US533685A

US533685A - Apparatus for casting

Info

Publication number: US533685A
Authority: US
Publication date: 1895-02-05
Anticipated expiration: 1912-02-05

Description

(No Model.)

3 Slgeets8heet 2. H. G. UNDERWOOD. APPARATUS FOR CASTING.

Patented'f'eb. 5,1895.

ma NORM! was: on. PHGTD-LITHD, WkSHINGTON, D c.

(No Model.) 3 SheetsSheet 3.

H. G. UNDERWOOD. APPARATUS FOR UASTING.

No. 533,685. Patented Feb. 5, 1895.

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Urirno STATES ATENT rerun.

HERBERT G. UNDElRvVOOD, OF YONKERS, ASSIGNOR TO HERBERT H. FRANKLIN, OF SYRACUSE, NEIV YORK.

APPARATUS FOR CASTlNG.

3PEGIFICATION forming part of Letters Patent No. 533,685, dated February 5, 1895.

Application filed May 8,1894. erial No.5l0,44.2. {No model.)

paratus for Casting; and I do hereby declare that the following is a full and exact description thereof, reference being bad to the accompanyingdrawings, and to the letters of referonce marked thereon, making a part of this specification.

This inven tion relates to the moldin g of articles which should be turned out of the mold in a practically perfect condition in order that the manufacture maybe conducted econominally.

In another application for Letters Patent, filed August 8, 1893, and numbered serially 484,448, there have been described and shown a certain method and an apparatus for accomplishing the general result referred to above. The apparatus is found to work well in practice, particularly when using metals which have a comparatively low fusing point. In the practical operation of the apparatus, however, it has been found that certain modifications and improvements can be employed with good eifect, particularly in working with metals which have a comparatively high f using point. In working with the harder metals it is especially desirable that the mold itself should be brought as close as possible to the body of molten material in the melting pot in order that the molten metal may not chill during its passage into the mold. For the same reason and also that no part of the apparatus may be clogged by chilled metal it is desirable that the high temperature of all parts except the mold should be maintained and that all of the molten metal which is separated from the whole mass at each operation and is not forced into the mold itself should be returned at once to the whole mass case have been devised to meet the several requirements above alluded to and as a result it has become possible to produce successfully and economically molded articles of hard metal which require practically no finishing after their removal from the molds.

Various features of improvement will be described in detail hereinafter and different forms of apparatus in which the improvements may be embodied will be described, but it will be observed that all the forms of apparatus shown embody such an arrangement of parts that the cylinder or its equivalent chamber and the plunger or piston, by means of which the portion of molten metal is forced into the mold, are so supported as to be submerged within the mass of molten material, that the port through which the molten metal is forced from the cylinder into the mold is so placed as to permit the metal not carried away with the mold to drop back beneath the surface of the mass of molten metal to be virtually encompassed by the whole body thereof, and that the mold itself is adapted to be held with its ingate practically in close and immediate contact with the port through the wall of the cylinder.

In the drawings: Figure 1 is a partly sectional elevation of a furnace and melting pot equipped with one form of the improved apparatus, the melting pot being broken out to show the means for forcing the metal into the mold. Fig. 2 is a vertical, central section through the cylinder and plunger shown in Fig. 1. Fig. 3 is a vertical, central section through an apparatus of a slightly different form from that shown in Fig. 1, the means for operating the plunger being broken off. Figs. 4. and 5 are vertical, central sections through other forms of the apparatus, the cylinder and plunger being horizontally disposed. Fig. 6 is a bottom view of a mold and cut-0E which may be used. Fig. 7 isa longitudinal section of the mold and cut-0d shown in Fig. 6. Figs. 8 and 9 are respectively a bottom View and a longitudinal section showing another arrangement of the cut-off; and Figs. 10 and 11 are respectively a top view and a longitudinal section showing still another arrangement of the cutoff. Fig. 12 is a detail view in section, illustrating a modified form of the cylinder or chamber and its plunger. Fig. 13 is a partial section on the line ww ofFig.12. Figs. 14 and 15 are similar views showing a different arrangement of the cylinder or chamber and plunger, the line y-y of Fig. 1e indicating the plane of section of Fig. 15.

Referring first to Figs. 1 and 2 it will be seen that a crucible or melting pot A of an ordinary shape is supported within a furnace B. As represented, the crucible or pot is supported by lugs c, c, on the under side of a plate 0 which covers or extends across the top of the pot A. The plate 0, whatever may be its position, is adapted to receive and support upon its upper surface the mold which is to be used and is provided with an aperture or port 0 which registers and makes close con tact with the ingate of the mold or with an opening through a plate which may be considered as a part of the mold, as will be more particularly described hereinafter. To the under or inner side of the plate 0 is rigidly secured, so as to be practically in one piece therewith, a chamber or cylinder D which has in its upper wall a port (1 which registers with the port 0 in the plate 0.

It will be readily understood that the plate 0 and the cylinder D might be formed in one piece, it being merely essential that the port 0 d, shall be formed through the upper wall of the cylinder in such position that the mold may be held firmly with its ingate against said port and that whatever may pass inward through such port shall fall within the cylinder.

