Improvements in or relating to the Manufacture of Artificial Stone.
Year: 1899

page_text: Date of Application, 15th July, 1899
Complete Specification Left, 14th Apr., 1900-Accepted, 14th July, 1900
PROVISIONAL SPECIFICATION.
Improvements in or relating to the Manufacture of Artificial Stone.
I, WILLIAM OWEN, Engineer, of Pontsarn, Woking, in the County of Surrey,
do hereby declare the nature of this invention to be as follows:-
-
This invention relates to the manufacture of artificial stone from a mixture of
say slaked lime and sand or marble dust or of other suitable granular materials.
According to this invention a mass of the ingredients of the stone after a pre-
liminary mixing and a moistening or slaking with water (preferably hot water) is
subjected to considerable pressure say by a hydraulic or screw press, in moulds
which impart to the mass the finished shape it is intended to have; next the
moulded mass is placed in a chamber into which superheated steam or other
heating agent is delivered to extract the residual moisture therefrom and to
harden it so that when withdrawn from the chamber it is a finished product
ready for immediate use and not needing to be "weathered" or otherwise treated.
It is to be understood that the process above described is applicable not only
to the manufacture of large slabs or masses such as building blocks but to the
production of smaller articles such as tiles and bricks, which, like the larger masses,
are turned out of accurate form, unwarped or undistorted by the final hardening
operation.
It is preferred that a relief valve should be kept open continuously upon the
chamber aforesaid whilst the superheated steam or other hot medium is flowing
into it, so that the pressure in the chamber may not rise beyond a predetermined
limit.
Improvements in or relating to the Manufacture of Artificial Stone.
I, WILLIAM OWEN, Engineer, of Pontsarn, Woking, in the County of Surrey,
do hereby declare the nature of this invention and in what manner the same
is to be performed, to be particularly described and ascertained in and by the
following statement.:-
This invention relates to the manufacture of artificial stone from a mixture of
say slaked lime and sand or marble dust or of other suitable granular materials.
According to this invention a mass of the ingredients of the stone after a pre-
liminary mixing and a moistening or slaking with hot water is subjected to con-

page_text: siderable pressure say by a hydraulic or screw press, in moulds which impart to
the mass the finished shape it is intended to have; next the moulded mass is
placed in a chamber in which the usual hardening operation takes place. Accord-
ing to this invention however, superheated steam is employed in this operation
and has the effect of simultaneously hardening and drying the stone, so that
when withdrawn from the chamber it is a finished product ready for immediate
use and not needing to be weathered" or otherwise treated.
It is to be understood that the process above described is applicable not only
to the manufacture of large slabs or masses such as building blocks but to the
production of smaller articles such as tiles and bricks, which, like the larger
masses, are turned out of accurate form, unwarped or undistorted by the final
hardening operation.
It is preferred that a relief valve should be kept open continuously upon the
chamber aforesaid whilst the superheated steam or other hot medium is flowing
into it, so that the pressure in the chamber may not rise beyond a predetermined
limit. In practice this limit would be about 85 to 90 lbs. per square inch.
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 a process for the manufacture of artificial stone the employment of super-
heated steam for simultaneously drying and hardening the materials.
2. In a process for the manufacture of artificial stone moulding the ingredients
under pressure and hardening and drying the moulded mass simultaneously by
superheated steam substantially as described.
3. The process for the manufacture of artificial stone consisting in slaking the
mixed materials with hot water moulding them under pressure and hardening
and drying the moulded mass simultaneously by superheated steam substantially
as described.
Dated this 12th day of April 1900.
Witness to the signature of the said William Owen.
W. HEADON OWEN.
Pontsarn, Woking.
12th April 1900.
WILLIAM OWEN.
Boult, Wade & Kilburn,
Agents for the Applicant.