US1272062A - Apparatus for making metal castings. - Google Patents

Description

s; LAKE, APPARATUS FOR MAKING METAL CASTINGS.

APPLICAT ON FILE'] AUG.9, IQIY. 1 %7%@@%Q Patentedl'fiuly 9, 1918.

2 SHEETS-SHEET1.

' b. LAKE. APPARATUS FOR MAKING METAL CASTINGS.

ARH ICATION FILED Aue 9.1917.

latented. July 9, 1918;

2 SHEETS-SHEET 2.

QSIMONILAKE, or MILFORD, coivivnc'rrcu'r.

' APPARATUS FOR MAKING METAL CASTINGS.

Specification of Letters Patent.

' Patented July 9, 1918.

Application filed August 9, 1917. Serial No. 185,277.

To all whom it may concern.-

Be it known" that I, SIMON LAKE, a citizen of the United States, residing at Milford, in the county of New Haven and State of Connecticut, have invented certain new and useful Improvements in Apparatus for Making Metal Castings, of which the following is a specification.

The invention has for its object to provide an apparatus which will permit themolten metal to flow freely into the mold without trapping air, thereby providing a solid or dense casting in which blow holes and sur face indentations or imperfections are positively avoided, hence minimizing the cost of machining and planing, and the consequent cost in the production of the finished article, the construction and'operation being such that a partial vacuum is created within the mold 'to permit the free flow of the molten metal as it is poured into the mold. Another object of the invention is to provide means for stamping the metal so as to positively. exclude all air pockets, said stamping means also serving as a valve for controlling theadmission of the metal to the mold. An-

other object of the invention is to provide means for permitting the escape of excess quantities of air and gases which may accu mulate in the mold either during the process of pouring the metal, or through dampness of the molding sand.

The invention consists in constructing a mold of two sections, commonly known as the cope and drag, said sections being connected air-tight and mounted upon a base,

and covered by a top plate, the said top plate being also connected air-tight to the cope and having a hopper mounted thereon into 40.

which the molten metal is, poured and allowed to set sufliciently to permit air bubbles to escape therefrom, said hopper having a plunger valve controlling the admission of the molten metal to the mold, and said plate also having an exhaust pipe connected thereto and adapted for connection with a suction pump whereby to withdraw air from the mold so as to create a partial vacuum therein, and said plate also having a vent normally closed by a diaphragm of considerably less strength than the framing of the cope and drag so as to permit the escape of air and gas without injury to the framing of the apparatus. -The invention further consists in certain novel features of construction, combinations and arrangements of parts as will be hereinafter described and then claimed.

In the drawings, illustrating the invention, in the several figures of which like parts are similarly designated, Figure l is a side elevation of my improved mold. Fig. 2 is a vertical transverse sectional View of the same, parts being broken away. Fig. 3 is a partial vertical section of a modified form of the lower section. 1

The mold proper is preferably constructed of two sections or flasks,'-viz., a lower section or flask 1, providing a frame for holding the drag 2, and an-upper section or flask 3 for holding the cope 4, the sections or flasks 1 and 3 being flanged at their upper and lower ends, as at 5, the abutting flanges of the said sections being securely fastened together as by bolts and nuts 6, as shown. The abutting faces of the said flanges are provided with registering grooves 7. adapted for receiving a suitable plastic quick hardening material, such as plaster of Paris, putty, or a mixture of litharge and sand, so as to provide a seal between the joint formed between the said flanges. Channels 8 are formed in the flanges 5 of the upper section and have their outer ends provided with threaded sockets9 into which are screwed nipples of a pump or pumps 10 by which the sealing material may be forced into the grooves 7.

The lower end of the section or flask 1 is closed'preferably by a base plate 11, whichis bolted to the lower flange 5 of the section or flask 1, and the lower face of the said flange and the upper face of the said base plate 11 are provided with registering re cesses to provide annular grooves or recesses 12 to which are connected pumps 13 for forcing a sealing material into the said grooves 12 in a similar manner to that described with respect to the grooves 7 While I show the base plate as a separate and detachable element of the lower section, it will, of course, be understood that it i may be formed integral with said section as shown in Fig. 3, thus avoiding the necessity of providing a sealed joint between the lower end'of the lower section and its base. As shown in Fig. 3, 1 is the lower section and 11 isits integral base. The grooves? and [12 are provided with vents 14 located, pref- The upper end of the section or flask 3 is closed by a plate 15, bolted to the upper flange 5 of the section or flask 3 and having its lower surface provided with an annular 5 recess designed to register with .a similarly shaped recess formed in the upper face of the upper flange 5, providing an annular recess 16 adapted to receive a suitable packing material to form an air-tight joint between the'plate or cover and the section or flask 3.

