US3090090A

US3090090A - Insert core for slide shut-off device

Info

Publication number: US3090090A
Application number: US51657A
Authority: US
Inventors: Jr James Woodburn
Original assignee: Amsted Industries Inc
Current assignee: Amsted Industries Inc
Priority date: 1960-08-24
Filing date: 1960-08-24
Publication date: 1963-05-21
Anticipated expiration: 1980-05-21

Description

May 21, 963 J. WOODBURN, .1R

INSERT CORE FOR sLDE SHUT-OFF DEVICE 2 Sheets-Sheet l Filed Aug. 24, 1960 May 21, 963 1. wooDBURN, JR 3,090,090

INSERT CORE FOR SLIDE SHUT-OFF DEVICE 2 Sheets-Sheet 2 Filed Aug. 24, 1960 i2 .sa 52 5J"150 35 OO 0 o 100 -Jao 118 i/zg INVENTOR.

128 Q22/ 13%/ 32 Jannes gorffzmyn. BY

United States Patent O 3,090,096 ENSERT CURE FR SLIDE SHU'BFF DEVCE .lames Woodburn, Sir., Wheaton, lll., assignor to Arnsted Industries Incorporated, Chicago, Ill., a corporation of New Jersey Filed Aug. 24, 196i), Ser. No. 51,657 4 Claims. (Ci. 2.2-84) This invention relates to the art of bottom casting in which molten metal or other fluid material is Iforced into a bottom gate o-f a mold, and the invention relates more particularly to novel means for cutting off flow of such material and to a method of producing such means.

According to prior art pnactices, the fluid material enters the gate through -an aperture of a cut-off slide which is actuated to `close the gate when the mold has been filled. According to such practices, the aperture has been bushed to accommodate reuse of the slide.

However, such practices have been limited to low melting point alloys such as white metal and other low melting point nonferrous metals which do not cause excessive erosion `of the bushings during the pouring.

According to .the invention, it has been discovered that conventional core sand bushings, although eiective in such prior art practices, are not suitable for the casting of iron, steel, and similar high melting point ferrous and nonferrous metals which must be poured at temperatures in excess of 1500 F. and at velocities which cause excessive erosion of such prior ant bushings.

Early efforts to solve this problem involved the substitution of a fired refractory material `for prior art sand core bushings; however, such material proved to be costly and to require expensive molding or machining to suitable form.

According to the invention it has been discovered that a satisfactory composite bushing can be produced by forming a conventional core sand mix sleeve around the perimeter of a tired refractory liner in such manner that the sleeve and liner are bonded to each other to form a composite bushing which can be quickly and economically assembled by manual insertion intothe top of an aperture in a cut-off slide.

The foregoing and other objects of this invention will become apparent :from a consideration of the ifollowing specification and the accompanying drawings, wherein:

FIGURE 1 is a perspective View of casting appanatus embodying a preferred form of the novel composite bushma;

FIGURE 2 is atop plan View ofthe cut-off slide assembly shown in yFIGURE l;

FIGURE 3 is a fragmentary sectional view on line 3 3 of FIGURE 2;

FIGURE 4 is a Ifragmentary side elevational view of the structure shown in FIGURE 2;

FIGURE 5 is a sectional view on Iline 5 5 of FIG- URE 4;

FIGURE 6 is a central vertical sectional View through a core box and composite bushing `formed therein according to one manner of practicing the novel process; and

FIGURE 7 is a view corresponding -to FIGURE 6 but show-ing another manner of practicing the novel process.

Describing the invention in detail, a mold .assembly generally designated 2 (FIGURE 1) comprises a mold 4 which may be of a chill material, such as graphite or of any other desired ceramic material well known in the art, such as sand or shell. The assembly 2 also cornprises a car 6 to which the mold 4 may be clamped by conventional clamps 7 or by force of gravity. The mold 4 and car 6, during a pouring oper-ation, as hereinafter described, move together as a unit or assembly 2 and may be interconnected in any desired manner.