As the cylinder itself is submerged in the molten material in the pot it will be seen that such portion of the molten metal as is forced into the mold at each operation has only a short distance to travel (the mold being separated from the pot only by the thickness of the plate 0) and that Whatever metal maybe returned through or from the port 0 d falls below the surface of themass of molten metal and is encompassed by the whole mass, being therebyimmediately brought to the required temperature. Moreover, as the cylinder D is submerged in the mass of molten metal the plate 0 is kept very hot and as a result the -metal is not chilled on its way to the mold and the port 0 d is kept clear. The mold, however, is protected by the plateG from the intense heat of the molten mass, and being kept in contact therewith only for a short time at intervals, may be kept at a suitably low temperature.

An ordinary solid plunger, fitting freely inside of the cylinder D, might be used to force the molten metal outward through the port 0 d, but certain advantages are secured by using what may be termed an outside plunger or bucket E, the same being a cylinder with closed bottom and working freely on the outside of the cylinder D. Movement of the cylinder or of the plunger may be produced by any suitable means.

As represented, the plunger may be carried by rods f,f, from a cross-head F, the latter being connected by a link f to an operating lever G. The upper edge of the plunger or bucket E is cut away somewhat, as at e, to permit the bucket to fill without being dropped wholly below the end of the cylinder D.

As the bucket is filled at every operation the extent of movement necessary to be imparted to the cross-head F to fill a certain mold can be more exactly determined than would be possible with an inside plunger when the level of the molten metal in the pot changes. Moreover, by reason of the reasonably large inside diameter of the bucket E a smaller movement thereof is required to force a given quantity of metal through the port 0 d.

In some cases, Where a particularly high temperature is required, it is desirable that the plate which supports the cylinder D shall be sunk below the level of the rim of the crucible, as represented at O in Fig. 3, and, in lesser degree, in Figs. 4 and 5. The upper end of the cylinder D and the walls of the port 0, being surrounded by the heat of the crucible, are thus maintained at a high tom peratur'e.

In Fig. at are represented a furnace B, and

melting pot A which are covered or bridged as before by a plate 0. The latter is adapted to receive and support the mold in close contact with its upper face and is provided with a port 0 which registers with a port d in the upper wall of the cylinder D, which is supported in a horizontal position. The cylinder D is adapted to be submerged in the molten metal and, as in the construction shown in Fig. 1, the material which drops back through the port 0 d, is encompassed by the mass of molten metal in the pot. The outside plunger or bucket E has an arm F which is secured to a slide rod G to be operated by any suitable means. In this View, Fig. 4;, the cylinder D is shown as integral with the bridge plate 0'.

The construction represented in Fig. 5 is substantially the same as that shown in Fig. 4 except that a solid plunger E working freely inside of the cylinder D replaces the outside plunger or bucket. After a mold has been filled it might be removed from the filling devices without attempting to shear off the sprue or the sprue might be sheared off by sliding the mold upon the plate or bridge 0 or C. In order, however, that better results may be secured and particularly that the sprue may be sheared off readily while the metal in the mold is still under pressure, it is preferable to employ an independent cut-off which is atlinear movementacross the opening in the body of the mold, In the construction shown in Figs. 6 and 7 the main part H of the mold is represented as having pins h, h, which may be engaged with eyes on the supporting plate for convenience in holding the mold firmly over the port 0 d. To the part II is hinged the part I through which the ingate '11 is formed. The cut-0d K in this case is pivoted upon the part I so that it may slide with a curvilinear movement across the opening i and is a flat plate so that it may make close contact both with the part I on the one side and with the plate G or C on the other. It is provided with an aperture which is in effect the ingate of the mold and when the mold is being filled is so placed as to register with the opening 2'. As soon as the filling is completed and while the metal in the mold is still under pressure from the filling devices the cut-cit is moved to shear off the metal across the opening 11, leaving the corresponding side of the molded article smooth. The small portion of metal which remains in the aperture ll; will fall out of itself when the mold is raised.

In the construction shown in Figs. Sand 9 the plate I, which forms a part of the mold and is provided with the aperture '1', has ways 1;, i, in which the cut-off plate K, having the aperture is, may slide to and fro. An operating lever L may be mounted upon the plate I and be connected to the cut-off by a link Z.

In Figs. 10 and 11 the plate I which as before forms a part of the mold and has an aperture i, is represented as having a guideway i in which slides a bar or plate K being operated by a lever L. The bar or plate K is not formed with an aperture but its end, which when the mold is being filled forms a part of one side of the ingate,shears the metal in its movement across the opening 2'.

As shown in Figsl, 2, 3, 4: and 5 the chamber D or D is cylindrical in form, but it is obvious that this part of the apparatus might have some form other than cylindrical and the term cylinder, as employed herein, is used with that understanding. Thus, in Figs. 12 and 13 the cylinder or chamber D is shown as substantially triangular with an open side while the plunger is in the form of a plate valve E which has a bearing at the bottom and fits freely between the parallel walls of the chamber so that it may be moved to force the molten metal out through the port 0 in its upper wall.- The plunger may be operated by a rod G connected to an arm F which is rigidly secured to the plunger, the rod G working through a hole in the plate 0. In Figs. 14: and 15 the chamber or cylinder D is shown as reversed, the plate E being supported by a shaft F in a suitable bearing at the top of the chamber and operated by a lever G which is secured to the shaft F.

