US2509154A - Casting arrangement - Google Patents

Description

y 3, 1950 'R. T. LEISK 2,509,154

CASTING ARRANGEMENT Filed Jan. 25, 1947 3 Sheets-Sheet 1 i .J v

IN VEN TOR.

May 23, 1950 1-, LElsK v 2,509,154

CASTING ARRANGEMENT Filed Jan. 25, 1947 3 Sheets-Sheet 2 May 23, 1950 R. T. ILEISK 2,509,154

' CASTING ARRANGEMENT Fiied Jan. 25, 1947 3 Sheets-Sheet 3 IN V EN TOR.

Q jg zzuwacy Patented May 23, 1950 CASTING ARRANGEMENT R lan '1. Lei k, East Louis, 1 1-, ass gns)! to American te l ou d s, fl ees 1 .1,, a cerrora ioh f ew Jer y Application January 25, 1e44, Serial h 724,425

4, Cla ms.

This invention relates to the casting of metal and more particularly to the production of ferrous castings.

,In the production of ferrous castings, such as axle housings forlocomotive tender trucks and passenger car trucks, wherein unusually lar e a e of e ta ting mus be d y m t n metal to prevent shrinkage cavities, it has been necessary according to the practices of the prior art to utilize large risers and connected Dads dis.- re d arou d h se io s o be ed- A e e t, ca in Of t i y e ha be f rmed wi large heads and p ds urroun in th po ti n o he c s in to b fed. F r ex mple. axle housi eastinss h be n on en i na ly eas wi h imme e ri e s an p ds nte r y co nec d o the r ser an o th bel -s a ed nds of the eas nss This s rplus met t eth h the a s. fr flu nt w gh d as mueh or mo e t a the fini hed cas n thus affording a ield of bout 40% in view of melting and foundry losses. Furtherx ore v n i u inal h inka of suc cast ings has tended to produce hot tears at the throats formed by the junct e f he inte mediate portion of the casting with the bellshap d ends ereo inasmu h as the r se a d padding around these end resisted shrinkage in the molding sand, as hereinafter discussed. This tendency to tearing has been customarily avoided by the use of chills in the throat at each end of the casting.

Accordingly, it is a primary object of the pres.- ent invention to provide a novel method and means for economically producing ferrous metal casting and increasing yields in the production of such castings. Another object of the invention is to provide a novel method and means for reducing the size of the riser and padding around castings such as above described.

Another object of the invention is to reduce finishing costs by eliminating integral padding around the casting.

Another object of the invention is to provide a novel method and means for eliminating hot tea-rs in elongated castings with risers at the ends thereof.

Another object of the invention is to eliminate the necessity for chills in the throats of elongated castings with e larged portions which must be fed by associated risers. s i l n h o ect f h enti n is to pr d a n vel method and means. for h atin a section of a casting 1 be fed With ariser while the m l n metal ows rom h riser in o t sec io to eve t sh i k g avities the e nst l no he ob ect f the. in ent on s o pr duce sound cast g h be ter surfac cond t ons, the eby reducing e amount of m h fin sh The foregoing and other object and advantages of the invention will become apparent from a consideration of the following specification and the accompanying drawings wherein:

Figural is a fragmentary plan view of the drag of a conventional sand mold with the casting- -therein partlyshown in section along the line I--l of Figure 2 to disclose the central core, a portion of which is broken away;

Figure 2 is a vertical cross-sectional view through the mold taken onthe-line 2-2 of Figure :1 with the casting and" cores shown in ele vation Figure 3. isa fragmentary longitudinal section through the mold at the gate side of the casting which is shown inelevation;

Figure. 4,is..a perspectiveview of the unfinished casting after it has been removed fromthemold;

Figure 5 is a perspective viewof the finished casting;

Figure 6 is. a. fragmentaryiplan view similar to Figure 1 illustrating a modification of the invention, thev casting being partly shown in section along the line 6-6 of Figure-7;

Figure 7 is a fragmentary sectional view corresponding to: Figur 2. but illustrating the modification of Figure 6;

Figure 8 isa, fragmentary lnn itudinalsectional view eorreependihs to. Fi ure 3 but illustr tin the mod fi at on oi F -u e 6; and