3,690,096 Patented May 21, 196s ICC The car 6 comprises wheels 8 which roll on tracks 10 and 'also comprises a cut-off or gate closing device generally `designated 12. The cut-off 12 is best seen in FIG- URES 2 4 and includes a slide support 14 having an opening or hole 15 with a bushing 16 (FIGURE 3) formed .as hereinafter described. The slide support 14 has a cut-out or slot 18 (FIGURE 2) pantly defined by an inner edge 20 for a purpose hereinafter described.

A slide or plate 22 preferably of cast iron, copper or -any other desired chill material is slidably mounted on the support 14 and comprises an opening or aperture 24 having la bushing 26 similar in form and composition to bushing 16, as hereinafter described. The slide 22 is supported within a channel 28 (FIGURE 4) of the support 14 and is seated -along a surface thereof immediately below another channel '34 within which is positioned a loose insert 36 (FIGURES 2 and 3) which is complementary -to and removably mounted in an opening 3S of a top plate or panel 4t) of the car 6.

The support 14 is releasably interlocked with the panel dit by means of ears 42 on the support having apertures within which are received lugs 46 on the underside of panel 40. The lugs 46 are slotted to receive wedge keys 48 which are driven to locking position shown in FIGURE 4 and which may be quickly removed by an impact against the small ends of the keys 48.

The insert 36 is provided with an opening or aperture 50 having a bushing 52 (FIGURE 3) similar in form and material to bushings 16 and '26, whereby when apertures li5, 24 and 5d are aligned, they define a continuous passage for the ow ofv molten metal into a gate 54 (FIG- URE 3) of the mold 4.

The `assembly Z rolls along rails 10= (FIGURE 1) until the

apertures

15, 24 and Sti are located in vertical alignment with the top of a pouring tube 58 (FIGURE 4), the lower end of which communicates with a source of fluid material (not shown) lto be cast, such Ias a ladle of molten steel. Under these conditions, the wheels 8 are supported by rail segments 10a which are separable from rails 1d and are vertically movable.

The segments 10a are supported by a frame 60 which is in turn supported at its corner-s, as by conventional wormgear screw jacks 62. The jacks are mounted on founda-` tion-supported beams 66 and raise or lower the frame 60 as desired. The car 6 is guided at each side thereof in aligned relationship with the top of tube 58 by foundationmounted guide rails 71 (FIGURE l) which snugly confine therebetween a pin 73 on panel 4i) of car 6.

When the assembly .2 is aligned with the top of tube 58, the jacks 62 are actuated to lower the frame 60 until a tapered recess 74 in the bottom of the support 14 engages a complementary tapered portion 76 (FIGURE 4) of the upper end of tube 58. The frame continues to lower until the support `i4- is clamped by force of gravity or Iby other means (not shown) against the tapered portion of tube 58 to afford a seal tight to liquid metal between the tube and the support 14, whereupon the molten steel in which the tube 14 is immersed is pressurized (as for example in the manner disclosed by U.S. Letters Patent No. 2,847,739 is-sued August 19, 1958 to E. Q. Sylvester) to flow the metal upwardly through

apertures

15, 24 and Sii and gate 54 until the mold has been filled. Tilting of the car 6 during pouring is limited by lugs 75 (FIG- URE 1) mounted on the top of brackets 114, hereinafter described.

After the mold has been filled the slide 22 is actuated, as hereinafter described, to cut-olf flow of molten metal through the gate, whereupon pressure on the molten metal is released, the rail `segments lita are elevated to mating relationship with rails 10, andl the assembly 2 is rolled along the rails away from tube 58, andv another assembly 2 is rolled into position and poured as heretofore described.`

The manner in which the cut-off 12 is actuated can best be seen in FIGURE 4, wherein it will be seen that when the assembly 2 is supported on top of the tube S8, a power device 78 mounted on a cover 80 of a chamber or tank 81 containing the molten steel is disposed between the slide 22 and an abutment 82 depending from the underside of car panel 40 so that actuation of the device 78, as by hydraulic or pneumatic pressure, to expand the device 78 axially thereof causes a cylinder member 84 of the device 78 to engage the abutment 82 and a ram 0r piston member 86 of the device 78 to engage the cut-off slide 22.

