An Improved Process for the Manufacture of Lithographic Stones.
Year: 1889

page_text: Date of Application, 5th Oct., 1889
Complete Specification Left, 19th Dec., 1889-Accepted, 15th Feb., 1890
PROVISIONAL SPECIFICATION.
An Improved Process for the Manufacture of Lithographic Stones.
1, CHARLES LUMLEY, of 6 Brookville Road, Walham Green, in the County of
Middlesex, Patent Concrete Manufacturer, do hereby declare the nature of this
invention to be as follows:
My invention consists of an improved process whereby finely ground cementitious
material may be formed into a dense and homogeneous stone, suitable for the
preparation on the face thereof, of lithographic drawings, and which may be ground
down for repeated use, and may be used for printing purposes similarly to the
natural stone, known as lithographic stone.
My improved process enables an excellent stone to be made for lithographic
purposes, at a much cheaper price than that at which the natural stone can be
bought.
From many experiments I have found that though suitable materials for the
formation of such an artificial stone may be readily found and prepared in an
ordinary manner such stones do not offer a useful result if manufactured in any
usual method, since they are found to be porous, of an un-even density, and are
filled with small air recesses.
To avoid these drawbacks, in an artificial stone, I have devised the following
process
1 take a suitable, finely ground, cementitious material and moisten it (thoroughly
agitating the materials during the process of mixing) until the mixture becomes
plastic and of a consistency suitable for entering the mould.
The mould in which the stone is formed is placed under a receiver, of suitable size,
and construction to which thero is a hopper attached. The hopper communicates
with the interior of the receiver by means of a tube with stop cock attached the
lower aperture of the tube entering the interior of the receiver directly over some
convenient portion of the mould.
The air is exhausted from the receiver until a vacuum is formed. The material
previously described is placed in the hopper the interior of the receiver being
in vacuo (as before mentioned) when the stop cock is opened, the pressure of the air
on the upper surface of the material in the hopper forces the same through the supply
tube and into the mould.
The speed with which the material enters the mould should not be too quick, and
is perfectly under control by means of the stop cock in the supply tube. During
the time the material is entering the mould, the exhaust pump must be kept at work,
The effect
and as perfect a vacuum be kept as is possible under the circumstances.
of this is that the air contained in the plastic material leaves it in the form of bubbles
as the material is forced into the mould thus giving a density and grain which is
quite uniform throughout the entire substance of the stone.
11
1000
FELL & WILDING,
1, Queen Victoria Street, Agents for the Applicant

page_text: COMPLETE SPECIFICATION.
An Improved Process for the Manufacture of Lithographic Stones.
I, CHARLES LUMLEY, of 6 Brookville Road, Walham Green in the County of
Middlesex, Patent Concrete Manufacturer, do hereby declare the nature of this inven
tion and in what manner the same is to be performed to be particularly described and
ascertained in and by the following statement :-
My invention consists of an improved process whereby finely ground cementitious
material may be formed into a dense and homogeneous stone, suitable for the
preparation on the face thereof of ligthographic drawings and which may be ground
down for repeated use and may be used for printing purposes similarly to the natural
stone known as lithographic stone.
My improved process enables an excellent stone to be made for lithographic
purposes at a much cheaper price than that at which the natural stone can be
bought.
From many experiments I have found that though suitable materials for the
formation of such an artificial stone may be readily found and prepared in an
ordinary manner, such stones do not offer a useful result if manufactured in any
usual method since they are found to be porous, and of an uneven density, and are
filled with small air recesses.
To avoid these drawbacks in an artificial stone I have devised the following process
and in order that my invention may be the better understood I now proceed to describe
the same in relation to the drawings hereunto annexed.
Fig. 1, is a side elevation of the apparatus by which the process is carried out.
Fig. 2, is an end elevation of the same.
Fig. 3, is a sectional view of fig. 1.
:
Fig. 4, is a plan of the apparatus in which the top of the hopper is removed
from the line X X.
I take suitable finely ground cementitious material and moisten it (thoroughly
agitating the materials during the process of mixing) until the moisture becomes
plastic and suitable for entering the mould.
The mould A fig. 3 in which the stone is formed is placed within a reservoir B,
of a suitable size and construction to which a hopper C, is attached.
The hopper C. communicates with the interior of the reservoir B, by means of
a tube with a stop cock D attached. The lower aperture of the tube entering the
interior of the reservoir directly over some convenient portion of the mould.
The reservoir B, has a door E, provided at one end (through which the tray A
is introduced into and withdrawn from the reservoir) which is jointed to the edges
of the reservoir by means of strips of india rubber or other suitable material,
the door F, being retained in position and the joint made by the fastening
handles G.
The lower edge of the door may be conveniently arranged to engage in the
groove H, so that upon introducing the door E, into the groove H in an angular
position to the face of the receiver and then brought up into contact with the said
face, the lower part of the joint is made by the pressure afforded by this action and
the rest of the joint is made and maintained by the fastening handles G, as before
described.
The process of making the lithographic stones is as follows.
The air is exhausted from the reservoir B, by the pipe L. until a vacuum is
formed by means of any convenient air pump or other means attached to the
pipe L.
The material as before described is placed in the hopper C, and upon the stop
cock D being opened the pressure of air on the upper surface of the material in
the hopper will force the same through the cock D, into the mould A.

page_text: The speed at which the matter enters the mould should not be too quick and can
be easily regulated by means of a stop cock D, during the time the material is entering
the mould.
The exhaust pump must be kept at work so as to maintain as good a vacuum.as
possible under the circumstances.
The effect of this is that the air contained in the plastic material leaves it in the
form of bubbles and the material is forced into the mould thus giving a density and
grain which is quite uniform throughout the entire substance of the stone.
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 :-
1st. A process for the manufacture of lithographic stone from Cementitious
materials in which the said Cementitious material is delivered into a mould and
allowed to set therein under a vacuum whereby all the air is removed from the body
of the Stone and a homogeneous stone of uniform grain is produced substantially as
described.
2nd. In such a process of manufacturing lithographic stones the apparatus con-
sisting of a hopper connected by a suitable stop cock to an hermetically closed receiver,
within which the mould for the stone is situated, and means for exhausting the air
from the said receiver substantially as described.
Dated this 19th day of December 1889.
FELL & WILDING,
1, Queen Victoria, Street, E.C., Agents for the Applicant.