Molten metal pouring device

A molten metal pouring device is disclosed, wherein there are provided two pairs of link mechanisms whose links are adapted to be moved in parallel relation to each other, so that, regardless of an inclined angle of a ladle, a molten metal-dropping locus may follow a constant path when a molten metal is poured from a ladle into a mold. The molten metal pouring device equipped with these link mechanisms can be readily automated, as well as permits the reduction in cross sectional area of a sprue of a mold. Thus, temperature drop of a molten metal is avoided, with the result of production of castings of an improved quality.

BACKGROUND OF THE INVENTION 
This invention relates to a molten metal pouring device, wherein a molten 
metal-dropping locus may follow a constant path, when a molten metal is 
poured into a mold. 
Where it is desired to pour a molten metal into a mold arranged on a 
casting line, it must be taken into consideration that a molten metal 
should accurately drop into a sprue of a mold. Generally speaking, a locus 
of a molten metal which is dropping from a beak of a ladle varies 
depending on a case where a large amount of molten metal is filled in a 
ladle or where only a small amount of molten metal is filled therein. It 
is a common practice that a variation in molten metal-dropping locus is 
compensated for by enlarging the cross sectional area of a sprue. 
Variation in molten metal-dropping locus, however, results in difficulty 
in detecting a molten metal level in a sprue, and causes scattering of a 
molten metal to the exterior of the sprue, and hence damages on various 
kinds of instruments provided on the molten metal pouring device. An 
enlarged sprue is bound to an increase in amount of a molten metal 
dwelling in a sprue, and it takes a long time for such a large amount of a 
molten metal to flow into a cavity of a mold. In this case, the 
temperature of molten metal is lowered, and a smooth flow of molten metal 
can not be achieved, leading to degradation in quality of castings 
produced. 
OBJECTS OF THE INVENTION 
It is accordingly an object of the present invention to provide a molten 
metal pouring device, wherein, regardless of an inclined angle of a ladle, 
a molten metal-dropping locus may follow a constant path, so that the 
cross sectional area of a sprue in a mold may be reduced, and the pouring 
of molten metal into a mold may be readily automated. 
It is another object of the present invention is to provide a molten metal 
pouring device, wherein the scattering of a molten metal over the 
surroundings of a mold may be avoided. 
It is a further object of the present invention to provide a molten metal 
pouring device, wherein the cross sectional area of a sprue in a mold is 
reduced, thereby producing castings of an improved quality. 
SUMMARY OF THE INVENTION 
The molten metal pouring device according to the present invention is 
characterized in that there are provided two pairs of link mechanisms 
whose links are moved in parallel relation to each other, and a ladle is 
secured to the free ends of respective links of one pair of link 
mechanisms, said ladle being adapted to be turned about a point, at which 
an extension of a line connecting the free ends of respective links of the 
pairs of link mechanisms together intersects with an extension of a line 
connecting the other ends of the links mounted on supporting shafts 
together, whereby a molten metal dropping locus may follow a constant 
path, when a molten metal is poured, independently of inclinations of the 
ladle.