The device 78 has a limited stroke and at the endY of said stroke, the slide 22 is at a position whereat its aperture 24 is beyond edge 20 of the support 14, whereupon molten metal in aperture 24 is dumped through slot 18 so that the lbushing 26 need not be replaced for each pouring operation. Also release of pressure on the molten metal in the tank 81 dumps the metal in bushing 16 so that it need not lbe replaced for each pouring operation.

The device 78 is afforded a oating support so that, upon actuation thereof, the forces developed by the device 78 to actuate the cut-oi 12 to closed position are self-contained within the assembly 2. This support comprises a bracket 88 mounted on top of the cover 80 as by welding at 90. The bracket comprises a V-shaped channel 92 (FIGURE 5) -within which a complementary slide 94 is positioned. The cylinder member 84 is clamped into the slide 94 by clamp rollers 98 on levers 100 pivotally fulcrumed -at 102 (FIGURE 5) to the slide 94 and actuated by a compression clamping spring 104.

Upon energization of device 78, as heretofore described, the slide 94 permits enough axial movement of the device 78 so that the forces developed thereby are self-contained within assembly 2 and substantially no reactive forces are transmitted to bracket 88 or cover 80.

Upon removal of cylinder 84 from the clamps 98, which can be accomplished by manually lifting the cylinder to compress spring 104, the spring 104 is held in position upon bosses -112 of levers 100 by a slight force provided by a tension spring 113 connected to the lower ends of lever 100. Y Y

' It may be noted that the cover 80l may be clamped to the top of its container 81 by clamp means (not shown) mounted on foundation-supported brackets 114, and the rail segments a may be manually removed from and replaced upon the frame 60 to accommodate insertion and removal of the cover 80 and a ladle (not shown) of molten steel into which the tube 58 extends. The construction of the container 81, the ladleV (not shown), the cover 80 and tube 58 is per se no part of the present invention and may be of the type disclosed in said U.S. Letters Patent, or if desired, may be of any other desired construction and arrangement, with the tube mounted on the cover or elsewhere in communication with the molten steel in the container 81.

It should 'be noted that

bushings

16, 26 and 52 are ilanged at their upper ends so that in their aligned position shown in FIGURE 7, the flange of bushing 16 engages slide 22, the liange of `bushing 26 engages insert 36 and the flange of bushing 52 engages the mold 4 around its gate 54.

According to the inventiomeach bushing 16, 26, and 52 is of novel form and comprises a prered refractory -liner 118 bonded to a flanged sleeve 120, as shown for example in FIGURE 6, wherein a novel method of making such a bushing is disclosed. The liner 118 is formed of `a hard tired material such as graphite containing clayrefractories so that the liner 1-18 does not erode substantially during the pouring and shut-oft steps of a cycle as heretofore described. Such material cannot beV economically molded to the desired bushing form and, according to prior `art practices, must be machined to that shape from a segment of a refractory tube, which is also an expensive procedure.

According to the invention, the liner 118 is cut to desired length from a standard tube and is sleeved over a complementary boss or center arbor 119 of an annular member 122 having -a metal ring 124 sleeved thereon to form a metal core box which can be preheated to a desired temperature. The ring 124- is recessed as at 126 to define a larger diameter portion of the opening in ring 1.24, within which opening the liner 118 is positioned.

A mixture of conventional shell mold Zircon sand and 2% (by volume) phenolic liquid thermosetting resinis poured around the liner I118 and is struck olf ush with the top of the ring 124. rIhis mixture bonds with the liner 118, the contacting surface of which is of sufficiently irregular contour to aiord a good bond. After the resin has set, the novel composite bushing 118120 is removed from the core box 122, `124 by ejecter pins 128 having release springs 129.

FIGURE 7 shows a modification of the novel process wherein the shell mold sand mixture heretofore described is blown into

core box

122, 124 by a conventional blow head 138, the member 122 being provided with suitable vents 132 screened as at 134.

It will be understood that, if desired, the apparatus of FIGURE 7 can be utilized to form a sleeve 120 from a sodium silicate-CO2 bonded sand by blowing into core box 122, 124 a mixture of silica sand and 5% (by volume) sodium silicate. In this practice, the

core box

122, 124 is not heated and after the blow head 130 has been removed, a similar blow head is positioned on

core box

122, 124 to -blow CO2 gas through the core box until the sleeve has hardened.

