US2772454A - Apparatus for casting - Google Patents

Description

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4 V 4 M f 4 d i INVENTOR. JOSEPH BFEENA/A/V T. ATTO/VEYS.

APPARATUS FOR CASTING Joseph B. Brennan, Cleveland, Ohio Original application June 4, 1949, Serial No. 97,195. Divided and this application May 28, 1952, Serial No. 293,184

1 Claim. (Cl. 22-57.3)

This invention relates to continuous pressure casting of a head of molten metal through an orifice or conduit against the face of a moving heated band of dissimilar metal under constant pressure control and constant tem perature control so that a lamination of two or more metal strips or shapes is produced by passing the joined cast and moving band of bimetal through a die defining the contour and cross-sectional dimensions of the nished strip.

This application is a division of my copending application Serial No. 97,195, tiled June 4, 1949.

According to this invention I am able t continuously bond a cast molten metal such as a leaded bronze to a heated and continuously advanced strip of cold rolled steel which can be used for making split bearings.

A feature of this invention is a synchronized means of advancing and withdrawing a strip of steel for example through a die wherein for example the molten bronze is applied thereto in such a manner that no serious strain is applied to the steel strip during the application of the molten metal thereto.

Another feature of this invention is a temperature control means throughout the passage of the to-be-bonded metal strip through the die and during the application of the molten metal layer thereto.

Another feature of this invention is 4the atmospheric pre-cleaning and control of the to-be-bonded strip prior to the entrance into the lamination die.

Another feature of this invention is the constant rate of feed and withdrawal mechanism for the feeding of molten metal to the lamination die.

Another feature of the invention is the provision of apparatus which may be used to feed molten metal at a constant rate and constant temperature and pressure onto a to-be-bonded strip of temperature controlled heated metal in such a way that a good bond is assured.

The apparatus of this invention may be used at atmospheric pressures or at superatmospheric or subatmosphen'c pressures such as in conjunction with apparatus dis closed in my pending application Serial No. 25,756, filed May 7, 1948, now Patent No. 2,569,150, dated September 25, 1951.

Other objects and advantages will become apparent as the following description proceeds.

To the accomplishment of the foregoing and related ends, said invention, then, comprises the features herein after fully described and particularly pointed out in the claims, the following description and the annexed drawings setting forth in detail certain illustrative embodiments of the invention, these being indicative, however, of but a few of the various Ways in which the principle of the invention may be employed.

ln said annexed drawings:

Fig. l s a vertical cross-sectional view of one embodiment of this invention;

Fig. 2 is a vertical cross-sectional view of another embodiment of this invention;

nited States Patent O 2,772,454 Patented Dec. 4, 1956 rice Fig. 3 is a fragmentary cross-sectional view of the roll in Fig. 2; and

Fig. 4 is a cross-sectional view taken substantially along the line 4--4, Fig. l.

Referring to the drawings which accompany this specification, the numeral 1 in Fig. l represents a tiltable feeding crucible for feeding molten metal to the Crucible 2 so as to preferably maintain a constant head of metal 3 therein which is done by means of the overiow 12 which overflows into `the receptacle 4.

The Crucible 2 and its contents 3, Fig. l, are preferably heated by high frequency coils 7 to a constant temperature and feeds a stream of molten metal 8 therefrom through opening 13 to slit ended die 14 which slit ended die is constant temperature controlled preferably by means of the high frequency coils 7a at a zone adjacent the entrance feed of the molten metal 8 into the slit ended die 14.

The metal 5 to be bonded is fed in flat strip form 6 through a reducing cleaning gas flame supplied by jets 15 to the surfaces thereof and into the slit end of the die 16 by means of a belt 9 backed up by a joined series of permanent or coil magnets 9a advanced therewith as a supporting belt.

The magnetic belt 9 may be a single continuous belt having magnets attached to the inside face thereof as best shown in Fig. 4 and moving therewith to feed the strip 6 of, for example, flat precleaned steel into the feed-in slit of die block 16 and all along underneath said steel strip 6 until it emerges after being coated with a surface of, for example, leaded bronze at the exit slit 11 of die block 17. The magnets 9A may be recessed to receive rollers 9B for engaging support 9C to thereby facilitate the movement of the joined series of magnets 9A longitudinally along the support 9C.

