IMPROVEMENTS IN CASTING METALS
Year: 1855

page_text: LETTERS PATENT to John Henry Johnson, of 47, Lincoln's Inn Fields,
in the County of Middlesex, and of Glasgow, North Britain, Gentleman,
for the Invention of "IMPROVEMENTS IN CASTING METALS."-A commu-
nication from Jackson Brothers, Petin Gaudet, and Company, of Rive
PROVISIONAL SPECIFICATION left by the said John Henry Johnson at
the Office of the Commissioners of Patents, with his Petition, on the
12th November 1855.
I, JOHN HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of
Middlesex, and of Glasgow, North Britain, Gentleman, do hereby declare
the nature of the said Invention for "IMPROVEMENTS IN CASTING METALS," a
communication from Jackson Brothers, Petin Gaudet, and Company, of Rive
de Gier, in the Empire of France, Engineers, to be as follows:-
This Invention relates to certain peculiar constructions and arrangements of
machinery or apparatus for casting wheel tyres and rims, either toothed or
plain, hoops, bands, drums, and all other articles of an annular form, by the aid
of centrifugal force, whereby the central core hitherto employed. for casting
such articles is dispensed with, and the work is effected with greater accuracy
and economy both of time and labour than by the existing modes of casting
objects of this description. The improvements consist in the employment of
a circular chill or mould fitted on to the end of a shaft, working either hori-.
zontally or vertically in suitable bearings, and rotated at a high velocity by
gearing or driving pulleys. The interior circumference of the chill is made to

page_text: correspond to the design of the periphery of the article to be cast; thus, if a
wheel tyre is to be cast, the internal circumference is shaped accordingly. The
metal is poured into the centre or near the centre of the rotating chill or
mould, and is immediately driven by the centrifugal force to the circumference,
where it is allowed to set or cool. When sufficiently cool the face or top
plate of the mould or chill is removed, and the tyre or other article is with-
drawn with facility. Rings or bands of any strength may be cast by this
process, and may be made sufficiently thin for saws or springs, or other purposes
where very thin flexible rings are required. Some of the moulds may be made
with a flat bottom, the driving spindle being cast on the outside or back
thereof, whilst others may be made with an internal boss, and are keyed on to
the end of the driving shaft. The sides of this boss are made to slope or curve
outwards towards. the circumference of the mould, so that the metal may the
more readily run off from the centre. The face or top plate in some cases may
consist of a ring of sufficient width to keep the metal from being thrown out,
such metal being poured in at the central opening of the cover.
Another form of cover consists of a closed disc, having merely a central
pouring funnel mouth fitted or cast thereon. When the shaft revolves hori-
zontally the metal must be introduced by a fixed spout or funnel, its lower
extremity projecting inside the revolving mould.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said John Henry Johnson in the Great Seal Patent Office on
the 12th May 1856.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of Middlesex,'
and of Glasgow, North Britain, Gentleman, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twelfth day of November, in the year of our Lord
One thousand eight hundred and fifty-five, in the nineteenth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said John Henry Johnson, Her special license that I, the said John
Henry Johnson, my executors, administrators, and assigns, or such others
as I, the said John Henry Johnson, my executors, administrators, or assigns,"
should at any time agree with, and no others, from time to time and at all
times thereafter during the term therein expressed, should and lawfully might
make, use, exercise, and-vend, within: the United Kingdom of Great Britain;

page_text: and Ireland, the Channel Islands, and Isle of Man, an Invention for "IMPROVE-
MENTS IN CASTING METALS," a communication from Jackson Brothers, Petin
Gaudet, and Company, of Rive de Gier, in the Empire of France, Engineers,
upon the condition (amongst others) that I, the said John Henry Johnson,
by an instrument in writing under my hand and seal, should particularly
describe and ascertain the nature of the said Invention, and in what manner
the same was to be performed, and cause the same to be filed in the Great
Seal Patent Office within six calendar months next and immediately after
the date of the said Letters Patent.
NOW KNOW YE, that I, the said John Henry Johnson, do hereby declaro
the nature of the said Invention, and in what manner the same is to be
performed, to be particularly described and ascertained in and by the fol-
lowing statement, reference being had to the accompanying Drawings, and
to the letters and figures marked thereon, that is to say :-
The said Invention relates to certain peculiar constructions and arrange-
ments of machinery or apparatus for casting wheel tyres and rims, either
toothed or plain, hoops, bands, drums, and all other articles of an annular form,
by the aid of centrifugal force, whereby the central core hitherto employed for
casting such articles is dispensed with, and the work is effected with greater
accuracy and economy both of time and labor than by the existing modes of
casting objects of this description.
When
The improvements consist in the employment of a circular chill or mould
fitted on to the end of a shaft, working either horizontally or vertically in
suitable bearings, and rotated at a high velocity by gearing or driving pulleys.
The interior circumference of the chill is made to correspond to the design or
shape of the periphery of the article to be cast; thus, if a wheel tyre is to be
cast, the internal circumference is formed with an annular cavity in it to
form the flange. The metal is poured into the centre or near the centre
of the rotating chill or mould, and is immediately driven by the centrifugal
force to the circumference, where it is allowed to set or cool.
sufficiently cool the face or top plate of the mould
the tyre or other article is withdrawn with facility.
strength may be cast by this process, and may be
saws or springs, or other purposes where very thin
Some of the moulds may be made with a flat bottom, the driving spindle
being cast on the outside or back thereof, whilst others may be made with an
internal boss, and are keyed on to the end of the driving shaft. The sides of
this boss are made to slope or curve outwards towards the circumference of the
mould, so that the metal may the more readily run off from the centre. The
or chill is removed, and
Rings or bands of any
made sufficiently thin for
flexible rings are required.