The several forms of cut-offs and of devices for forcing the molten metal into the mold shown in the drawings and described above are practical and efiicieut. They are chosen merely to illustrate the improvements, however, and it will be understood that it is not intended to restrict the invention to the specific forms shown. Many other forms will be readily suggested by the special requirements of diderent cases. W'hatever may be the special form of the cut-off it permits the mold to be brought very close to the body of molten metal, closes the opening into the mold while the metal is still under pressure, shears off the sprue neatly and quickly whether the metal be hard or fluid, and in the latter case italso chills the metal between the casting and the ingate and thereby insures a better finish for the corresponding side of the casting.

It will be observed that in the constructions shown in Figs. 10 and 11 the cut-off bar or plate forms at least a part of one side of the mold itself, or, in other words, that a part of the mold is made movable to shear the sprue.

I claim as my invention 1. In an apparatus for casting, a pot or crucible for the molten metal, a support to which the same is attached, a chamber within the pot or crucible also attached to said support submerged in the molten metal and having a port in its upper wall, a mold also resting on said support and having its ingate just above the port of the chamber with means for fore ing the molten metal from the chamber into the mold; substantially as described.

2. The combination of a pot for molten metal, a cylinder supported within said pot to be submerged in the molten metal therein and having a port through its upper wall, a plunger and means to operate the same to force molten metal out through said port and a stationary support upon which a mold may be held with its ingate adjacent thereto and forming a close joint with said port, whereby the molten metal has the shortest possible.

distance to move and is therefore not likely to be chilled in its passage into the mold, and whereby the metal not carried away as the mold is removed may fall back from the port into the cylinder and within the body of molten metal in the pot.

3. The combination of a'pot for molten metal, a stationary bridge plate across the top of said pot and having an aperture, a cylinder suspended below said plate to be submerged in the molten metal in said pot and having an aperture registering with the aperture in said plate to form a discharge port, a plunger and means to operate the same to force molten metal out through said port, said bridge plate forming a support upon which a mold may be held with its ingate forming a close joint with said port.

4. The combination of a pot for molten metal, a bridge plate across the top of said pot and having an aperture, a cylinder suspendedbelow said plate to be submerged in the molten metal in said pot and having an aperture registering with the aperture in said plate to form a discharge port, aplunger and means whereby relative movement of said cylinder and plunger may be produced to force-molten metal out through said port, said bridgeplate being depressed below the level of the top of the pot to form a support upon which a mold may be held with its ingate forming a close joint with said port.

5. The combination of a pot for molten metal, a cylinder supported within said pot to be submerged in the molten metal therein and having a port through its upper wall, a bucket plunger fitting freely over the outside of said cylinder, means to cause a relative movement of the cylinder and plunger to force molten metal out through said port, and a support upon which a mold may be held with its ingate in communication with said port.

6. Thecombination of a pot for molten metal having an outlet port, means to force the molten metal out through said port, a mold having an aperture, a support upon which said mold may be held with its aperture in communication with said port, and a cut-off plate interposed between said mold and supported and adapted to be moved across the aperture in said mold while the latter is in position upon said support.

7. The combination of a pot for molten metal having an outlet port, means to force the molten metal out through said'port, a mold having an aperture, a support upon which said mold may be held with its aper ture in communication with said port, and a cut-01f plate interposed between said mold and said support and having an aperture to register with the aperture in said mold, said plate being movable across the aperture in said mold.

8. The combination of a pot for molten metal having an outlet port, means to force the molten metal out through said port, a mold having an aperture, a support upon which said mold may be held with its aperture in communication with said port, and a cut-oft plate movably attached to the bottom chamber attached to said support extending below the same such a distance as to be submerged in the pot of molten metal, a mold above said chamber and resting on said support, with suitable ports in the chamber and mold registering with one another, and means for forcing the material from the submerged chamber into the mold; substantially as described.

10. In an apparatusfor casting, the combination with the pot or crucible for the moiten metal, a cylinder supported within the pot, to be submerged in the molten metal therein and having a port through its upper wall, and a hollow plunger with means for moving the same in relation to the cylinder to force molten metal out through said port and a mold with its ingate adjacent to and in close communication with said port; substantially as described,

11. In an apparatus for casting a pot or crucible for the molten metal with means for supporting it within the furnace, a chamber within the pot or crucible with a stationary support to which it is attached, said chamber being submerged in the molten metal and having a port in its upper wall, and a mold placed above the chamber, and having an ingate registering with the port of the chamber, and in close communication therewith, with means for forcing the material from the submerged chamberinto the mold; substantially as described.

In testimony whereof I have signed my name to this specification in the presence of two subscribing Witnesses.

HERBERT G. UNDERNOOD.

Witnesses:

FRANCIS B. GILL, GILES I-I. STILWELL.