US2071890A

US2071890A - Forehearth

Info

Publication number: US2071890A
Application number: US707950A
Authority: US
Inventors: Henry E Mcwane
Original assignee: Individual
Current assignee: Individual
Priority date: 1934-01-23
Filing date: 1934-01-23
Publication date: 1937-02-23
Anticipated expiration: 1954-02-23

Description

Feb. 23, 1937.

H. E. MCWAN A 2,071,890

FOREHEARTH Filed Jan. 23, 1954 Patented Feb. 23, 1937 UNITED STATES PATENT OFFICE 41 Claims.

My invention relates to a method and apparatus for casting articles, and in particular it relates to casting articles from molten material such as metal.

The process has peculiar adaptability in making chilled castings though it is not to be limited exclusively to this type of operation.

It is an object of my invention to enable castings, such as chilled castings, to be made with great speed and yet with high accuracy;

A further object of my invention is to enable the capacity of a fore-hearth and cupola to be more nearly employed in casting articles, whereby expensive loss of heat units is minimized and the plant can be more nearly operated at capacity of the cupola.

A still further object of my invention is to greatly reduce the labor in casting articles, and to reduce the steps necessary in producing a cast article from the time the metal leaves the cupola until the casting is removed from the mold.

A yet further object of my invention is to devise a fore-hearth having a plurality of outlets located beyond the baffle so that a plurality of streams of molten metal free from slag and dross can be discharged from the fore-hearth.

Among the features of my invention which I may employ are the handling steps for the material. Where I am using cupola furnaces, such as I have shown in the drawing, I pass the material from the cupola directly to a fore-hearth. The fore-hearth may be tapped in a plurality of points and may discharge to a plurality of rotatable ladles having molds attached thereo. Thus the casting operation may be quickly adjusted to take care of a large amount of molten metal in a fore-hearth in a short space of time.

With these and other objects in view, which may be incident to my improvements, the invention consists in the parts and combinations to be hereinafter set forth and claimed, with the uncal effect without limiting the improvements in their useful applications to the particular constructions, which, for the purpose of explanatiom have been made the subject of illustration.

In the drawing: Figure 1 is a top plan view of my layout.

Figure 2 is a sectional view of the layout taken on the line 2 2 of Figure 1.

Figure 3 is a view taken along line 3 3 of Figure 2.

In the drawing I have shown a cupola furnace I of the usual type lined with fire resistant and heat insulating material which I have designated by numeral 2. This furnace is provided with the usual air inlet main 3 which discharges air under pressure through tuyres 4 located at the bottom of the furnace. The air inlet pipe 3 delivers t/o a manifold 5 which is in communication with the tuyres 4. The bottom of the cupola furnace is slanted as indicated at 6. The furnace is suitably supported on peripheral bracing members I -and central bracing member 8.

The cupola furnace I discharges through an outlet 9 into a reservoir section II of a forehearth which is generally designated by numeral I2. This fore-hearth may be made of re resistant brick and may consist of an outer layer of such brick VI3 and an inner layer of brick I4, The fore-hearth I2 is constructed with a main reservoir I5 and a supplemental reservoir I6.

The lower wall or floor of the fore-hearth is slanted as indicated at I I. There is a dividing wall `III between the main reservoir II and the supplemental reservoir I6. The baille wall is so constructed that there is a passage I9 provided under the baiiie -wall so that the molten metal of the main reservoir II can escape under baiiie wall I3 and into the supplemental reservoir I6. Both reservoirs are provided with a cover of fire resistant construction 2 I. A manhole 22 is provided on top of the reservoir II.

The molten metal passes from the cupola I through the egress port 9 located in the bottom of the cupola and into reservoir I I. The slag and dross float to the top and the baiiie wall I8 prevents them from passing into'supplemental reservoir I6. However, the molten metal does pass from main reservoir II into the reservoir I6, and this metal is relatively free from the slag and dross which have accumulated on the top ofthe metal in the main reservoir II.

There are three egress ports provided from the supplemental reservoir I6. These I have designated by the

numerals

23, 24 and 25. These egress ports are of iire resistant construction as is plain- 1y apparent from Fig. 3 and they discharge into

spouts

26, 2I and 28, respectively. These spouts are lined with suitable fire resistant material as indicated in Figure 2.

Each of the spouts discharges into a rotatable ladle which I have designated by the numeral 30.

" terior of the cover plate 3l.

are provided four egress ports 33 over which fitV the inlet ports (not shown) of mold members 34.

