AN IMPROVEMENT OR IMPROVEMENTS IN THE CASTING PROCESS COMMONLY CALLED CHILL CASTING
Year: 1880

page_text: LETTERS PATENT to Samuel Benjamin Whitfield, of Birmingham, in the County
of Warwick, Metallic Bedstead Manufacturer, for an Invention of "AN
IMPROVEMENT OR IMPROVEMENTS IN THE CASTING PROCESS COMMONLY CALLED
CHILL CASTING."
PROVISIONAL SPECIFICATION left by the said Samuel Benjamin Whitfield
•
at the Office of the Commissioners of Patents on the 18th March 1880.
SAMUEL BENJAMIN WHITFELD, of Birmingham, in the County of Warwick,
Metallic Bedstead Manufacturer. "AN IMPROVEMENT OR IMPROVEMENTS IN THE
CASTING PROCESS COMMONLY CALLED CHILL CASTING."
The process commonly called chill casting consists in casting metals, particularly
cast iron, upon articles of wrought iron by the use of cast iron or metal moulds,
the conducting power for heat of the cast iron or metal moulds causing the rapid
solidification of the molten cast iron, and producing a hard casting. The process of
chill casting is principally employed where it is wished to cast ornamental castings
or junction pieces on metallic rods or tubes, or sheets, so that the cast iron moulds
can be readily arranged and used where sand moulds could not be applied. The
said process of chill casting is largely employed in the manufacture of the head
and foot rails of metallic bedsteads and other articles of like manufacture, that is,
articles in which rods or tubes or other parts are joined by chill casting junction
them.
pieces upon
The process of chill casting is wholly or mainly restricted to the manufacture of
articles of wrought iron, and is rarely, if at all, applied to articles made of brass or
of iron coated with brass. The heat of the melted cast iron either melts or
injuriously affects the brass on which it is cast, and hence the process of chill
casting as ordinarily conducted is practically inapplicable to articles composed
wholly or partially of brass.
My Invention consists of the improvement or improvements herein after described
in the process of chill casting, whereby it is made applicable to the casting of
ornaments or junction pieces upon brass or brass coated articles, as well as upon
metals and alloys to which the ordinary process is inapplicable.
In chill casting according to my Invention I proceed as follows:-
I
prepare the part or parts of the rods or tubes or other articles of brass on which
the junction or other piece is to be cast by enveloping it or them by one or more

