An Improvement in Foundry Sand.
Year: 1889

page_text: Date of Application, 12th Sept., 1889
Complete Specification Left, 11th June, 1890-Accepted, 12th July, 1890
PROVISIONAL
SPECIFICATION.
An Improvement in Foundry Sand.
I, JOSEPH PATRICK, of Frankfort on Main, Germany, Engineer, do hereby declare
the nature of this invention to be as follows:-
This Invention has for its object to obviate the disadvantages attending the use of
ordinary foundry sand; and it consists in the addition of coal-tar asphalt bitumen,
or a similar viscous body to the sand. The addition of the residues of the distillation
of wood or peat has also proved advantageous.
The coal tar (or other material mentioned) liquefied by heat is poured into an
equal quantity of hot water and the whole then poured onto sand of suitable quality.
In a short time the whole of the sand becomes uniformly impregnated with the
tar and may then be immediately employed for moulding.
The best proportions are five parts of tar and five parts of water for one hundred
parts of sand.
The sand thus prepared forms moulds and cores which are very firm, coherent, and
porous after being dried. The sand adheres but slightly to the casting so that cleaning
is often unnecessary and can be performed in two-thirds the time usually required.
The sand is more easily moulded, its plasticity being almost equal to that of glaziers'
putty and it may be used repeatedly. Any suitable sand may be used, the quality
being of minor importance and of whatever kind it may be it will be improved by
the addition of the tar. The quantity of tar added varies according to the quality of
the sand and the nature of the casting.
Exhaustive trials with moulding sands of different grain have exhibited peculiar
results. If tar be mixed with sand of such fineness as to be so impermeable by air
that it is suited neither for cores nor moulds its porosity becomes so much increased
that it is peculiarly well suited for casting. If sand or even gravel which on
account of its coarse grain has no cohesive power be mixed with tar, its density and
cohesion are so much increased that it may be employed for moulds. It will render
the highly esteemed fine sand capable of attaining a degree of accuracy for fine
castings hitherto unknown, whilst rendering possible the employment of gravel for
rough founding, thus enabling a considerable saving to be made in the cost price of
the materials.
By this invention time and money are saved, offensive dust-laden air arising in the
ordinary process is obviated, and materials hitherto unsuitable are rendered available,
the improved material being distinguished either by the fineness of the casting or by
its cheapness.
T: 0L 1
1
1000
COMPLETE SPECIFICATION.
An Improvement in Foundry Sand.
I, JOSEPH PATRICK of Frankfort on Main, Germany, 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 to obviate the disadvantages attending the use of
ordinary foundry sand; and it consists in the addition of coal-tar, asphalt, bitumen,
or a similar viscous body to the sand. The addition of the residues of the distillation
of wood or brown coal has also proved advantageous.

page_text: In the following description, I have for convenience referred to the use of coal-tar
only but I would have it understood that when coal-tar is referred to I intend to
include the other materials above mentioned.
The coal tar liquefied by heat, is poured into an equal quantity of hot water and the
whole then poured on to sand of suitable quality. In a short time the whole of the
sand becomes uniformly impregnated with the tar and may then be immediately
employed for moulding.
The best proportions are five parts of tar and five parts of water for one hundred
parts of sand.
The sand thus prepared forms moulds and cores which are very firm, coherent, and
porous, after being dried. The sand adheres but slightly to the casting, so that
subsequent cleaning is often unnecessary and in any case can be performed in two-
thirds the time usually required. The sand is more easily moulded, its plasticity being
almost equal to that of glaziers' putty and it may be used repeatedly. Any suitable
sand may be used, the quality being of minor importance; but of whatever kind it
may be it will be improved by the addition of the țar. The quantity of tar added
varies according to the quality of the sand and the nature of the casting.
Exhaustive trials with moulding sands of different grain have exhibited peculiar
results. If on the one hand tar be mixed with a sand which owing to its fineness
is so impermeable by air as to be suited neither for cores nor moulds its porosity
becomes so much increased as to render it peculiarly well suited for casting. If on
the other hand a coarse sand, or even gravel which on account of its coarse grain
has no coliesive power, be mixed with tar its density and cohesion are so much
increased that it may be employed for moulding. The addition of tar will render the
highly-esteemed fine sand capable of attaining a degree of accuracy for fine castings
hitherto unknown whilst rendering possible the employment of gravel for rough
founding, thus enabling a considerable saving to be made in the cost price of the
materials.
By this invention time and money are saved, offensive dust-laden air arising in the
ordinary process is obviated, and materials hitherto unsuitable are rendered available,
the improved material being distinguished. either by the fineness of the casting
or by its cheapness.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is;
The herein-described manufacture of the improved foundry sand, which consists in
the addition of coal-tar or of the other materials above referred to, to ordinary sand,
or gravel or other similar material of comparatively fine grain, as specified.
Dated this 11th day of June 1890.
Dated Gifs fith day on un
J. PATKICK.
By A. M. & Wm. Clark,
53, Chancery Lane, London, Patent Agents.