page_text: face or top plate in some cases may consist of a ring of sufficient width to keep
the metal from being thrown out, such metal being poured in at the central
opening of the cover.
Another form of cover consists of a closed disc, having merely a central
pouring funnel mouth fitted or cast thereon. When the shaft revolves hori-
zontally the metal must be introduced by a fixed spout or funnel, its lower
extremity projecting inside the revolving mould.
And in order that the said Invention may be fully understood, I shall now
proceed more particularly to describe the same, and for that purpose I shall
refer to the several Figures on the Sheet of Drawings hereunto annexed, the
same letters of reference indicating corresponding parts throughout all the
Figures.
Figure 1 represents a vertical sectional elevation of one arrangement of
centrifugal moulding apparatus for casting wheel tyres, rims, or other hoops or
rings of any diameter and thickness.
A, A, are two standards or supports carrying the driving shaft H, which is
fitted with fast and loose driving pulleys J, J, and carries a bevil wheel G at
one end, which gives a rotatory motion to the vertical shaft C by means of a
second bevil wheel G' keyed thereon. This shaft is supported near its upper
end by the collar bearing in the bracket B, and works at its lower end in the
adjustable footstep bearing M. On the upper end of the shaft C is fitted the
circular mould or chill E, which is keyed on to the disc D, formed on the end
of the shaft. A funnel mouth O is formed in the centre of the mould, into
which the molten metal is poured. The rapid rotatory motion which is
imparted to the mould by the driving shaft and bevil gearing causes the metal
to fly off by centrifugal force from the centre of the mould to the periphery,
and there form a ring of perfectly even thickness all round, and of an external
contour corresponding to the shape of the periphery of the mould.
In the arrangement shewn at Figure 1 the mould is intended to produce
a plain ring, suitable for the rim of a wheel or other similar purpose; Figure 2
represents a similar construction of mould to Figure 1, but rotating vertically
in place of horizontally, the bevil gearing in this place being dispensed with.
The pouring spout O is fixed and detached from the mould, and is made to
protrude into the central opening to convey the moulten metal into the mould.
Figure 3 represents an arrangement of mould for casting wheel tyres; it is
of a somewhat similar construction to Figure 1, with this exception, that the
top plate or cover F is bolted on to the body of the mould, which is shaped so
as to produce the flange of the tyre.
In Figure 4 the mould is rotated by bevil gearing, as in Figure 1, and rests'

page_text: upon and is bolted at N to a disc D on the end of the vertical shaft C. An
internal boss is made in the centre of the mould, through which boss and the
end of the shaft a key is driven to connect them together. The sides of the
boss are curved or sloped all round from the top outwards, so as to cause
the moulten metal which is poured in at 0, 0, to run more freely towards
the periphery, which is so shaped as to form a wheel tyre. The ring or
annular cover F is bolted on to the mould by the bolts N, N, in order to
prevent the metal from flying out during the rapid rotation of the mould.
By suitably shaping and indenting the periphery of the mould, the rims of
external toothed gearing of all kinds may be cast with facility; or by having
the internal periphery plain and pouring in a suitable amount of metal, thin
circles or hoops of cast-steel may be formed suitable for ribbon saws or
springs.
From the above description it will be obvious that annular articles of all
kinds may be cast of any metal without the necessity of making separate
moulds and using internal cores, and the rings so cast may afterwards, if found
requisite, be submitted to a rolling mill or forge hammer, for the purpose of
further working the same, and reducing them to the desired size and form.
By afterwards cutting the rings so formed, they may be rolled out straight into
lengths or bars, which may be used for any suitable purpose.
Having now described and particularly ascertained the nature of the said
Invention, and the manner in which the same is or may be used or carried
into effect, I would observe, in conclusion, that I do not confine or restrict
myself to the precise details or arrangements which I have had occasion to
describe or refer to, as many variations may be made therefrom without
deviating from the principles or main features of my said Invention; but what
I consider to be novel and original, and therefore claim as the Invention
secured to me by the herein-before in part recited Letters Patent, is, the
casting of annular articles of all kinds, such as wheel tyres and rims, by the aid
of centrifugal force and rotating moulds or casting boxes.
In witness whereof, I, the said John Henry Johnson, have hereunto
hand and seal, the Twelfth day of May, One thousand eight
set my
hundred and fifte siv
J. HENRY JOHNSON. (L.s.)