page_text: layers of paper, linen, or other like material, which by contact with the molten iron
becomes charred, and is thereby converted into a layer of an imperfect conductor of
heat between the melted iron and the brass on which it is cast. This layer of
carbon effectually protects the brass from fusion and injury.
Although paper, linen, and the like answer well in practice, yet I do not limit 5
myself to their use as other imperfect conductors of heat may be used with the
same or nearly the same effect. For example, a layer of chalk or lamp black
mixed with gum water, and applied by means of a brush, may be employed instead
of paper or linen, but I prefer the use of paper or linen.
By thus isolating the brass from contact with the molten iron cast upon it, the 1
brass is not only not melted, but it is not injuriously affected, and chill casting
upon brass can by the use of my Invention be readily and efficiently practised.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Samuel Benjamin Whitfield in the Great Seal Patent Office on the
10th September 1880.
SAMUEL BENJAMIN WHITFIELD, of Birmingham, in the County of Warwick,
Metallic Bedstead Manufacturer. "AN IMPROVEMENT OR IMPROVEMENTS IN THE
CASTING PROCESS COMMONLY CALLED CHILL CASTING."
The process commonly called chill casting consists in casting metals, particularly
cast iron, upon articles of wrought iron by the use of cast iron or metal moulds, the
conducting power for heat of the cast iron or metal moulds, causing the rapid
solidification of the molten cast iron and producing a hard casting. The process of
chill casting is principally employed where it is wished to cast ornamental castings
or junction pieces on metallic rods or tubes, or sheets, so that the cast iron moulds
can be readily arranged and used, where sand moulds could not be applied. The
said process of chill casting is largely employed in the manufacture of the head and
foot ends of metallic bedsteads and other articles of like manufacture, that is,.
articles in which rods or tubes or other parts, are joined by chill casting junction
pieces upon them.
The process of chill casting is wholly or mainly restricted to the manufacture of
articles of wrought iron, and is rarely if at all applied to articles made of brass or
of iron cased with brass..
The heat of the melted cast iron either melts or injuriously affects the brass on
which it is cast, and hence the process of chill casting as ordinarily conducted is
practically inapplicable to articles composed wholly or partly of brass.
My Invention consists of the improvement or improvements herein after
described in the process. of chill casting, whereby it is inade applicable to the
casting of ornaments or junction pieces upon brass or brass cased articles as well
as upon metals and alloys to which the ordinary process is inapplicable.
In chill casting according to my Invention I proceed as follows:-
I prepare the part or parts of the rods or tubes, or other articles of brass on
which the junction or other piece is to be cast by enveloping it or them by one or
more layers of paper, linen, or other like material, which by contact with the
molten iron becomes charred, and is thereby converted into a layer of an imperfect
conductor of heat between the melted iron and the brass on which it is cast. This
layer of carbon effectually protects the brass from fusion and injury. The thin
film or layer of carbon which separates the casting from the tube or article on
which the casting is made does not affect the firmness. of the junction, as the con-
traction of the casting on the tube or article is somewhat greater than it otherwise
would be in consequence of the tube or article not having been so much expanded
as usual, the layer of carbon preventing to some extent the heating of the tube or
article. After the casting has been effected the superfluous pieces are chipped off
in the usual way, and the casting finished by japanning and ornamenting, and the
brass cleaned, polished, and lacquered in the usual way.
I prefer to cover with paper, not only the part on which the casting is to be
effected, but also the whole or such parts of the tube or article on which there is
risk of molten iron falling during the casting process. By this covering of paper
injury to the brass or metal on which the casting is made is prevented. One layer
of thin brown paper is enough for ordinary purposes, but when the casting to be
made is large, two or more layers may be employed. I attach the paper by pasting
or gumming the edges together after the paper has been tightly coiled or other-
wise closely placed upon the article. After the covering of paper has been applied
I place the article for a time in a japanner's stove, or otherwise warm it prior to
performing the casting process in order that the moisture of the paste or gum, as
well as that in the paper, may be thoroughly got rid of.

page_text: Although paper, linen, and the like answer well in practice, yet I do not limit
myself to their use, as other imperfect conductors of heat may be used with the
same or nearly the same effect. For example, a layer of chalk or lamp black
mixed with gum water, and applied by means of a brush, may be employed instead
of paper or linen, but I prefer the use of paper or linen. In this case as when paper
is used the article must be thoroughly dried before the casting is effected.
By thus isolating the brass from contact with the molten iron cast upon it, the
brass is not only not melted, but it is not injuriously affected, and chill casting upon
brass can by the use of my Invention be readily and efficiently practised.
The chill or metal moulds which I employ are of the ordinary kind; I prefer
however to make the air holes of the mould somewhat larger than those ordinarily
inade, as in addition to the air, which has to pass out at the said holes, the gaseous
matter produced by the decomposition of the paper or other organic matter as the
paste and gum has also to escape by the said holes.
Although I have described the manner in which my Invention is to be performed
with reference to the casting of junction or other pieces upon rods or tubes, or
other articles of brass or cased with brass, yet my Invention is applicable to chill
casting upon copper and German silver, and is also applicable to the joining of
articles of iron, as in the manufacture of fenders, to the joining of rods or rails for
various purposes, and generally to all such purposes as chill casting as ordinarily
practised is applicable to.
Having now described the nature of my Invention and the manner in which the
same is to be performed, I wish it to be understood that I claim as my Invention
of "An Improvement or Improvements in the Casting Process commonly called
Chill Casting," coating that part of the article on which the casting is to be
effected with a layer of paper or other imperfect conductor of heat, so as to protect
the metal on which the casting is effected from fusion and injury by the action of
the molten cast iron or other metal upon it, substantially as herein before
described.
In witness whereof, I, the said Samuel Benjamin Whitfield, have hereunto set
my hand and seal, this Eighth day of September, in the year of our Lord
One thousand eight hundred and eighty.
Witness,
RICHARD SKERRETT,
37, Temple Street,.
Birmingham.
SAMUEL BENJAMIN WHITFIELD. (L.S.)