Also, if desired, the sleeve 120 may be formed in the core box 122, 1-24 of 4FIGURE 7 by charging blow head with a conventional mixture of, for example, l1/% (by volume) corn cereal, 2% (by volume) linseed oil, 3% (by volume) water, and the remainder conventional silica core sand. After the

core box

122, 124 has been filled with this mixture by blow head 130, the latter is removed, and the core is ejected and baked in a conventional core oven until hard, as for example, at about 425 F. for about two hours.

After the composite bushing L18-4120 has been formed as heretofore described, it is hand tted into an assembly such as heretobefore described in connection with FIG-

URES

2 and 3, and it will be understood that all

bushings

16, 26 and 52 may be formed as composite bushings 118-120 and may be assembled in the foregoing manner.

Moreover, if desired, the composite bushing 118-120 may be formed in situ within its

opening

15, 24, or 50 by eliminating member 124 and inserting member 122 in such opening and thereafter forming the bushing 118- 120 by any of the foregoing methods.

I claim:

l, In a device for pouring molten high melting point metal into a mold through a bottom gate, the combination of a cut-ohc slide having an aperture registered with -the gate, a bushing in said aperture comprising a sleeve with a flange recessed in the slide, a hollow cylindrical refractory liner in the sleeve, said sleeve being snugly tted in the aperture and being formed of sand particles bonded to each other and to said liner by a binder said liner being formed of a refractory material more resistant to erosion by said molten metal than said sleeve, and means for actuating the slide to a position where it cuts olf fiow of said molten metal from said bottom gate when the mold has been tllled therewith.

2. In a method of forming a bushing for a cut-off slide having an aperture through which molten high melting point metal flows into a mold gate, the steps of inserting a refractory liner into said aperture, and then filling the aperture around said liner with a mixture of sand particles and fluid bonding material which, when set, bonds the particles to each other and to the liner and slide, to form a sleeve around the liner.

3. In a device for pouring molten high melting point metal into a mold through a bottom gate, the combination of a cut-off slide having an aperture registrable with the gate, a bushing in said aperture comprising a sleeve with a ilange recessed in the slide, a cylindrically shaped refractory liner in the sleeve, said sleeve being snugly tted in the aperture and being formed of sand particles bonded to each other and to said liner by a binder.

4. In a cut-off device for molds for high melting point metals, the combination of: a cut-off slide having an aperture therethrough; a bushing in said aperture com- 15 prising a sleeve with a ange recessed in said slide; a refractory liner in said sleeve; said sleeve being snugly tted in the aperture and being formed of sand particles bonded to each other and to said liner by a binder; said liner being formed of a refractory material more resistant to erosion by said molten metal than said sleeve.

References Cited in the file of this patent UNITED STATES PATENTS Phillips Aug. 16, 1938 2,309,608 Wessel Jan. 26, 1943 2,495,064 Horvath I an. 17, 1950 2,757,219 Clough et al July 31, 1956 2,836,865 Bravard et al. June 3, 1958

Claims

1. IN A DEVICE FOR POURING MOLTEN HIGH MELTING POINT METAL INTO A MOLD THROUGH A BOTTOM GATE, THE COMBINATION OF A CUT-OFF SLIDE HAVING AN APERTURE REGISTERED WITH THE GATE, A BUSHING IN SAID APERTURE COMPRISING A SLEEVE WITH A FLANGE RECESSED IN THE SLIDE, A HOLLOW CYLINDRICAL REFRACTORY LINER IN THE SLEEVE, SAID SLEEVE BEING SNUGLY FITTED IN THE APERTURE AND BEING FORMED OF SAND PARTICLES BONDED TO EACH OTHER AND TO SAID LINER BY A BINDER SAID LINER BEING FORMED OF A REFRACTORY MATERIAL MORE RESISTANT TO EROSION BY SAID MOLTEN METAL THAN SAID SLEEVE, AND MEANS FOR ACTUATING THE SLIDE TO A POSITION WHERE IT CUTS OFF FLOW OF SAID MOLTEN METAL FROM SAID BOTTOM GATE WHEN THE MOLD HAS BEEN FILLED THEREWITH.