US1013548A - Art of making castings. - Google Patents

Description

0. M. REY. ART OF MAKING QASTINGS. APPLIUATION FILED SEPT. 25, 1911.

I 1,013,548. Patented Jan.2,1912.

WITNESSES 4 Q [NVENTOR i W M v I Affomeya CVzarZesfYGrg r rice, I

CHARLES M. GREY, OF EAST ORANGE, NEW JERSEY.

ART OF MAKING .CASTINGS.

useful Improvements in the Art of Making Castings, of which the following is a specification.

This invention is a process of making castings, and while it is capable of quite.

general application it is of special advantage and utility in making die. castings, and I will particularly describe its application to this latter art.

Several processes are in use for making die castings the aim of all of which is to produce solid castings, z'. 6., castings free from blow holes and entrained gases, and, also, castings which are uniformv in weight and size. The processes in use involve such expe-dients as forcing the metal into the die by pressure, producing a partial vacuum in the die, etc. Moreover, in most of the commercial processes of the prior art employing a vacuum in the die, a valve is used to control the flow of molten metal to the die, with the result that the metal frequently freezes around the valve, or its associated mechanism, thereby renderingthe valve defective and precluding the production of good castings. None of the processes heretofore used, produce uniform solid castings,

and, as a result, die castings have not gone into such extensive use as experts in the art predicted.

The present processis not only simple and economical, but results in castings which are exceptionallysolid, uniform and accurate, and entirely free from the defects heretofore existing in die castings.

With the specifiedobjectsin view, the invention,- in one of its broadest aspects, embodies a method of controlling the flow of molten metal to the mold or diefThis method consists in confining the metal-in two chambers or compartments which com} municate only beneath the surface of the metal, one of the'chambers being connected with the die or mold' space, producing a partial vacuum of the same degree in the two chambers whereby the. metal is restrained from flowing toward the die, z'.'e.,

retaining it in a balanced-condition, and,

Specification of Letters Patent. Application filed September 25, 1911. Serial No. 651,047.

in two chambers, preferably by increasing the pressure in the chamber not directly Patented Jan. 2, i912.

connected with the die, whereby the metal is Y forced into said die.

The process consists further in combining the foregoing 1 operation 'or operations with the step of simultaneously producing a vacuum in the die and also in the passage connecting the metal chamber with the die, whereby, when pressure is applied to the metal chamber not directly connected with the die, the metal is quickly and forcibly ejected into the mold as a result of the vacuum forwardly of the metal and the die, and the pressure rearwardly of the metal. It is apparent, therefore, that a valve is not required to control the flow. of metal from the metal chamber to the die. The pressure employed may be produced by mechanical appliances, such asthose heretofore employed in this art, though for simplicity and effective operation I prefer to employ fluid pressure produced by compressed air.

Looking at the process in a more detailed and Specific aspect, particularly with respect to the type of apparatus illustrated and described herein for practicing the inven'- tion, said process consists in confining the molten metal in a substantially U-shaped, or equivalent, receptacle having two communicating chambers or compartments, the communication between which .is sealed by the fused metal, one of said chambers having unobstructed communication with the die; exhausting the air from the die and the coinmunication between the die and the said metal chamber, and simultaneously exhausting the air from the other metal chamber whereby a partial vacuum is produced forwardly of themet-al, e., in the passage leading therefrom to the die as well as in the die, and, also, in the metal chamber not directly connected with the die, thereby restraining the metal from flowing toward the die; then,'while maintaining the vacuum in the die and passage leading thereto, applying fluid pressure on the surface of the metal 7 in the chamber not directly connected with the die, whereby the, metal is quickly and forcibly advanced into said die.

Other features of'the invention and the advantages thereof, not heretofore 'adverted to, will be obvious from the following detailed descripti n of the practical way of carrying out the process.

In the accompanying, drawing I have illustrated an apparatus, somewhat diagram matically, which I have found suitable for practicing the process, but it will be understood that such apparatus is merely illustrative of a type of apparatus which may be'employed, and not in any manner exa and b, respectively, said chambers having r a connection near their lower ends which is thedie or mold space h being positioned between said members. The mold G is posi-.

normally sealedsby molten metal 0 in the receptacle A space (i is left in chamber a above the metal, and .a corresponding space 6 is left in chamber 12 above the metal.

C is a die or mold, of usual type, having an upper member f and lower member 9,

tioned on a supporting member 2', and an inlet or passage is is provided in the lower member g whereby metal may. be introduced into said mold, said passage is connecting through an opening in base member 71 with space e in the upper part of chamber 6. The mold or die space It is provided with the customary air ducts Z leadlng therefrom to a common chamber, from whlch chamber extendsan exhaust pipe 07.. Exhaust pipe n is connected with a suitable pump or exhausting-mechanism D, whereby air may be exhausted from the mold or die and, also, from the space '6 in the upper part of chamber '6, thereby producing a partial vacuum in space 6 and mold space 71..