DESCRIPTION OF PREFERRED EMBODIMENTS 
Referring first to FIGS. 1 and 2 which show top and side views of the 
molten metal pouring device according to the present invention, a control 
device 1 is placed on a wheeled platform 2 and contains a hydraulic 
device. The wheeled platform 2 has wheels 2a so as to freely travel along 
a pair of rails. Posts 3 are rigid with the wheeled platform 2. A first 
pair of link mechanisms 4 are each composed of links 4a and 4b, one ends 
of which are mutually rotatably mounted on a supporting shaft 5. Each link 
4a is journaled on a supporting shaft 6 at the other end, which link is 
supported on the post 3. A second pair of link mechanisms 7 are each 
composed of links 7a and 7b, one ends of which are mutually rotatably 
mounted on a supporting shaft 8. Each link 7a is journaled on a supporting 
shaft 9 at the other end, which link is supported on the post 3, as well. 
The links 4b and 7a are mutually rotatably supported on a supporting shaft 
10 at their mid points. The links 4b and 7b, at their other ends, 
removably engage supporting shafts 11 and 12, which in turn are attached 
to a ladle 13. The links 4a of the first pair of link mechanisms 4 and the 
links 7a of the second pair of link mechanisms 7 are arranged in parallel 
relation to each other, and the links 4b of the first pair of link 
mechanisms 4 and the links 7b of the second pair of link mechanisms are 
arranged in parallel relation to each other. Shown at A is a point, at 
which an extension of a line connecting the free ends of the links 4b and 
7b together, intersects with an extension of a line connecting the other 
ends of the links 4a and 7b together, which are supported on the posts. 
The ladle 13 is so arranged that a beak 13a of a ladle 13 thereof is 
located in accord with the intersection A. A link drive mechanism 14 is 
composed of a sprocket 15 mounted on the supporting shaft 6, a chain 16 
and a drive motor 17. The drive motor 17 may be an electric motor, and 
should preferably be a hydraulic motor from the viewpoint of simplicity of 
construction. Load detecting means 18 are attached to the links 4b and 7b, 
respectively. 
In operation, when the drive motor 17 is operated to rotate the links 4a of 
the first pair of link mechanisms 4 in the counterclockwise direction, 
then the links 7a of the second pair of link mechanisms 7 are rotated in 
the counterclockwise direction through the mediary of the links 4b. The 
rotation of these links 4a and 7a causes the links 4b and 7b to move in 
cooperation therewith, whereby the ladle 13 will be turned about the 
intersection A of the two extensions in the counterclockwise direction, to 
thereby assume a molten metal pouring position, as shown by a two-dotted 
line in FIG. 2. 
So far as the sprue 13a of the ladle 13 is located in accord with the 
intersection A, a molten metal drops from a beak 13a of the ladle 13 into 
a sprue of a mold, describing the constant locus, irrespective of an 
amount of a molten metal remaining in the ladle 13. This permits reduction 
in cross sectional area of the sprue. 
The load detecting means 18 are useful for detecting an amount of a molten 
metal remaining in the ladle 13, and an amount of a molten metal in the 
ladle may be accurately detected, without a visual check of an operator. 
FIG. 3 diagrammatically shows the link mechanisms of the molten metal 
pouring device shown in FIGS. 1 and 2. Since the construction is the same 
as the above-described, no further description is given. 
When it is desired to pour a molten metal into a mold manually, the ladle 
13 is demounted from the link mechanisms, and in turn, suspended by means 
of wires, with a handle attached to the ladle. 
FIG. 4 diagrammatically shows the link mechanisms in a modified form, 
wherein the first link mechanisms 19 are each composed of links 19a and 
19b, and the second link mechanisms 20 are each composed of links 20a and 
20b. An extension of a line connecting those other ends of the links of 
the first and second link mechanisms 19 and 20, together, which ends are 
respectively supported on the posts, intersects at a point A' with an 
extension of a line connecting one free ends of the links of respective 
link mechanisms together. 
FIG. 5 diagrammatically shows a further modification of the link mechanisms 
comprising of the first and second link mechanisms. The first link 
mechanisms 21 composed of links 21a and 21b, respectively, while the 
second link mechanisms 22 are composed of links 22a and 22b, respectively. 
An intersection which is obtained in like manner as in the former 
embodiment is indicated at A". 
According to the present invention, a molten metal is poured into a mold, 
describing a constant molten metal-dropping locus, independently of an 
amount of molten metal remaining in the ladle. This enables the pouring of 
a molten metal even into a reduced sectional area of a sprue in a mold, 
with the resultant easiness in control of a molten metal in a sprue in a 
mold as well as in detection for a level of a molten metal in the sprue. 
The molten metal pouring device equipped with two pairs of link mechanisms, 
if employed, for example, on a casting line, enables the automatic pouring 
of an optimum amount of a molten metal into molds arranged on a casting 
line, with the freedom of scattering of a molten metal over the 
surroundings of these molds, so that an intended automated molten metal 
pouring system may be achieved. 
Furthermore, reduction in cross sectional area of a sprue of a mold may be 
achieved in the molten metal pouring device of the invention, thereby 
retarding lowering of a temperature of a molten metal, with the resultant 
smooth flow of a molten metal into a cavity in a mold. This insures 
production of castings of an improved quality.