As stated, the flask 1 is designed to receive the drag 2 of the mold, and the upper section or flask 3 is designed to .receive and 15 hold the cope 4, and it might be stated here,

that, in practice,.both the drag and the cope are constructed of any suitable material,

passage or channel 19 leading into its base or lower end, and-with an outlet 20 extending from the extreme upper end of the mold, .30 said outlet being in communication with an exhaust passage extending from a vacuum pump (not shown), as will be hereinafter referred to, whereby as the molten metal is poured into the mold, the metal will be permitted to flow freely into every crevice or compartment of the mold as will be best.

understood from the subsequent general description of the operation of the apparatus. The top plate 15 'is formed with a boss 21 upon which is securely bolted a casing 22 having a bore 23 registering with a bore 24 formed in the plate 15. Bolted upon the upper flanged end of the casing 22 is a hopper 25 into which the molten metal is' poured prior to its delivery to the mold. The walls of the hopper 25 are lined with a suitable refractory material 26, the said material being extended down into the bore 23 and into the opening 24, and of substantially cylindrical-form to provide a cylindrical passage 31 to receive the lower end of a plunger 27, which latter serves as, a valve to control the flow of the molten metal into the passageway 19 leading to the mold.

proper, The plunger is preferably constructed 'of a metallic core upon which is baked fire-clay, porcelain, or other suitable refractory material 30, and the said metal core or rod is provided throughout its length with a plurality of'concentrlc grooves or ribs 29 to provide a locking means'so as to prevent the displacement of the refractory material 30. The lower end of the hopper 25 and the refractorylining 26, as

before stated, terminate in a cylindrical bore the hopper with the material to be fedthe mold, and which may also serve;

- furnace.

31, and the inner face of the cylindrical bore of the refractory material 26, adjacent to the lower end of the cylindrical portion thereof, is provided with an annular recess 31, which communicates with a bore'or passage 32 formed in the lining 26 and having its outer end in open communication with a bore 33 in a lug 33 integral with the casting 22, said bore 33 having its outer end threaded to receive the shank of a suitable pump 34 whereby to force suitable packing materials into the recess 31 so as to provide a sealed joint between the periphery of the plunger 27 and the cylindrical portion of the lining 26. I 30 The plate 15 is formed, preferably diametrically opposite the boss 21, with a boss 39 having a transverse groove 40 in its upper face, which, with a plate 4l bolted upon the upper surface thereof provides a chan- '85 nelway for the reception of a ate-valve 42, the purpose of which will; e explained hereinafter. Screwed into the plate 41 is an exhaust pipe 43, preferably lined with a refractory porous material, as shown at 44, in Fig. 2. The pipe 43is extended from a suitable suction pump (not shown), and is provided witha valve 45, whereby passage through the said pipe 43 may be controlled.

'Arranged centrally of the plate 15 is a vent 46, the outer end of whichis closed by a diaphragm 47 of comparatively lightweight material, which is designed to. form a relief valve to permit the escape of excess pressures-of gases, air, or steam within the mold which might accrue in the molding of the castings, and which ofttimes occur owing to dampness in the molding sand, and in the formation of gases during the melting and pouringv of the metal into the mold. The hopper 25 is formed with a spout 48, and with a channel 49 leading into the hopper 25, whereby the hopper may be drainedv of materials after the mold has been filled,

and, of course, before the metals have thoroughly cooled. The channel 49 is held normally closed by a plug 5 0, as shown in Fig. 2.