Under such conditions the magnetic belt 9 holds the strip steel 6 firmly and feeds it through the molten metal application zone in die 14 While the steel is heated on at least its exposed face to l950 F.-20Q F. even though the heated section of strip 5, Fig. l, has Yternporarily lost its magnetic character due to heat while in the molten metal zone of die 14.

The drawing herewith shows the magnetic feed and withdrawal belt 9 as in left-hand and right-hand sections both driven by chain 10 as a preferred construction.

A large hollow magnetic roll could be used instead of the belt 9 to advance the strip in and out of the metal application die 14, Fig. 1, if preferred.

Feed magnetic rolls synchronized at both ends of the slotted die could also be used to feed and withdraw the steel strip 6 through the molten metal application die 14 if preferred.

According to my invention the steel strip and the molten metal being applied thereto and the bimetallic strip resulting from such application are enclosed on the top, bottom and sides by means of the die .14, as `well as die shoe 16 and belt 9 and die shoe 17 and belt 9 so that when the bimetallic strip is withdrawn it is chilled to hold its shape which is substantially the crosssection of the right-hand slot of die 14.

Die shoe 17 has a slot therein equal to cross-section of vslot at right-hand exit or Withdrawal end or" die i4 and in conjunction with upper surface of right-hand belt 9 completely encloses the bimetalllic strip il. until it emerges.

Cooling coils 18 gradually cool the produced bimetallic strip 11 as it progresses and also restore the magnetic character to the steel strip as it is cooled.

The belt surface 9 may be grooved to a depth equal to or greater than the thickness and width of the resultant strip 11 or the die shoes 16 and the die 14 and the die shoe 17 are preferably grooved, as illustrated in Fig. 4

arreglar for example, in which case the upper surface of belts 9 may be smooth.

In any case the belts 9 function so as to snugly hold the advancing strip 6 in place against the die shoe 16 and the die 14 and the withdrawing strip 11 is held against the die 14 and the die shoe 17 snugly.

The upper and lower parts of the die 14 are in fixed relation when metal is being laminated but may be made adjustable as to width and thickness to suit desired strip dimensions of the finished product.

The coil of steel may be enclosed in a deoxidizing atmosphere if preferred and may also be placed in a pressure chamber with all the apparatus shown in Fig. 1 if desired except the exit end of the die where the strip 11 emerges.

Such a pressure chamber as is suitable is shown in my pending application Serial No. 25,756, filed May 7, 1948, now Patent No. 2,569,150, dated September 25, 1951.

The die 14 plus its extension made up of die shoe 16 and the left-hand belt 9 and the die shoe 17 and the righthand belt 9 define a groove just to fit the strip steel 6 as it feeds in then to accommodate the molten metal and heat zone 14 then to define the cooling Zone for strip 11 as and after it is shaped and cooled.

The base 19 may be made in sections and the die 14 may be removable and is preferably so.

Separate electric sources may be used to control heat coils 7, 7a and heat coil 20.

Heat coil 20 can be a high frequency surface preheater applied to only one side of strip 6 so that only the top side of the strip is heated to plasticity or thereabout as it passes thereunder as is disclosed in my pending application Serial No. 25,756, filed May 7, 1948, now Patent No. 2,569,150, dated September 25, 1951.

Cooling coils 18 may be separate, part situate in the discharge Zone of die 14 and part situate in die shoe 17, Fig. l.

These cooling coils 18 insure that the strip 11 emerges solid and also that the steel part of the strip 11 is magnetic as it emerges and prior thereto.

The high frequency coils may be packed in an insulation where used with a conductive die or die shoe such as graphite.

Fig. 2 illustrates apparatus similar to that described in my Patent No. 2,569,150, aforesaid.

The numeral 31 in Fig. 2 represents sectionally a pressure dome as of metal locked over a base 32.

Inside the dome 31 and the base 32 is a Crucible 33 surrounded by a high frequency induction coil 34 for heating the metal 35 and maintaining the same molten.

A gas pressure feed line 36 enters the dome 30 to supu ply pressure thereto and a graphite die 37 extends as a molten metal conduit from the bottom of the Crucible 33 which conduit or die in turn is heated by high fre quency coil 38 and is cooled by fluid chamber 39 surrounding the same.