E is a pressure regulator, of well known type, consisting of a two part casing, the saidparts being lettered 0 and p, respectively, and positioned between which is a diaphragm (1 providing a chamber 1 on one side thereof, and a corresponding chamber 8 on .the opposite side. Two valve rods, t and I), respectively, are secured to the diaphragm, rod t connecting with and operating a valve working in valve casing t positioned in i ,pipe at. Valve rod 4) is connected with'and operates valve 4; working in valve casing 0 positioned in pipe 0 which establishes communication between a pipe 0 and the exhaust device D. Pipe 0 is provided with a valve 0 the function of which will be presently described. Pipe 0 connects the space 01 in the upper part of chamber a with the exhaust device D through'the intermediate pipe connection 0. Forming an extension.

of the'p'ipe is a pipe d, connected with a source of compressed fluid, notshown, said pipe d being provided with a valve d extends from pipe at a 'fiowing into the die,

point above the valve therein, to the chamber '77 on one side, of diaphragm q, and a corresponding by-pass 6 extends from the pipe 0=, at a point above the valve therein, to space 8 on the opposite side of the diaphragm, the function of all of which will be hereafter described.

A pressure relief valve is shown at f. c Having described an apparatus which may be used in carrying out the process its operation will be readily understood, and may 'be-desc-ribed, briefly, as follows: As-

suming the mold G is properly prepared for casting, and the furnace A contains molten metal, the exhausting apparatus D is put into operation. This results in the production of a partial vacuum in ,chamber 6, metal passage 70, and mold s ace h,through exhaust pipe n connected wit the exhauster and, also, in the simultaneous production of a partial vacuum in chamber d through exhaust pipes 0 and 0?. The partial vacuum is of the same degree in chamber 03 as it is in chamber 6 and mold space h, and this condition is effected by the pressure regulator E, the operation of which will be briefly described. The suction apparatus D,at the commencement of the exhausting operation,

exhausts equally through pipes n and 0?, but if at any time the degree of vacuum be cdmes greater in one pipe than in the other,

e." g.-, greater in pipe 01, leading from the chamber 6 and mold spaceh than in pipe 0 leading from chamber (1, the excess pressure in pipe 0 would be communicated to diaphragn. 9 through by-pass e thereby forcing the valve 25 to its seat and permitting the entire suction of apparatus D to be exerted on pipe 0 through the medium of the. same-degree in chambers d and e, and

mold space h,-- isto restrain the metal from Y i. e. to hold said metal in a balanced condition or state of .equilib'- rium. When the vacuum has-reached the degree desired, 0., when the air is sufii-. ciently exhausted from the die spacefh, and it isdesired to force ,the metal into said die space, valve 0 is closed and valved simultaneously opened, thereby allowing compressed fluid, 6. 9., compressed a r, to enter pipe '0 and ex'ert'its pressure on the surface of the metal in chamber 03, i the suction continues through pipe at, the molten metal is quickly nd forcibly shot into the m die, completely filling it, and? producing a firm, solid casting, and one entirely free from blow holes or entrained gases.

It will be understood, of course, that a plurality of castings may be made simultaneously, and that. the described operation cerns precluding the formation of air or gas holes in the castings, and that this result is secured without clogging up any valves or other parts of the apparatus. Applying suction to both surfaces of the metal prior to casting frees it from all entrained air and gases, and should any air work down into the molten metal, as the result of applying air pressure to thesurface of the metal in chamber d, this would be subsequently removed by the exhaustion incident to preparing for another. casting operation.

Prior to opening the moldO- to take out the casting, the air pressure will be shut off by closing valve (F, and the pressure in pipe c and chamber a may be'relieved, and normal atmospheric pressure restored. therein, by opening valve f: v

It will be understood that the process described may be modified as to details, such as the substitution of equivalents, and that one or more stepsof the-process may be em-- ployed without necessarily using the complete process. a

Having thus fully described the invention,

whatI claim'as new, and desire to secure by Letters Patent is 1. In the art of making castings, the process which consists in confining fluid material in two chambers having communication beneath the surface of said material, and pro-,

ducing a partial vacuum in the said two chambers above the metal therein by exhausting air' from both of-said chambers.

2. In the art of making castings, the proc-v ess which consists in confining fluid material in two chambers having communication beneath the surface of said material, producing a partial Vacuum in the said two chambers above the metal therein by exhausting air from both of said chambers, and .then

6 ess which consists in confining fluid materialintroducing the material into a mold.

3. In the art of'making castings, the process which consists in confining fluid material 'in two chambers having communication be neath the surface of said material, producing apartial .vacuum in the said two chambers abovethe metal therein by exhausting air from both of said chambers, and then introducing the material into a mold by changing the relative pressures in the two chambers.

