Improvements in and relating to Method of and Apparatus for Coating and Drying Molds.
Year: 1899

page_text: Date of Application, 18th Apr., 1899-Accepted, 17th June, 1899
COMPLETE SPECIFICATION (AMENDED).
Improvements in and relating to Method of and Apparatus for
Coating and Drying Molds.
We, WILLIAM JOSHUA PATTERSON and ALOYSIUS WICKLAND, Manufacturers,
residing respectively at Hotel Schenley, and No. 121, Edmond Street, in the City
of Pittsburgh, County of Allegheny and State of Pennsylvania, United States
of America, 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:-
Our invention relates to a method of and apparatus for coating the interiors of
molds in metal casting apparatus where a number of molds are mounted on a
travelling carrier, the molds being poured at one end of the apparatus and
discharged at the opposite end.
In the known method of casting pig metal the metal is poured into molds
partially submerged in water, which molds are passed in a horizontal course
through said water in the partially submerged state, and then said molds are
passed in a horizontal course through said water in a completely submerged state.
The molds are mounted on an endless carrier or chain, and after they have dis-
charged their contents they pass down and return to point of pouring in an inverted
position. These molds, whether formed of cast-iron, wrought-iron or steel, are
subjected to severe usage due to the expansion and contraction which takes
place when the mold is poured and is passed through the cooling liquid.
Furthermore, it is found expedient in such form of casting apparatus to have
the molds formed with lips which overlap each other, so that when the metal
is poured said overlapping lips will prevent the metal from falling in between
the molds. If the metal drops on these lips it is liable to adhere thereto, so that
this metal which has fallen on said lips will form a fin-like portion on the pig,
which will be broken off when the pig is discharged into the receptacle at the
discharge end of the apparatus, or if a portion still adheres it will be worn off
or broken up in the handling of the pig afterwards. This metal is wasted and is a
matter of great loss.
Various methods of coating the moulds with carbonaceous or other suitable
material have been proposed. The object of our invention is to provide a simple
and efficient means for the coating of the molds, as they return in their inverted
position to the point of pouring, with a coating which will relieve the wear and
tear on the molds and prevent the metal adhering to the overlapping lips in the
manner above referred to, while at the same time the molds will be dried where
they pass through a cooling liquid, as in the method of casting hereinbefore
referred to.
To these ends our invention consists, generally stated, in the method of coating
molds in pig-metal casting apparatus, consisting in burning a fuel beneath said
molds in their inverted position as they return to the point of pouring which

page_text: will deposit a coating of carbon on the interiors of the mold, and at the samé
time dry said molds where required.
To enable others skilled in the art to make and use our invention, we will
describe the same more fully, referring to the accompanying drawing, in which-
Figure 1 is a side elevation of a portion of a suitable casting apparatus, to
which our invention is applicable; Figure 2 is a cross-section of same on line 2-2
Figure Figure 3 is an enlarged view of a portion of the travelling mold-carrier.
Like letters of reference indicate like parts in each of the figures of drawings
referred to.
While we have above referred to our invention as applicable to a known method
of casting pig metal, and will describe it in connection with said method in the
present application, yet we do not wish to limit its application in any sense to said
known method of casting.
In the drawing Figure 1 illustrates a portion of a suitable metal casting
apparatus in which the reference letter " designates the frame or the
portion thereof adjacent to the pouring end of the apparatus. The
tank is supported by the frame a, and within said tank is the
track upon which the wheels d of the endless chain e travel. The track f is the
return track supported by the frame a, and the wheels & travel on said track when
the molds return in their inverted position to the pouring point.
The endless chain or mold-carrier e may be of any suitable construction, and as
it forms no part of our present invention a detailed description is not deemed
necessary. The molds g are secured to the endless chain e, said molds having the
over-lapping lips gl which prevent the spilling of the metal in pouring between
the molds, and at the same time allow for the elongation of the endless chain due
to wear without creating a gap between the molds.
The chaine is mounted on suitable sprocket-wheels arranged at each end of the
frame, the sprockets at the pouring end only being shown.
The tracks h may be used to carry the ladle conveying the molten metal from
the blast-furnace, while i represents the pouring ladle.
Beneath the frame a are the pits k with tracks m arranged transversely of the
frame a. Upon these tracks are supported the trucks which sustain the pots or
furnaces o of any suitable construction. These furnaces are arranged at suitable
intervals apart and any number required for the purpose of our invention may
be employed. The fire-chamber of is provided with the grate-bars 2, and
the door for the admission of fuel. The furnaces o when in the position shown in
Fig. 2 are directly under the frame a, and the molds g in their inverted position
travel directly over said furnaces. In order to direct the products of combustion
into the molds the conical hood is provided.
is
When the metal casting apparatus is in operation the metal is poured into the
molds as they pass under the pouring ladle. The molds are then carried through
the cooling liquid of the tank, and when they arrive at the opposite end of the
frame the pigs are discharged from said molds. The molds then return in an
inverted position, as shown in Figure 1. As they pass over the tops of the
furnaces the smoke or unconsumed carbon enters the molds and coats the
inner walls of the same with carbon in the form of lamp-black. Bituminous coal
may be employed where furnaces like those described are used. Only enough
air is admitted to the furnaces to support combustion so that slow combustion
takes place, which deposits the coating on the molds. It is, of course apparent
that any suitable fuel may be employed for this purpose whether gaseous, liquid
or solid. Any fuel containing carbon or which when imperfectly consumed will
deposit the carbon on the molds may be used, and oils or tarry substances might
be employed.
Any suitable form of furnace or burner may be employed, and we do not wish
to limit ourselves in any manner to the particular form of apparatus for burning
fuel beneath the molds.
This combustion of fuel beneath the molds will also act to dry the interiors

page_text: thereof so that when brought around to the pouring point they will be sub-
stantially dry when the molten metal enters them.
If furnaces such as illustrated are employed to burn solid fuel, when the
apparatus is not in operation the furnaces may be run to one side of the frame
on the tracks m, so that undue heating of the molds when at a stand-still is
avoided.
In pouring, the metal, as stated, is liable to drop on the over-lapping lips gl
and adhere thereto, so that when the molds arrive at the point of discharge this
fin-portion is broken off by the fall of the pigs into the receptacle placed there
to receive them, or in the later handling of the pigs, and is lost. By the
coating of the molds in the manner above set forth, the metal instead of adhering
to these lips, slips back into the mold and no fins are formed. The coating
further acts to protect the molds when the metal is poured.
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed, we declare that what
we claim is: -
1. The method of coating molds in pig-metal casting apparatus, consisting
in burning fuel beneath the inverted molds and depositing the carbon derived
therefrom on the inner faces of the molds, substantially as set forth.
2. In metal casting apparatus, having a suitable frame, and endless chain, and
molds carried by said chain, the combination therewith of fuel-burning apparatus
beneath said molds, substantially as set forth.
this 18th day of April 1899.
JENSEN & SON,
77, Chancery Lane, London, W.C., Patent Agents.