Each of the molds 34 is supported at an angle to the perpendicular of the front cover 3 l. This construction is to permit the rotation of the ladles 30 without causing the contents of the molds 34 to be discharged back into the interior of the ladle. The inlet port of each mold acts as a trap for material in the mold. f

The egress port of each mold may be heat lagged to prevent quick solidication of the molten material with consequent disadvantages, in operation. Each mold 34 is supported on a bracket 35 which is fastened to the front cover plate 3l. There is a removable portion 36 for each mold and pivoted fastening devices 3l which hold the non-removable portion of each mold to the removable portion.

In operation, the

spouts

26, 21 and 28 discharge into their respective ladles 30 and the ladles are rotated so that the metal in the ladles will be caused to fill each of the molds as its inlet port passes below the surface of the molten metal in the ladle. As the mold passes 'with its inlet port above the surface of molten metal in the ladle, removable portion 36 of each mold can be removed and the cast article taken out of the mold. The removable portion 36 is then again fastened in place and the operation continued.

It is contemplated that the ladles may be driven intermittently so that there shall be a position of rest during the removal of the removable portion of each mold and its subsequent replacement into operative condition.

This is merely one feature of the process and it is not necessary in every instance that the rotation of the ladles be actually arrested at this point.

Each ladle is supported on an I-beam base construction 48. On the cover plate of each ladle is a support shaft 4E which is ilanged at 42 and suitably attached by bolts 43 or otherwise to the cover` plate 3|. This shaft is journalled in a bearing member 44 which is supported by frame 45 which rests on the main support means 40.

A frame 46 supports idler rollers (not shown) which engage with a track 41 formed on the ex- There is a big gear V 48 formed on the main body 32 of the ladle. The

support 46 also carries idler gears (not shown) which mesh with this main gear 48 and help support the ladle in rotatable position. The position of these idler rollers is indicated by dotted lines in Fig. 2 and I have designated these rollers by numeral 58. The position of the idler gears is indicated in that gure by dotted lines and I have applied numeral 5| to these. There is a track formed at 52 on the exterior of the main body 32 of the ladle and in this track are adapted to t idler rollers 53 (see Fig. 2) which are supported on support members 54 that are carried on I- beams 55, supported by supports 58 which rest on members 48. It is to be noted that the ladle has a wide circular aperture 51 in its back to which the spout from the fore-hearth may iit. Mounted on framework 68 is a motor which I have indicated as an electrical motor 6l which drives gear 62, which meshes with main gear 48 to impart rotary motion to the ladle.

It is contemplated that the ladle can be driven intermittently to permit removal of the cast articles in each mold in succession, and replacement of that mold in condition to receive a new charge of material.

By having the fore-hearth deliver a plurality of streams to a plurality of rotatable ladles in the type of system shown I am enabled to use a .larger portion of the capacity of the cupola and fore-hearth than is possible with hand pouring methods, or a method in which the charge may befed to one automatic or semiautomatic unit only. This effects, as is readily apparent, considerable economies in the operation of the system and reduces expense and labor.

While I have shown and described the preferred embodiment of my invention, I wish it to be understood that I do not coniine myself to the precise details of construction herein set forth, by way of illustration, as it is apparent that many changes and variations may be made therein, by those skilled in the art, without departing from the spirit of the invention, or exceeding the scope of the appended claims.

I claim:

l. In a fore-hearth construction, in combination, a main reservoir, a baille wall, a second reservoir, a passageway below the baille wall communicating with the second smaller reservoir, a plurality of egress ports located in said second reservoir whereby a plurality of streams of metal free from dross can simultaneously be discharged from the fore-hearth, and an opening in the top of the main reservoir through which dross may be removed.

2. In a forehearth construction, in combination, a main reservoir, a baiile wall, a second reservoir, the passageway below the baffle wall communicating with the second reservoir, a plurality of egress ports located in said second reservoir whereby a plurality of streams of metal free from dross can be simultaneously discharged from the forehearth, and an opening in the top of the forehearth through which the dross may be removed.

3. In a forehearth construction, in combination, a main reservoir, a baffle wall, a. second reservoir, a passageway in the baille wall below the normal level of the molten metal through which the reservoirs are in communication, a plurality of egress ports located in said second reservoir whereby a plurality of streams of metal free from dross can be simultaneously discharged from the forehearth, and an opening in the top of the forehearth through which dross may be removed.

4. In a forehearth construction, in combination, a main reservoir, a baille wall, a second reservoir, a passageway in the baiile wall below the normal level of the molten metal through which the reservoirs are in communication, a plurality of egress ports located in said second reservoir whereby a plurality of streams of metal free from dross can be. simultaneously discharged from the forehearth, and an opening in the top of the main reservoir through which the dross may be removed.

HENRY E. MCWANE.