US1652445A - Heat control in castings - Google Patents

Description

Dec. 13, 1927. H, s LEE 1,652,445

I HEAT CONTROL I`N CAISTING Filed Aue;.22, 1925 2 Sheets-Sheet 1 el e f f' /Z Q I) Q1 l l 2./6' r1 VC- Off 1|' 'al 1 G E t ,n L] :.0 IJ; gl -j 'I- i y l I z T l l l) l; l 1 l I I" l'" 'I v il l 1 I l 1f i u Y 1 1 l1 T :n i m- .r l I l. i l l 1 'VI l v ,4 v l l" L 1 --i' f L a i l l O 'O 1 l Ill, L nlm |111 g ,-L-- -11 -1 l l ,1. IHIU NIU ,4. yy 1 L- Li Li U INVENTOR.

I By

' ATTORNEY.

Y H. S. LEE

HEAT CONTROL IN CASTING Filed 111111.22, 1925 2 sheets-sneu 2 I N VEN TOR.

ATTORNEY.

`Patented Dec. 13, 1927.

UNITED STATESv HARRY S. LEE, OF PLYMOUTH, MICHIGAN.

HEAT CONTROL IN' CASTINGS.

Application ined August 22, 1925.

This invention relates to moulds and has for its object a permanent mould construction of a sectional character in which the sub-sections are en'iployed both for varying the heat conditions in certain parts of the mould and also for the purpose of pre-vent,- ing the distortion of the mould sections, due to unequal heat conditions.

The invention alio relates to a method of controlling the character of a casting by varying the abstraction of heat in certain areas of the cooling casting. This will be more fully explained in the specification hereinafter.

In the drawings: v

' Fig'. l is an elevational View of the back of a mould section.

Fig. 2 an elevational View of the front of the same.

Fig. 3 is a cross section taken on the line a--z-s of Fig. 1.

Fig'. 4- is a perspective view of the enclosing frame.

Fig. 5 is a section on the line 5-5 of L' Fig. 2.

' Fig'. 6 is the elevation of the inside of a modified form of mould section.

Fig. 7 is a longitudinal section of still another form of permanent mould.

Permanent moulds ordinarily are made in the form of iron castings which have the cavities which receive the molten metal impregnated with certain materials to protect the mould from fusing, or else the face of the cavity is coated with a lire resisting material, such as kieselguhr, lire clay and other materials very often mixed with sodium silicate in order to apply them to the face of the mould.

The success of casting iron With permanent moulds depends largely upon a proper control of the heat conditions in order to get the correct results in avoiding chilling, etc. A chilled casting is very diiiicult, if not 45 impossible to machine. -However, under certain conditions, it may be desirable to chill some portion of the casting,`while other portions which vare to be machined should be protected from chilling so far as is possible.

Another factor in successful casting by permanent moulds is mould distortion. An elongated mould section is quite liable to distort and bow, due to greater heat on one side than on the other.

It is the object of the present invent-ion to provide a permanent mould construction in Serial N0. 51,723.

which not-only can these desired heat conditions be substantially obtained, but also in a large measure distortion of the mould sections more or less avoided. To this end I construct the mould section (which here vare two halves of the mould) in a plurality of sub-sections.

Referring to Fig. 4 I employ a frame which is preferably rectangular and ordinarily of wood. This is designated a. The sides of this are grooved as at b and preferably a pair of vertical rods c are employed. At the top of the frame is a bowed spring d for exercising pressure on the several parts that go to make up the complete sub-section. These parts, as shown in Figs. l and 2 are simply. sub-sections vof the mould section made by dividing the complete mould sec` tion horizontally. Hence, the mould section is built up by threading layer upon layer on to the guide rods after the top bar e of the frame has been removed by taking out the screws f. The top is then replaced and the screws put back after all the layers have been threaded on to the rods and guided into the grooves of the side bars.

It will be noticed from the examination of Fig. 5 that each of these sub-sections or layers is `provided with a grooveand tongue joint g so that the several parts or sub-sections t nicely together.

