Improvements in the Manufacture of Artificial Stone and Concrete Blocks.
Year: 1888

page_text: Date of Application, 4th Oct., 1888
Complete Specification Left, 2nd July, 1889-Accepted, 24th Aug., 1889
PROVISIONAL SPECIFICATION.
Improvements in the Manufacture of Artificial Stone and Concrete
Blocks.
I. JOHN WILMER RANSOME of 297 Amhurst Road, Stoke Newington, in the County
of Middlesex, Civil Engineer do hereby declare the nature of this invention to be as
follows:
:―
This invention has for its object improvements in the manufacture of artificial stone
and concrete blocks.
In the manufacture of artificial stone and like blocks it is usual to mix the
materials (say for example portland cement and sand) with water and then to
introduce the wetted materials into a mould of the shape desired to produce the
block.
Now according to iny invention I place the material in the mould in a dry state.
and whilst in the mould I expose them to pressure; after which I apply water
preferably from beneath and allow this to be absorbed by the materials whilst they are
held in the mould. The materials absorb the necessary amount of water and set into
a solid block from which the mould is then removed.
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COMPLETE SPECIFICATION
Improvements in the Manufacture of Artificial Stone and Concrete
Blocks..
I, JOHN WILMER RANSOME of 297 Amhurst Road, Stoke Newington, in the County
of Middlesex, Civil Engineer, 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 has for its object improvements in the the manufacture of artificial
stone and concrete blocks.
In the manufacture of artificial stone and like blocks it is usual to mix the
materials (say for example portland cement and sand) with water and then to
introduce the wetted materials into a mould of the shape desired to produce the
block.
Now according to my invention I place the materials in the mould in a dry state
and whilst in the mould I expose thein to pressure; after which I apply water
preferably from beneath and allow this to be absorbed by the materials whilst they
are held in the mould. The materials absorb the necessary amount of water and set
into a solid block from which the mould is then removed.
The following is the manner in which I proceed when producing for example stone
slabs suitable for paving. I provide moulds of wrought iron consisting of a frame
say three feet long by two feet broad and 4 inches deep open at the top and bottom;
Also I provide a press capable of applying a pressure of 20 lbs. per square inch over
the area of this mould say 8 or 9 ton's total. I prepare a dry mixture of one part
Portland cement and three parts granite chippings broken so that the pieces are
about the size of peas.
I take care that the mixture shall be uniform throughout. I
place the mould on the bed of the press and then fill it with the mixture, striking off
the surface level at the top of the mould, then apply the pressure by the aid of a
stout plate which fits the mould. Next I release the mould and pass it along a
shelf into a shallow wooden trough containing water to the depth say of half an inch.
This trough may be formed by fixing laths on to the edge of the shelf.

page_text: The mould is allowed to stand in the shallow water for about half an hour and it is
then taken out and set up to dry in the air. After a short time the stone slab will
become loose in the mould and it is then removed.
Finally I place the slab in a solution of silicate of soda specific gravity 1.400.
After half an hour I remove the slab and set it aside to dry in the air. In a few days
it is ready for use.
Or sometimes I place silicate of soda in the trough which first receives the mould
with the pressed slab within it. Then when the slab leaves the mould it requires no
further treatment and in a few days it will be thoroughly dry and hardened and
ready for use. By working in the manner described in place of mixing the
materials wet as heretofore I obtain a better result. The materials also inay be mixed
in as large quantities as may be convenient and can be kept so mixed in a dry place
for an indefinite time; whereas where the materials are mixed wet the mixture inust
be used promptly or it will harden and spoil.
Other articles besides slabs may in like manner be moulded in a dry state by
pressure from artificial stone producing materials and then allowed to absorb water
and so to be hardened.
A concrete mixture of gravel or sand and cement may in a similar manner he
moulded dry and afterwards caused to absorb the moisture required to harden it.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what I
claim is
The manufacture substantially as described of articles of artificial stone and concrete
blocks by moulding the materials in a dry state by pressure and then allowing the
moulded article to absorb the moisture necessary to harden it as herein set forth.
Dated this 29th day of June 1889.
J. WILMER RANSOME.