4. In the art of making castings, the procin two chambers having communication beneath the surface of said material, producing a partial vacuum in the said two chambers above the metal therein, and then introducin two chambers having communication be-.

neath the surface of said material, producing a partial vacuum in the said two chambers above the metal therein, and then introducing the material into a mold by applying pressure interiorly of one of the chambers while continuing suction on the other.

6. In the art of making castings, the proci ess which consists in confining fluid material intwo chambers having communication beneath the surface of said material, producing a partial vacuum in the said two chambers above the metal therein by'exhausting air from both of said chambers, and then introducing the material into a mold by applying gaseous pressure interiorly of one of the chambers.

7 In the art of making castings, the process which consists in confining fluid material in a receptacle having two chambers communicating beneath the surface of the material, connecting one of said chambers with a mold through an unobstructed passage, producing a partial vacuum in bothchambers,

in the mold, and in the said passage, and then-forcing the material into the mold by applying pressure to the metal in the Chainber not connected with said passage.

8. In the art of making castings, the process which consists in confining fluid material in a receptacle having two chambers communicating beneath the surface of the material, connecting one of said chambers with a mold through an unobstructed passage, producing a partial vacuum in both chambers, in the mold, and in the 'said passage by exhausting air from both of said chambers, and then forcing the material into the mold by applying gaseous pressure to the metal in the chamber not connected with said passage.

9. In the art of making casting, the process which consists in confining fluid material in a receptacle-having two chambers communicating beneath the surface of the,

material, connecting one of said chambers with a mold through an unobstructed passage, producing ,a partial vacuum in both chambers, in the mold, and in the said passage, and then forcing the material into the mold by applying pressure to the metal in the chamber not connected with said passage while continuing suction on the mold.

10. In the art of making castings, the process whichconsists in confining fluid material in a receptacle'having two chambers communicating beneath the surface of the material 'connecting one of said chambers with a mold through'an unobstructed passage, exhaustingair and gases directly from one of said chambers, exhausting air and. gases from the other chamber through the mold whereby substantially the same degree of Vacuum is produced in the two. chambers and the mold, and then relieving the suction on the chamber not connected with the mold whereby the same is placed 'under atmospheric pressure and the material forced into the die. 4 I

11. In the art of making castings, the process which consists in confining fluid material in a receptacle havingtwo chambers communicating beneath the surface of the 'material, connecting one of said chambers;

' with a mold through an unobstructed pas- .pressure to the chamber not nected to the mold, whereby the material is sage, exhausting air and gases directly from one of said. chambers, exhausting air and' gases from the other chamber through the mold whereby substantially the same degree of vacuum is produced in the two chambers 5 and the mold, and then applying gaseous directly conforced into the mold.

12. The 'rocess ofmakin'g die castings which conslsts, in confining'molten metal in two chambers having communication be-' neath the surface ofgth'e metal and one of which is connected with a die,-producing a partial vacuum of substantially the same de- 5 gree in both of said chambers and also in the; die whereby the metal is restrained from entering the die, andthen applying pressure 1 to the metal in the chamber not directly coni "nected with the die whereby the metal is;

. forced into thejdie.

40. which cons sts in confining molten metal in I m that leg of the receptacle 'nected with the die.

' mold.

.name to 'two subscribing w1tnesses.-

14. In the'art of making castings, the prom ess which consists in confining fluid ma-' terial in two chambers having communication beneath the surface of said material, producing a partial vacuum in the said two chambers above the metal therein while pre cluding any How of metal toward the mold, and then introducing the material into' a mold,

15. In'the art of making castings, the process which consists in confining fluid ma.-

terial in two chambers having communication beneath the surface of said material, producing a partialvacuum in the said two chambers above the metal therein while pre- 1 eluding any flow of metal toward the mold,

and then introducing the material into a Old changing the relative pressures 1n the two chambers' a '16. In the art of makingcastings, the process which consists in confining fluid material in two chambers having communication beneath the surface of said material,

producing a partial vacuum in, the said two chambers above the,metal therein while pro eluding any flow of metal toward the mold,

and then introducing the material intoa,

byapplying gaseous pressure interiorly of one of, the chambers, 'f-

17. Inthe art of making castings, the proc-' ess which :con'sists in confining fluid ma "terial ina receptacle-having two chambers communicating beneath the surface of the material, connectingone'of said chambers with. a mold through an unobstructed passage, producing a partial vacuum in both chambers, in themold, andinthe said pas-f sage,=.;while precluding. any. flow 0f metaltoward the mold, and then forcing thema-f terialinto the mold by applying gaseouspressure-to themetal in the chamber not connected with said passage.

' In. -test1mony whereof-I'have this specification thepre'sence of QHABLES-M, GREY.

Witnesses;

, JAs'. H. GRIFFIN,

" H. ILBERNHARD.

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