US1797041A - Apparatus for casting metal - Google Patents

Description

'March 17, 1931. I Q BECKER 1,797,041

APPARATUS FOR GASTI NG METAL Filed July 17, 1929 5 Sheets-Sheet. l

INVENTOR.

BYM JKW ATTORNEY.

March 37, 1931. c. E. BECKER APPARATUS FOR CASTING METAL Filed Jul 17', 1929 s Shee ts-Sheet, 2

AZORNE I March 17, 1931. c, BECKER 1,797,041

APPARATUS FOR CASTING METAL Filed July 17, 1929 3 Sheets-Sheet. 3

- INVENTOR Carl Z5. Beckc r A TTORNEY Patented Mar, 17, 1931 UNITED STATES CARL E. BECKER, an autumn, NEW JERSEY APPARATUS FOR CASTIDIG METAL Application filed July 17,

This invention relates -to an improved method and apparatus for casting metals, andhas for one of its outstanding objectsto provide for the pouring of metals in such manner as to prevent the metals while in a molten state and during the pouring operation from coming into contact with air. A It has been observed that in the making of fine metallic castings wherein smooth finished l0 surfaces are desired together with perfect conformity with the attern configurations of the mold, that if air is allowed to strike the metal or'come in contact therewith, even during the short interval of time when the molten metal is flowing from an elevated crucible into the passages of the mold assembly, the resultant castings are quite apt to present roughened or pitted surfaces and also the pattern impressions in the mold are not accuratelyreproduced. This is due possibly to the chilling of the metal or its oxidation, but irrespective of the theory I have found it to be a fact that when the metal is so poured that it does not come into contact with the oxyb the finished castings are obtained.

It is another object of the invention to pour the metal from the bottom of the crucible or,- stated in other words, to provide means 3 whereby the molten metal is withdrawn from the crucible and delivered to the molds by being taken from the bottom of the crucible below the charcoal, dross and other impurities carried inthe crucible on the top of the molten metal.

In the attainment of these ends, I have provided casting mechanism consisting of a closed air-tight chamber in which the cruci-' ble containing the molten metal is disposed in an upright position. I then arran e within the crucible a riser which exten s through the center of thecrucible to the metal in the bottom thereof the lower end ofthe riser terminating slightly above the bottom wall of the crucible. I then introduce a fluid under" super-atmospheric pressure into the chamber, permitting the pressure of this fluid to be applied to the surface of the metal contained in the upper portion of the crucible.

the pressure of the fluid being so. regulated en of the air greatly improved results in 1929. Serial No. 378,986.

as to cause the molten metal to pass upwardly through said riser and to then flow into the passages of the several molds arranged in the structure above thecrucible.

It is, another object of the invention to permit this method to be rapidly carried out so there will be little or no drop in the temperature of the metal while the latter is being forced into the mold passages orpockets.

For a further understanding of the invention reference is to be had to the following description and the accompanying drawings wherein: A

Figure 1 is a vertical sectional view taken through the molding apparatus used in Q carrying out the present invention,

Figure 2 "is a horizontal sectional View taken on the line 2-2 of Figure 1,

Figure 3 is a similar vlew taken on the line 3-3 of Figure 1, i Figure 4 is a perspective view of one of the molds, V V

Figure 5 is a plan view of the lower platen,

Figure 6 is a view in side elevation of the pour ng riser, and r Figure 7 is an end elevation thereof.

Referring more particularly to the drawings, the numeral 1 designates the frame of the molding apparatus utilized in carrying out the present invention. This frame is formed to include a bottom plate 2 which is provided at its corners with a plurality of upstanding rods 3. The upper ends of these rods are formed with seats for the reception of a top plate 4, and nuts 5 are threaded on the upper ends of the rods so that the latter, together with the plates 2 and 4, will form a rigid and substantial frame assembly.

The bottom plate 2 is formed with a longitudinally extending groove 6, which receives a depending tongue or rib 7 provided on the 1 bottom of a removable receptacle 8. This receptacle is preferabl formed from cast iron and includes a close bottom and opened top, the top being provided with an enlarged 95 flange 9, while the interior of the receptacle is formed to comprise a chamber 10 in which is removably' positioned the pouring crucible 11. In practice, the metals are heated in the crucible to a molten state and are covered 19.

with a thick layer of charcoal from the time it is melted in a furnace (not shown) until 1 it is positioned in the chamber 10. By sliding the receptacle Son the bottom plate 2, beyond the confines of the rods 3, as shown by the extension 12 in Figure 2, the crucible may be readily positioned in said receptacle with the protecting layer-of charcoal, as indicated at 13, on the top of the molten metal body 14, and the receptacle then restored to an operating position.

Above the receptacle there is provided a moldassembly consisting of a horizontal member 15 comprising a lower platen. This platen receives a plurality of molds 16 arv 'an up'per platen 24, and threaded tie bolts 25 are employed t9 connect the upper and lower platens so as to securely clamp the mold sections therebetween. In addition to the tie bolts 25, however, pressure is applied to the mold assembly by means of a threaded screw 26. This screw has its lower end secured by means of a pin 27 to the hub 28 formed upon the upper surface of the platen 24. The upper end of the screw receives a nut 29 which is connected with a hand Wheel 30, the said nut being rotatably received in an axial hearing 31 formed in connection with the top plate 4. It will be seen that by the rotation of the hand wheel and the nut 29 vertical movement may be imparted to the screw 26, thus forcing the latter downwardly wlth great pressure on the mold assembly to hold the latter firm and rigid during the pourlng operation. In addition, the lower platen 15 is provided with an annular rib 32 WhlCh engages with a compressible metal gasket 33 which is seated upon the flange 9 of the receptacle 8, thus providing a fluid-tight o1nt between the receptacle and the lower platen.

