US1669694A - Casting apparatus - Google Patents

Description

May 15. 1926. I 1,669,694

S. W. CRAWFORD CASTING APPARATUS Filed Nov. 5, 1923' & A

in y Patented May 15, 1928.

y 1,669,694 ENT OFFICE.

SAMUEL W. CRAWFORD, OF ST. LOUIS, MISSOURI, ASSIGNOR, BY MESNE ASSIGN- MENTS, TO NATIONAL BEARING METALS CORPORATION, OF ST. LOUIS, MISSOURI,

A CORPORATION OF NEW YORK.

CASTING APPARATUS.

Application filed November 5, 1923. Serial No. 672,781.

This invention relates to an improvement in the casting or molding of metals and has for its primary object the purpose of providing an improved method of introducing the molten metal to the mold.

Another object of the invention is in pro viding an improved method and apparatus for the casting of alloyed metals which are compounded from a combination of metals.

A further object of the invention is in providing an improved method of molding metals in which the consistency thereof is comprised of various ingredients which vary in specific gravity and in which it is required that metals of such nature be quickly solidified after the castingor pouring operation has been carried on.

A still further object of 'the invention is in providing an improved mold for casting bushings or annular castings such as bearing bronzes or brasses.

Other and further objects will appear in the specification and be specifically pointed out in the appended claims, reference being had to the accompanying drawings, exemplifying the invention, and in which:-

Figure l is a horizontal section taken through this improved mold for carrying out this improved casting method.

Figure 2 is a vertical section taken on the line II-II of Fig. 1.

With reference to the accompanying drawings, 1 designates a mold which is comprised of a pair of outer arranged semi-circular sections 2 and 3 which are preferably constructed of ferrous metal, said sections being hinged to one another as designated at 4.

As already set forth in one or more of the objects of the invention, this improved mold is primarily intended for the casting of annular bodies such as bushings or brasses and in which means are provided for the shrink age of the solidifying alloy or metal. In

this connection a centrally arranged cylin;

drical shaped core 5 is provided, said core at its upper end 6 being of a diameter which is approximately equal to a diameter of the chamber 7 provided by the semi-circular sections 2 and 3 of the mold 1, the approximate lower half 8 of the core however, being of lesser diameter than the upper portion of the core 6 so as to provide an annular chamber 9 between the lower half of the core 8 and the inner walls of the mold sections 2 and 3, the upper end of the annular chamber 9 being closed by the shoulder 10 of the lower portion of the inner walls of the sec tions' 2 and 2; are each undercut as designated at 11.

Before the core 5 is introduced Within the mold chamber 7, a relatively flat circular core 12 is laidupou the molding floor 13 and the mold sections 2 and 23 mounted thereover as shown in Fig. 2, the diameter of the core 12 being approximately the diameter of the undercut portion 11 of the mold so that the core 12 can snugly tit therein and close the lower end of the mold chamber 7. The core 12 is of a thickness so that an annular space 14 is provided beneath the shoulder 15 which is formed by the underat their outer ends extending short of reach ing the periphery of the core as clearly shown in both of the figures of. the drawings.

The core 5 is provided with a vertically extending centrally arranged ingate 17 and when said core is mounted within the mold chamber 7 the lower portion of the core will rest upon the upper surface of the core 12 and the ingate 17 of the core 5 will communicate with the inner ends of the grooves 16,.said grooves when the core 5 is mounted thereover forming sprues which lead to the lower end of the annular chamber 9.

In. the operation of this improved method of casting brasses and the like, on account of the alloy of which the castings are comprised beingof a nature in which the several materials of the alloy vary in specific gravity, it is desirable thatthe ingredients of the alloy be continually agitated during the pouring operation until the mold is com- .pletely filled, and after which rapid solidification of the alloy must be brought about so that the ingredients of the poured alloy can not separate in crystal form due to their difierence in gravity.

Afterthe mold has been assembled and the core 5 mounted therein so as to provide the annular chamber 9 for the reception of the molten metal, pouring of the molten metal is carried on through the centrally arranged ingate 17 inwhich the metal will enter the series of grooves 16 and discharge into the bottom of the annular chamber '9 as shown in Fig. 2. During the continued pouring of the molten metal through the ingate 17 the molten metal upon entering the annular chamber 9 through the series of radially disposed grooves 16 will cause a continual agitating of the molten metal within the annular chamber 9 as the molten metal rises in the annular chamber 9 during the continued pouring of the molten metal through the ingate until the annular chamber 9 is entirely filled.