Associated with the hopper 25 is a-ladle 51, shown in dotted lines in Fig. 1 of the drawings, which may extend from or be. associated with suitable smelting furnaces, and which serves as a conveyer to sup '1 chute to guide the molten metal into mold as it is delivered .from the smelting The advantages of my improved apparatus may be best understood from the following description of the operation of the device After the mold is baked, and while still warm, the pouring receptacle or hopper-25 a d the vent pipe 43 are secured to the upper each time a casting is made; it

plate 15 and the plate valve 42 is inserted in the slot 40 and sealed so as to provide an air-tight joint, the inner end of the slot being preferably closed tight by a suitable sealing material, such as putty, litharge and sand, or other suitable material so that the air Within the mold mayv be withdrawn through the said pipe 43. Metal is now poured into the hopper, and when bubbling ceases the plunger 27 is elevated suificiently to permit the liquid metal to flow through the opening 19 into the mold, enough metal being poured into the mold to allow it to rise into the lower end of the vent tube a distance proportionate to the vacuum maintained and the specific gravity of the metal being poured. As soon as the mold is filled the valve plate 42 is driven in through the slot, thus shutting oflf further rise of metal in the vent pipe 43. The plunger 27 is then forced down upon the plastic metal to compress it in the mold, hence making the metal more compact and homogeneous. I

When a number of castings are to be made from the same pattern, instead of using all sand surrounding the pattern in the flasks, I purpose making a semi-permanent mixture of cement or plaster, leaving only a small quantity of sand to be dried in the oven being understood that no moisture should be in the sand surrounding the casting, otherwise steam might be generated and burst the mold. However, in order to avoid injury to the mold in such an event, I provide the vent 46, which. is covered by the plate 47, as previously described. It will be seen that the plate 47 then acts as a safety valve, and is of such strength only as to permit of its being blown out or broken before there is enough pressure to burst the flask or blow off the coverof the mold or otherwise injure the mold.

It will thus be seen that my invention provides, first, for pouring the metal so that no air will be trapped in the mold during the process of pouring; second, for taking off all gases from the mold as rapidly as formed by forming a vacuum in the mold; third, for creating the equivalent of a high gate to the mold by atmospheric pressure while pouring; fourth, for so preparing the mold that it will withstand high pressures.

without distortion, and fifth, for applying a high compression to the metal in the mold while still in a liquid or plastic state.

What I claim is i 1. In combination, a flask and its base adapted to form the drag, and a flask and its top plate adapted to form the cope, the meeting edges of the flasks being hermetiafter it enters the mol cally sealed, a mold arranged in the flasks and having a feeding passage or channel leading thereto at or near one end and an exhaust passage leading therefrom at or near the opposite end, and means to control the introduction of molten metal to the feeding passage and apply pressure thereto after it enters the mold.

2. In combination, a flask and its base adapted to form the drag, and. a flask and its top plate adapted to form the cope, the meeting edges of the flasks being hermetically sealed, a mold arranged in the flasks and having a feeding passage or channel leading to its bottom and an exhaust passage leading therefrom at or near its top, a hopper erected on the plate of the cope and terminating in a cylindrical portion opening into the feeding passage, and a plunger arranged in said hopper and adapted to control the flow of metal from the hopper through the cylindrical portion to the feeding passage and then to be moved toward the feeding passage to apply pressure to the metal fed from the hopper into the feeding passage.

flask and its base its top plate adapted to form the cope, the

meetlng edges of the flasks being hermetlcally sealed, a mold arranged in the flasks and having a feeding passage or channel leading thereto at or near one end and an exhaust passage leading therefrom at or near the opposite end, and means to control the introduction of molten metal to the feeding passage and ap ly pressure thereto the exhaust passage being intercepted transversely by a sliding valve.

4. In combination, a flask and its base adapted to form the drag, and a flask and its top plateadapted to form the cope, the meeting edges of the flasks being hermetically sealed, a mold arranged in the flasks and having a feeding passage or channel leading thereto at or near one end and an exhaust passage leading, therefrom at or near the opposite end, and means to control the introduction of molten metal'to the feeding passage and apply pressure thereto after it enters the mold, the exhaust passage being intercepted transversely by a sliding valve, and a frangible relief valve located in the cope plate.

In testimony whereof I have hereunto set my hand this 2 day of August, A. D. 1917.

SIMON LAKE. Witnesses:

O. E. ADAMS,

M. D. BLONDEL.

to form the drag, and a flask and

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