IMPROVEMENTS IN FURNACES FOR MELTING BRASS AND OTHER METALS OR ALLOYS."
Year: 1880

page_text: LETTERS PATENT to John Fletcher, of Ashton-under-Lyne, in the County of
"
Lancaster, Brass Founder, for an Invention of IMPROVEMENTS IN FURNACES
FOR MELTING BRASS AND OTHER METALS OR ALLOYS."
.
PROVISIONAL SPECIFICATION left by the said John Fletcher at the Office
of the Commissioners of Patents on the 4th October 1880.
JOHN FLETCHER, of Ashton-under-Lyne, in the County of Lancaster, Brass
Founder. "IMPROVEMENTS IN FURNACES FOR MELTING BRASS AND OTHER METALS
OR ALLOYS."
My Invention relates to the furnaces employed in the melting of brass,
gun-metal, and alloys, and particularly to the description of furnace for which
Letters Patent, bearing date the Second day of February, in the year 1877, and
numbered 441, have been granted to me. In the Invention to which the said
Letters Patent relate the furnace proper is suspended within an outer casing, and
the blast is introduced into a space surrounding the furnace, the products of
combustion being conveyed from an opening at the upper end of the furnace to a
chimney. The object of my present Invention is to utilise a portion of the waste
heat which now escapes from the upper part of the furnace, and also to expedite
the process of melting. To this end I apply a supplementary heating chamber to
the upper part of the furnace, and I cause the heated products of combustion to
flow through this chamber before leaving the apparatus, and I heat the metal or
alloy in this chamber preparatory to the melting in the furnace proper. The form
of the said chamber and the manner of applying it to the furnace may be varied,
but I will indicate the arrangement I now consider to be suitable. I arrange for
the said chamber to act as a cover for the mouth of the furnace, and I hinge the
said chamber upon a suitable joint pin, so that it can swivel horizontally into
position to cover or uncover the said mouth. When the said chamber is over the
mouth of the furnace, as when metal is being melted, the products of combustion
pass upwards through an opening in the bottom of the chamber and escape through
a side opening, which is provided with an elbow pipe which is formed and arranged
to swivel in the mouth of a pipe or conduit leading to a chimney, the axis of
movement of the said elbow pipe co-inciding with the axis of movement of the
chamber upon the said joint pin. In cases wherein it is not necessary to convey
the said products into a chimney the swivel joint pipe may be dispensed with. .I do
not confine myself to the application of my Invention to the particular description
of furnace herein before mentioned.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said John Fletcher in the Great Seal Patent Office on the 2nd April
1881.
JOHN FLETCHER, of Ashton-under-Lyne, in the County of Lancaster, Brass
Founder. "IMPROVEMENTS IN FURNACES FOR MELTING BRASS AND OTHER METALS
OR ALLOYS."
My Invention relates to the furnaces employed in the melting of brass,
gun-metal, and alloys, and particularly to the description of furnace for which
Letters Patent, bearing date the Second day of February, in the year 1877, and
numbered 441, have been granted to me.
In the Invention to which the said Letters Patent relate the furnace proper is
suspended within an outer casing, and the blast is introduced into a space
surrounding the furnace, the products of combustion being conveyed from an
opening at the upper end of the furnace to a chimney. The object of my present
Invention is to utilise a portion of the waste heat which now escapes from the
upper part of the furnace, and also to expedite the process of melting. To this end
I apply a supplementary heating chamber to the upper part of the furnace, and I
cause the heated products of combustion to flow through this chamber before leaving
the apparatus, and I heat the metal or alloy in this chamber preparatory to the
melting in the furnace proper.
And in order that my said Invention may be well understood I have attached
hereunto a Sheet of Drawings, made to a scale of about three inches to the foot,
and marked with letters of reference, corresponding marks indicating the same
parts in the various Figures.
Referring to the said Drawings, Fig. 1 represents a vertical section of the
improved furnace, and Fig. 2 a section on the line A, Fig. 3 being a curtailed plan
partly in horizontal section. In the said Figs. B is the melting furnace containing
the melting crucible d. The furnace B is constructed substantially as in the case
of the furnace described in the Specification of my former Invention, for which
Letter Patent were granted to me in the year 1877, as aforesaid, the only
important alteration being the substitution of the heating chamber C for the cover
used in the first arrangement. The said chamber consists principally of a metal
shell c, which is provided with a lining c¹ of fire-bricks or of other suitable refractory
material. In the example the said lining is composed of refractory bricks shaped
to fit together to form each ring of the lining, as indicated in Fig. 2, which represents
the second ring of bricks from the bottom of the chamber. In this second ring
three of the bricks are longer than the others, so that their ends project inwards
beyond the general surface of the lining. These projecting bricks sustain the
heating crucible c. The shell of the chamber C is cast, formed, or provided with a
projecting arm, in which is secured a hinge pin f, which turns in a seat which is
drilled or formed in a projection upon the outer shell of the melting furnace B. To
or upon the upper part of the shell of the chamber C is fixed or formed an elbow
pipe g, and the lower end of this pipe is fitted to turn within the mouth of a
second elbow pipe or conduit h, which is cast with a bracket by means of which it
is bolted to the shell of the furnace B. By preference the parts of g and h which
come together are turned and bored so that the one can turn smoothly within the
other. The axis of motion of the pipe g should coincide with the axis of the hinge
pin f. When so arranged the chamber C can be turned bodily upon the said hinge
pin so as to uncover the mouth of the melting furnace. To render the joint between
the chamber and furnace suitably tight I face the under surface of the flanch at the
bottom of the said chamber, and I furnish the upper part of the melting furnace
with a faced ring k, of wrought iron or steel, but this method of construction may

page_text: be varied. The chamber C is provided with a cover c², which is lined with refractory
material, and rests upon a faced joint ring, as in the case of the chamber. The said
lid turns upon a hinge . The elbow pipe g is formed with a through passage,
which is closed at its upper end by means of a hinged cover m, which can be
readily opened when it is desirable to cleanse the thoroughfare. As has been
herein before mentioned, a charge of metal is placed in the crucible in the chamber C
to become heated during the melting of a charge in the furnace B, the heated gases
from the furnace rising into the said chamber and surrounding the crucible therein,
and passing out through the pipes g and h. When the melted metal has been
poured the heated crucible in the chamber C may be taken out and be placed
within the furnace B, and if required another charge may be placed in a crucible in
the chamber C to become heated. In cases wherein it is not considered to be
necessary to convey the products combustion into a chimney the pipes g and h
may be dispensed with. The heating chamber forming a cover for a melting furnace
may be adapted to furnaces otherwise constructed than in accordance with my said
Invention of the year 1877.
Having now fully set forth and indicated the nature of my said Invention, and
the manner in which I prefer to carry the same into practical effect, I would have it
to be understood that I claim,―
First. The combination and arrangement of parts, substantially as and for the
purpose set forth and indicated herein before and in and by the accompanying
Drawings.
Secondly. The heating chamber forming a cover for a melting furnace, substan-
tially as set forth and indicated.
Thirdly. The furnace B, provided with a hinged cover c, which is formed to
contain a crucible for holding metal to be heated preparatory to a subsequent
melting.
And, Lastly. The chamber C, turning upon a hinge pin f, and the elbow pipe g,
turning at the same time within a pipe h, with coinciding axes, substantially as and
for the purpose set forth and indicated.
In witness whereof, I, the said John Fletcher, have hereunto set my hand and
seal, this Thirty-first day of March, in the year of our Lord One thousand
eight hundred and eighty-one.
JOHN FLETCHEK. (L.S.)