The entering of the molten metal through the series of lower arranged grooves or sprues 16 at the bottom of the annular chamher 9 obviously prevents the first deposit of molten metal at the bottom of the chamber 9 from setting or solidifying on account of the continued inrush of molten metal at the bottom of the chamber 9 and inasmuch as the outlets l8of the grooves or sprues 16 are spaced apart on account of the radial disposition of said sprues, a continued agitation of the molten metal is carried on even after its entry into the annular chamber and during the rising thereof while the chamher is being filled. The backing of the metal in the ingate 17 during the pouring of the molten metal therein, will determine that the mold or annular chamber 9 is filled and a the casting operation has been completed.

Immediately after the pouring operation, the solidifying or' setting of the cast metal occurs, and rapidity thereof is brought about by the chilling action provided by the metallic encasement of the sections 2 and 3 of the mold.

In the casting of annular members such as brasses in a mold of this improved character in which rapid setting of the metal is brought about after the pouring operation, it is obvious that a rapid degree of contraction is given to the setting casting. For permittingthe action of rapid contracting of the cast annular members and at the same time preventing the casting from cracking, the core 5 is designed to cooperate with the contracting casting, said core being made of a material such as sand or clay having a consistency which will stand the pouring of the hot metal and at the same time yield to the shrinking of the setting metal or poured casting.

' From the aforesaid description of this improved mold and the method of operation carried on thereby for casting metal alloys especially in the form of annular members, improved means are provided for keeping the ingredients of the alloy thoroughly mixed or agitated during the pouring of the molten alloy into the mold chamber, the quick setting thereof after the pouring holding the ingredients of the alloy in their mixed state in which the ingredients will be uniformly distributed thereby providing a casting of uniform material with a much finer and closer grain than heretofore, such a character of casting having strength which is a load carrying'factor in castings of this character which are generally used for bearings of vehicles such as locomotives.

As bushings or brasses are generally made from an alloy of non-ferrous metals such as copper, tin, lead, and zinc, in order to provide a uniform mixture of the component parts in the casting, it is wholly necessary that a quick action of setting be given to the poured casting immediately after the pouring so that the component parts or ingredients of the alloy will be caught in their agitated or mixed state which was given to the ingredients of the alloy during the pouring thereof and while the molten metal is rising in the mold chamber from the bottom during the filling thereof. This quick setting of the poured molten alloy and the thoroughly mixed ingredients thereof provides a thorough amalgamation of the alloyed parts in which the density of the cast material is greatly increased and therefore made non-porous and in addition thereto the casting is made approximately 5% heavier thereby providing a bushing or bearing of maximum strength.

In the event that bushings or castings are required to be made thicker under this improved method of casting, it has been found desirable to construct the central core 5 of the mold of sections constructed of ferrous metal so that the thicker casting will be chilled from the inside as well as the outside, provision however, being made whereby the sectional ferrous metal core can be moved inwardly so as to allow for the shrinkage of the casting.

What I claim is:

1. An apparatus for casting annular nonferrous metal members comprising an encasement of ferrous metal, a core having an ingate exten n'g the length thereof dis-,

1 ncasemeiit" so as to form an core having a. portion-forengagement with the wall of said encasement, and a series of sprues leading from said ingate of said core to the bottom of the mold.

I 2. An apparatus for casting brasses comprising an annular metallic mold, a core slightly smaller in diameter than said mold located in said mold having a portion for d encasement, said engagement with the wall of said mold, said core having an mgate extending the length thereof, and a series of sprues leadin from said ingate to the bottom of the mol 3. An apparatus for casting annular members comprising an annular metallic mold, a core disposed in said mold so as to provide an annular chamber within said mold, said core being provided with means for co-operation with the side wall of said mold for disposing it centrally of said mold, and a series of radially disposed sprues leading to the. mold chamber and entering the mold chamber from the bottom thereof.

4. An apparatus for casting brasses comprising an annular metallic mold, a core having an outwardly extending annular shoulder located in said mold in engagement with the side wall thereof, said core having an ingate extended through the length thereof, and aseries of sprues leading from said ingate to the bottom of the mold.

5. An apparatus for casting brasses comprising an annular metallic mold, a core havin an outwardly extending annular shoul er located in said mold in enga ement with the side wall thereof, said core aving an ingate extended through the len h there of, and a series of sprues leading rom said ingate .to the bottom of the mold, said shoulder of said core providing for the disposal I of said core centrally of the mold.

SAMUEL W. CRAWFORD.

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