This construction wherein the mould section is divided from side to side successfully minimizes the warping or bowing tendencies of an elongated mould section. The mould section here shown is for a sash weight. The mould section is elongated in a Vertical direction, as shown in the drawings. Under ordinary circumstances the mould gets very much hotter on the inside than on the back and consequently it tends to bow outwardly due to the expansion on the inside. This will not only distort the casting but it tends to prevent the mould sections from meeting accurately and presents a rather serious condition.

N ow it will be obvious that by the con struction, such as already described, that the mould section is divided into a number of parts along its length and consequently any tendency to distort is relieved by the divlsion lines so that whatever bowing there is due to unequal heat condition is so small as to be practically negligible. This is one of the purposes of the improved construction.

The second purpose is an important one,

` special heat consideration the single to wit: It permits the insertion of diierent character of metals. As is well known, metals vary greatly in their heat conductivity. Some have a very high capacity-some relatively low. With certain castings it may be desirable to chill one portion of the casting, while protecting another portion of the casting from chilling, or, all sorts of conditions may be desired with different characters of castings, some requiring protection against chilling and others it may be desirable to chill at cert-ain points. The construction that I have described enables this to be very nicely carried out by inserting, for instance, a layer in mould section having relatively great heat conductivity. It will be apparent that the heat will be extracted vfrom the casting very rapidly and cause a chill. On the other hand, the employment of a section of metal relatively low in heat conductivity will result in protecting the casting from any serious chilling.

It will be obvious that there may be many mean conditions between the extremes of complete chilling and complete protection from chilling, and these may be nicely applied as conditions require. The sash weight mould shown is simply for the purpose o1" illustrating the construction. This is possibly not a very good representative of a class of articles that need varying heat treatments, but. it answers the purpose in explaining the matter. l

In Fig. 6 I have shown a mould section divided also along vertical lines. This makes the subsections even smaller and permits even greater localization of the desired heat conditions and also prevents distortions of the casting from side to side.

In Fig. 7 I have shown a mould section with a single insertion h. In some mould sections where the shape of the section is such the distortion is not great and where only one small part of the casting requires lug h may be used. Or, on the other han with such a form of casting some other means of resisting the distortion of the mould sect-ion such as mechanical or thermostatic devices may be employed. However, all these forms come within my general conception.

What I claim 1s:

1. In a mould, a mould section made up of a plurality of metal subsections, each subsection extending completely across the mold section and being connected to adjoining subsections, the connection consisting of a joint which permits each subsection to move in obedience to heat conditions, the sections having diil'erent co-eiicients of heat conductivity.

2. In a mould, a mould section made up A of a plurality of solid parts secured together` parts, the parts having their co-eiiicients of heat conductivity determined in accordance with the desired heat conditions for the casting.

4. In a mould, amould wall composedl of a number of metal parts, these parts being joined together to form the normal shape of the mould wall, the joining of the parts being such as to permit relative movement between the parts in obedience to heat conditions whereby distortion of: the entire mould Wall is prevented.

5. In a mould, a. mould section made up of a plurality of subsections which are lined up to form the mould section wall, and means for holding the subsections in proper align ment with each other.

6. In a mould, a mould section in the form oi' a frame and a plurality of solid parts itted together in said frame to com plete the mould section and arranged to minimize distortion and abstract heat from certain local areas of a casting in accordance with desired conditions.

T. In a mould, a mould section made up of a plurality of subsections which are disposed in abutting relation to form the mould section walls, and resilient means vfor urging the sections toward each other to hold them inabuttingI relation.

8. In the art of casting ferrous metals in permanent moulds, the method of controlling the hardness of the castmetal which comprlses, regulating the rapidity with 'which the heat is abstracted from the cooling metal by the use of metals for dissipating the heat by conduction, said metals having variant co-eiicients of heat conductivity.

9. The method of casting ferrous metals in permanent moulds and controlling the hardness of the surface by heat control, which comprises the use of metals in juxtaposition with the cooling casting having determined but variant co-eicients of heat conductivity. f

10. The method of casting ferrous metals in permanent moulds and controlling the hardnessk of the surface by placing metals of greater or less heat conductivity in juxtaposition with the cooling casting for .the purpose of dissipating the heat with varying derfrees of rapidit In testimony whereof I have aiixed my Signature HARRY S. LEE.

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