Entering the receptacle 8 is a valved pipe line 34 by means of which compressed air or other suitable fluid may be introduced into the chamber 10. It will be seen that when the parts are positioned as shown in Figure 1, the

. opening of the control valve 35 in the pipe line 34 will admit compressed air into the chamber 10, permitting the compressed air to exert its pressure on the molten metal contained in the crucible 11. It will be noted that the lower platen 15 carries a riser or gate tube 36, which extends axially into the.

crucible and terminates a slight distance above the bottom of said crucible, where it is emersed in the molten metal body 14. Thus, when the chamber 10 is under air pressure the molten metal is forced upwardly through the tube 36 from the bottom of the crucible and passes from the tube 36 through the pockets, openings and gates 21, 22 and 23 respectively in the mold assembly, permitting the pockets or other metal receiving spaces of the molds to be properly filled with the metal.

Thus by. the provision of this arrangement I am enabled to pour metals without permitting the oxygen of the air to come into contact therewith, and in attaining this end the metals instead of being poured from the upper rim or edge of the crucible, as is customary, are removed or poured from the bottom of the crucible. In this operation the molten metal in the crucible remains covered with a thick layer of charcoal, to keep air from contacting with the metal, from the time it is melted in the furnace until it has entered the molds. After the metal is melted under a thick layer of charcoal, the latter remains on the molten metal in the crucible. The crucible is then taken out of the furnace and lowered into the chamber 10 of the receptacle 8, and the latter together with the crucible in it are then pushed or otherwise forced under the pouring press. This press with the molds or flasks located between the upper and lower platens is then securely tightened and forced downwardly on the marginal flange of the receptacle so that the chamber 10 will be rendered air-tight. At this time the compressed air is admitted into the receptacle so that it may press on the top of the metal in the crucible, forcing the metal through the gate tube up into the molds.

Since the toppart of the molten metal in the crucible always contains impurities or dross which is very often responsible for defective castings, it has been the aim of foundry workers to-pour the metal from the bottom of the crucible and this has been done with indiflerent success. In my invention the pure metal is forced up through the gate tube from the bottom of the receptacle and the amount of metal required to fill the molds can be so calculated that a certain amount, which is considered impure, will remain in the crucible after the molds are filled, and consequently there will be no loss in castings through the accidental employment of impure metal. Furthermore, the operation with the apparatus herein disclosed is so rapidly carried out that the temperature of the molten metal remains constant during the pouringoperation "and very uniform results are secured. This is in distinct contrast with earlier methods wherein molds have been successively poured and the temperature of the metal allowed to cool sufliciently so that the last poured -molds are apt to produce defective castings.

What is claimed is:

1. In metal casting apparatus, a frame' structure formed to include a base plate, an open top receptacle movably mounted on said base plate, said receptacle being adapted to receive a removable crucible containing a body of molten metal, upper and lower platens adapted to receive between them a plurality of horizontally placed molds, clamping means uniting said platens to retain said molds in stationary and fixed relationship, adjustable means carried by said frame structure for moving said platens and molds bodily and vertically relative to said receptacle, a gate tube connectin the molds arranged between said platen wlth the molten metal contained in a crucible arranged in said receptacle, and means 'for admitting a gaseousfluid under pressure into said receptacle to coact with the molten metal arranged in the vertical movementby the rods of said frame, Q

rows of horizontally placed molds arranged between said platens, clamping means uniting said. latens to retain said molds in rigid assemble relationship, a gate tube carried by the lower platen and arranged to be positioned in the molten metal contained in said crucible, means for introducing a gaseous fluid into said receptacle for .forcing the metal contained in said crucible upwardly through said tube and into the mol s positioned between said platens, and a gasket of compressible material positioned between adjoining portions of the lower platen and said receptacle.

In testimony whereof I affix my signature.

CARL E. BECKER.

crucible to force such metal upwardly through the gate tube into the passages of the bowl assembly.

2. 'In metal casting apparatus, a frame structure comprising fixed upper and lower members, an open top receptacle movably mounted on the lower member and adapted to receive a crucible containing a body of molten metal, a mold assembly vertically suspended from the upper member of said rame structure and movable intoand out of receptacle, and means for admitting a gaseous fluid into said receptacle and thereby into coaction with the molten metal contained in the crucible to force such metal upwardly into said mold assembly.

3. In metal casting apparatus, areceptacle formed with a chamber adapted for the removable reception of a crucible containin molten metal, a mold'assembly consisting o a plurality of separable members rigldly umted, means for positively maintaining fluid tight joints between the relatively engaging portions of said receptacle and said mold assembly, and means for introducing a gaseous fluid into said receptacle for coactionwith the molten. metal contained in the crucible carried thereby, whereby to force [such metal upwardly from the crucible into the superposed mold assembly.

4. In metal castmg apparatus, a frame structure comprising horizontall dis osed base and top members and space vertically extending rods uniting said members, a reengagement with'the upper portion of said

Images