the 1 Machinery and Apparatus Used in Connection therewith.
Year: 1885

page_text: I
C
acture
Ilaster,
Ա ILI
the
1
Machinery and Apparatus Used in Connection therewith.
"
I, ROBERT STONE, of 101 Leadenhall Street, in the City of London, Engineer,
do hereby declare the nature of my Invention for IMPROVEMENTS IN THE
MANUFACTURE OF PLASTER, AND IN THE MACHINERY AND APPARATUS USED IN
CONNECTION THEREWITH to be as follows:-
First I soak or wet the raw materials, such as chalk limestone, or such like
materials, with vitriol or sulphuric acid as produced from the chemical works, by
immersing such materials in tanks or otherwise, as they are produced in their raw
unmanufactured state, from the Quarries. I then load them into furnaces or kilns,
by mixing fuel, such as coke or coals paraffin, or other mineral oil, or any other
high heating solid or liquid substance, suitable for the purpose of raising an intense
heat, about equal to an iron smelting heat, which will have the effect of reducing
the materials, so as to prevent contraction, and at the same time remove the
sulphuric acid. And in order to assist in producing this intense heat, I store in a
convenient place a large body of compressed air, either hot or cold and continue to
force this body of air among the materials until thoroughly calcined. This volume
of blast, I sustain either by reciprocating or rotary blowing machines.
When the materials are thus burned, I grind them direct from the furnaces or
kilns, by the machinery hereinafter described. Thus the complete manufactured
plastic material is produced direct from the raw quarried materials, by one simple
inexpensive, process which is suitable for all building and analogous operations,
and is also fire proof.
When I require the plaster to work under water, very hard, I mix a proportion
of alumina, such as that derived from damp river mud, unmanufactured, direct
from the mud bank, with or without silicate materials and burn these down with
the chalk or lime soaked in vitriol or sulphuric acid and grind all together, ready
for use. By this cheap and simple mode of manufacture the plastic material can
be mixed with sand and used generally, instead of using ordinary lime. My
machinery for fine grinding consists of a large heavy roll, say of 3 to 6 tons
weight. This roll works by a to and fro rocking action, in a suitable pan. The
rocking action may be produced by cams or eccentrics or otherwise. Above the
roll I place a balancing weight, against which the cams or eccentrics may work,

page_text: and assist the rocking motion. The roll is usually from 4 to 6 feet in length and
6 feet diameter. It may also work at the bottom of the pan, or may have shafts
or struts at the ends to keep it in position. In the bottom of this pan a delivery
opening is provided to let out the ground material which material may be
immediately acted upon by another smaller roll or rolls underneath, or by a sifter.
These rolls may be made of steel, or chilled iron, or any other hard wearing
material that will sustain the grinding. The wearing parts of the machine may
be made removable, so as to be replaced when worn. The large roll may have
grooves at or in those parts which receive the material, so as to assist the feeding
and grinding actions. The large roll may be cylindrical, semi-cylindrical, elliptical,
oval, or wedge shaped or a combination of such forms.
The crushing rolls which operate on the rough material before it enters the fine
grinding machine, consists of a large pair of rolls with sunk or grooved faces
gearing into each other; these sunk or grooved surfaces run all round the roll, not
across the face of the roll. The crushing rolls gear into each other, driven by
large cog wheels. The rolls can be made of steel or chilled cast iron, and of about
6 feet in diameter, more or less.
The iron or steel trucks or boxes, into which the chalk or limestone is loaded at
the Quarries on arrival at the works, are flooded with the liquid vitriol, and simply
run off to the next truck or box, and so on from one to another, as owing to the
chalk or lime being saturated in this manner a very small quantity of vitriol is
consumed, which effects the purpose, owing to the intense heat of the furnaces or
kilns. By means of the blast the carbonic acid is at once removed, and fire proof
plaster of a very durable quality is obtained.
When the wagons or boxes are run alongside the furnaces or kilns, I lift them to
the top by a pitch chain, which works on large toothed wheels. On this chain
I fasten the wagons or tanks, and run them up for discharging their contents into
the mouth of the furnace or kiln.