Fi ures 9 and l a s ectively a fra men a y s de, evation an al reshienter end view ti he nes hown in Fi ures -8 ith the sates h e eh aw y a d the co es emoved- Referring first to Figures 1-5, the; invention is llus ted a a ied to n axle housin a ine g neral y d g t lend omp i n 11 1- ewelonee e tu ul r or ion-.4 wi h e be lheree end o h B at e ch e tremi the e Th c s n s show n igu s 1- i ha ate 8. runn rs 0 and p esl co e ti g ea h unner ill to the associated hub 6. Each of the hubs is connected bya neck l4 to an open riser l5 have ing heating pad, portions 18,- disposed around the 111 b 6 and spaced therefrom by a ring core 20. T r 201. e e ably rm dei 1 1 se men s, two of which are indicated at 22: and inthe drag. 6 o the o d and th eere-ihd e t d 3& and ,2 h-the:s Pe .34; as best his:

ure 2. The center segment 36 of the cope portion of the core i preferably pasted to the segments 28 and 32 and is provided with a suitable opening accommodating the neck 14 of the riser.

A center core, generally designated 36, is also provided and is preferably formed in two halves pasted or doweled together in the usual manher. The core 36 is preferably supported at its ends in the molding sand of the drag and is provided with a longitudinal vent 38 formed by matching grooves in the adjacent faces of the two halves of the core 36.

It may be noted, as best seen in Figures 2 and 3, that the partin line of the cope and drag portions of the mold is in the horizontal plane coinciding with the line ll of Figure 2; and the longitudinal axis of the casting cavity in which the casting 2 is formed lies substantially in the plane of the parting line.

In pouring the casting, the molten metal flows from the gate 6 through the runners in and into the sprues l2 and thence into the mold cavity to form the casting 2. The molten metal flows upwardly through the necks l4 to form the risers l6 and heating pads l8. As the molten metal cools within the mold, each hub section 6 is fed with molten metal from the associated riser 16 through its neck (4 to prevent shrinkage cavities in this section. The hub section is heated at this time by the pads 18 to facilitate feeding of the entire hub section as the casting solidifies. The finished casting is formed by breaking or burning off the necks l4 and the sprues l2, and the casting is then ground to the desired finish as shown in Figure 5.

It may be noted that according to prior art practices which have been utilized for years, the riser l6 and pads I8 have been cast integral with the hub sections 6, thereby forming immense ends on the casting. These ends have reduced the metal yield and have increased finishing costs by necessitating burning and grinding of the entire hub section. Furthermore, longitudinal shrinkage of the casting tended to produce hot tears in the throats of the casting, indicated at 46, at the juncture of the hub portions 6 with the intermediate portion 4, thereby necessitating the use of chills in the mold to prevent hot tears at these points.

According to the present invention, however, these chills have been successfully eliminated inasmuch as the relatively small riser necks yield against the thrust of the molding sand thereby reducing stresses in the throats as the casting shrinks. Thus castings of this type have been successfully produced with a lower percentage of defective castings and at much lower cost than in accordance with the prior art practices which have long been regarded as preferred techniques in this art.

Referring now to Figures 6-10, a modification of the invention is shown wherein certain additional advantages are achieved. In this embodiment of the invention each riser 52 is connected to the hub section of the casting 54 through a neck 56 extending through a complementary opening in a core 58 which is formed as a complete ring preferably having two drag segments 66 and 62 and three cope segments 64, 66 and 6B. In this embodiment, the riser 52 is a blind riser, and preferably a green sand core lfl projects into the top of the riser to afford a V notch, as seen in Figure 8. This notch permits atmospheric pressure to rupture the top surface of the metal within the riser 52, thereby facilitating feeding of molten metal therefrom to the casting 54, as will be readily understood by those skilled in the art.

It may also be noted that in the embodiment of Figures 6-10 the heating pads 12 are reduced in width and are disconnected from the riser 52 so that molten metal flows from the gate 14 into the runner l6 and thence from three sprues I8, and 82 into the heating pads 72 and into the hub section of the casting 54. In this connection, it will be seen from a consideration of Figures 8 and 9 that the sprue 86 through which metal enters the heating pad cavity is at the lowest point within the mold beneath the level of the sprues I8 and 82. Thus any loose sand which may be washed from the gate of the mold enters the sprue 80, thereby insuring that such sand enters the heating pad 12 rather than the casting 54. Furthermore, in the embodiment of Figures 6-10, the riser 52 is disconnected from the pad I2 so that the metal within the riser is not utilized to feed the pads. This arrangement permits a considerable reduction in the size of the riser.

