Year: 1887

page_text: Date of Application, 24th Mar., 1887.
Specification Accepted, 26th Apr., 1887.
J
1, JOHAN AUGUST BRINELL, Engineer of Fagersta, Westanfers, Sweden, 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:-
My invention relates to the production of tubular blanks or ingots of steel or other
metal for the manufacture of pipes or tubes.
In making a blank or ingot according to my said invention 1 cast the steel or
other metal in a melted state into a chill or mould of suitable shape and size. In
consequence of the cooling influence of the chill or mould the fluid metal at the sides
and at the bottom of the chill sets first. When the metal next to the wall of the chill
or mould has solidified the metal in the middle of the mould while still fluid is drawn
off or removed, whereby a blank or ingot is obtained having an opening extending
through the greater part of its length.
In the accompany drawing
Figure 1 is a vertical section of a mould suitable for use in connection with my
invention and filled with metal.
Figure 2 is a view similar to Figure 1, but showing the central fluid portion of the
metal removed a shell being left adjacent to the sides of the mould.
Figure 3 is a view illustrating a modification, and
Figures 4, 5 and 6 are views illustrating another modification.
In order that the walls of the pipe or tube shall be of equal thickness at the upper
and lower ends, it is necessary to ensure that the cooling of the upper part of the
mould which is last filled with metal, takes place more rapidly than the cooling of
the lower part. With the mould shown, Figure 1 this end is attained by making the
walls of the mould thinner at the lower end than nearer to the top. This thicker
part of the mould conducts the heat more quickly than the thinner part and thus
effects a more rapid cooling at the thicker part, so that the fluid metal sets to the
same thickness along the whole length of the mould.
A more rapid cooling of one part of the mould than of another part can also be
effected in other manners, as for instance by means of water.
The removal of the central fluid portion of the casting may be effected either from
the top or from the bottom of the mould. In the arrangement shown in Figure 1 the

page_text: emptying is effected from the top of the mould the said mould being suspended on
two trunnions so that it can be reversed so as to place the end A downwards. When
so reversed the metal still fluid in the interior of the mould flows out.
In order that this fluid metal shall be able to flow out, it is necessary to prevent the
casting from setting on the surface before the emptying takes place. This is attained
partly by making the walls at the top of the mould as thin as possible, as shown
Figure 1, and partly by not casting the mould quite full, in order after the filling a
layer of coal dust slag-wool or some other matter conducting heat badly may be
spread upon the melted metal.
With the view of economizing the metal, the bottom of the pipe or tube is made as
thin as possible; the bottom of the mould can thus conveniently be provided with a
block of fire proof clay see Figure 1.
The metal flowing out when emptying may be utilized either for renewed melting,
or the mould may be disposed in such a manner that the metal remains in the same
and only moves to another part of it, when the mould is overturned. Such a disposi-
tion is shown in Figures 1 and 2. Figure 1 represents the mould after the metal, of
which the pipe is to be formed, has been filled in, and Figure 2 when the mould has
been overturned. The massive part thus formed at one end of the pipe may, after
having been separated from the ingot by means of a saw be utilized for further
treatment as a common ingor.
If it be desired to obtain pipes of a small section, it sometimes happens in spite of
precautions, that the upper surface of the metal sets so rapidly as to make the removal
of the central portion of the same impossible. In order to avoid this difficulty, the
top of the mould can be made of a greater cross-section, or the top may be lined with
or consist of some material conducting heat badly to ensure that the middle of the
upper surface of the metal remains fluid for a longer time than otherwise.
Figures 4, 5 and 6 shew one of the dispositions which may be employed, when the
metal is to be emptied from the bottom of the mould. In adopting this mode two or
more moulds may be connected with a common bottom channel, so that the filling
or emptying of all the moulds takes place simultaneously. The casting of the metal
takes place in the most central mould, and the emptying is effected by removing one
of the moulds from the common bottom channel as shewn in Figure 6, whereby the
metal still fluid in the middle of the moulds flows out through the bottom channel
and through the opening formed by the removal of the one mould as aforesaid. This
bottom channel must have a sectional area sufficiently great to allow the metal in the
same to maintain itself fluid sufficiently long to be able to take this course when being
emptied. The channel may, as shewn on the drawing, be lined with a refractory
material which cools less rapidly than iron.
Having now particularly described and ascertained the nature of my said invention
and in what manner the same is to be performed, I declare that what I claim is :-
The manufacture of tubular ingots of iron, steel or other metal by filling chills or
moulds with molten metal allowing the portion of the same in proximity to the walls
of the chills or moulds to set, and then before the central portion of the casting has
set, removing or emptying such central portion from the chills or moulds.
Dated this with day of Muh 1007