The die 37 terminates over a rotatable hollow wheel 40 as of graphite and a high frequency coil 41 is adjacent the exit of die 2 and a high frequency coil 42, Fig. 3, is situate near said termination of said die over said wheel and inside said Wheel so as to heat the Zone of molten metal application as well as the traveling steel strip 43 fed from roll 44 through slot 45 in carbon shoe 46 recessed and spaced from outer surface of wheel 40 sufficiently lto form a groove for passage snugly therethrough of steel strip 43 to the egress of die 37 so that as and when the molten metal emerges from die 37 the strip steel 43 is heated to about 2000 F. due to high frequency coils 41 and 42 and the molten metal penetrates one side of the strip steel pores and is formed into a uniform layer onto the exposed upper face of the strip steel, the thickness of said layer being regulated by the spacing of the steel band 43 passing by the right-hand side of the lfeed die 37 which has a groove of added thickness on its righ-thand side to regulate the thickness of the molten metal Vrs as it is applied to the steel strip and as the steel strip advances over the outer surface of the roll 40 the steel strip coated with the molten metal 35 advances into a cooling zone which has a grooved die shoe thereover 47 heated by high frequency coil 48 and cooled by coolant circulation tubes 49 to regulate the temperature of the advancing bimetallic strip and to solidify same.

Added sprays for coolant are supplied after the bimetal emerges.

The hollow roll 40 may be grooved and/or flanged.

The roll 40 may be magnetic to assist in advancing the steel strip without distortionthereof at 2G00 F., it being solid at its entrance and exit.

The rolls 50 may be used to drive hollow roll 40.

The steel coil 44 may be enclosed in a chamber 51 held at a desired pressure and having an atmosphere and temperature such as will assist in the process depending on the metals being used.

Fig. 3 is a fragment of roll 4t) and bearing thereof having high frequency coil 42 therein.

This roll 40 may be made of anodized aluminum or carbon or graphite or quartz or metal or ceramic material and should be temperature controlled.

The temperature of the zone of metal application must be above the temperature of the melting point of the molten metal being applied to the advancing strip metal.

The heating of the metal strip and the die at the point of application of the molten metal thereto is an essential feature of this invention.

Solid metal strips comprising only the metal 35 may be cast by the same apparatus continuously by blocking the slit entrance 45 and filling the groove in the die shoe 46 with a metal band to which metal 35 will not stick.

Having described my invention what I claim is:

Casting apparatus for continuously producing com posite strip metal, comprising a longitudinally extending fluid-cooled ceramic die including a stationary wall and a longitudinally movable Wall which are laterally spaced apart a distance corresponding to the thickness of the composite strip which it is desired to produce, means for moving said movable wall, said die having an inlet at one end for solid strip vmetal and molten metal of lower melting point than the strip metal and an outlet at the other end for emergence of composite strip metal composed of solidified molten metal united to the strip metal, means for conducting a solid metal strip through said die with one side in Contact with said movable wall for movement of the strip in synchronism therewith in substantially unstressed condition and with the opposite, exposed side laterally spaced from said stationary wall, molten metal supply means having a discharge opening leading into the inlet of said die for flow of molten metal therethrough in contact with such opposite side of the solid metal strip and with said stationary wall for emergence from the outlet in solidified condition, and induction heating means along said die having a heating field effective (a) to inductively heat such opposite side of the solid metal strip as it enters the inlet of said die to a temperature rendering said opposite side plastic and exceeding the melting point of such molten metal, and (b) to maintain molten by induced current said molten metal adjacent the inlet of said die whereby said molten metal is united to the solid metal strip, and is hot-formed and troweled in said die while carried by the strip metal in longitudinally sliding Contact with the stationary wall of said die, and cooling means in said die extracting heat from the hot-formed and troweled molten metal at a rate to solidify the latter prior to emergence from the outlet of said die.

(Other references on foilowiug page) 5 UNITED STATES PATENTS Davis Dec. 6, 1927 Stocketh Mar. 19, 1935 Fiegel Aug. 31, 1927 McCarroll et a1. Sept. 7, 1937 Hudson Sept. 6, 1938 Edwards June 11, 1940 6 Eldred May 20, 1941 Reynolds Mar. 6, 1951 Brennan Sept. 25, 1951 Horn Feb. S, 1952 FOREIGN PATENTS Great Britain Apr. 26, 1939

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