is fitted between the
middle piece and the crank bearing to allow of the parts being set in their best.
relative positions.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said David Stratton in the Great Seal Patent Office on the 3rd May
1881.
DAVID STRATTON, of Edinburgh, in the County of Midlothian, North Britain.
"IMPROVEMENTS IN MACHINES FOR BREAKING OR REDUCING STONES AND OTHER
MATERIALS." A communication from abroad by Arthur Hope, of Melbourne,
Australia.
The said said Invention relates to machines for breaking or reducing stones and
other materials, and of the class having a fixed jaw, near which an inclined jaw
works with a small vibratory motion, whilst the stones or materials pass down
between the jaws, and become gradually broken or reduced. The vibrating jaw is
worked by a rotating crank, which gives a vertical reciprocating movement to a
connecting bar forming the middle piece of a toggle combination acting horizontally
or nearly so between the back of the vibrating jaw and a stationary bolster, which
last is adjustable by a wedge for setting the vibrating jaw at a suitable distance
from the fixed jaw. Toggle pieces or struts are placed between the vibrating jaw
and the middle piece, and between the middle piece and the bolster; and the
present Invention consists principally in shaping the toggle pieces and the parts
between and on which they act, so as to obtain two or three strokes for one as
compared with existing machines of the same class. The ordinary toggle piece
is made with a single bearing or acting point or surface at each end, but each
toggle piece of the improved arrangement is made with a single bearing part at
one end, and with two or three bearing parts at the other end. The bearing parts
of the toggle pieces may be convex, and fit in concavities formed on the jaw,
middle piece, and bolster; or the toggle pieces may be made with concave bearing
parts, and the jaw, middle piece, and bolster with convexities. The effect of the
improved arrangement is as though during one revolution of the crank shaft the
middle piece were acting on two or three pairs of toggle pieces in succession,
instead of on a single pair, and in consequence the number of bites of the jaws is
doubled or trebled for a given number of revolutions of the shaft. An adjustable
wedge is fitted between the middle piece and the crank bearing to allow of the
parts being set in their best relative positions.
And in order that the said Invention and the manner of performing the same
may be properly understood, there is hereunto appended a Sheet of explanatory
Drawings to be hereinafter referred to, and representing stone breaking machinery
as, made with the improvements. In these Drawings the same reference numerals
are used to mark the same or like parts wherever they are repeated.
One modification of the improved toggle pieces and bearing surfaces is shown in
vertical section in Figure 1, and in plan in Figure 2; Figure 3 is a vertical section
of another modification; and Figure 4 is an elevation corresponding to Figures 1
and 2. Each of the two toggle pieces 8, 9, is formed with a single curved face 10
to bear on the middle piece 11, and with two curved faces 12 at their outer ends
to bear on corresponding double faces on the vibrating jaw 13 and bolster 14
respectively. The double faces 12 on the toggle pieces 8, 9, may be concave, as
in Figure 1, or convex as in Figure 3, the faces they bear on being shaped to
correspond. As shown in Figure 4 the part on each toggle between the concave
faces 12 projects more than in Figure 1, which causes a modified action of the
jaw, tending to produce more screenings.
Figure 5 is a plan, Figure 6 a side elevation, and Figure 7 a vertical section of
a stone breaking machine, as made with the improvements. This machine is of a
well known construction, excepting as regards the toggle pieces 8, 9, and the parts

page_text: of the jaw 13 and bolster 14 on which they act. The main shaft 15, having on it
a pair of flywheels 16, and a pulley 17 for a driving belt, is formed with a crank
of small throw, which gives a vertical reciprocating motion to the connecting bar
or middle piece 11. In consequence of the improved configuration of the acting
surfaces of the toggle pieces 8, 9, and of the jaw 13 and bolster 14 twice as many
vibrations are imparted to the jaw 13, with a given number of revolutions of the
crank shaft 15, as is done in ordinary machines.
Having thus particularly described the said Invention, and the manner of
performing the same, I have to state that I do not restrict myself to the precise
details herein described or delineated, but that what I believe to be novel and
original, and claim as the Invention secured to me by and in terms of the herein-
before in part recited Letters Patent is,-
The peculiar construction of toggle pieces and toggle faces, combined and arranged
in the manner and for the purposes hereinbefore described and explained, and as
shown in the accompanying Drawings.
In witness whereof, I, the said David Stratton, have hereunto set my hand
and seal, this Second day of May, in the year of our Lord One thousand
eight hundred and eighty-one.
D. STRATTON. (L.S.)