Another advantage of the modification of Figures 6-10 may be noted in that the metal enters the heating pad cavities at substantially the same rate as the casting cavity within which the casting 54 is formed. Thus the ring core is relieved of stresses which result when the casting cavity is filled first so that the ring core temporarily supports the weight of the metal within the hub portion of the casting cavity.

It will be understood that as the casting solidifies it is fed with molten metal through the neck 56 of the riser 52, the pads I2 being effective to heat the hub section of the casting so that the same cools gradually at this time, thus accommodating the feeding of the metal from the riser into the casting. As above-mentioned, atmospheric pressure ruptures the top surface of the metal within the riser 52 so that atmospheric pressure on the molten metal therewithin facilitates feeding of the casting. After the casting and riser 52 have completely solidified, as seen in Figures 9 and 10, the riser contains a shrinkage cavity, indicated at 84 from which the molten metal has been fed into the casting.

It may be noted that the invention has been described with respect to the casting of an axle housing; however, the invention is equally applicable to other types of castings wherein it is desired to feed unusually large sections or where it is desired to feed an isolated section of the casting without the use of an extra riser.

It is to be understood that I do not wish to be limited by the exact embodiments of the device shown which are merely by way of illustration and not limitation as various and other forms of the device will, of course, be apparent to those skilled in the art without departing from the spirit of the invention or the scope of the claims.

I claim:

1. In means for supplying molten metal to feed shrinkage in a solidifying casting, the combination with a mold having a casting cavity and a communicating reservoir for molten feed metal, of a heating pad cavity adjacent to and spaced from the section of said casting cavity communicating with said reservoir, a gate having a connection to said casting cavity, said pad cavity being connected to said reservoir and extending downwardly from opposite sides thereof below the level of said connection and substantially surrounding the casting cavity.

2. A mold comprising a casting cavity having a section to be fed by a riser of molten metal, a riser cavity in said mold above said section and adapted to contain said riser, a pair of heating pad cavities connected at their upper ends to said riser cavity and extending downwardly around said section to a point below the lowest point of said section, a heat permeable sand core spacing said pad cavities from said section, said core having a smaller cross-sectional area than that of each pad, and passage means through said mold for delivering molten metal to at least one of said cavities at a point above the lower extremities of said pad cavities.

3. A metal casting mold comprising a top cope section and a bottom drag section containing a casting cavity and having a partin line along a plane substantially on the longitudinal axis of the cavity, a non-metallic core substantially annular in form and supported in said drag section as a separable unit substantially encircling a portion of said cavity, another core extending through said cavity and supported in said drag section whereby the cores define an annular section of the casting cavity, a riser cavity in the cope portion above said annular section and connected thereto through an opening in the firstmentioned core, heating pad cavities connected to opposite sides of the riser cavity and extending through both mold sections and substantially encircling the first-mentioned core, and a gate having a connection to said annular section at a point below said plane and above the lowest level of said pad cavities whereby feeding of the cooling metal in said annular section by the metal in said riser cavity is ensured.

4. A metal casting mold comprising a top cope section and a bottom drag section containing a casting cavity and having a parting line along a substantially horizontal plane passing through the cavity, a riser cavity connected to the top of the casting cavity, a gate connected to the casting cavity in the drag section at spaced points disposed at opposite sides of a substantially vertical plane passing through said casting cavity, and a heating pad cavity extending upwardly from below said points to at least the level of the connection between the riser and casting cavities, said heating pad cavity being spaced a substantially uniform distance throughout its circumference from said casting cavity and said heating pad cavity being connected to one of said riser and casting cavities.

ROLAND T. LEISK.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,456,855 Midgley May 29, 1923 1,572,428 Grimes Feb. 9, 1926 1,678,655 Sipp July 31, 1928 1,716,833 Rich June 11, 1929 1,828,271 Arnold Oct. 20, 1931 1,938,707 Mann Dec. 12, 1933 2,313,517 Cameron Mar. 9, 1943 2,431,879 Mebs Dec. 2, 1947

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