page_text: Improvements in the Manufacture of Plaster, and in the
Machinery and Apparatus Used in Connection therewith.
I ROBERT STONE, of 101 Leadenhall Street in the City of London, Engineer,
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:―
First, I soak or wet the raw materials, such as chalk, limestone, and analogous
materials, with vitriol or sulphuric acid, as produced at chemical works or mineral
oils, by immersing such materials in tanks or otherwise, as they are taken from the
quarries, in an unmanufactured state. I then load them into furnaces or kilns
mixed with fuel, such as coke, coals, paraffin, or other mineral oil, or any other
highly inflammable solid or liquid fuel, suitable for producing a very high
temperature, equal to that used in smelting iron, which has the effect of reducing
the materials, so as to prevent subsequent contraction.
In order to assist in raising the heat and producing such high temperature,
I provide a reservoir filled with compressed air, either hot or cold, from which
reservoir a continual supply is forced among the materials until thoroughly
calcined. The supply of this air is maintained by suitable blowing machines.
When the materials are thus thoroughly burned, I transfer them direct from the
furnaces to the grinding machinery herein after described. By which means
economy of production is greatly promoted, and a superior description of plastic
material is produced, which is suitable for all building and analogous operations,
and for fire proof construction.
When the plaster is required to set very hard, I mix a proportion of alumina,
such as that derived from river mud, unmanufactured, as obtained direct from the
river bank, with or without silicate and burn these with the chalk or lime or
limestone soaked in vitriol or sulphuric acid or mineral oils and grind all together,
after which it is ready for use.
By this cheap and simple method of manufacture, the plastic material, mixed
with sand, in suitable proportions, may be used instead and in the place of lime
and sand as a mortar.
Before passing the material, prepared as aforesaid, to the fine grinding machine,
it is passed to crushing rolls, consisting of a large pair of cylindrical rolls, with
annular grooved or corrugated surfaces.
The corrugations gear into each other, and the rolls are driven by toothed
wheels. The rolls may be made of steel or chilled cast iron, and of about 6 feet in
diameter, more or less.
In some cases I grind the aforesaid materials to a powder before saturation;
and, in other cases, I mix the liquids with the wet or dissolved river mud before
putting the materials into the kilns.
My improved machinery for fine grinding consists of a large corrugated cylinder
preferably of 3 to 6 tons weight. This cylinder is caused to roll upon the material
to be ground, by a revolving or by a to and fro motion, in a suitable pan or trough;

page_text: •
the reciprocating motion being imparted to the cylinder by means of cranks and
connecting rods, in an analogous manner to that described in Fig. 12 in Letters
Patent granted to Thomas Corry Stone N° 2535, and also in Letters Patent
granted to me N° 207080 and 1534. A convenient diameter for the cylinder is
six feet or thereabouts.
Or
The bottom of the pan is provided with a delivery opening, to admit of the
passage of the ground material, which material may be immediately acted upon
by another smaller cylinder or cylinders below the first cylinder and trough. This
latter cylinder or roller, or cylinders or rollers, have reduced diameters towards
and at the ends, and operating in connection with and against fixed curved
surfaces of approximately corresponding form and of suitably hard materials.
a screen for sifting and sorting the material may be placed below the trough, into
which the ground material may be passed. The rolls may be formed of steel,
chilled iron, or any other suitably hard material capable of enduring friction. The
wearing parts of the machine may be made moveable so as to be replaced when
worn. The large rolls may have grooves or corrugations at or in those parts which
receive the material, for the purpose of assisting the feeding and grinding actions;
as described in the said Specifications Noa 2535, 207080, and 153.
The sectional form of the large roll may be cylindrical, semi-cylindrical, elliptical,
oval or otherwise.
In conveying the material from the quarries to the works, the iron or steel
trucks conveying the same are successively brought under a reservoir of vitriol,
which is allowed to pour upon the material and saturate it.
When the trucks are run alongside the furnaces or kilns, I cause them to be
lifted to the top by a pitch chain or pitch chains, which gear into suitable toothed
wheels. On this chain, or these chains, I fix the wagons, trucks or tanks, and
raise them to the mouths of the furnaces or kilns.
Having now particularly described and ascertained the nature of my said
Invention and in what manner the same is to be performed I declare that what
I claim is :-
1. In the manufacture of plaster or plastic materials as aforesaid, the use and
mixture therewith of vitriol or sulphuric acid and other substances substantially as
and for the purposes herein before described.